Progress 07/01/06 to 06/30/11

Outputs
OUTPUTS: This research investigated the use of extrusion technology to enhance the nutritional quality of extruded-expanded products, extruded-textured products, and low fat cheese by the incorporation of fibers or fat replacers. The principal investigator directed the research done by graduate and undergraduate students on this project, submitted papers for publication and gave conference presentations about the use of extrusion technology to enhance the nutritional quality of foods. Specific research conducted included research on the replacement of cornstarch with dietary fiber (cellulose, wheat and oat) in extruded-expanded products containing 32% whey protein at levels of 18, 36 and 48% and extrusion-textured products containing 50.4% protein at levels of 7, 15, and 22%. The goal was to determine the maximum amount of fiber that could be added to each product with minimal detriment to product texture. Samples were extruded in triplicate producing 30 samples for each product. The extrudates were analyzed for solids lost (SL) and water holding capacity (WHC) at 3 pH values (3, 5, and 7) and 4 temperatures (25, 50, 70 and 90 C) and the ratio of SL/WHC was calculated and presented as FPR (functional performance ratio). The extrudates were also analyzed for urea, sodium-dodecyl sulfate (SDS) and beta-mercaptoethanol (BME), water, and BME soluble proteins. Soluble protein samples were also analyzed by sodium-dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) to determine the specific proteins solubilized by each solvent. Three different fat replacers were added to low fat cheese to determine the influence of the fat replacers on the texture of the cheese. Low fat cheese (2% fat) was ground to a size of 2 mm. Three different fat replacers at three concentrations (Temp Pro (whey protein based) (4%, 0.40%, 2.20%), Novagel RCN15 (cellulose based) (2%, 0.125%, 1.06%) and Simplesse 500 (protein based) (1%, 0.50%, 0.75%) were added to the cheese and the cheeses were then extruded. The cheeses were extruded in triplicate and analyzed for texture profiles (hardness, springiness, adhesiveness, and cohesiveness) over three months. PARTICIPANTS: This research is being done solely at Utah State University. TARGET AUDIENCES: This research will be used by the food industry, to help optimize the ingredients used to produce healthy dairy based products. The end target audience is the general US population that will purchase the healthy food products. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
The addition of dietary fiber to extruded-expanded products affected the physical and chemical properties of the extrudates. As the concentration of fiber in the extrudates increased, there was a significant decrease in expansion ratio, air cell size, water soluble carbohydrate, and water solubility index, and a significant increase in extrudate density, breaking force, moisture content, and water absorption index. The main effects observed were attributed primarily to a decrease in the amount of normal cornstarch and secondarily to the presence of fiber. The possibility exists to incorporate dietary fiber at concentrations <18% into an extruded product with limited detrimental effects to the physical and chemical properties. The addition of fiber to extruded-textured products increased the fibrous characteristics of the products and was similar among each of the fibers used. The addition of fiber did not lead to significant differences compared to no fiber on the percent soluble protein but did reduce the functional performance ratio. This is attributed to the lack of starch which yielded a decrease in water holding capacity in samples with fiber. Replacement of starch for a final fiber content of 7% will not significantly influence the characteristics of the extruded-fibrous product. We added three different fat replacers at three concentrations to ground low fat cheese to investigate the change in cheese texture. None of the fat replacers used were effective in improving the texture of low fat cheese significantly. Since none of the treatments statistically improved the texture of low fat cheese, in the next part of the study, extrusion and WPC 1 were then used to produce low fat cheese with a high protein content by blending low moisture aged Cheddar cheese and nonfat cheese. Extrusion of cheese blends with or without fat replacer yielded cheese with high protein level. It was concluded from this study that the fat replacers we used were not effective in improving the texture but extrusion of aged Cheddar cheese with nonfat cheese and whey protein can yield high protein cheese.

Publications

• No publications reported this period

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

Outputs
OUTPUTS: With an increasing rate of obesity and consumer awareness about health, the quest to make healthy foods is increasing. Cheese is one such type of food products where making it a low calorie, healthy food option has always been a challenge because of flavor and texture deficiency. This research is investigating the addition of fat replacers and aged cheddar (full fat) to shredded low-fat cheese followed by extrusion to improve the texture, flavor, and consumer acceptance. Previously we investigated the size of cheese (0.5, 1 and 2 mm) that would be appropriate as a starting material for extrusion. The extruder parameters of screw-paddle configuration, pressure, temperature, and feed rate were also varied to achieve optimal cheese extrusion. This past year we investigated the addition of three different fat replacers (one cellulose based and two protein based) at three levels to low-fat cheese (2% fat) and the cheeses were extruded under optimal conditions and analyzed for texture profiles (hardness, springiness, adhesiveness, and cohesiveness). Low-fat cheddar cheese (2% fat) with three different fat replacers at three concentrations based on manufacture recommendations were extruded; Temp Pro (whey protein based) (4%, 0.40%, 2.20%), Novagel RCN15 (cellulose based) (2%, 0.125%, 1.06%) and Simplesse 500 (protein based) (1%, 0.50%, 0.75%). Extruded cheeses were analyzed for texture at 1 day, 1 week and 1 month. This experiment was done in triplicate and each sample analyzed in duplicate. PARTICIPANTS: This research is being done solely at Utah State University. TARGET AUDIENCES: This research will be used by the food industry, specifically dairy processing facilities, to help optimize the ingredients used to produce healthy dairy based products. The end target audience is the general US population that will purchase the healthy food products. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
The results of these experiments show that the type of fat replacer as well as the concentration used were significantly different. With respect to hardness, the use of all fat replacers at all concentrations improved the hardness of low fat cheddar cheese (decreased the hardness) except for the use of Temp Pro at the middle concentration. Although the hardness was still significantly more than traditional cheddar cheese, it was similar to reduced fat (16% fat) cheddar cheese. The fat replacers with the lowest hardness levels were Novagel and Simpless, both at the lowest concentrations. The hardness values for these two samples remained the same over a one month period. The results for springiness show that only one fat replacer, Simpless at the lowest concentration, significantly improved this parameter in low fat cheese, and this was retained over one month period. The results for adhesiveness showed that only Novagel at the lowest concentration positively impacted the texture of low fat cheese, which was retained over a one month period. There were no significant differences in the cohesiveness parameter among all samples. The results show that the use of extrusion with the addition of fat replacers (Simpless at 0.75%, and Novagel at 1.06%) can improve the texture (specifically hardness, springiness and adhesiveness) of low fat cheese.

Publications

• Garg, N., Martini, S., Britt, D. Walsh, M. 2010. Characterization of lactose-amines in oil-in-water emulsions. Food Research International., 43:1111-1115.
• Walsh, M., Wood, A. 2010. Properties of extrusion-expanded whey protein products containing fiber. International J. Food Properties, 134:702-712.

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

Outputs
OUTPUTS: With an increasing rate of obesity and consumer awareness about health, the quest to make healthy foods is increasing. Cheese is one such type of food products where making it a low calorie, healthy food option has always been a challenge because of flavor and texture deficiency. This research is investigating the addition of fat replacers and aged cheddar (full fat) to shredded low-fat cheese followed by extrusion to improve the texture, flavor, and consumer acceptance. This past year we investigated the size of cheese (0.5, 1 and 2 mm) that would be appropriate as a starting material for extrusion. The extruder parameters of screw-paddle configuration, pressure, temperature, and feed rate were also varied to achieve optimal cheese extrusion. The use of three different fat replacers (one cellulose based and two protein based) at three levels was added to low-fat cheese (2% fat) and the cheeses were extruded under optimal conditions and analyzed for texture profiles (hardness and cohesiveness). Additionally, the texture of cheddar cheese (32% fat) and cheeses containing 13 and 6% fat were also determined. This information allowed us to calculate the expected fat level in the low-fat cheeses with added fat replacers. PARTICIPANTS: This research is being done solely at Utah State University. TARGET AUDIENCES: This research will be used by the food industry, specifically dairy processing facilities, to help optimize the ingredients used to produce healthy dairy based products. The end target audience is the general US population that will purchase the healthy food products. PROJECT MODIFICATIONS: Additional Objectives added for one-year extension of project Objective 1: To optimize the physiochemical (formulation, temperature and pressure) and configuration parameters (screw and paddle sequences) of the extruder to allow extrusion-modification of low fat cheese and continue until product characteristics are improved. Objective 2: To extrude low fat cheese (2%) with the fat replacers and dietary fibers (choosing from Temp Pro, Novagel RCN15, Simplesse, Vitacel MCG, Vitacel Plus and other cellulose based if available) at 3 concentrations and analyze extruded cheese for texture, color and nitrogen at 3 different time periods i.e. 1day, 1 week and 1 month. Cheese will be stored frozen and at room temperature for analysis. Additional parameters to be investigated will be press pressure (0-30 psi) and time (15 min to hours) to allow the extruded cheese to knit. Objective 3: To extrude blends of high fat aged cheese (aggiano) with non fat cheese, to achieve high protein cheese, with the fat replacers or dietary fibers (choosing from Temp Pro, Novagel RCN15, Simplesse, Vitacel MCG, Vitacel Plus and other cellulose based if available) at 2-3 concentrations based on the results from objective 2 and analyze extruded cheese for texture, color, nitrogen at 3 different time periods i.e. 1day, 1 week and 1 month. Cheese samples will again be stored frozen and at room temperature.

Impacts
We have determined the extruder conditions that allow for extrusion of ground cheese. We are currently using a screw and paddle configuration that promotes high shear without pressure. The dry feed rate is 800 rpm, the screw speed is 200 rpm, the five individual temperature zones are 24, 36, 37, 46, and 41 C with an exit melt temperature of 45 C at 0 psi. It is necessary to keep the exit temperature below 45 C, higher than this the cheese melts and we feel the texture is negatively affected. The appropriate particle size of the shredded cheeses was determined to be 2 mm after testing shreds of 0.5, 1 and 2 mm. The nonfat cheese is facile to grind, while the full fat cheeses are sticky. We plan to blend the cheeses after grinding to minimize the stickiness of the full fat grounded cheeses. Low-fat cheddar cheese (2% fat) with three different fat replacers at three concentrations based on manufacture recommendations were extruded; Temp Pro (whey protein based) (4%, 0.40%, 2.20%), Novagel RCN15 (cellulose based) (2%, 0.125%, 1.06%) and Simplesse 500 (protein based) (1%, 0.50%, 0.75%). Extruded cheeses were analyzed for texture (hardness, cohesiveness, springiness), over storage time. Texture analysis of cheddar cheese at three fat concentrations (2%, 13% and 32%) resulted in linear relationships (R2 values >0.9) between fat content and hardness or cohesiveness allowing the determination of fat replacer effectiveness. The type of fat replacer as well as the concentration used were significantly different. The predicted fat level of cheese with added Simplesse decreased from 36 to 27% with the low and high concentrations based on the hardness data while the predicted fat level was 34% with all use levels based on the cohesiveness data. The predicted fat level for Temp Pro was 24% based on the hardness values and 33% based on the cohesiveness values at all use levels. Novagel was significantly different from the other fat replacers resulting in no significant changes from the 2% fat cheese based on the cohesiveness data, but resulted in higher than 32% fat with the hardness data. Preliminary data suggests that the use of Simplesse and Temp Pro results in texture parameters more similar to full-fat (32%) cheese. The texture of the cheeses will be monitored over storage time.

Publications

• Walsh, MK, CE Carpenter 2009. Textured Whey Protein Product. U.S Patent Number 7,597,921.
• Walsh, M. AM Wood 2009. Properties of extrusion-expanded whey protein products containing fiber. International . J. Food Properties.

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

Outputs
OUTPUTS: This research is investigating the replacement of cornstarch with dietary fiber in extruded-expanded products containing 32 percent whey protein (objective 2) and extrusion-textured products (TWP) containing 50.4% protein (objective 3). The results of objectives 1 and 2 have been completed and were included in previous CRIS reports. Research on Objective 3 was initiated in 2007 and continued through 2008. Oat, wheat and cellulose fibers were blended with WPC 80 and starch to yield compositions of 50.4 % protein with fiber levels of 0%, 7%, 15%, and 22% (w/w). Samples were extruded in triplicate producing 30 TWP samples. The 30 TWP extrudates and a commercially available textured soy product (TVP) were analyzed for solids lost (SL) and water holding capacity (WHC) at 3 pH values (3, 5, and 7) and 4 temperatures (25, 50, 70 and 90 C) and the ratio of SL/WHC was calculated and presented as FPR (functional performance ratio) and this data was reported in my 2007 report. In 2008, the extrudates were analyzed for urea, sodium-dodecyl sulfate (SDS) and beta-mercaptoethanol (BME), water, and BME soluble proteins. Soluble protein samples were also analyzed by sodium-dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) to determine the specific proteins solubilized by each solvent. The amount of protein in extrudates solubilized by SDS/BME was approximately 50% for each extrudate, independent of the amount of fiber in the extrudates. The amount of protein solubilized by urea was approximately 20%, and the amount of protein solubilized by water was 15%, again independent from the amount of fiber in the extrudates. Since water will solubilize proteins not involved in any ionic/covalent bonds, approximately 15% of the protein in all extrudates was free (unassociated with either other proteins or carbohydrate). The amount of additional protein solubilized by urea was 5%; therefore 5% of the whey protein was associated via ionic interactions. The additional amount of protein solubilized by SDS-BME was approximately 30%, which would include protein covalently bound via disulfide bonds. Approximately 50% of the whey protein was not solubilized with any of the solvents and was presumably associated via covalent interactions. The only significant difference in the amount of protein solubilized was in the commercial TVP with SDS/BME which gave 60% soluble protein. Preliminary SDS-PAGE analysis of the protein solubilized with water show protein bands that correspond to caseins while the protein bands solubilized with SDS/BME corresponded to the whey proteins. This indicates that the residual casein in the whey protein does not interact with other proteins and the whey proteins are capable of forming stable protein:protein interactions. PARTICIPANTS: This research is being done solely at Utah State University. TARGET AUDIENCES: This research will be used by the food industry, specifically dairy processing facilities, to help optimize the ingredients used to produce healthy dairy based products. The end target audience is the general US population that will purchase the healthy food products. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
This research will enhance the nutritional value of the extrusion-textured food products by replacing starch with dietary fiber. The beneficial effects of dietary fiber include improved human health through reduced incidence of coronary heart disease, obesity, diabetes, and some cancers. Since consumers are only ingesting half the current recommended level of fiber, these extrusion-textured products will aid in increased fiber consumption leading to improve human health.

Publications

• Walsh, MK and CE Carpenter 2008. Creating whey protein-based meat analogs using twin-screw extrusion.. Whey Processing, Functional Properties, and Health Benefits, 185-199.
• Walsh, M.K., D.J. McMahon and S. Duncan. 2007. Milk and Dairy Foods. Food Chemistry Second Edition: Principles and Applications, 19-1 to 19-23.

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

Outputs
OUTPUTS: This research is investigating the replacement of cornstarch with dietary fiber in extruded-expanded products containing 32 percent whey protein (objective 2) and extrusion-textured products (TWP) containing 50.4% protein (objective 3). The results of objectives 1 and 2 have been completed and were included in my 2006 CRIS report. Briefly, the results of objective 2 showed that the possibility exists to incorporate dietary fiber at levels of approximately 20% in extruded whey and cornstarch products without significant detrimental affects on product physical and chemical characteristics. Research on Objective 3 was initiated in 2007. For this objective, the following fibers were screened at the 10 % level (Vitacel Oat fiber HF 600, Vitacel Wheat Fiber WF 600, Vitacel Apple fiber AF 401, and Vitacel Powdered Cellulose L601 FCC) for suitability in a fibrous-textured product. The oat, wheat and cellulose fibers were selected to continue objective 3. Each fiber was blended with WPC 80 and starch to yield compositions of 50.4 % protein with fiber levels of 0%, 7%, 15%, and 22% (w/w). Samples were extruded in triplicate producing 30 TWP samples. The 30 TWP extrudates and a commercially available textured soy product (TVP) were analyzed for solids lost (SL) and water holding capacity (WHC) at 3 pH values (3, 5, and 7) and 4 temperatures (25, 50, 70 and 90 C) and the ratio of SL/WHC was calculated and presented as FPR (functional performance ratio). In general, the WHC decreased with an increase in fiber in the samples. The WHC increased with an increase in pH and an increase in temperature. The WHC of samples is related to the amount and functionality of the starch, not the type of fiber or the amount of protein in the products. The whey samples showed a lower WHC than the TVP. The SL increased with an increase in fiber in the samples as well as with increases in pH and temperature. The solids lost is related to the amount and type (protein:protein or protein:carbohydrate) of crosslinks formed in the TWP. The inclusion of fiber may have reduced the amount of crosslinks formed, leading to higher SL values. The TVP showed a significantly lower SL than the whey control samples. There was a decrease in FPR with an increase in fiber which may be due to the decrease in starch. There also was an increase in FPR with an increase in both pH and temperature and overall, the soy sample showed the highest FPR under all conditions tested. PARTICIPANTS: This research is being done solely at Utah State University. TARGET AUDIENCES: This research will be used by the food industry, specifically dairy processing facilities, to help optimize the ingredients used to produce healthy dairy based products. The end target audience is the general US population that will purchase the healthy food products.

Impacts
This research will enhance the nutritional value of the extrusion-textured food products by replacing starch with dietary fiber. The beneficial effects of dietary fiber include improved human health through reduced incidence of coronary heart disease, obesity, diabetes, and some cancers. Since consumers are only ingesting half the current recommended level of fiber, these extrusion-textured products will aid in increased fiber consumption leading to improve human health.

Publications

• Wash, M.K. 2007. Immobilized enzyme technology for food applications. In Novel Enzyme Technology for Food Applications . R. Rastall Ed. Woodhead Publishing, Cambridge UK.
• Allen, K.E, C.E. Carpenter and M.K. Walsh. 2007. Influence of protein level on the physical and chemical properties of extruded-expanded whey products. Int J Food Sci Technol 42:953-960.
• Walsh, M.K., D.J. McMahon and S. Duncan. 2007. Milk and Dairy Foods In Food Chemistry Second Edition: Principles and Applications. Y. Hui, Ed. Publisher: Science Technology System, West Sacramento CA, USA.

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

Outputs
This research is investigating the replacement of cornstarch with dietary fiber in extruded-expanded products containing 32 percent whey protein. Twelve different commercial fibers were extruded with cornstarch and whey protein to produce extrudates containing 30 percent dietary fiber and 32 percent whey protein (objective 1). Three different fibers were selected based on the extrudate expansion ratio and ease of extrusion to continue with objective 2. The three dietary fibers that produced extrudates with acceptable visual expansion ratios and did not result in difficulty during extrusion were cellulose, wheat fiber, and oat fiber. These three fibers were blended with whey protein, waxy cornstarch (10 percent) and cornstarch to yield blends of 0, 18, 36 and 48 percent dietary fiber and 32% whey protein. Each fiber level (18, 36 and 48 percent fiber) and was extruded in triplicate for each fiber type and a control with no fiber added was also extruded in triplicate yielding 30 samples. Extrudate characteristics were evaluated on physical (expansion ratio, air cell size, density, and breaking force) and chemical (moisture content, water absorption index, water solubility index, water and total soluble protein and water soluble carbohydrate) parameters. The physical and chemical characteristics of the extrudates were found to be greatly affected by combined interaction of the fiber type and level of fiber in the extrudate. As the amount of fiber in the extrudate increased, moisture content (p < 0.0001), density (p < 0.0001), breaking force (p < 0.0001) and water absorption index (p < 0.0001) increased while expansion ratio (p < 0.0001), air cell size (p < 0.0001), and water solubility index (p = 0.0013) decreased. This research showed that the possibility exists to incorporate dietary fiber at levels of approximately 20% in extruded whey and cornstarch products without significant detrimental affects on product physical characteristics.

Impacts
This research will enhance the nutritional value of extrusion-textured food products by replacing starch with dietary fiber. The beneficial effects of dietary fiber include improved human health through reduced incidence of coronary heart disease, obesity, diabetes, and some cancers. Since consumers are only ingesting half the current recommended level of fiber, these extrusion-textured products will aid in increased fiber consumption leading to improved human health.

Publications

• Taylor, D.P., C.E. Carpenter and M.K. Walsh. 2006. Influence of sulfonation on the properties of expanded extudates containing 32 percent whey protein. J. Food Sci. March, Vol 71 Nr 2, pp. E17-24
• Walsh, M.K. and C.E. Carpenter. 2006. Creating whey protein-based meat analogs using twin-screw extrusion. In Whey: Processing, Functional Properties, and Health Benefits. Dr. Peter Huth, Charles Onwulata, Ph.D. Eds. Blackwell Publishing, Ames, IA. USA