Progress 12/01/13 to 11/30/16
Outputs
Target Audience:The target audiences include food and nutritional scientists from academia and students majoring in food and nutritional sciences, winery owners, small farmersand product development scientists in food industry. Changes/Problems:According to the experiment conducted at 140ºC, 15% GP resulted in significant darkening of extruded product, and 19% extrusion moisture lead to hardening of product which was very difficult to break and grind. Therefore, for the experiment conducted at 160ºC, the GP content was reduced to 2.5, 5, and 10%, and moisture was changed to 13, 15 and 17%. What opportunities for training and professional development has the project provided?Training:Two graduate studentwere trained to conduct (1) vitamin extraction and analysis, (2) starch hydrolysis and reducing sugar determination, (3)methods forevaluating product oxidation.Three undergraduate students were trained to conduct total dietary fiber determination, TBARS determination and reducing sugar analysis. One Research Technician was trained to conduct product formulation and extrusion experiment. Professional development:One trained graduate student is now the lab research technician who is able to supervise undergraduate student to conduct similar experiments.Another trained graduate student graduated in December 2015 and is now working in a food inspection organization inChina. The trained research technician has enrolled in Ph.D. program in Fall 2016. Two of the trained undergraduate students are offered research internship and will participate internship program in Oak Ridge National Lab in 2017. How have the results been disseminated to communities of interest?Early results were disseminated in 2015 USDA-AFRI PD meeting in Chicago, the results of GP on dietary fiber content of extruded product were presented in 2016 Spring ACS National Meeting, the findings of impact of GP on vitamin retention was presented in 2016 North Carolina Association of Family and Consumer Sciences (NCAFCS) conference and NC A&T 2016 Small Farmer Field Day, the effect of GP on the oxidative stability of extruded products was presented in 2016 ACS South East Regional Meeting. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Impact of the project: The goal of this project is to collect preliminary data about the impacts ofgrape pomace (GP) incorporation on dietary fiber content,in vitro digestibility of starch and vitamin retention of extruded products during extrusion cooking, and lipid oxidation during storage.The ultimate goal is to improve the nutritional quality and oxidative stability of extruded food products without reducing the sensory quality by using GP, an underutilized by-product of wine grapes.The results shows that the GP could served as an inexpensive source of dietary fiber and polyphenolto improve the nutritional quality and storage stability of extruded food products if it is used at proper level.This will help increase Americans' dietary fiber consumptionwhich willcontribute toobesity prevention. The findings of this projectare also importantto the value added utilization of GP whichwill benefit grape growers and wineries. (1) Major activities completed / experiments conducted A 2x4x3 two-factor factorial design was used for extrusion experiment. The three factors were extrusion temperature (140C and 160 C), the level of grape pomace added and moisture content to the formula. Yellow corn-grits was mixed with four fat soluble vitamins (vitamin A acetate, vitamin D3, vitamin E and vitamin E acetate) each 200 ppmdifferent amount of ground grapeand water. The mixture wereextruded under same extrusion temperature and screw speed (175 rpm). The product with 0% GPserved as control and the product with 0% GP and 0.02% BHA/BHT was used as reference for comparison. The products were evaluated total polyphenols content, total dietary fiber content,starch digestibility, vitamin retention and oxidative stability. Objective 1: The proximate compositions of extruded samples without and with GP were determined. The effect of GP and extrusion condition on the overall digestibility of extruded products was evaluated by total dietary fiber (TDF) of products containing different GP and moisture. The TDF was determined according AOAC method . Objective 2:The effect of GP and extrusion condition on the digestibility of starch of extruded products was evaluated by in vitro amylase digestion and simulated gastric digestion methods in which the reducing sugar content of digesta was used as indicator of starch digestion. Objective 3:The oxidative stability of extruded product was evaluated by accelerated oxidation process by storing samples at 37 °C,which is the typical temperature of tropical areas, for different time (0-8 weeks). Because extruded food products were low in lipid content, thereby, TBARS was measured weekly as indicator of degree of product oxidation.The influence of GP inclusion on the retention of fat soluble vitamins were evaluated by measuring individual vitamin content of samples containing GP using HPLC method and comparing it to the vitamin content of extruded products without GP. 2) Data collected Objective 1: Total polyphenol contents (TPC) of the extruded product increased linearly with GP level. Without GP the TPC of the products was in the range of 740-884 µg/g (0.074-0.088%), depending on the moisture content of the product. In the presence of GP, the TPC of the product was in the range of 2583±31 (0.26%) to 7430±235 µg/g (0.74%) depending on the GP and moisture contents. It was also found that moisture content ofthe formulaaffected the puff of the final products. The TDF content of the extruded product increased with increasing amount of GP almost linearly, and was affected by the moisture of formula. The TDF of extruded product was 2.76-3.09 % without GP, 7.26-7.5% with 5% GP, 9.33-11.77% with 10% GP and 14.22-15.78% with 15%GP. Total insoluble dietary fiber contents of extruded product increased from about 1% to 7.5% in GP dose dependent manner. The study suggests that GP could serve as a dietary fiber source in extruded food products. Objective 2: The reducing sugar content of amylase digested samples decreased by 2.4 to 22.9%when GP content increased from 2.5-10%. For samples obtained from simulated gastric-intestine digestion, only those containing 10%GP showed significantly reduced reducing sugar content in the digesta. These data indicate significantly reduced starch digestibility in the presence of GP. Objective 3.In one experiment, extruded samples containing 5, 10 and 15% GP were stored at 37ºC for 15 days and samples were taken every 3 days for TBARS measurement. Data obtained show that, the TBARS of products containing 5% GPwere the lowest(P<0.05), but the TBARS of samples with 10 and 15% GP were similar to those of controls.In another experiment, samples containing 2.5, 5 and 10% GP were stored at 37ºC for 8 weeks, samples were taken weekly to measure TBARS. Data show that there were no obvious changes in TBARS in the first three weeks for all samples, but TBARS increased gradually from week 3 to week 6 and TBARS increased sharply from week 6 to week 7. At same GP level, high moisture samples showed lower TBARS than low moisture samples. Samples containing BHA/BHT exhibited lowest TBARS in all situations. However, samples containing GP showed faster increase in TBARS from week6 to week 8 than other samples although not in GP dose dependent manner. GP exhibited great protection on vitamin A acetate, vitamin D3 and Vitamin E acetate during extrusion cooking of corn-based products. The retention of these added vitamins varied with GP content. The highest vitamin retention was observed at 10% GP. Products containing 5% and 10% GP had higher contents of vitamin A acetate, vitamin D3 and Vitamin E acetate than sample containing 0.02% BHA/BHT (P<0.05). However, GP did not show protective effect on vitamin E. 3) Summary statistics and discussion of results Regression analysisshows thatTDF increase linearly with GP level (R2=0.975-0.997) and every 1% increase in GP, there is an average of 0.78% increase of TDF in the extruded product. This indicates that the overall digestibility of extruded food was reduced in the presence of GP. Duncan's multiple range comparison shows that the in vitro starch digestibility of corn-based extruded product was significantly reduced due to the addition of 5% or more of GP in the ingredient mixture (P<0.05). The total extractable polyphenol contents in the extruded products containing 10-15% of GP were 0.43-0.74%, these might be too high compared with 0.02% of BHA/BHT. One percent increase of GP in the ingredient resulted in about 400ug/100g increase of total polyphenol in the product. Polyphenol at high dose may act as prooxidant not antioxidant. Therefore, the TBARS of extruded samples containing GP were higher than that of negative and positive controls (P<0.05). At the GP levels used in study, GP showed protection on some but not all fat soluble vitamins tested. This may also associated with the prooxidant activity of GP polyphenols at high concentration. In addition, vitamin E is a powerful antioxidant. It may be oxidized before GP polyphenols. 4) Key outcomes or other accomplishments realized. The finding of studies generate the knowledge that grape pomace could served as an inexpensive source of dietary fiber and polyphenol of extruded products to improve the nutritional quality and storage stability of extruded food products. Adding GP in the formula of corn-based extrusion product also reduce the digestibility of corn starch compared with product without GP, which is important in reducing dietary energy intake and obesity prevention. The GP could alsobe an inexpensive source of antioxidant to inhibit the oxidation and reduce vitamin loss of product during extrusion cooking and after extrusion storage, but the level of GP added to the formula has to be well controlled to prevent the prooxidant activity of the GP polyphenols. This is important to food industry that is interested in use GP as a food ingredient to increase product stability.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2016
Citation:
Jianmei Yu, Ivy Smith, Si Zhu, Guibing Chen. Grape pomace content and oxidative stability of extruded products. 2016 ACS South East Regional Meeting, October 23-26,2016, Columbia, SC.
- Type:
Other
Status:
Published
Year Published:
2016
Citation:
Yu, J., Chen, G., Maman, R., Smith, I., Hordge, L, and Zhu, S. Applications of grape pomace flour in a variety of food products. 2016 Small Farm Field Day. June 30, 2016, North Carolina A&T State University Farm, Greensboro, NC.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2016
Citation:
Jianmei Yu, Si Zhu, Ivy Smith, Shu Fang, Guibing Chen. Impact of Grape Pomace Addition on Vitamin Retention in Food Product During Extrusion Cooking. 2016 NCAFCS Annual conference, April 8-9, 2016, New Bern, NC.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2016
Citation:
LaQuana Hordge, Ivy Smith, Jianmei Yu. Determination of Total Dietary Fiber in Extruded Food Products Containing Grape Pomace. 2016 Spring ACS National Meeting. March 13-17, 2016, San Diego, CA.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2015
Citation:
Yu, J., Fang, S., Smith I., and Chen, G. The Impacts of Grape Pomace Inclusion on The Nutritional Quality of Extruded Food Products. 2015 USDA/NIFA PI-PD meeting. July 10, 2015, Chicago, IL.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2017
Citation:
Valencia Cobb, Ivy Smith, Si Zhu, Guibing Chen Jianmei Yu*. Grape Pomace Content and Digestibility of Extruded Products. The 99th Annual Conference of NCAFCS, March 2-4, 2017, Charlotte, NC.
|
Progress 12/01/14 to 11/30/15
Outputs
Target Audience:The target audiences include food scientists from academia and students majoring in food and nutritional science,winery owners andproduct development scientistsin food industry. Changes/Problems:During the next reporting period, the research teamwillmake following changes to solve the problems of hardening and high TBARS of extruded product containing grape pomace. 1. Add vitamins directly to the formula without dissolving them in oil to minimize volume shrinking and hardness of the extruded product. 2. Reduce the amount of grape pomace added to the formula to eliminate the possible prooxidant effects of high polyphenol content What opportunities for training and professional development has the project provided?Training: One graduate studentwas trained to conduct vitamin extraction and analysis; starch hydrolysis and reducing sugar determination; andmethods forevaluating product oxidation.Two undergraduate students were trained to conduct total dietary fiber determination and TBARS determination. One research technician was trained to conduct product formulation and extrusion experiment. Professional development: The trained graduate student is able to supervise undergraduate students to conduct similar experiments. The trained research technician will enroll in the Ph.D. program inFall2016. How have the results been disseminated to communities of interest?Results were disseminatedat the2015 USDA-AFRI PD meeting in Chicago. Resultswill alsobe disseminated among small farmers in NC A&T 2016 Small Farmer Field Day, and ACS 2016 National Meeting and North Carolina Association of Family and Consumer Sciences (NCAFCS) 2016 Annual meeting. What do you plan to do during the next reporting period to accomplish the goals?During next reporting periodscientists will complete all research activities planned in the proposal, write manuscript and submitit to scientific journal for publication, evaluate the project achievement and write a final report.
Impacts
What was accomplished under these goals?
1) Major activities completed / experiments conducted During the reporting period of 12/01/2014-11/31/2015, project activities in Objective 3 were completed toevaluate the effects grape pomace inclusion on the oxidation stability of extruded corn-based products produced at 140 °C and fat soluble vitamin retention during extrusion. A two-factor factorial design was used to for extrusion experiment. The two factors were the level of grape pomace added and moisture content to the formula. Yellow corn-grits was mixed with four fat soluble vitamins (vitamin A acetate, vitamin D3, vitamin E and vitamin E acetate) each 100 ppm, different amount of ground grape (0, 5, 10 and 15%, w/w ) and water (15, 17 and 18%, w/w) the mixture were produced under same extrusion temperature (140ºC) and screw speed (175 rpm). At each moisture level, the product with 0% grape pomace was served as control. The products were evaluated for vitamin retention and oxidative stability. The change of individual vitamin content due to the addition of grape pomace was determined by HPLC method. Theoxidative stability of extruded product was evaluated by accelerated oxidation process by storing samples at 37 °C for 3, 6, 9, 12 and 15 days, and TBARS was measured as indicator of degree of product oxidation. 2) Data collected Total polyphenol contents (TPC) of the extruded product increased linearly with the amount of GP added to the formula. Without GP the TPC of the products was in the range of 740-884 µg/g (0.074-0.088), depending on the moisture content of the product. In the presence of GP, the TPC of the product was in the range of 2583±31 (0.26%) to 7430±235µg/g (0.74) depending on the GP and moisture contents. In the presence of GP theproduct became darker, and the darknessincreased withGP content. Effects of grape pomace on the oxidation of extruded products:One of the goals of this project was to explore if adding GP to the formula of corn-based product could inhibit or slow down the product oxidation during post-extrusion storage. Data obtained show that the TBARS of products containing 5% GP were significantly lower than those of controls (P<0.05), but the TBARS of samples with 10 and 15% GP were similar to those of controls. Therefore adding 5% GP could inhibit the oxidation of extruded products during post-process storage, but 10-15% of GP in extruded products may not inhibit product oxidation. Effects of grape pomace on vitamin retention: GP exhibited great protection on vitamin A acetate, vitamin D3 and Vitamin E acetate during extrusion cooking of corn-based products. The retention of these added vitamins varied with GP content in the formula. The highest vitamin retention was observed at 10% GP. At 15% GP, vitamin retention decreased significantly. Products containing 5% and 10% GP had higher contents of vitamin A acetate, vitamin D3 and Vitamin E acetate than sample containing 0.02% BHA/BHT (P<0.05). However, GP did not show protective effect on vitamin E. 3) Summary statistics and discussion of results As shown in the data collected, the total extractable polyphenol contents in the extruded products containing 10-15% of GP were 0.43-0.74%, these might be too high compared with 0.02% of BHA/BHT. Polyphenol at high dose may act as prooxidant not antioxidant. Therefore the TBARS of extruded samples containing 10-15% of GP were not lower than that of negative and positive controls. At the GP levels used in study, GP showed protection on some but not all vitamins tested. This may also associated with the prooxidant activity of GP polyphenols at high concentration. In addition, vitamin E is a powerful antioxidant. It may be oxidized before GP polyphenols. More study is undergoing to test oxidative stability and vitamin retention of extruded products containing lower levels of GP. 4) Key outcomes or other accomplishments realized The finding of these studies generate the knowledge that grape pomace does have potential to be used as inexpensive source of antioxidant to inhibit the oxidation and reduce vitamin loss of product during extrusion cooking and after extrusion storage, but the level of GP added to the formula has to be well controlled to prevent the prooxidant activity of the GP polyphenols. This is important to the food industry that is interested in the use GP as a food ingredient to increase the dietary fiber and antioxidant content of their product(s).
Publications
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2016
Citation:
LaQuana Hordge, Ivy Smith, Jianmei Yu. Determination of Total Dietary Fiber in Extruded Food Products Containing Grape Pomace. 2016 Spring ACS National Meeting,San Diego, California.
- Type:
Conference Papers and Presentations
Status:
Submitted
Year Published:
2016
Citation:
Jianmei Yu*, Si Zhu, Ivy Smith, Shu Fang, Guibing Chen. The impact of Grape Pomace Addition on Vitamin Retention in Food Product During Extrusion Cooking. 2016 NCAFCS Annual Conference,April 7-9, 2016
New Bern, NC
|
Progress 12/01/13 to 11/30/14
Outputs
Target Audience: The target audiences include food scientists from academia andstudentsmajoring infood and nutritional scienceat North Carolina A&T State University. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? One undergraduate student was trained to conduct proximate composition and TBARSanalysis. One graduate student is undergoing trainnigto conduct in vitro digestibility experiments, and vitamin analysis. How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals? Duringthe next reporting period,researcherswill complete allresearch activities listed under each objective.The results generated during the reporting period of december 2013 to November 2014 will be presented in2015 ACS South East Regional Meeting, and will aso bepresented in graduate seminar classin our department.One manuscript will be written based on the results from the whole project period and will be submitted to a peer reviewed journal for publication.
Impacts
What was accomplished under these goals?
The purpose of this projectis to generate knowledge that the incorporation of grape pomace incorn-based producthas potential toimprove the nutritional quality of the extruded products by increasing dietary fiber, slowning down lipid oxidation,reducing the digestability of corn starch and reducing vitamin loss. This type of product should help inobesity prevention.Theresultsprovide scientific insight for value added utilization of GP to improve the nutritional quality of extruded foods. The achievement during this reporting period include following: Major activities completed: Objective 1 and part of Objective 3 werecompleted. The frozen grape pomaces fromMuscadine Carlos grapes, collected in September 2013 weredried to moisture content4.89%in a humidity controled dark room for two days (48 hours), then ground into powder. Yellow corn-based extruded food products was usded as food model. A 4x3 two factor-factorial design was used to conduct extrusion experiments. two factors weregrape pomacecontent (0, 5, 10 and 15%) and moisture content of formula (15, 17 and 19%). The products were formulated bymixing corn grits,vitamin mixturecontaining 100ppm ofvitamin A acetate, vitamin D3 and vitamin E, respectively (vitamins were dissolved in corl oil before added to the corn grits),and grape pomace powder.The formulas were extruded under same extrusion temperature (120ºC) and screw speed (175 rpm). The effects grape pomace content and moisture of the product formula onthe proximate composition, total insoluble dietary fiber content,and color of the extruded products were evaluated. The products without grape pomace were used as controls, and the products that containing 0.02% of BHA/BHT were used as references. Color parameters(Hunter's L, a and b values), proximate composition,dietary fiber contents and total polyphenol contentsof all extruded products were determined. Results of Objective 1: As GP content increases, the brightness and yellowish of extruded product decreased as shown by decreased L and b values and increased a value. Moisture content of extruded product is not significantly affected by the percentage of GPincluded in the formula (P>0.05), but significantly affected by the water content of the formula (P<0.05). Adding GP in the formula resulted in increased fat content of the extruded product from about 1% to 3.5% in dose dependent manner, because Muscadine Carlos pomace contains about 3.7%fat which is mainly unsaturated fat with linoleic fatty acid (C18:2) as dominating fatty acid. The protein content of the extruded product was not significantly changed because GP used in the study has similar protein content as corn grits (about 10%). The mineral content (determined as ash) increased significantly with GP inclusion because the high ash content of GP (about 5%). Total insoluble dietary fiber contents of extruded product increasedwith GP dose linearly. It was also found that moisture content ofthe formulainhibited puffing and textureof the final products. When the moisture was 19%, the final product was very hard and was only slightly puffed. Results of Objective 3: Polyphenol and antioxidant activity of GP containing extruded product increased compared with those of controls. For samples stored at -22ºC for 2 months, no difference was observed on the content of thiobarbituric acid reactive substances (TBARS) between GP containing samples and controls. Accelerated oxidation techniques may be needed to test the effects of GP on the oxidation of extruded food products during storage. Outcome/Impact: These results indicate that addition of GP in the formulacould enhance the nutritional value of thecorn-based extruded products in terms of increasing dietary fiber, healthy fat, minerals and antioxidants contents. But the moisture content of the formula has to be well controlled to ensure product quality.
Publications
|