Source: KENTUCKY STATE UNIVERSITY submitted to
POTENTIAL APPLICATION OF ELECTROLYZED WATER AND SOME NATURAL COMPOUNDS IN FOOD SAFETY
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
EVANS-ALLEN
Reporting Frequency
Annual
Accession No.
0231386
Grant No.
(N/A)
Project No.
KYX-50-12-25H
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Oct 1, 2012
Project End Date
Sep 30, 2015
Grant Year
(N/A)
Project Director
Wang, CH.
Recipient Organization
KENTUCKY STATE UNIVERSITY
(N/A)
FRANKFORT,KY 40601
Performing Department
Human Nutrition & Health
Non Technical Summary
There is a growing need for alternative technology to reduce the use of synthetic chemical disinfectants and preservatives but still keep our foods safe. This project will focus on the potential use of electrolyzed water in the processing of fish products and vegetables. In addition, this project will evaluate the antimicrobial activities of natural compounds in purple sweet potato and purple tomatoes and evaluate their potential us in food preservation. The specific objectives are: 1. To determine the effects of electrolyzed water on the microbial load and quality of paddlefish caviar and meat. 2. To determine the effects of electrolyzed water on the microbial load, appearance, texture and nutritional composition of vegetables; 3. To determine the antibacterial activities of natural compounds extracted from purple sweet potato and purple tomatoes using acidic electrolyzed water. Results from this project will be disseminated through publications in scientific journals, presentations at scientific meeting and workshops for farmers and the general public. This project is relevant to the goals of United States Department of Agriculture. It is consistent with the priority area of Food Safety, Nutrition and Health for the National Institute of Food and Agriculture. This project will address food safety issues related to food products from the aquaculture program, and the Organic Vegetable programs, which are focus areas for the College of Agriculture, Food Science and Sustainable Systems at Kentucky State University.
Animal Health Component
0%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
7121430110010%
7121450110010%
7121460110010%
7123799110020%
7121430200010%
7121450200010%
7121460200010%
7123799200020%
Knowledge Area
712 - Protect Food from Contamination by Pathogenic Microorganisms, Parasites, and Naturally Occurring Toxins;

Subject Of Investigation
1450 - Sweet potato; 1430 - Greens and leafy vegetables; 1460 - Tomato; 3799 - Cultured aquatic animals, general/other;

Field Of Science
2000 - Chemistry; 1100 - Bacteriology;
Goals / Objectives
Eliminating pathogenic microbes from food during production and processing is critical for assuring the safety of foods. Very often chemical disinfectants and food preservatives are used to kill or inhibit microbial growth in the environment or in the food. As the public becomes more health conscious, there are growing concerns expressed about the efficacy and the environmental impact of these chemicals. Therefore, food scientists and the food industry are challenged to find alternative technology to reduce the need for the use of such chemicals. Acidic electrolyzed water has been shown to be an effective disinfectant that can be used in the food industry. It is nontoxic to humans and has very little impact on the environment. This project will focus on the potential use of electrolyzed water in the processing of fish products and organic vegetables. Purple sweet potato and purple tomatoes are rich in natural compounds with antioxidant activities. These compounds can be extracted efficiently with the use of acidic electrolyzed water. The antibacterial property of these compounds needs to be evaluated for their potential us in food preservation. The specific objectives of the this project are: 1. To determine the effects of electrolyzed water on the microbial load and quality of paddlefish caviar and meat. 2. To determine the effects of electrolyzed water on the microbial load, appearance, texture and nutritional composition of vegetables; 3. To determine the antibacterial activities of natural compounds extracted from purple sweet potato and purple tomatoes using acidic electrolyzed water. Outputs This project will provide opportunities to mentor graduate and undergraduate students in the field of food safety, and train farmers and food processing personnel on techniques to reduce microbial contamination of fish products and fresh produce through Kentucky State University's field days and workshops. This project will introduce the electrolyzed water as an alternative technology for keeping food products safe. This project enhances the collaboration among scientists in food and nutrition and those in aquaculture and agriculture and horticulture at Kentucky State University. It will also strengthen our partnership with food producers and marketers such as the Grasshopper Distribution. Results from this project will be disseminated through scientific publications and presentations at the annual meetings of Institute of Food and Technologists, Kentucky Academy of Science and the Experimental Biology. The information will also be made available through Kentucky State University website, extension articles and newsletters.
Project Methods
This project will evaluate the effects of electrolyzed water on microbial load, appearance, texture, indicators for lipid oxidation and protein degradation in paddlefish caviar and meat. Paddlefish eggs rinsed with one of the five types of water: tap water, dilute bleach (50 ppm chlorine), acid electrolyzed water, alkaline electrolyzed water or alkaline electrolyzed water followed by acidic electrolyzed water. Samples will be taken from each group periodically and tested for changes in quality parameters and microbial load. Paddlefish fillets will be rinsed in tap water, dilute bleach (50 ppm chlorine), acidic electrolyzed water, alkaline electrolyzed water or alkaline electrolyzed water followed by acidic electrolyzed water before they will be stored frozen in individual Ziploc bags at -20 0C. Two fillets per group will be removed from storage and tested for changes quality parameters and microbial load. To determine the effects of electrolyzed water on microbial load, appearance, texture and nutritional composition of leafy green vegetables, organically and conventionally produced leafy green vegetables collected from the research farm of Kentucky State University and four other farmers. Each type of vegetables from each collection site will be divided into three batches. Each batch will be rinsed with tap water, dilute bleach (50 ppm chlorine), acidic electrolyzed water, alkaline electrolyzed water, or alkaline electrolyzed water followed by acidic electrolyzed water before they are placed into Ziploc bags and stored at 40 C. Samples (about 10g) will be collected from each bag periodically to be tested for quality changes and microbial load.Purple sweet potato and purple tomato will be freeze dried and ground into powder. One extract will be made from 10 g purple sweet potato or 10 g purple tomato powder will be extracted by mixing with acid electrolyzed water in a 500 ml round flask with 200 ml solution of water/hydrochloric acid (19:1, v/v) or acidic electrolyzed water stirred at 100?C for 3 h. For comparison, 10 g purple sweet potatoes powder or 10 g purple tomato powder will be heated to reflux temperature in a Soxhlet extractor with 500mL of hexane, chloroform, methanol and distilled water each for 3 h. 2010). Each of the fractions way will be tested for its antibacterial activity using the disk diffusion assay and the minimum inhibition concentration assay. During the conduct of the project, the principal investigators will ensure that each activity specified in the timetable will be completed on schedule. Our Associate Research Director and Chair of the Division of Food and Animal Science will objectively evaluate the progress of the project quarterly. A report of the project activities will be made quarterly to the university administration and to collaborators. Regular discussions will be held with individuals involved in the project to facilitate progress of the project. Students will be closely supervised and trained in all procedures used in the project.

Progress 10/01/12 to 09/30/15

Outputs
Target Audience:We have shared the results of our study with 30 people attending the Third Thursday Thing workshop held on the Research Farm of Kentucky State University and 25 people attending the Small Farm Conference. These individuals are either farmers or people who are interested in agriculture. We have built a collaborative relationship with a commercial fish processing and marketing company that is interested in learning about the technology and adopting the technology in the future. Changes/Problems:Our research facility was being renovated and unavailable for research activities. The planned purchase of a mobile research building was delayed and no space has been available for the installation of a freeze drier necessary for making sweet potato extracts. What opportunities for training and professional development has the project provided?During this period, one graduate student was trained in microbiological evaluation of fish and vegetable samples, safe handling of microbial cultures, experimental design, and data analysis. Students and staff members made 5 presentations of research results at the annual meeting of Kentucky Academy of Science. We have shared aspects of this project and the results with 8 undergraduate students and two graduate students attending Kentucky State University. The project was also discussed at a seminar course with 20 graduate and undergraduate students. How have the results been disseminated to communities of interest?Research results have been disseminated in a Master's degree thesis, and presentations at the annual meeting of Kentucky Academy of Science. Results have also been shared through presentations and discussion at a local workshop and with attendees at the Small Farm Conference. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? fish tanks with artificial lighting. Collard green, basil and Bok Choi were grown on a foam board floating in fish tanks with artificial lighting at the Aquaculture Center of Kentucky State University. Edible portions of collard greens, Swiss chard and Bok Choi were cut into 1 cm length with sterilized scissors and mixed thoroughly before 10 g of the sample was homogenized with 90 ml of peptone water for 2.5 min in a Stomacher bag. One ml of the homogenized sample was inoculated onto Petrifilm plates for total aerobic count and E. coli/coliform, respectively, after 10, 100, and 1000 times of dilution. Plates were incubated in a culture chamber at 32 °C for 24 hr period before the colony forming units were counted manually. Separate samples were taken from the same pooled sample and were rinsed with tap water or acidic electrolyzed water for 5 min in a plastic container. After the rinse water was drained off, the rinsed samples were analyzed in the same way as described for the unrinsed samples. Tap water rinse reduced microbial load of the vegetables but rinsing with electrolyzed water reduced it further. These results indicate rinsing with acidic electrolyzed water was effective in reducing microbial load of vegetables produced hydroponically in fish tanks with artificial lighting. We also assessed the effects of rinsing with acidic electrolyzed water on the microbial load of vegetables grown hydroponically in fish ponds. Basil and butter head lettuce were grown on a foam raft floating in fish ponds. Edible portions of basil and butter head lettuce were cut into 1 cm length with sterilized scissors and mixed thoroughly before 10 g of the sample was homogenized with 90 ml of peptone water for 2.5 min in a Stomacher bag. One ml of the homogenized sample was inoculated onto Petrifilm plates for total aerobic count and E. coli/coliform, respectively, after 10, 100, and 1000 times of dilution. Plates were incubated in a culture chamber at 32 °C for 24 hr before the colony forming units were counted manually. Separate samples were taken from the same pooled sample and were rinsed with tap water or acidic electrolyzed water for 5 min in a plastic container. After the rinse water was drained off, the rinsed samples were analyzed in the same way as described for the unrinsed samples. Tap water rinse reduced microbial load of basil leaves by 40% and rinsing with acidic electrolyzed water lowered it by 60%. For butter head lettuce, tap water rinse reduced the microbial load by about 90% and rinsing with acidic electrolyzed water lowered it by 98%. These results indicate that it was more difficult to reduce microbial load of basil leaves than that of butter head lettuce leaves. Rinsing with acidic electrolyzed water was more effective than tap water in cutting down the microbial load of vegetables produced hydroponically in fish ponds. We also examined the microbial load of vegetables from aquaponics in comparison with vegetables grown under conventional and organic conditions. Romaine lettuce was harvested from an aquaponics farm in Versailles, KY, and conventional and organic Romaine lettuce was purchased from a local super market on the same day. The top 1/3 and bottom 1/3 of the plants were sampled for analysis. Each sample was cut into 1 cm length with sterilized scissors and mixed thoroughly before 10 g of the sample was homogenized with 90 ml of peptone water for 2.5 min in a Stomacher bag. One ml of the homogenized sample was inoculated onto Petrifilm plates for total aerobic count and E. coli/coliform, respectively, after 10, 100, and 1000 times of dilution. Plates were incubated in a culture chamber at 32 °C for 24 hr before the colony forming units were counted manually. Microbial load on the lower 1/3 was significantly higher than top 1/3 of romaine lettuce. Lettuce produced conventionally had the highest microbial load and lettuce produced hydroponically had the lowest microbial load regardless of the sampling location. These results indicate that vegetables produced through aquaponics are less likely to be contaminated by microbial organisms than conventional and organic vegetables. Considering the higher microbial load on the bottom portion of the plant, marketing with roots attached may result in more contamination during distribution. In addition, we determined the effects of pretreatment with hot water and acidic electrolyzed water on the microbial load and quality characteristics of pawpaw fruits. Pawpaw fruits were harvested from the research orchard of Kentucky State University. They were randomly assigned to receive no pretreatment, pretreatment with heating in water at 60 C for 5 min, rinsing with tap water or acidic electrolyzed water for 2 min. Three fruits from each group were analyzed for weight loss, hardness, pulp color and Brix value on day 1, 7, 10 and 14 after the pretreatment. The fruits were also inspected visually. Microbial load was relatively high at the beginning and became lower during the experiment. Pretreatment with acidic electrolyzed water reduced the microbial load but did not delay the deterioration of the fruit. The hardness of the fruits declined for all groups but slightly less for the hot water treated group. As time increased, fruits tended to turn dark in skin color and number of sagging spots increased. However, appearance of the hot water treated group remained acceptable up to 14 days, indicating that hot water treatment delayed the maturation process and extended slightly the shelf life of pawpaw fruits.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Changzheng Wang, Lingyu Huang, Cecil Butler, Michael Bomford. 2015. Effectiveness of acidic electrolyzed water in reducing microbial load on lettuce produced in a high tunnel. Program book of 2015 Annual conference of American Society for Horticultural Science, Page 60.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Lingyu Huang, Cecil Butler, Changzheng Wang. 2015. Microbial Load of Vegetables Grown under Conventional, Organic or Aquaponic Conditions. http://www.kyacademyofscience.net/kas/members/viewabs.php?page=expand&id=276&year=2015
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Cecil Butler, Lingyu Huang, Changzheng Wang. 2015. Effects of acidic electrolyzed water on microbial load of vegetables grown hydroponically in fish tanks with artificial lighting. http://www.kyacademyofscience.net/kas/members/viewabs.php?page=expand&id=445&year=2015
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Gidgett Taylor, Lingyu Huang, Cecil Butler, Cheri Crabtree, Jeremy Lowe, Kirk Pomper, Changzheng Wang. 2015. Effects of hot water and acidic electrolyzed water on microbial load and quality characteristics of Pawpaw fruits. http://www.kyacademyofscience.net/kas/members/viewabs.php?page=expand&id=443&year=2015
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Kelly Yufeh, Lingyu Huang, Cecil Butler, Changzheng Wang. 2015. Effects of acidic electrolyzed water on microbial load of vegetables grown hydroponically in fish ponds. http://www.kyacademyofscience.net/kas/members/viewabs.php?page=expand&id=444&year=2015
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Changzheng Wang, Lingyu Huang, Cecil Butler. 2015. Disassociation between knowledge and behaviors related to body weight status of adults in Kentucky. FASEB J. 29:595.25.


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

Outputs
Target Audience:We have shared the results of our study with 30 people attending the Third Thursday Thing workshop held on the Research Farm of Kentucky State University and 25 people attending the Small Farm Conference. These individuals are either farmers or people who are interested in agriculture. We have built a collaborative relationship with a commercial fish processing and marketing company that is interested in learning about the technology and adopting the technology in the future. Changes/Problems:Our research facility was being renovated and unavailable for research activities. The planned purchase of a mobile research building was delayed and no space has been available for the installation of a freeze drier necessary for making sweet potato extracts. What opportunities for training and professional development has the project provided?During this period, one graduate student was trained in microbiological evaluation of fish and vegetable samples, safe handling of microbial cultures, experimental design, and data analysis. Students and staff members made 5 presentations of research results at the annual meeting of Kentucky Academy of Science. We have shared aspects of this project and the results with 8 undergraduate students and two graduate students attending Kentucky State University. The project was also discussed at a seminar course with 20 graduate and undergraduate students. How have the results been disseminated to communities of interest?Research results have been disseminated in a Master's degree thesis, and presentations at the annual meeting of Kentucky Academy of Science. Results have also been shared through presentations and discussion at a local workshop and with attendees at the Small Farm Conference. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? We determined the effects of rinsing with acidic electrolyzed water on the microbial load of vegetables grown hydroponically in fish tanks with artificial lighting. Collard green, basil and Bok Choi were grown on a foam board floating in fish tanks with artificial lighting at the Aquaculture Center of Kentucky State University. Edible portions of collard greens, Swiss chard and Bok Choi were cut into 1 cm length with sterilized scissors and mixed thoroughly before 10 g of the sample was homogenized with 90 ml of peptone water for 2.5 min in a Stomacher bag. One ml of the homogenized sample was inoculated onto Petrifilm plates for total aerobic count and E. coli/coliform, respectively, after 10, 100, and 1000 times of dilution. Plates were incubated in a culture chamber at 32 °C for 24 hr period before the colony forming units were counted manually. Separate samples were taken from the same pooled sample and were rinsed with tap water or acidic electrolyzed water for 5 min in a plastic container. After the rinse water was drained off, the rinsed samples were analyzed in the same way as described for the unrinsed samples. Tap water rinse reduced microbial load of the vegetables but rinsing with electrolyzed water reduced it further. These results indicate rinsing with acidic electrolyzed water was effective in reducing microbial load of vegetables produced hydroponically in fish tanks with artificial lighting. We also assessed the effects of rinsing with acidic electrolyzed water on the microbial load of vegetables grown hydroponically in fish ponds. Basil and butter head lettuce were grown on a foam raft floating in fish ponds. Edible portions of basil and butter head lettuce were cut into 1 cm length with sterilized scissors and mixed thoroughly before 10 g of the sample was homogenized with 90 ml of peptone water for 2.5 min in a Stomacher bag. One ml of the homogenized sample was inoculated onto Petrifilm plates for total aerobic count and E. coli/coliform, respectively, after 10, 100, and 1000 times of dilution. Plates were incubated in a culture chamber at 32°Cfor 24 hr before the colony forming units were counted manually. Separate samples were taken from the same pooled sample and were rinsed with tap water or acidic electrolyzed water for 5 min in a plastic container. After the rinse water was drained off, the rinsed samples were analyzed in the same way as described for the unrinsed samples. Tap water rinse reduced microbial load of basil leaves by 40% and rinsing with acidic electrolyzed water lowered it by 60%. For butter head lettuce, tap water rinse reduced the microbial load by about 90% and rinsing with acidic electrolyzed water lowered it by 98%. These results indicate that it was more difficult to reduce microbial load of basil leaves than that of butter head lettuce leaves. Rinsing with acidic electrolyzed water was more effective than tap water in cutting down the microbial load of vegetables produced hydroponically in fish ponds. We also examined the microbial load of vegetables from aquaponics in comparison with vegetables grown under conventional and organic conditions. Romaine lettuce was harvested from an aquaponics farm in Versailles, KY, and conventional and organic Romaine lettuce was purchased from a local super market on the same day. The top 1/3 and bottom 1/3 of the plants were sampled for analysis. Each sample was cut into 1 cm length with sterilized scissors and mixed thoroughly before 10 g of the sample was homogenized with 90 ml of peptone water for 2.5 min in a Stomacher bag. One ml of the homogenized sample was inoculated onto Petrifilm plates for total aerobic count and E. coli/coliform, respectively, after 10, 100, and 1000 times of dilution. Plates were incubated in a culture chamber at 32°Cfor 24 hr before the colony forming units were counted manually. Microbial load on the lower 1/3 was significantly higher than top 1/3 of romaine lettuce. Lettuce produced conventionally had the highest microbial load and lettuce produced hydroponically had the lowest microbial load regardless of the sampling location. These results indicate that vegetables produced through aquaponics are less likely to be contaminated by microbial organisms than conventional and organic vegetables. Considering the higher microbial load on the bottom portion of the plant, marketing with roots attached may result in more contamination during distribution. In addition, we determined the effects of pretreatment with hot water and acidic electrolyzed water on the microbial load and quality characteristics of pawpaw fruits. Pawpaw fruits were harvested from the research orchard of Kentucky State University. They were randomly assigned to receive no pretreatment, pretreatment with heating in water at 60 C for 5 min, rinsing with tap water or acidic electrolyzed water for 2 min. Three fruits from each group were analyzed for weight loss, hardness, pulp color and Brix value on day 1, 7, 10 and 14 after the pretreatment. The fruits were also inspected visually. Microbial load was relatively high at the beginning and became lower during the experiment. Pretreatment with acidic electrolyzed water reduced the microbial load but did not delay the deterioration of the fruit. The hardness of the fruits declined for all groups but slightly less for the hot water treated group. As time increased, fruits tended to turn dark in skin color and number of sagging spots increased. However, appearance of the hot water treated group remained acceptable up to 14 days, indicating that hot water treatment delayed the maturation process and extended slightly the shelf life of pawpaw fruits.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Changzheng Wang, Lingyu Huang, Cecil Butler, Michael Bomford. 2015. Effectiveness of acidic electrolyzed water in reducing microbial load on lettuce produced in a high tunnel. Program book of 2015 Annual conference of American Society for Horticultural Science, Page 60.
  • Type: Websites Status: Other Year Published: 2015 Citation: Lingyu Huang, Cecil Butler, Changzheng Wang. 2015. Microbial Load of Vegetables Grown under Conventional, Organic or Aquaponic Conditions. http://www.kyacademyofscience.net/kas/members/viewabs.php?page=expand&id=276&year=2015
  • Type: Websites Status: Other Year Published: 2015 Citation: Cecil Butler, Lingyu Huang, Changzheng Wang. 2015. Effects of acidic electrolyzed water on microbial load of vegetables grown hydroponically in fish tanks with artificial lighting. http://www.kyacademyofscience.net/kas/members/viewabs.php?page=expand&id=445&year=2015
  • Type: Websites Status: Other Year Published: 2015 Citation: Changzheng Wang, Lingyu Huang, Cecil Butler. 2015. Relationship between hot pepper consumption and body weight status among adults http://www.kyacademyofscience.net/kas/members/viewabs.php?page=expand&id=276&year=2015
  • Type: Websites Status: Other Year Published: 2015 Citation: Gidgett Taylor, Lingyu Huang, Cecil Butler, Cheri Crabtree, Jeremy Lowe, Kirk Pomper, Changzheng Wang. 2015. Effects of hot water and acidic electrolyzed water on microbial load and quality characteristics of Pawpaw fruits. http://www.kyacademyofscience.net/kas/members/viewabs.php?page=expand&id=443&year=2015
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Changzheng Wang, Lingyu Huang, Cecil Butler. 2015. Disassociation between knowledge and behaviors related to body weight status of adults in Kentucky. FASEB J. 29:595.25.
  • Type: Websites Status: Other Year Published: 2015 Citation: Kelly Yufeh, Lingyu Huang, Cecil Butler, Changzheng Wang. 2015. Effects of acidic electrolyzed water on microbial load of vegetables grown hydroponically in fish ponds. http://www.kyacademyofscience.net/kas/members/viewabs.php?page=expand&id=444&year=2015


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

Outputs
Target Audience: During this period, we have discussed this project and the results with 8 undergraduate students and two graduate students attending Kentucky State University. We have also shared the results of our study with 36 people attending the Third Thursday Thing workshop held on the Research Farm of Kentucky State University and 16 people attending the Small Farm Conference. These individuals are either farmers or people who are very interested in agriculture. Five individuals interested in food processing asked questions about the technology and its practical applications. Changes/Problems: Kentucky experienced extremely cold weather in the Spring of 2014. Our attempts to collect paddlefish eggs were not successful because the fish either had low egg counts or the quality of the eggs was too low to be processed into caviar. This year, we will try again to collect paddlefish eggs for the study of microbiological quality of fish caviars. We have made contacts with two caviar processors for assistance to ensure supplies of paddlefish eggs for the study. Our research facility was being renovated and unavailable for research activities. A freeze drier needed for making sweet potato extracts could not be installed because of space limitation. This will be remedied by the purchase of a mobile research facility so the equipment could be used for our research project. What opportunities for training and professional development has the project provided? One graduate student and two staff members were trained in microbiological evaluation of fish and vegetables samples, safe handling of microbial cultures, experimental design and data analysis. The graduate student completed his M.S. degree. Staff members presented research data at a regional conference. Five undergraduate students and two high school students were introduced to the project and learned about the potential use of the technology and career opportunities in food and nutrition. How have the results been disseminated to communities of interest? Research results have been disseminated in a Master's degree thesis, and presentations at the annual meeting of Kentucky Academy of Science. Results have also been shared through a presentation and discussion at a local workshop and with attendants at the Small Farm Conference. What do you plan to do during the next reporting period to accomplish the goals? The following experimental activities are planned: to test the antimicrobial activities of extracts from purple sweet potatoes and to determine the potential use of electrolyzed water in caviar processing.

Impacts
What was accomplished under these goals? 1. To determine if acidic electrolyzed water (AEW) could reduce microbes inoculated onto hybrid striped bass fillets. Fillets were collected from 10 hybrid striped bass before they were divided into 25 g pieces with similar dimensions (2cm×3cm×1cm). Each side of each fillet piece was inoculated by spreading 0.1mL of the prepared E. coli O157: H7, Salmonella spp. or L. monocytogenesinoculums with q pipette tip and an L-shaped spreader and allowed to dry in the laminated hood at room temperature for 30 min on both sides. After inoculation, the fillet pieces received one of three treatments: a. No rinse; b. Rinsing in tap water for 5 min; or c. Rinsing in AEW for 5 min. For the rinsing treatment, each of the inoculated fillet pieces was placed into sterilized plastic containers with 500ml of treatment solution (tap water or AEW). The containers were placed on a multi-purpose rotator (Thermo Scientific Model No: 2314) running at 80 rpm for 5 min at room temperature (22°C). Each of the processed fillet pieces were placed into a Stomacher bag with 225 mL peptone water to be homogenized before they were analyzed for total microbial load. AEW demonstrated 88.2%, 86.9%, and 89.2% reduction of E. coli O157:H7, Salmonella spp., and L. monocytogenes count, respectively, relative to tap water rinsing only. These results indicate that AEW rinsing may be used to reduce bacterial load on fish fillets to improve food safety. 2. Effects of acidic electrolyzed water on microbial load of black seed lettuce irrigated with rainwater in a high tunnel. To assess the microbial load on vegetables irrigated with rain water, black seed lettuce, mixed lettuce and red radish were grown in two high tunnels. They were irrigated with rainwater collected in black plastic tanks and transferred with a solar powered pump. Vegetables were harvested manually and transported to the lab in a cooler for analysis. Samples of the vegetables (10g/sample) were mixed with 90 ml of peptone water, homogenized in a stomacher for two minutes before the solution was diluted 10, 100 or 1000 times and inoculated to petrifilm plates for total aerobic count of E. coli. The plates were incubated at 37 C for 24 hours before the colony forming units were counted manually. Vegetables grown in the high tunnel with high weed pressure tended to have higher microbial loads than vegetables grown in a high tunnel with little weed pressure. Radish roots had the highest microbial load followed by mixed lettuce. The black seed lettuce had the lowest microbial load. E. coli was also found on the vegetables. Samples of the rainwater from the collection tank contained over 2000 colony forming units with half of them attributed to E. coli. These results showed that rainwater collected from the tank had significant amounts of microbes including E. coli. Vegetables irrigated with rainwater carried microbes including E. coli. Root vegetables like radish had the highest microbial load. These results indicate the vegetables irrigated with rainwater may need to be washed so they would not contaminate other vegetables and the environment. To determine the effects of acidic electrolyzed water on microbial load of black seed lettuce produced rinsed with AEW, lettuce leaves (100 g) were cut into one centimeter length and mixed well before samples of 10 g each were taken. The samples were treated with no rinsing, rinsing with tap water or acidic electrolyzed water. For the rinsing treatment, black seed lettuce was rinsed with 500 ml of tap water or 500 ml acidic electrolyzed water in a plastic container placed on a shaker at 20 rpm for 5 minutes. The leaves were mixed with 90 ml of Peptone water, homogenized in a stomacher for 2 minutes before the solution was inoculated onto petrifilm plates for total aerobic count after proper dilution. The total aerobic bacteria counts were 2425, 1485 or 25 CFU/g for lettuce with no rinse, rinsed with tap water or acidic electrolyzed water, respectively. Rinsing with tap water reduced the microbial load by 40%, whereas rinsing with acidic electrolyzed water reduced the microbial load of lettuce leaves by 99%. These results indicate that acidic electrolyzed water can be an effective decontaminating treatment for vegetables irrigated with rainwater during production.

Publications

  • Type: Theses/Dissertations Status: Published Year Published: 2014 Citation: Jiashuo Ma, 2014. Application of electrolyzed water in food fish processing. Thesis. Kentucky State University,Frankfort, KY. Wang, C, Huang, L. and Butler, C. 2014. Body weight status reflects knowledge and attitudes related vegetable consumption among Kentucky adults. Presented to Experimental Biology 2014, San Diego, April 26-30, 2014. Lingyu Huang, Changzheng Wang, Cecil Butler, Michael Bomford. 2014. Effects of acidic electrolyzed water on microbial load of black seed lettuce irrigated with rainwater in a high tunnel. Presented to Annual meeting of Kentucky Academy of Science, Lexington, KY Nov. 14-16, 2014. Cecil Butler, Lingyu Huang, Michael Bomford, Changzheng Wang. 2014. Microbial load on vegetables irrigated with rainwater in high tunnels. Presented to Annual meeting of Kentucky Academy of Science, Lexington, KY Nov. 14-16, 2014. Changzheng Wang, Jiashuo Ma, Robert Durborow, Lingyu Huang, Cecil Butler. 2014. Decontamination of pathogenic bacteria from Hybrid Stripped bass fillets by acidic electrolyzed water. Presented to Annual meeting of Kentucky Academy of Science, Lexington, KY Nov. 14-16, 2014.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Wang, C, Huang, L. and Butler, C. 2014. Body weight status reflects knowledge and attitudes related vegetable consumption among Kentucky adults. Presented to Experimental Biology 2014, San Diego, April 26-30, 2014.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Wang, C. 2013. Body Weight Status and Awareness of Food Safety Among Kentucky Adults. Presented to Kentucky Academy of Science, Morehead, Kentucky, November 8-9, 2013.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Huang, L. 2013. Detection of Compounds in Purple Sweet Potato Extract using HPLC with Charged Aerosol Detector and Photodiode Array Detector in tandem. Presented to Kentucky Academy of Science, Morehead, Kentucky, November 8-9, 2013.


Progress 10/01/12 to 09/30/13

Outputs
Target Audience: Producers and processors of fish and vegetables are our target audience. In addition, the scientific community and consumers who are concerned about the safety of the food they eat. We have discussed the results with two individuals involved in the processing and marketing of fish products, and 30 individuals involved in agriculture at a workshop. Changes/Problems: The delivery of the electrolyzed water generator was delayed so we did not have the electrolyzed water to conduct the study on paddlefish caviar during the season when caviar was being produced. We are prepared to conduct that part of the study in the Spring of 2014. What opportunities for training and professional development has the project provided? One graduate student was mentored in the project. He was trained ingenerating the electrolyzed water, monitoring of the water quality, handling of the fish and fish meat samples, microbiological techniques needed to take samples, and in conducting the evaluation of the microbiological tests. In addition, he was mentored in designing experiments and analyzing results obtained. He also had the opportunity to present results at regional and national conferences. Four undergraduate students also participated in the project and wereencouraged to pursue studies in food and nutrition. Thirty people participated in a workshop as part of the “Third Thursday Thing” where we discussed issues related to food safety and nutrition and the potential use of electrolyzed water in farm operations. How have the results been disseminated to communities of interest? Results have been presented at the annual meeting of Kentucky Academy of Science and the annual meeting of World Aquaculture Society. Results have also been shared through interactions with the public at the Kentucky state fair and a community event in Lexington, KY. What do you plan to do during the next reporting period to accomplish the goals? The following experiments will be conducted: 1. To determine the effects of electrolyzed water on the microbial load and quality of paddlefish caviar; 2. To determine the effects of electrolyzed water on microbial load of kale; and 3. To test the antimicrobial activity of extracts from purple sweet potato.

Impacts
What was accomplished under these goals? During this reporting period, 1. we first determined if acidic electrolyzed water could reduce the microbial load on hybrid striped bass meat. Fillets were obtained from Hybrid striped bass weighing approximately 1 kg, then cut into 25 g pieces of similar sizes. The meat pieces were randomly assigned to be rinsed in 500 ml of tap water, chlorine solution (100ppm Chlorine), alkaline or acidic electrolyzed water for 5 min individually (3 pieces/treatment). Each piece of the meat was placed into a stomacher bag containing 225 ml of peptone water, and then homogenized for 3 minutes at 230 RPM. Samples were taken from each bag and diluted 10, 100 and 1000 times, before one ml of each sample was placed on a petrifilm plate. The plates were incubated at 32 C for 48 hours before the colony forming units were counted manually. There were no significant differences among the treatment groups in the aerobic bacteria count. These results indicate that rinsing the fish meat with chlorine solution, acidic or alkaline electrolyzed water did not reduce microbial load on the fish meat. It was found that shaking was necessary for the bacteria to be exposed to the bactericidal effects of the solutions. 2. We determined if acidic electrolyzed water could reduce the microbial load on hybrid striped bass (HSB). Hybrid striped bass weighing approximately 1 kg were assigned randomly to be rinsed in tap water, acidic electrolyzed water for 5 minutes alone, or alkaline electrolyzed water for 5 min followed by acidic electrolyzed water for 5 min. One side of each fish was swabbed with a sterilized cotton ball before the rinse and the other side of the fish was swabbed with another cotton ball. Each cotton ball was placed in 99 ml of peptone water and mixed at 230 RPM for 3 minutes in a stomacher. Samples were taken from each stomacher bag and diluted 10, 100, 1000, 10,000 times. One ml of each sample was placed on a petrifilm plate. The plates were incubated at 32 C for 48 hours before the colony forming units were counted manually. Microbial load was reduced 72% by rinsing with tap water, but reduced 94% or more by the other treatments. Our results indicated that rinsing fish in tap water does reduce microbial load on the fish; rinsing with acidic electrolyzed water, with or without rinsing with alkaline electrolyzed water, removed nearly all bacteria from the surface of the fish. 3. We determined the effect of electrolyzed water treatment on the whole fish on the microbial load of fillets produced from the treated fish. We found that fillets from the treated fish had much lower microbial load and microbial load on the fillets stayed low during a 10-day storage at refrigerated temperature but microbial load on fillets from untreated fish increased drastically during refrigerated storage.

Publications

  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2013 Citation: Ma, Jiashuo, Changzheng Wang, Robert Durborow, Steven Mims, Lingyu Huang, Cecil Butler. 2013. Reduction of microbial load on hybrid striped bass by acidic electrolyzed water. Presented at the Annual Meeting of Kentucky Acade my of Science, Morehead, Nov. 8-9, 2013 Ma, Jiashuo, Changzheng Wang, Robert Durborow, Steven Mims, Lingyu Huang, Cecil Butler. 2013. Effects of acidic electrolyzed water on aerobic bacteria count on hybrid striped bass meat. Presented at the Annual Meeting of Kentucky Acade my of Science, Morehead, Nov. 8-9, 2013 Wang, Changzheng, Jiashuo Ma, Robert Durborow, Steven Mims, Lingyu Huang, Cecil Butler. 2013. Using acidic electrolyzed water to reduce microbial load on hybrid striped bass, Morone chrysops x saxatilis. Presented to Annual meeting of World Aquaculture Society, Seattle, Feb.9-11, 2014.