Quality and Safety of Fresh-cut Vegetables and Fruits

QUALITY AND SAFETY OF FRESH-CUT VEGETABLES AND FRUITS

Sponsoring Institution

National Institute of Food and Agriculture

Project Status

TERMINATED

Funding Source

HATCH

Reporting Frequency

Annual

Accession No.

0190811

Grant No.

(N/A)

Project No.

CA-D-PLS-6928-RR

Proposal No.

(N/A)

Multistate No.

S-294

Program Code

(N/A)

Project Start Date

Oct 1, 2011

Project End Date

Sep 30, 2016

Grant Year

(N/A)

Project Director
Cantwell, M.

Recipient Organization
UNIVERSITY OF CALIFORNIA, DAVIS
410 MRAK HALL
DAVIS,CA 95616-8671

Performing Department
Plant Sciences

Non Technical Summary
The market for fresh-cut vegetable and fruit products is estimated at $10-12 billion annually, accounting for more than 15% of all fresh produce marketed in the U.S. Due to the highly perishable nature of fresh-cuts compared to intact produce, the retail value of fresh-cut produce losses may exceed $1 billion annually. The appearance, convenience, and generally high nutritive value of fresh-cut vegetables and fruits drive sales of fresh produce, but repeat sales of the fresh-cuts is dependent upon assurance of its safety and the products having pleasing texture and flavor. The industry primarily relies on established technologies derived mainly from practical experience to maintain visual quality and shelf-life with less consideration of the quality characteristics that drive repeat sales such as good flavor retention, maintenance of an appealing texture, and increased microbial quality leading to extended shelf stability and food safety. As a result of physiological and microbial deterioration occurring during storage and marketing of fresh produce, and especially fresh-cut produce, there is a need to develop effective, non-damaging treatments for maintaining the quality (appearance, flavor, texture, nutritional value) and food safety of fresh harvested produce. With over 200 different vegetable and fruit crops with potential for development as fresh-cut products, each with unique physiology and handling requirements, an integrated, scientific approach to research and development including microbiological interactions with these products is critically needed. The conditions on the cut surface of fresh-cut products, with the presence of water and compounds that microbes can use for nutrition, provide ideal conditions for growth of microbes. Unfortunately, as produce consumption has increased in the U.S. in recent years, so has the number of produce-related outbreaks of foodborne illness. Such outbreaks can also be very costly to growers, processors, shippers and restaurants and result in lowered confidence in safety of fresh produce. To ascertain food safety risks involving fresh and fresh-cut produce, it is critical to be able to determine the survival and persistence of viable or infectious human pathogens under environmental conditions occurring in produce handling and processing facilities, on harvested crops, and on intact or fresh-cut products. Therefore, methods for detection and enumeration of target microbes, including bacteria and viruses, are of core relevancy to this project. Due to the relatively short shelf lives of most types of fresh produce, rapid methods for detection and enumeration are of special relevance to the goals of this work. Integration of physiological, pathological, food safety, and instrumental and sensory quality measurements is essential for developing the most effective handling procedures and innovative, technologies for maintaining quality and shelf stability of fresh-cut products. Much experimental work is needed to optimize and integrate new treatments in diverse fresh-cut products. This project outlines a multidisciplinary approach to addressing some of these issues.

Animal Health Component

(N/A)

Research Effort Categories

Basic

(N/A)

Applied

(N/A)

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
204	2499	1020	50%
503	1499	1060	50%

Knowledge Area
204 - Plant Product Quality and Utility (Preharvest); 503 - Quality Maintenance in Storing and Marketing Food Products;

Subject Of Investigation
2499 - Plant research, general; 1499 - Vegetables, general/other;

Field Of Science
1020 - Physiology; 1060 - Biology (whole systems);

Keywords

fresh-cut fruits and vegetables

minimally processed fruits and vegetables

fruit and vegetable quality and safety

methods for quality determination

Goals / Objectives
The overall goal of the project is to provide relevant research-based information to the segment of the horticultural industry involved in value-added processing of fruits and vegetables. Objective 1. Evaluate methods of sampling and measuring flavor and nutrition of fresh-cut products to facilitate comparison to traditional shelf life factors. Objective 2. Develop new strategies to improve and better maintain inherent fresh-cut product quality and nutrition. Objective 3. Improve understanding of physiological mechanisms that affect fresh-cut product quality. Objective 4. Determine critical factors in controlled inoculation studies with human pathogens and surrogates that influence the outcome of quantitative microbial risk assessments. Objective 5. Evaluate and control unintentional and intentional microbial contamination of intact and fresh-cut produce. Expected Outcomes 1, Relevant information will be available to fresh-cut processors to assist them in making decisions on harvest maturity, processing procedures, handling and packaging conditions to best maintain fresh-cut product quality and safety. 2. The fresh-cut industry will achieve considerable savings (potentially millions of dollars a year) from reductions of product losses and recalls. 3. Consumers will benefit from increased availability of fresh-cut products with improved sensory quality and higher nutritional value through improvements in cultivars and more effective preparation and handling practices. 4. Incidence of fresh-cut products at retail with insufficient shelf life for consumer satisfaction will decrease. 5. Human health will be improved as a result of increased consumption of vegetables and fruits. 6. Availability of best-practice guidance and standardized methods for food safety risk assessments of fresh-cut product treatments will reduce the likelihood of food safety events by replacing ineffective food safety practices with science-based procedures. 7. Food safety risk will be reduced through availability of new, more efficacious, strategies for controlling human pathogens. 8. Researchers will have standard protocols for quantifying flavor-based shelf life and standard microbiological methods. 9. Longer-term scientific benefits will be derived from obtaining a better understanding of ethylene and stress physiology of wounded plant tissues. Cantwell will conduct research to address Objectives 1-3 and will contribute to expected outcomes 1-5 and 8-9.

Project Methods
Produce will be prepared/cut under sanitary conditions at refrig. temps. Post-cutting treatments and packaging will be performed using good manufacturing practices. After treatment, the fresh-cut products and intact control samples, will be stored in appropriate refrig. temps. Standard sensory and instrumental measures of flavor and compositional quality will be used in work encompassing the first 3 objectives. Visual quality of fresh-cut products will be evaluated by hedonic scoring systems, reflectance color measurements, and spectrophotometric analysis of chlorophyll, anthocyanin, carotenoid, and phenolic pigments. Textural alterations will be analyzed using mechanical measurements of tissue firmness. Flavor quality will be analyzed by sensory panels and flavor volatiles by instrumental means. Obj.1 Procedure: 1)Compare methods being used by project members for consumer and sensory panel testing of fresh-cut products and develop standard procedures. 2)Conduct coordinated shelf life tests and develop standard procedures for measuring the shelf life of fresh-cut products in terms of retention of accept. flavor. 3)Relate instrumental with sensory measurements of quality using newly developed instruments and statistical tech. Obj.2 Procedure:1)Identify germplasm with outstanding sensory quality. 2)Identify optimum whole product quality factors relating to improved flavor-based shelf life. 3)Investigate improved processing and packaging strategies to better maintain fresh-cut product quality. Obj.3 Procedure: Investigate role of ethylene and stress physiology in fresh-cut product quality and shelf life; determine the effects of wounding and heat stress on the tissue anti-oxidative capacity and concentrations of bioactive components. Obj.4 Procedure:1)develop research best-practice guidance and standardized methods for food safety risk assessments and efficacy of disinfection measures. 2)evaluate the influence of inoculum production, method of application, rate of drying, potential for sub-lethal injury on quantitative and qualitative recovery of pathogens. 3)validate culture-based and non-cultural methods for improved sensitivity and specificity of detecting fecal contaminants. 4)determine the potential for fresh-cut product/MAP combinations that influence pathogen virulence. Obj.5 Procedure: 1)test novel intervention strategies and compare to standard commercial practices for control of human pathogens on fresh-cut produce; 2)assess the potential for reducing the transfer of microorganisms the potential for injured cells to proliferate. Results from the proposed research activities will be disseminated via presentations at scientific and industry meetings/conventions, and will be published as project reports posted to the S-294 web site, as well as in peer-reviewed and non-refereed publications. The project will have two subcommittees ('Quality and Physiology Subcommittee' and the 'Microbiology Subcommittee') and members will be those whose research falls under the subcommittee area. The purpose of the subcommittees is to review/coordinate research activities within each research area, foster grant-writing, and create reports for distribution.

Progress 10/01/11 to 09/30/16

Outputs
Target Audience:Target audiences are technical personnel in the fresh-cut industry and their suppliers; they receive technical and research reports on specific studies conducted on their behalf as well as attend seminars and workshops at UC Davis dealing with fresh-cut products. In September 2016 we held our 20th workshop on Fresh-cut products, was attended by 75 people. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?We conducted our 20th annual workshop on fresh-cut products (Fresh-cut products: maintaining quality and safety) at UC Davis, Sept 13-15, 2016 How have the results been disseminated to communities of interest?In addition to the publications reported above and our annual fresh-cut products workshop, our unpublished reports and studies are requested by technical personnel in the fresh-cut industry and suppliers. We are often consulted regarding discussions of fresh-cut product challenges, especially in relation to raw material quality, appropriate modified atmosphere packaging, quality assessment, and managing shelf-life. What do you plan to do during the next reporting period to accomplish the goals?continue research on using ammonia as a freshness indicator for leafy greens. continue research of fresh-cut nopalitos (cactus stems).

Impacts
What was accomplished under these goals? Our studies on fresh-cut products are applied and usually conducted at the request of the industry or suppliers. The papers reported above, published in the proceedings from the 2015 international Fresh-cut conference, are an example of the types of studies conducted. We organize a unique annual workshop on fresh-cut products, with instructors from academia (UC Davis, Univ. Florida), USDA, and the private sector (http://postharvest.ucdavis.edu/Workshops/Fresh-cut_Products_Workshop__Maintaining_Quality_-_Safety/). It was attended by 75 in 2016.

Publications

Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Cantwell, M.I., A.A.M. Melo, G. Hong and S. Klose. Quality of waterjet- and blade-cut romaine salad. Acta Horticultuae 1141: 153-158.
Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Buccheri, M. and M.I. Cantwell. Fruit ripening conditions affect the quality of sliced red tomatoes. Acta Horticulturae 1141: 159-166.
Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Hong, G., C. Crisosto and M.I. Cantwell. Quality and physiology of two cultivars of fresh-cut figs in relation to ripeness, storage temperature and controlled atmospheres. Acta Horticulturae 1141: 213-219.
Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Tanamati, F., G. Hong and M.I. Cantwell. Impact of storage temperatures and modified atmospheres on quality of fresh-peeled garlic cloves. Acta Horticulturae 1141: 221-227.
Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Mastrandrea, L., M.L. Amodio and M.I. Cantwell. Modeling ammonia accumulation and color changes of arugula (Diplotaxis tenuifolia) leaves in relation to temperature, storage time and cultivar. Acta Horticulturae 1141: 275-282.
Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Dong, T., Y. Feng, J. Shi, M.I. Cantwell, Y. Guo and Q. Wang. Ethanol fumigation can effectively inhibit the browning of fresh-cut burdock (Arctium lappa L.). Acta Horticulturae 1141: 343-348.
Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Wang, T., Q. Wang, F. Pupin and M.I. Cantwell. Control of red discoloraiton of fresh-cut sunchoke tubers. Acta Horticulturae 1141: 349-355.
Type: Other Status: Other Year Published: 2016 Citation: Cantwell, M.I. A Freshness Indicator for Leafy Greens. Research report to the California Leafy Greens Research Program.
Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Cantwell, M.I., G. Hong, L. Schmidt, and H. Ermen. 2016. Impact of modified atmospheres on the Vitamin C content of salad-cut romaine and other lettuces. Acta Horticulturae 1141 : 167-174.
Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: Albornoz, K. and M.I. Cantwell. Fresh-cut kale quality and shelf-life in relation to leaf maturity and storage temperature. Acta Horticulturae 1141: 109-115.
Type: Other Status: Other Year Published: 2016 Citation: Cantwell, M.I. Postharvest Physiological Disorders: Pinking in Romaine Hearts Research report to the California Leafy Greens Research Program.

Progress 10/01/14 to 09/30/15

Outputs
Target Audience:Target audiences are technical personnel in the fresh-cut industry and their suppliers; they receive technical and research reports on specific studies conducted on their behalf as well as attend seminars and workshops at UC Davis dealing with fresh-cut products. In September 2015 we also organized a research conference for technical personnel and researchers of fresh-cut products; it was attended by 150 people. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Besides organizing the annual Fresh-cut Products workshops and the International Conference on Fresh-cut Produce in 2015, we are often consulted for our recommendations on fresh-cut aspects: raw material quality, appropriate modified atmospheres and quality assessments. I frequently discuss fresh-cut product quality, processing options, raw material and other aspects with technical personnel from the industry. How have the results been disseminated to communities of interest?Besides the publications noted, our unpublished studies and reports are requested by technical personnel in the fresh-cut industry and suppliers. We do product testing when requested. We are often consulted for our recommendations on fresh-cut aspects: raw material quality, appropriate modified atmospheres and quality assessments. What do you plan to do during the next reporting period to accomplish the goals?work continues on leafy greens with particular emphasis on determination of freshness. work on new products for retardation of browning being tested on apples and potatoes. work on raw material quality and preprocessing storage conditions. We will organize the 20th Fresh-cut products workshop at UC Davis Sept 13-16, 2016

Impacts
What was accomplished under these goals? Our studies are applied and usually address problems identified by fresh-cut processors or suppliers. Two published papers on fresh-cut sunchoke, a nonstarchy rootcrop edible raw and cooked, addressed discoloration problems that limit its usefulness as a fresh-cut product. Three papers presented at the international CA/MA conference in 2013 addressed tolerance of products (Brassicas, grape tomato, sugar snap peas) to modified atmospheres were published. We published one paper from studies on pre-processing handling of tomatoes, which focused impact of injury to slice quality. Our research is also shared at the annual Fresh-cut workshop at UC Davis. This is a unique workshop in the U.S. and is recognized as providing an excellent overview of fresh-cut preparation and handling. In 2014, the 19th year of the workshop, we had 64 attendees including speakers, and they represented a large contingent of California based fresh-cut processors, as well as some suppliers (packaging, sanitizers), researchers, and quality control personnel. Speakers are from academia (UC Davis, Univ. Florida), USDA, and the private sector (equipment manufacturers, water sanitation systems). The 2015 fresh-cut workshop was replaced by the ISHS III International Conference on Fresh-cut Produce (http://fresh-cut2015.ucdavis.edu/), Sept 13-18, 2015, for which I was the convener and proceedings editor. About 60 invited and oral/poster presentations are currently be edited for publication in an Acta Horticulturae in 2016.

Publications

Type: Conference Papers and Presentations Status: Under Review Year Published: 2016 Citation: Cantwell, M., ed. 2016. Proceedings III International Fresh-cut Produce: Maintaining Quality and Safety. volume of Acta Horticulturae.
Type: Journal Articles Status: Published Year Published: 2014 Citation: Buccheri, M. and M. Cantwell. 2014. Damage to intact fruit affects quality of slices from ripened tomatoes. LWT-Food Science and Tech., 59:327-334.
Type: Journal Articles Status: Published Year Published: 2014 Citation: Wang, Q., X Nie and M. Cantwell. 2014. Hot water and ethanol treatments can effectively inhibit the discoloration of fresh-cut sunchoke (Helianthus tuberosus L.) tubers. Postharvest Biol. Tech. 94:40-57.
Type: Journal Articles Status: Published Year Published: 2015 Citation: Wang, Q. and M. Cantwell. 2015. Quality changes and respiration rates of fresh-cut sunchoke tubers (Helianthus tuberosus L.). J. Food Processing Preservation 39: 634-644.
Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Cefola M., B. Pace, G. Colelli, and M. Cantwell. 2015. Compositional and Marketable Quality of Fresh-cut Florets of Four Specialty Brassicas in Relation to Controlled Atmosphere Storage. Acta Hort.1071: 455-462
Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Cantwell, M. and M.Saltveit. 2015. Tolerance of Sugar Snap Peas to Modified Atmospheres with High Concentrations of Carbon Dioxide. ActaHort. 1071: 619-625.
Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Cantwell, M. and M. Saltveit. 2015. Tolerance of Grape Tomatoes to Controlled Atmospheres at Low Temperature. Acta Hort.1071: 627-634.

Progress 10/01/13 to 09/30/14

Outputs
Target Audience: Target audiences are technical personnel in the fresh-cut industry and their suppliers; they receive technical and research reports on specific studies conducted on their behalf as well as attend seminars and workshops at UC Davis dealing with fresh-cut products. Also there were numerous meetings with personnel from the fresh-cut industry. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Research on this project is conducted by PI Cantwell, research assistant Gyunghoon Hong, and in 2013-2014 by 1 M.S. graduate student and 2 visiting scholars. Opportunity for training is mainly done via the annual 3 day Fresh-cut Workshop at UC Davis, and both the graduate student and two visiting scholars attended the workshop. The PI organizes and teaches in the workshop. The graduate student presented her fresh-cut kale work at a Chile-UCDavis conference on Oct 11, 2014 at UC Davis. One visiting scholar presented a poster at the United Fresh Produce Association Convention "scientific poster' session in June 2014 in Chicago. How have the results been disseminated to communities of interest? PI Cantwell presented results from the project to technical personnel at state-wide vegetable meeting (Dec, 2013), at a Melon Food Safety training workshop at UC Davis (July 2014), at the Fresh-cut workshop at UC Davis (Sept 23-25, 2014), at the Postharvest Short Course at UC Davis (June, 2014), at the Wageningen Postharvest Short Course (Oct 2014). In addition, research results are disseminated directly to technical personnel in the fresh-cut industry (phone, email). What do you plan to do during the next reporting period to accomplish the goals? 1. Host the ISHS III International Fresh-cut Produce Conference at UC Davis, Sept 13-18, 2015. Publish the proceedings in a timely fashion (early 2016). 2. complete ongoing research on fresh-cut products and complete publications of this work.

Impacts
What was accomplished under these goals? Our studies are applied and usually address problems identified by fresh-cut processors or suppliers. One published paper on fresh-cut sunchoke, a nonstarchy rootcrop edible raw and cooked, addressed discoloration problems that limit its usefulness as a fresh-cut product. Three papers presented the international CA/MA conference in 2013 addressed tolerance of products (Brassicas, grape tomato, sugar snap peas) to modified atmospheres, increasingly important as more blends and specialized fresh-cut products are marketed. We published one paper from studies on pre-processing handling of tomatoes, which focused impact of injury to slice quality. Our research is also shared at the annual Fresh-cut workshop at UC Davis. This is a unique workshop in the U.S. and is recognized as providing an excellent overview of fresh-cut preparation and handling. In 2014, the 19th year of the workshop, we had 64 attendees including speakers, and they represented a large contingent of California based fresh-cut processors, as well as some suppliers (packaging, sanitizers), researchers, and quality control personnel. Speakers are from academia (UC Davis, Univ. Florida), USDA, and the private sector (equipment manufacturers, water sanitation systems). the 2015 fresh-cut workshop is being replaced as UC Davis hosts the ISHS III International Conference on Fresh-cut Produce (http://fresh-cut2015.ucdavis.edu/), Sept 13-18, 2015.

Publications

Type: Other Status: Published Year Published: 2014 Citation: Cantwell, M. (ed. compiler). 2014. Fresh-cut Products: Maintaining Quality and Safety. Univ. California Postharvest Horticulture Series No. 10. UC Postharvest Research and Information Center (http://postharvest.ucdavis.edu/bookstore/Fresh-cut_Workshop-Binder_and_Portfolio/). Hard copy and pen drive components. New edition Sept 2014.
Type: Journal Articles Status: Published Year Published: 2014 Citation: Buccheri, M. and M. Cantwell. 2014. Damage to intact fruit affects quality of slices from ripened tomatoes. LWT-Food Science and Tech., 59:327-334
Type: Journal Articles Status: Published Year Published: 2014 Citation: Wang, Q., X Nie and M. Cantwell. 2014. Hot water and ethanol treatments can effectively inhibit the discoloration of fresh-cut sunchoke (Helianthus tuberosus L.) tubers. Postharvest Biol. Tech. 94:40-57.
Type: Conference Papers and Presentations Status: Awaiting Publication Year Published: 2015 Citation: Cefola M., B. Pace, G. Colelli, and M. Cantwell. 2015. Compositional and Marketable Quality of Fresh-cut Florets of Four Specialty Brassicas in Relation to Controlled Atmosphere Storage. Proc. CAMA2013, Trani, Italy, 3-7 June, 2013. Acta Hort., in press.
Type: Conference Papers and Presentations Status: Awaiting Publication Year Published: 2015 Citation: Cantwell, M. and M. Saltveit. 2015. Tolerance of Grape Tomatoes to Controlled Atmospheres at Low Temperature. Proc. CAMA2013, Trani, Italy, 3-7 June, 2013. Acta Hort., in press.
Type: Conference Papers and Presentations Status: Awaiting Publication Year Published: 2015 Citation: Cantwell, M. and M. Saltveit. 2015. Tolerance of Sugar Snap Peas to Modified Atmospheres with High Concentrations of Carbon Dioxide. Proc. CAMA2013, Trani, Italy, 3-7 June, 2013. Acta Hort., in press.

Progress 01/01/13 to 09/30/13

Outputs
Target Audience: Target audiences are personnel in the fresh-cut industry and their suppliers; they receive technical reports on specific studies conducted on their behalf as well as attend seminars and workshops at UC Davis dealing with fresh-cut products. Also there were numerous meetings with personnel from the fresh-cut industry. Changes/Problems: I did not receive the small funding allotment from this project to support attendance at annual meeting and for project related travel. What opportunities for training and professional development has the project provided? Research on this project is conducted by PI Cantwell, research assistant Gyunghoon Hong, and in 2013 by 1 M.S. graduate student and 2 visiting scholars. Opportunity for training is mainly done via the annual 3 day Fresh-cut Workshop at UC Davis, and both the graduate student and two visiting scholars attended the workshop. The PI organizes and teaches in the workshop. Both visiting scholars and one graduate student presented posters at the 2013 annual conference of the American Society for Horticultural Science. How have the results been disseminated to communities of interest? 1. specific research reports 2. Annual Fresh-cut workshop at UC Davis; http://postharvest.ucdavis.edu/Education/. 3. participation in the 2013 International Controlled and Modified Atmosphere Research conference, http://www.cama2013.org/. What do you plan to do during the next reporting period to accomplish the goals? handling tomatoes for fresh-cut processing; water relations of broccoli in relation to textural changes; waterjet cutting comparison with commercial blade cutting; fresh-cut root crops performance.

Impacts
What was accomplished under these goals? Our studies are applied and usually address problems identified by fresh-cut processors or suppliers. One published paper on spinach addressed persisting off-odors issues with this perishable product; changes in ammonia production were associated with off-odor development. Three papers presented the international CA/MA conference addressed tolerance of products (Brassicas, grape tomato, sugar snap peas) to modified atmospheres, increasingly important as more blends and specialized fresh-cut products are marketed. We also conducted studies on pre-processing handling of tomatoes, but the research is not yet published. Our research is also shared at the annual Fresh-cut workshop at UC Davis. This is a unique workshop in the U.S. and is recognized as providing an excellent overview of fresh-cut preparation and handling. In 2013, the 18th year of the workshop, we had 79 attendees including speakers, and they represented a large contingent of California based fresh-cut processors, as well as some suppliers (packaging, sanitizers), researchers, and quality control personnel. Speakers are from academia (UC Davis, Univ. Florida), USDA, and the private sector (equipment manufacturers, water sanitation systems).

Publications

Type: Other Status: Published Year Published: 2013 Citation: Cantwell, M. (ed. compiler). 2013. Fresh-cut Products: Maintaining Quality and Safety. Univ. California Postharvest Horticulture Series No. 10. UC Postharvest Research and Information Center (http://postharvest.ucdavis.edu/files/93535.pdf ). Hard copy and pen drive components. New edition Sept 2013.
Type: Journal Articles Status: Published Year Published: 2013 Citation: Tiwari, G., D.C. Slaughter , Marita Cantwell. 2013. Nondestructive maturity determination in green tomatoes using a handheld visible and near infrared instrument. Postharvest Biol. Tech. 86, 221-229.
Type: Journal Articles Status: Published Year Published: 2013 Citation: Tudela, J.A., A. Mar�n, Y. Garridoa, M. Cantwell, M.S. Medina-Mart�nez, M. I. Gil. 2013. Off-odour development in modified atmosphere packaged baby spinach is an unresolved problem. Postharvest Biol. Tech. 75, 75-85.
Type: Conference Papers and Presentations Status: Awaiting Publication Year Published: 2014 Citation: Cantwell, M. and M. Saltveit. 2014. Tolerance of Sugar Snap Peas to Modified Atmospheres with High Concentrations of Carbon Dioxide. Acta Hort., in press.
Type: Conference Papers and Presentations Status: Awaiting Publication Year Published: 2014 Citation: Cefola M., B. Pace, G. Colelli, and M. Cantwell. 2014. Compositional and Marketable Quality of Fresh-cut Florets of Four Specialty Brassicas in Relation to Controlled Atmosphere Storage. Acta Hort., in press.
Type: Conference Papers and Presentations Status: Awaiting Publication Year Published: 2014 Citation: Cantwell, M. and M. Saltveit. 2014. Tolerance of Grape Tomatoes to Controlled Atmospheres at Low Temperature. Acta Hort., in press.

Progress 01/01/12 to 12/31/12

Outputs
OUTPUTS: Objective 1. Develop, evaluate, and standardize subjective and objective quality evaluation methods in intact and fresh-cut fruits and vegetables. 1. I coordinated and taught in the annual 3 day workshop on fresh-cut products at UC Davis: Fresh-cut Products: Maintaining Quality and Safety, Sept 14-16, 2012. I compiled and edited materials, updated reference lists and recent research findings. See publication Cantwell, 2012. Objective 2. Develop new strategies to maintain fresh-cut product quality 1. Variations in head firmness and other quality characteristics studied in broccoli cultivars in relation to water relations. Results will be presented in 2013 and paper being prepared. 2. Storage conditions for cucumber and chili peppers in relation to temperature and varieties. Research reports prepared and some results will be presented at meetings/conferences in 2013. Objective 3. Improve understanding of biochemical, physiological and molecular mechanisms that affect fresh-cut product quality. 1. The impact of nitrogen nutrition on composition and textural properties was studied on spinach leaves produced in hydroponic and field production. This has relevance to performance of raw material in fresh-cut washing, drying and packaging operations. See publication by Gutierrez-Rodriguez et al. 2. The effect of Nitrogen fertilization on yield and quality of Bell Peppers. 3rd year of a project for the California Pepper Commission. Research report by LeStrange and Cantwell listed in publication list; also presented results at an International Pepper Conference. 3. Use of 1-MCP to moderate ripening of tomatoes was studied in relation to whether color stage indicated sufficient physiological uniformity to ensure useful and consistent delay in ripening but with final good color development. See publication Wang and Cantwell PARTICIPANTS: Research on this project is conducted by PI Cantwell, research assistant Gyunghoon Hong, and in 2012 by 2 M.S. graduate student and 2 visiting scholars. Opportunity for training is mainly done via the annual 3 day Fresh-cut Workshop at UC Davis, and both the graduate students and one visiting scholar attended the workshop. The PI organizes and teaches in the workshop. Both visiting scholars and one graduate student presented posters at the S-294 Science Symposium at the United Fresh Produce Association Convention. TARGET AUDIENCES: Target audiences are the fresh-cut industry and suppliers; they receive technical reports on specific studies conducted on their behalf as well as attend seminars and workshops at UC Davis dealing with fresh-cut products. Also there were numerous meetings with personnel from the fresh-cut industry. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Our applied studies are of direct relevance to successful pre- and post-processing handling of products by the fresh-cut industry. Value added and fresh-cut horticultural products continue to grow in importance. Our work in 2012 focused on various aspects of raw material quality (varieties, storage conditions). Most of the fresh-cut studies conducted during 2012 were at the request of fresh-cut processors or growers of vegetables for processors. Our research is also shared at the annual Fresh-cut workshop at UC Davis. This is a unique workshop in the U.S. and is recognized as providing an excellent overview of the fresh-cut industry. In 2012, the 17th year of the workshop, we had 66 attendees including speakers, and they represented mostly fresh-cut industry processors, suppliers, researchers, and quality control personnel.

Publications

Gutierrez-Rodriguez, E., H.J. Lieth, J.A. Jernstedt, J.M. Labavith, T.V. Suslow and M.I. Cantwell. 2013. Texture, composition and anatomy of spinach leaves in relation to nitrogen fertilization. J. Science Food Agriculture 93: 227-237
Tudela, J.A., A. Marina, Y. Garridoa, M. Cantwell, M. S. Medina-Martinez, M. I. Gil. 2013. Off-odour development in modified atmosphere packaged baby spinach is an unresolved problem. Postharvest Biol. Tech. 75: 75-85
Cantwell, M.I. and A. Thangaiah. 2012. Acceptable cooling delays for selected warm season vegetables and melons. Acta Hort. 934: 77-84
Le Strange, M. and M. Cantwell. 2012. The Effect of Nitrogen Fertilization on Yield and Quality of Bell Peppers. Annual report, California Pepper Commission
Le Strange, M. and M. Cantwell. 2012. Nitrogen Fertilization Affects Bell Pepper Yield but Has Minimal Impact on Postharvest Quality. Abstract and Poster. 21st International Pepper Conference Nov 4-6, 2012, Naples, Florida; http://conference.ifas.ufl.edu/Pepper2012/Proceedings.pdf; p. 35
Buccheri, M., L. Torrezan and M. Cantwell. 2012. Damage to Intact Fruit Affects Subsequent Slice Integrity of Fresh-cut Tomato. Abstract and poster. United Fresh Produce Association Show and Convention, Dallas TX, May 1-3, 2012. S-294 Abstracts 005-12
Cantwell, M., G. Hong. A. Fibriyanti, J. Ara and K. Albornoz. 2012. Postharvest Handling Considerations for Kale as Intact and Fresh-cut Product. Abstract and poster. United Fresh Produce Association Show and Convention, Dallas TX, May 1-3, 2012. S-294 Abstracts 017-12
Cantwell, M., G. Hong. I. Roque and A. Melo. 2012. Preliminary Assessment of Waterjet Cutting of Vegetables. Abstract and poster. United Fresh Produce Association Show and Convention, Dallas TX, May 1-3, 2012. S-294 Abstracts 020-12
Wang, L. and M. Cantwell. 2012. Application of 1-MCP at Different Ripeness Stages Affects Physiology and Final Tomato Fruit Quality. Abstract. American Society for Horticultural Science. HortScience 47(9): S165
Cantwell, M. (ed. compiler). 2012. Fresh-cut Products: Maintaining Quality and Safety. Univ. California Postharvest Horticulture Series No. 10. UC Postharvest Research and Information Center (http://postharvest.ucdavis.edu/files/93535.pdf ). Hard copy and CD components. New edition Sept 2012

Progress 01/01/11 to 12/31/11

Outputs
OUTPUTS: Objective 1. Develop, evaluate, and standardize subjective and objective quality evaluation methods in intact and fresh-cut fruits and vegetables. 1.I coordinated and taught in the annual 3 day workshop on fresh-cut products at UC Davis: Fresh-cut Products: Maintaining Quality and Safety, Sept 13-15, 2011. I compiled and edited materials, updated reference lists and recent research findings. See publication Cantwell, 2011. Objective 2. Develop new strategies to maintain fresh-cut product quality 1. Variations in raw material quality were studied in relation to broccoli and bell pepper varieties. Results presented at meetings and annual conference. See publications. 2. Storage conditions for honeydew melons in relation to temperature and use of 1-MCP were studied. See publications. Objective 3. Improve understanding of biochemical, physiological and molecular mechanisms that affect fresh-cut product quality. 1. The impact of nitrogen nutrition on composition and textural properties was studied on spinach leaves produced in hydroponic and field production. This has relevance to performance of raw material in fresh-cut washing, drying and packaging operations. See publication by Gutierrez-Rodriguez et al. 2. The effect of Nitrogen fertilization on yield and quality of Bell Peppers. 3rd year of a project for the California Pepper Commission. Research report. PARTICIPANTS: Research on this project is conducted by PI Cantwell, research assistant Gyunghoon Hong, and in 2011 by 2 visiting scholars. One visiting scholar was M.S. student and part of her research work was conducted as part of this project. Opportunity for training is mainly done via the annual 3 day Fresh-cut Workshop at UC Davis. The PI organizes and teaches in the workshop. TARGET AUDIENCES: Target audiences are the fresh-cut industry and suppliers; they receive technical reports on specific studies conducted on their behalf as well as attend seminars and workshops at UC Davis dealing with fresh-cut products. Also there were numerous meetings with personnel from the fresh-cut industry. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Our applied studies are of direct relevance to successful pre- and post-processing handling of products by the fresh-cut industry. Value added horticultural products continue to grow in importance. Our work in 2011focused on various aspects of raw material quality (varieties, storage conditions). Most of the fresh-cut studies conducted during 2011 were at the request of fresh-cut processors or growers of products for processors. Our research is also shared at the annual Fresh-cut workshop at UC Davis. This is a unique workshop in the U.S. and is recognized as providing an excellent overview of the fresh-cut industry. In 2011, the 15th year of the workshop, we had 66 attendees including speakers, and they represented mostly fresh-cut industry processors, suppliers, researchers, and quality control personnel.

Publications

Cantwell, M. (ed. compiler). 2011. Fresh-cut Products: Maintaining Quality and Safety. Univ. California Postharvest Horticulture Series No. 10. UC Postharvest Research and Information Center (http://postharvest.ucdavis.edu/files/93535.pdf ). Hard copy and CD components. New edition Sept 2011.
Gutierrez-Rodriguez, E., H.J. Lieth, J.A. Jernstedt, J.M. Labavith, T.V. Suslow and M.I. Cantwell. 2012. Texture, composition and anatomy of spinach leaves in relation to nitrogen fertilization. J. Science Food Agriculture, in press.
Bayogan, E. and M. Cantwell. 2011. Postharvest Quality and Chilling Tolerance of Bell Pepper Varieties. Amer. Soc. Hort. Sci. Annual Conf., Kona, Hawaii, 25-28 Sept 2011. Abstract #235 and poster. HortScience 46(9): S332.
Cantwell, M. and G. Hong. 2011. Composition and postharvest performance of broccoli varieties. Amer. Soc. Hort. Sci. Annual Conf., Kona, Hawaii, 25-28 Sept 2011. Abstract #236 and poster. HortScience 46(9): S332.
Tiwari G., Slaughter D.C., Cantwell M. 2011. Prediction of maturity in green tomatoes using visible and near infrared spectroscopy. IFT Annual Meeting & Food Expo, June 11 - 14, 2011, New Orleans, Louisiana, USA. Abstract and oral presentation.
Le Strange, M. and M. Cantwell. 2011. The Effect of Nitrogen Fertilization on Yield and Quality of Bell Peppers. Annual report, California Pepper Commission.
Cantwell, M. and G. Hong. 2011 Delays to Cool and 1-MCP treatment of Honeydew Melons. Research report.

Progress 01/01/10 to 12/31/10

Outputs
OUTPUTS: Objective 1. Develop, evaluate, and standardize subjective and objective quality evaluation methods in intact and fresh-cut fruits and vegetables. 1.I coordinated and taught in the annual 3 day workshop on fresh-cut products at UC Davis: Fresh-cut Products: Maintaining Quality and Safety, Sept 14-16, 2010. I compile and edit materials, update reference lists and recent research findings. The dates for 2011 are Sept 13-15. See publications. 2.I contributed to an updated version of rating scales for fresh intact and fresh-cut produce. This is useful for fresh-cut products because it identifies common causes of quality loss and provides scales for evaluation by QC personnel in the fresh-cut industry. See publications. Objective 2. Develop new strategies to maintain fresh-cut product quality 1.Chemical and physical treatments to control browning of fresh-cut potatoes. Treatments previously reported useful for browning control were evaluated on one source of russet potatoes for reference. These were compared with new experimental treatments. See publications. 3.Use of ammonia as indicator of stressful modified atmospheres for intact and fresh-cut vegetables. Preliminary work is summarized in a recent publication. See publications. Objective 3. Improve understanding of biochemical, physiological and molecular mechanisms that affect fresh-cut product quality. 1.Stage of ripeness of products at time of fresh-cut processing greatly affects shelf-life and quality. Procedures to effectively condition and/or ripen tomatoes, peppers and melons were studied and summarized in a publication for a workshop (Fruit Ripening and Ethylene Management) at UC Davis. See publications. 2.Different iceberg and romaine lettuce cultivars and their hybrids were evaluated for performance as fresh-cut salad pieces, with emphasis on induction of phenolic metabolism and browning. Research report. 3.Quality and integrity of sliced round tomatoes. The research involved the previously unexplored area of the impact of handling and ripening conditions on the quality of the fresh-cut slices: impact of temperature and ethylene treatment on fresh-cut slice quality and impact of simulated physical damage on fresh-cut slice quality. Manuscript for publication in preparation; poster to be presented at S294 meeting at UFPA, May 2011. 4.Fresh-cut figs. Evaluation of a range of potential sanitizers with comparison to more standard chlorinated water wash treatments. Four fig cultivars were tested and maturity stages were also characterized since decay is related to maturity. Research report. PARTICIPANTS: Research on this project is conducted by PI Cantwell, research assistant Gyunghoon Hong, and in 2010 by 3 visiting scholars. Opportunity for training is mainly done via the annual 3 day Fresh-cut Workshop at UC Davis. The PI organizes and teaches in the workshop. TARGET AUDIENCES: Target audiences are the fresh-cut industry and suppliers; they receive technical reports on specific studies conducted on their behalf as well as attend seminars and workshops at UC Davis dealing with fresh-cut products PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Our applied studies are of direct relevance to successful pre- and post-processing handling of products by the fresh-cut industry. Value added horticultural products continue to grow in importance. Our work in 2010 provided data on quality and compositional changes for several fresh-cut vegetable products. Most of the fresh-cut studies conducted during 2010 were at the request of fresh-cut processors or growers of products for processors. Our research is also shared at the annual Fresh-cut workshop at UC Davis, which is a unique workshop in the U.S. and is recognized as the workshop to attend for an excellent overview of the fresh-cut industry. In 2010, the 15th year of the workshop, we had 83 attendees including speakers, and they represented mostly fresh-cut industry processors, suppliers, researchers, and quality control areas.

Publications

Cantwell, M. 2010. Optimum Procedures for Ripening Melons. In J.T. Thompson and C. Crisosto, eds.: Fruit Ripening & Ethylene Management, UC Postharvest Hort. Series 9, pp. 71-79. http://postharvest.ucdavis.edu/Pubs/Pub_Desc_9.pdf.
Kader, A.A. and M.I. Cantwell (editor compilers.). 2010. Produce Quality Rating Scales and Color Charts, 2nd edition. UCD Postharvest Horticulture Series No. 23. 116pp. + appendices + CD. http://postharvest.ucdavis.edu.
Cantwell, M., G. Hong and X. Nie. 2010. Using tissue ammonia and fermentative volatile concentrations as indicators of beneficial and stressful modified atmospheres for leafy and floral vegetables. Acta Hort. 876: 165-171.
Cantwell, M. (ed. compiler). 2010. Fresh-cut Products: Maintaining Quality and Safety. Univ. California Postharvest Horticulture Series No. 10. UC Postharvest Research and Information Center (http://postharvest.ucdavis.edu/Pubs/pub_list.shtml#fresh-cut). Hard copy and CD components. Updated Sept 2010.
Ma, Y., G. Hong, Q. Wang and M. Cantwell. 2010. Reassessment of treatments to retard browning of fresh-cut Russet potato with emphasis on controlled atmospheres and low concentrations of bisulfite. International Journal Food Science and Technology 45: 1486-1494.
Cantwell, M. 2010. Optimum Procedures for Ripening Tomatoes. In J.T. Thompson and C. Crisosto, eds.: Fruit Ripening & Ethylene Management, UC Postharvest Hort. Series 9, pp. 106-116. http://postharvest.ucdavis.edu/Pubs/Pub_Desc_9.pdf.
Cantwell, M. 2010. Optimum Procedures for Ripening Peppers. In J.T. Thompson and C. Crisosto, eds.: Fruit Ripening &Ethylene Management, UC Postharvest Hort. Series 9, pp. 91-96. http://postharvest.ucdavis.edu/Pubs/Pub_Desc_9.pdf.

Progress 01/01/09 to 12/31/09

Outputs
OUTPUTS: Objective 1. Develop, evaluate, and standardize subjective and objective quality evaluation methods in intact and fresh-cut fruits and vegetables. 1.I coordinate and teach an annual 3 day workshop on fresh-cut products at UC Davis: Fresh-cut Products: Maintaining Quality and Safety, Sept 16-18, 2008. The workshop was co-sponsored by United Fresh Produce Association. I compile and edit materials, update reference lists and recent research findings (see publications). The dates for 2009 are Sept 22-24, 2009. 2.Use of ammonia as indicator of stressful modified atmospheres for intact and fresh-cut vegetables. See publications. Objective 2. Develop new strategies to maintain fresh-cut product quality 1. Evaluation of a range of modified atmospheres for vegetable trays (broccoli, carrot, celery, snap peas, tomatoes). The vegetables prepared for vegetable trays may be incompatible regarding recommended storage temperatures, but also may be incompatible regarding atmospheres provided by commercial packaging and handling scenarios. Research reports. 2.Evaluation of quality impacts of ozone, hot water or combination treatments to control Salmonella spp. and Escherichia coli O157:H7 on fresh-cut cantaloupe. Maturity of the melons affected efficacy of the treatments and storage quality of the fresh-cut pieces. This research was part of a USDA project. 2 papers were published (see publications). 3.Chemical and physical treatments to control browning of fresh-cut potatoes. Treatments previously reported useful for browning control were evaluated on one source of russet potatoes for reference. These were compared with new experimental treatments. Poster presented at United Fresh April 2009. 4.Modified atmospheres for microwaveable packaging for new potatoes. This was developmental work and involved evaluating different packaging under various storage temperatures and periods. Research report. 5.Determination of symptoms of freeze damage on fresh-peeled garlic. Color, electrolyte leakage and visual appearance were used to determine impact of storage at 0 to -10C. Objective 3. Improve understanding of biochemical, physiological and molecular mechanisms that affect fresh-cut product quality. 1.Modified atmosphere technology can have detrimental effect on the ascorbic acid content of lettuce. Low oxygen atmospheres do not impact ascorbic acid changes in romaine lettuce, but carbon dioxide atmospheres (3-9%) result in significant and important decreases of ascorbic acid after 6 days at 5C. Work in 2008 focused on changes in ascorbic acid metabolism and enzyme activity modified atmospheres typical of commercial packaged salad products. 2.Fresh-cut figs. The quality and physiology of 2 varieties of sliced figs were studied at different temperatures and atmospheres. Maturity was also considered. Exploratory work. 3.Fresh-cut vegetable papaya; performance of 2 varieties at 5C; exploratory work. PARTICIPANTS: Opportunity for training is mainly done via the annual 3 day Fresh-cut Workshop at UC Davis. The PI organizes and teaches in the workshop. TARGET AUDIENCES: Target audiences are the fresh-cut industry and suppliers; they receive technical reports on specific studies as well as attend seminars and workshops at UC Davis dealing with fresh-cut products. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Our applied studies are of direct relevance to successful pre- and post-processing handling of products by the fresh-cut industry. Our work in 2008 provided data on quality and compositional changes for several fresh-cut vegetable products. Most of the fresh-cut studies conducted during 2008 were at the request of fresh-cut processors. Our research is also used at the annual Fresh-cut workshop. In 2008, the 13th year of the workshop, we had 69 attendees, and most were from the fresh-cut industry and suppliers.

Publications

Cantwell, M. (ed. compiler). 2008. Fresh-cut Products: Maintaining Quality and Safety. Univ. California Postharvest Horticulture Series No. 10. UC Postharvest Research and Information Center (http://postharvest.ucdavis.edu). Hard copy and CD components. Updated Sept 2008.
Cantwell, M., G. Hong and X. Nie. 2009. Using Tissue Ammonia and Fermentative Volatile Concentrations as Indicators of Beneficial and Stressful Modified Atmospheres. Proceedings CA/MA2009, Acta Horticulturae, in press.

Progress 01/01/08 to 12/31/08

Outputs
OUTPUTS: Objective 1. Develop, evaluate, and standardize subjective and objective quality evaluation methods in intact and fresh-cut fruits and vegetables. . 1. I coordinate and teach an annual 3 day workshop on fresh-cut products at UC Davis: Fresh-cut Products: Maintaining Quality and Safety, Sept 16-18, 2008. The workshop was co-sponsored by United Fresh Produce Association. I compile and edit materials, update reference lists and recent research findings (see publications). Objective 2. Develop new strategies to maintain fresh-cut product quality 1. Evaluation of a range of modified atmospheres for vegetable trays (broccoli, carrot, celery, snap peas, tomatoes). The vegetables prepared for vegetable trays may be incompatible regarding recommended storage temperatures, but also may be incompatible regarding atmospheres provided by commercial packaging and handling scenarios. 2. Evaluation of quality impacts of ozone, hot water or combination treatments to control Salmonella spp. and Escherichia coli O157:H7 on fresh-cut cantaloupe. Maturity of the melons affected efficacy of the treatments and storage quality of the fresh-cut pieces. This research was part of a USDA project. 2 papers were published (see publications). 3. Chemical and physical treatments to control browning of fresh-cut potatoes. Treatments previously reported useful for browning control were evaluated on one source of russet potatoes for reference. These were compared with new experimental treatments. 4. Modified atmospheres for microwaveable packaging for new potatoes. This was developmental work and involved evaluating different packaging under various storage temperatures and periods. 5. Determination of symptoms of freeze damage on fresh-peeled garlic. Color, electrolyte leakage and visual appearance were used to determine impact of storage at 0 to -10C. Objective 3. Improve understanding of biochemical, physiological and molecular mechanisms that affect fresh-cut product quality. 1. Modified atmosphere technology can have detrimental effect on the ascorbic acid content of lettuce. Low oxygen atmospheres do not impact ascorbic acid changes in romaine lettuce, but carbon dioxide atmospheres (3-9%) result in significant and important decreases of ascorbic acid after 6 days at 5C. Work in 2008 focused on changes in ascorbic acid metabolism and enzyme activity modified atmospheres typical of commercial packaged salad products. 2. Fresh-cut figs. The quality and physiology of 2 varieties of sliced figs were studied at different temperatures and atmospheres. Maturity was also considered. Exploratory work. 3. Fresh-cut vegetable papaya; performance of 2 varieties at 5C; exploratory work. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Our applied studies are of direct relevance to successful pre- and post-processing handling of products by the fresh-cut industry. Our work in 2008 provided data on quality and compositional changes for several fresh-cut vegetable products. Most of the fresh-cut studies conducted during 2008 were at the request of fresh-cut processors. Our research is also used at the annual Fresh-cut workshop. In 2008, the 13th year of the workshop, we had 69 attendees, and most were from the fresh-cut industry and suppliers.

Publications

Cantwell, M. (ed. compiler). 2008. Fresh-cut Products: Maintaining Quality and Safety. Univ. California Postharvest Horticulture Series No. 10. UC Postharvest Research and Information Center (http://postharvest.ucdavis.edu). Hard copy and CD components. Updated Sept 2008.
Selma, M.V., A.M. Ibanez, A. Allende, M. Cantwell and T. Suslow. 2008. Reduction by gaseous ozone of Salmonella and microbial flora associated with fresh-cut cantaloupe. Food Microbiology 25(4): 558-565.
Selma, M.V., A.M. Ibanez, A. Allende, M. Cantwell and T. Suslow. 2008. Effect of gaseous ozone and hot water on microbial and sensory quality of cantaloupe and potential transference of Escherichia coli O157:H7 during cutting. Food Microbiology 25: 162-168.

Progress 01/01/07 to 12/31/07

Outputs
Objective 1. Develop, evaluate, and standardize subjective and objective quality evaluation methods in intact and fresh-cut fruits and vegetables. . 1. I coordinate and teach Fresh-cut Products: Maintaining Quality and Safety, Sept 25-27, 2007 workshop at UC Davis, co-sponsored by United Fresh Produce Association. I compile and edit materials, update reference lists and recent research findings (see publications). 2. Produce quality rating scales and color charts. Univ. California Postharvest Horticulture Series No. 23-CD. These quality rating scales were compiled as a first-step towards standardization of quality evaluation procedures and were most recently revised in May 2007. This publication is in hard copy and CD formats (see publications). Objective 2. Develop new strategies to maintain fresh-cut product quality 1. Use of 1-MCP to retard deterioration of leafy green vegetables. In 2007 we completed research on broccoli florets and postharvest evaluations and compositional analyses including glucosinolates. 1-MCP retarded changes in glucosinolates in relation to its effectiveness to retard senescence at 5 and 10C. 2. Impact of 1-MCP treatment of romaine lettuce heads in relation to preprocessing handling and storage and to quality of the salad cut lettuce. Pre-cutting 1-MCP treatment does not have important impact on cut-edge browning. 3. Impact of 1-MCP on intact leafy greens. Work was conducted on kale. Physiological age affects the benefit of 1-MCP treatment when product is stored in air or ethylene contaminated atmosphere. 4. Spinach fertilization and impact on leafy morphology, leaf texture and other quality attributes. Greenhouse hydroponic-grown spinach was produced in 4 experiments with 4 nitrogen levels. There were differences in leaf morphology and leaf texture. Compositional analyses (chlorophyll, carotenoids, sugars, acids, oxalate, nitrate, ascorbic acid) also differed among the spinach treatments. 5. Fresh-cut sunchoke or 'Jerusalem artichoke' root discolor and brown as do many other fresh-cut roots. Changes in respiration rates, PAL, PPO and total phenolics were evaluated in untreated and cut pieces (heat, chemical dips) stored at different temperatures. Various treatments can effectively retard surface discoloration. Objective 3. Improve understanding of biochemical, physiological and molecular mechanisms that affect fresh-cut product quality. 1. Modified atmosphere technology can have detrimental effect on the ascorbic acid content of lettuce. Low oxygen atmospheres do not impact ascorbic acid changes in romaine lettuce, but carbon dioxide atmospheres (3-9%) result in significant and important decreases of ascorbic acid after 6 days at 5C. Work in 2007 focused on ascorbic acid metabolism and enzyme activity in relation to typical packaged salad atmospheres.

Impacts
Our applied studies are of direct relevance to successful pre- and post-processing handling of products by the fresh-cut industry. Our work in 2007 provided data on quality and compositional changes for several fresh-cut vegetable products. Some of the studies conducted during 2007 were at the request of fresh-cut processors in California. Our research is also used at the annual Fresh-cut workshop. In 2007, the 12th year of the workshop, we had 65 attendees, most from the fresh-cut industry.

Publications

Cantwell, M. (ed. compiler). 2007. Fresh-cut Products: Maintaining Quality and Safety. Univ. California Postharvest Horticulture Series No. 10. UC Postharvest Research and Information Center (http://postharvest.ucdavis.edu). Hard copy and CD components. Updated Sept 2007.
Kader, A. and M. Cantwell. 2007. Produce quality rating scales and color charts. Univ. California Postharvest Horticulture Series No. 23-CD. UC Postharvest Research and Information Center (http://postharvest.ucdavis.edu). May 2007 revision.
Wang, Q. and M. Cantwell. 2007. Quality Challenges in a Fresh-cut Product from Sunchoke Tubers (Helianthus tuberosus). Abstract. United Fresh Produce Association FreshTech Conference, Palm Springs, CA. April 26-28, 2007
Cantwell, M., E. Catalano, E. Gutierrez, G. Hong, and X. Nie. 2007. Preharvest and Postharvest Conditions that Impact Spinach Quality. Abstract. United Fresh Produce Association FreshTech Conference, Palm Springs, CA. April 26-28, 2007
Cantwell, M. 2007. Postharvest Quality of Spinach. Abstract. International Spinach Conference, Seaside, CA. 24 September 2007.

Progress 01/01/06 to 12/31/06

Outputs
Objective 1. Develop, evaluate, and standardize subjective and objective quality evaluation methods in intact and fresh-cut fruits and vegetables. 1. I coordinate and teach in a Fresh-cut workshop held at UC Davis (Fresh-cut Products: Maintaining Quality and Safety, Sept 18-20, 2006). This workshop is co-sponsored the IFPA (International Fresh-cut Produce Association) which has recently merged with another industry association called UFPA (United Fresh Produce Association). I compile and edit materials and recent research findings as well as unpublished data on fresh-cut products (see publications). 2. Produce quality rating scales and color charts. Univ. California Postharvest Horticulture Series No. 23-CD was first published in Sept 2004. These quality rating scales were compiled as a first-step towards standardization of quality evaluation procedures and were revised in January 2006. This publication is in hard copy and CD formats and will continue to be updated during this project (see publications). 3. We have begun Time-Lapse Photography of research and educational tests of fresh-cut products to make video clips for presentations. We have 3 identical mobile set-ups that enable us to do studies of 3 conditions such as temperatures or other treatments. The time-lapse sequences will be merged into a video clip to represent quality changes in a dynamic way for the 3 conditions simultaneously. In 2006 we worked on sliced mushrooms (3 storage temperatures) and broccoli florets (1-MCP and temperature). Objective 2. Develop new strategies to maintain fresh-cut product quality. 1. Use of 1-MCP to retard deterioration of leafy green vegetables. In 2006 we did research on broccoli florets and the Postharvest evaluations and compositional analyses also included HPLC analysis of glucosinolates. 1-MCP retarded changes in glucosinolates in relation to its effectiveness to retard senescence at 5 and 10C. 2. Impact of 1-MCP treatment of romaine lettuce heads in relation to preprocessing handling and storage and to quality of the salad cut lettuce. Research was conducted with industry processor collaboration; 3 tests conducted in 2005 and 1 test in 2006 showed high variation in efficacy in relation to cultivar; pre-cutting 1-MCP treatment does not have important impact on cut-edge browning defect.Objective 3. Improve understanding of biochemical, physiological and molecular mechanisms that affect fresh-cut product quality. Objective 3. 1. Modified atmosphere technology has been reported to have a detrimental effect on the ascorbic acid content of lettuce. We conducted research on both cut iceberg and romaine lettuce in 2006 that showed that low oxygen atmospheres do not impact ascorbic acid changes, but that carbon dioxide atmospheres (3-9 percent) resulted in significant and important decreases of ascorbic acid (reduced ascorbic acid and dehydroascorbic acid forms determined by HPLC) after 6 days at 5C.

Impacts
Our applied studies are of direct relevance to successful pre- and post-processing handling of products by the fresh-cut industry. Our work in 2006 provided data on quality and compositional changes for fresh-cut vegetable products including lettuce, spinach, other leafy greens, melons, mushrooms, and broccoli. Some of the studies conducted during 2006 were at the requested of fresh-cut processors in California. Our research and that of others is also used at the annual Fresh-cut workshop. In 2006, the 11th year of the workshop, we had 46 attendees, most from the fresh-cut industry.

Publications

Cantwell, M. (ed. compiler). 2006. Fresh-cut Products: Maintaining Quality and Safety. Univ. California Postharvest Horticulture Series No. 10. UC Postharvest Research and Information Center (http://postharvest.ucdavis.edu). Updated Sept 2006.
Kader, A. and M. Cantwell. 2006. Produce quality rating scales and color charts. Univ. California Postharvest Horticulture Series No. 23-CD. UC Postharvest Research and Information Center (http://postharvest.ucdavis.edu). Jan 2006 revision.
Ermen, H., G. Hong, L. Marques and M. Cantwell. 2006. The Impact of Leaf Position on the Respiration, Composition and Visual Quality of Salad-cut Romaine Lettuce. Abstract. IFPA, April 27-30, 2006, Baltimore, MD.
Ermen, H., G. Hong, L. Marques and M. Cantwell. 2006. Comparing Visual and Compositional Quality Changes of Salad-cut Iceberg and Romaine Lettuce Stored at 3 Temperatures in Air or Controlled Atmosphere. Abstract. IFPA, April 27-30, 2006, Baltimore, MD.
Cantwell, M., G. Hong, and H. Ermen. 2006. Key physiological aspects of fresh-cut fruits and vegetables, and their consequences for product quality and shelf-life. Abstract. ISHS, Seoul, Korea, August 13-19, 2006.

Progress 01/01/05 to 12/31/05

Outputs
To assess the presence and physiological significance of nutrients and other functional components of fresh-cut vegetables and fruits as affected by storage and handling. a.Impact of 1-MCP treatment of romaine lettuce heads in relation to preprocessing handling and storage and to quality of the salad cut lettuce. Research conducted with industry processor collaboration; 3 tests conducted in 2005 showed high variation in efficacy in relation to cultivar. b.Quality of fresh-cut tomatoes. Effect of initial maturity stage on slice integrity at table-ripe stage of tomatoes was studied for several fresh market varieties. c.Use of 1-MCP to retard deterioration of leafy green vegetables (broccoli, herbs [chives, cilantro, dill]). This work done at reasonable storage temperature (5 degrees C) and temperature abuse conditions (10 degrees C). Visual quality attributes and compositional quality (sugars, chlorophyll, carotenoids, ascorbic acid, ammonia) evaluated, some physiology (respiration rates). Objective 3: To develop a better understanding of the physiology of fresh-cut vegetables and fruits in response to processing and during storage and handling. a.As coordinator of an annual Fresh-cut workshop held at UC Davis (Sept 13-15, 2005), I compile and edit materials and recent research findings as well as unpublished data on fresh-cut products. b.Golden honeydew melons as fresh-cut product. Storage temperature and time studied in relation to the quality and shelf-life of the fresh-cut product stored at 5 degrees C. Fresh-cut product evaluated for visual quality attributes, sugars, vitamin C, texture, color and aroma.

Impacts
Our applied studies are of direct relevance to successful pre- and post-processing handling of products by the fresh-cut industry. Our work provides benchmark data on quality changes and compositional changes for fresh-cut products. Some of the studies we have conducted have been specifically requested by fresh-cut processors.

Publications

None 2005

Progress 01/01/04 to 12/31/04

Outputs
Objective 1: To assess the presence and physiological significance of nutrients and other functional components of fresh-cut vegetables and fruits as affected by storage and handling. a. Impact of 1-MCP treatment of iceberg and romaine lettuce heads in relation to preprocessing handling and storage and to quality of the salad cut lettuce. Research conducted with industry and processor collaboration. b. Storage and conditioning of melons (cantaloupe, honeydew, and specialty melons) for improved aroma and quality. We are evaluating storage conditions, ethylene and 1-MCP applications and other treatments to enhance the overall quality, especially aroma, of cantaloupe and honeydew melons that are fresh-cut. Variety and stage of maturity at harvest are also part of the studies. c. Effect of preprocessing handling of peppers on pepper texture and other quality parameters. Mature-green peppers subjected to various periods of delay to cool and sun exposure and compositional and texture quality of dices evaluated. d. Use of 1-MCP to retard deterioriation of leafy green vegetables (collards, kale, parsley, other herbs). This work done at reasonable storage temperature (5 degrees C) and temperature abuse conditions (10 degree C). Visual quality attributes and compositional quality (sugars, chlorophyll, carotenoids, ascorbic acid, ammonia) evaluated. Objective 3: To develop a better understanding of the physiology of fresh-cut vegetables and fruits in response to processing and during storage and handling. a. As coordinator of an annual Fresh-cut workshop held at UC Davis (Sept 14-16, 2004), I compile and edit materials and recent research findings as well as unpublished data on fresh-cut products. b. Cauliflower intact and floret storage under a range of temperatures and atmospheres. Visual quality attributes, composition, and respiration rates monitored. Research conducted with industry and processor collaboration.

Impacts
Our applied studies are of direct relevance to successful pre- and post-processing handling of products by the fresh-cut industry. Our work provides benchmark data on quality changes and compositional changes for fresh-cut products. Some of the studies we have conducted have been specifically requested by fresh-cut processors.

Publications

Cantwell, M., (ed.). 2004. Fresh-cut Products: Maintaining Quality and Safety. Univ. California Postharvest Horticulture Series No. 10. UC Postharvest Research and Information Center (http://postharvest.ucdavis.edu).

Progress 01/01/03 to 12/31/03

Outputs
Objective 1: To assess the presence and physiological significance of nutrients and other functional components of fresh-cut vegetables and fruits as affected by storage and handling. a. Broccoli floret composition and shelf-life in relation to nitrogen fertilization and postharvest conditions. This is a 4-year project, with the last experiment in Dec 2003. Changes in sugars, chlorophyll, carotenoids, ascorbic acid were determined as well as glucosinolates (and sulfurophane on selected samples) from 5 N fertilization levels. Storage tests of the intact head and florets are also conducted. Partial data were presented at 2002 IFPA Conference as a poster and have been summarized as unpublished research reports. b. Compositional changes in garlic bulbs and cloves were stored under controlled atmospheres and important components (fructan, alliin, thiosulfinates) were evaluated (Published #1). Alliin and thiosulfinate and dry weight components of accessions from a germplasm collection were evaluated for the 4th year. c. Control of sprout development in garlic cloves. Heat shock treatment is very effective in retarding sprout growth in unpeeled or peeled garlic cloves. Results are summarized in Published #2. d. Effect of pre-processing storage conditions on quality of fresh-cut green pepper. Mature-green bell pepper were stored at chilling (2.5C) and nonchilling (7.5C) and evaluated for physiological changes (respiration, electrolyte leakage) and composition and quality after processing as dices and storing at 5C. Unpublished research report of experiments to date. e. Conditioning melons for improved aroma and quality. We are evaluating ethylene and other treatments to enhance the overall quality, especially aroma, of cantaloupe and honeydew melons. Variety, stage of maturity at harvest, and storage conditions are being considered. (Abstract #1) Objective 3: To develop a better understanding of the physiology of fresh-cut vegetables and fruits in response to processing and during storage and handling. a. As coordinator of an annual Fresh-cut workshop held at UC Davis (Sept 9-11 in 2003), I compile reviews and recent research findings as well as unpublished data on fresh-cut products (Published #3). b. Impact of storage temperature, ethylene exposure and 1-MCP on quality and shelf-life of spinach. Spinach generates substantial concentrations of ammonia when held at temperature abuse conditions or due to ethylene exposure. 1-MCP is effective in delaying senescence. Besides ammonia concentrations, other quality parameters including color, chlorophyll, carotenoids, sugars, ethanol and acetaldehyde, were measured. (Abstract #2). c. Evaluation of 1-MCP treatment of melons on their firmness and quality. In 2003 experiments were conducted on several varieties of cantaloupe, honeydew and watermelon. 1-MCP application benefited watermelon, but effects on cantaloupe and honeydew were minimal. One unpublished research was written summarizing the results.

Impacts
Our applied studies are of direct relevance to successful pre- and post-processing handling of products by the fresh-cut industry. Our work provides benchmark data on quality changes and compositional changes for fresh-cut products. Some of the studies we have conducted have been specifically requested by fresh-cut processors.

Publications

Cantwell, M.I., J. Kang and G. Hong. 2003. Heat treatments control sprouting and rooting of garlic cloves. Postharvest Biol. Tech. 30: 57-65.
Cantwell, M.I., A. Ma. Ibanez, G. Hong. 2004. The impact of maturity at harvest on the quality of honeydew melons after storage and conditioning. IFT Annual meeting and Food Expo, July 12-16.
Cantwell, M.I., P. Freitas, G. Hong and X. Nie. 2004. Storage temperature, ethylene exposure and 1-MCP affect spinach shelf-life and composition. IFT Annual meeting and Food Expo, July 12-16.

Progress 01/01/02 to 12/31/02

Outputs
Objective 1: To assess the presence and physiological significance of nutrients and other functional components of fresh-cut vegetables and fruits as affected by storage and handling. a. Broccoli floret composition and shelf-life in relation to nitrogen fertilization and postharvest conditions. Changes in sugars, chlorophyll, carotenoids, ascorbic acid were determined as well as glucosinolates and sulfurophane in samples from one N fertilization trial in 2002 (repeat of the 2001 field experiment) and several storage tests (temperature, controlled atmospheres, ethylene exposure).b. Garlic bulbs and cloves were stored under controlled atmospheres and important components (fructan, alliin, thiosulfinates) were evaluated . Alliin and thiosulfinate and dry weight components of accessions from a germplasm collection were evaluated for the 3rd year from 2 production sites. Objective 3: To develop a better understanding of the physiology of fresh-cut vegetables and fruits in response to processing and during storage and handling. a. As coordinator of an annual Fresh-cut workshop, we compile reviews and recent research findings as well as unpublished data on fresh-cut products b. Impact of controlled atmosphere storage on quality and shelf-life of spinach. Modified atmosphere packaging is not currently used by spinach processors and our objective was to determine why spinach does not respond well to these storage conditions. We found that spinach generates substantial concentrations of ammonia when held under atmospheres with relatively high concentrations of carbon dioxide. Besides analysis of ammonia, other quality parameters including color, chlorophyll, carotenoids, sugars, ethanol and acetaldehyde, were measured.c. Evaluation of possible benefits of 1-MCP treatment of cantaloupe, honeydew and watermelon on the firmness and quality of fresh-cut pieces. 1-MCP was applied to whole fruit or to fresh-cut pieces, and effects on firmness were minimal when fruit and pieces were stored in atmospheres without ethylene. Two unpublished research reports were written summarizing the results to date. d. fresh-cut melon pieces were treated with low concentrations of calcium chloride and the effects of these treatments on firmness and microbial growth of the fresh-cut pieces was evaluated for cantaloupe and honeydew .

Impacts
Our applied studies are of direct relevance to the pre- and post-processing handling by the fresh-cut industry. Our work provides reference data on quality changes and compositional changes for fresh-cut operations. Some of the studies conducted have been requested by companies involved in fresh-cut processing.

Publications

Wang, Q.M., S. Abel, M. Cantwell, X. Nie. 2002 Pre- and postharvest conditions which affect the concentrations of glucosinolates and sulfurophane in broccoli florets. In preparation.
Cantwell, M. and T. Suslow. 2002 Firming effect of calcium chloride on fresh-cut cantaloupe and honeydew melon depends on fruit ripeness. In preparation.
Suslow, T.V., F.L. Mercado, M. Zuniga, M.I. Cantwell. 2002 Effect of Calcium Treatments on firmness and microbial quality of minimally-Processed Honeydew Melon. In preparation.
Rodriguez, S. and M.I. Cantwell. 2002 Changes in ammonia concentrations of spinach leaves in relation to handling and storage conditions. In preparation for Postharvest Biology and Technology.
Abstract#1. Cantwell, M., G. Hong, H. Kang, M. LeStrange, Q. Wang, S. Abel, and X. Nie. 2002. Preharvest and Postharvest Conditions that Impact Broccoli Floret Quality. International Fresh-cut Produce Association, Phoenix, AZ, April 11-13.
Abstract#2. Freitas, P.M., M. Cantwell and T.C. Ripoli. 2002. Qualidade de broccolis(Brassica oleracea) sob exposicao de etileno. Simposio Internacional de Iniciacao Cientifica da Universidade do Estado de Sao Paulo, Piracicaba, Brazil, 5-6 Nov, 2002.
Abstract#3. Cantwell, M. 2002. Situacion actual de hortalizas minimamente procesadas. Invited presentation. 3er Congreso Iberoamericano de Tecnologia Postcosecha y Agroexportaciones, Santiago, Chile, Dec 3-6. Simiente 72(3-4): 38-39.
Abstract#4. Rodriguez, S. del C. y M. Cantwell. 2002. Efecto de atmosferas controladas en la conservacion de espinacas minimamente procesadas. 3er Congreso eroamericanode Tecnologia Postcosecha y Agroexportaciones, Santiago, Chile, Dec 3-6. Simiente 72(3-4): 77.
Published or in press 2002 Cantwell, M. (compiler). 2002. Fresh-cut Products: Maintaining Quality and Safety. Univ. California Postharvest Horticulture Series No. 10.
Cantwell, M. and T. Suslow. 2002. Postharvest handling systems: Minimally processed fruits and vegetables. Chpt. 32. In: Kader, A.K. (ed.). Postharvest Technology of Horticultural Crops, 3rd ed., Univ. California Special Publ. 3311, pp. 445-463.
Cantwell , M.I., G. Hong, J. Kang and X. Nie. 2002. Controlled atmospheres retard sprout growth, affect compositional changes, and maintain visual quality attributes of garlic. Proc. CA 2001, Rotterdam, The Netherlands. Acta Horticulturae, in press.