Isolation and Characterization of Natural Antioxidants and Value-added Uses

<p>NON-TECHNICAL SUMMARY:<br/> This project investigates producing natural plant extracts and evaluating these for antioxidant, antimicrobial, antimutagenic, anti-Alzheimer's, and anti-oxidative stress/inflammatory activities. Oxidative rancidity of lipids is an important and prevalent cause for rejection of food for human consumption. Lipids are utilized in a wide range of food products, and antioxidants are a major means of preserving edible fats, oil, and lipid containing foods. The food preservation is growing increasingly complex as new food products are being introduced into the market. Foods require longer shelf life and greater assurance of protection both from oxidative deterioration and microbial spoilage. Due to safety concerns and nutritional considerations, however, only a few synthetic antioxidants are approved for direct food applications. In view of these
developments, there is a pressing need to find safe, economic natural antioxidants to replace these synthetic chemicals. Food manufacturers have used food-grade antioxidants, primarily of a phenolic nature, to prevent quality deterioration of products and to maintain their nutritional value. Although phenolic compounds and some of their derivatives are very efficient in preventing autoxidation, only a few phenolic compounds are currently allowed as food antioxidants. Finding potent plant extracts that can effectively enhance inhibition of food-borne pathogens is a continuing opportunity. There is limited knowledge about utilizing plant phenolic extracts as antimicrobials and antioxidants. This project evaluates natural plant extracts not only for antioxidant activity but also for antimicrobial, antimutagenic, anticancer, ani-Alzheimer's, anti-oxidative stress/inflammatory activities,
thus designating potentials for plant extracts to be used as natural alternatives to synthetic and expensive antioxidants/anti-disease agents.

<p>APPROACH:
<br/>Food grade solvents will be used to extract antioxidants from fenugreek, soybean, rice bran and other grains, legumes and alternate crops. Procedures will be optimized and specifically designed for each plant product depending upon the constituents. The active antioxidant compounds in these systems will be identified. Total Phenolics of the extracts will be determined by Folin-Ciocalteu method. Phenolic acid constituents in the extract will be isolated, fractionated, and identified by our established chemical and HPLC procedures. Antioxidant activities of the extract/hydrolysed extracts/individual phenolics will be conducted in a model system for screening, and Oxidative Stabilty Instrument (OSI) for products including chicken fat due to its complex nature of lipids. The effectiveness of these extracts will be evaluated in a variety of food products to
prevent rancidity. Proteins will be hydrolyzed to varying molecular sizes, and the peptides with and without plant extracts (s) will be evaluated for synergistic antioxidant activity adn in vivo bioavailability using animal models. The extracts having potent antioxidant activities with and without food grade additives showing synergism will be selected, and incorporated into various products (poultry, meat, and cereals) and stored (meat and poultry at refrigerated and ambient temperatures). The stored products will be tested at intervals to monitor rancidity, color and flavor. For antimicrobial activity, the plant extract(s) alone and in combination will be tested for inhibition against Listeria monocytogenes, E.Coli, and Salmonella by established procedures. The extracts/combinations showing antimicrobial activities will be evaluated in meat, poultry, sea food, canned food, fruits and
vegetables. The antimutagenic effect of extracts will be assayed by the method of Ames, with slight modification. Anticancer activity, antioxidant activity by radical induced cytotoxicity and anti-inflammatory activities will be evaluated using cell culture models with assays for molecular markers such as cytokines. All assays will be designed using appropriate statistical models with triplicates and minimum standard deviations. Dietary intake of natural antioxidants could be an important factor in the body's defense mechanism against reactive oxygen species, and hence these extracts could potentate incorporation into several foods to prevent oxidative rancidity and long term oxidative stress. Thus the project's impact can be quantified by using these extracts as natural antioxidants in comparison to synthetic ones, and their application as a natural antioxidant agent on food products as
opposed to currently used synthetic antioxidants.

</p><p>PROGRESS:
<br/>2013/01 TO 2013/09
<br/>Target Audience: Food scientists, food companies, ingredient manufacturers, Wal-Mart, Ozark natural foods. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Project Participants: Navam Hettiarachchy, Ruiqi Li, Divya Sharma, Srinivas Rayaprolu, Eswaranandam Satchithanandam and Alok Jha. Provided hands on experience to graduate students and training for their professional career development. How have the results been disseminated to communities of interest? Natural products or co-products like green tea, pomegrante peels, pomace, bittermelon leaves, rice bran etc contain natural phenolics that could be used as natural antioxidants in suitable food products and carry the potential for commercialization by incorporating into food systems. The research was reported to
the industry colaborators who supported the project by providing the raw material. The study caters to impact industries producing large amounts of underutilized co-products which can be value added and can serve as a source of natural, inexpensive and health beneficial phenolic compounds against chronic diseases involving oxidant and peroxidant-induced stress to cells. What do you plan to do during the next reporting period to accomplish the goals? A study is also in progress to extract phenolic compounds from 6 colored soybean cultivars after dehulling, grinding and seiving (80 mesh) the hulls. Quantification of total phenolics and anthocyanins, and the antioxidant activities of the extracts are being investigated.

<br/>PROGRESS:
<br/>2012/01/01 TO 2012/12/31
<br/>OUTPUTS: Natural antioxidants were extracted from Saskatoon berry (Amelanchier alnifolia Nutt.) pomace and bitter melon (Momordica charantia) (BM) leaves. The solvent system for extraction of antioxidants were optimized for maximum extraction of total and individual phenolics. In the present study, we used "Green" solvents (water and ethanol), which are generally recognized as safe (GRAS), for phenolic extraction from Saskatoon pomace and bitter melon leaves and determined individual phenolics and antioxidant activity. Pomace phenolics extracted by 70% methanol showed the maximum amount of phenolics (43.3 mg CAE/g DW). Phenolics extracted by ""Green"" solvents ethanol at 70 % v/v showed the maximum amount of phenolics 39.9 CAE/g DW. Pomace extracts contains total phenolics of 43.3 g/kg total anthocyanins 2.8 g/kg, and total
flavonols 10.3 g/kg of dry weight. A high oxygen radical-absorbing capacity (ORAC) value of 119.4 umol TE/g DW and free radical scavenging activity of pomace extract (200 PPM, 87 %) were observed. Five major anthocyanins (Delphinidin-3-O-glucoside, cyanidin-glucoside, cyanidin-galactoside, delphinidin-3-O-arabinoside, and cyanidin-arabinoside), two flavonols (quercetin-arabinoglucoside; quercetin-galactoside) and three chlorogenic acids (5-caffeoylquinic acid; 4-caffeoylquinic acid; 3-caffeoylquinic acid) were indentified in pomace extracts. This study shows that Saskatoon berry pomace rich in antioxidant phenolics could be extracted by "Green" solvents (water and ethanol) and used in suitable food product applications. Assessment of total phenolics from bitter melon leaves showed that 25% EtOH, an extraction at 40 degrees C for 30 min served as optimal extraction conditions from BM (30.7 mg CAE/g). BM-EtOH extract (1%) showed the highest free-radical scavenging abilities (89% at 180 min) versus BM-water extract (62% at 180 min). The antioxidant capacity of BM-EtOH extract (1%) was almost comparable to that of butylated hydroxytoluene (2%) at 180 min. The antioxidant stability of BM-EtOH and water extracts improved with incorporation of 0.5% gum Arabic. Predominant phenolic compounds isolated from the extracts were o-coumaric, sinapic and ferulic acids. Bitter melon phenolic extracts contain potential free radical scavengers that could serve as natural and stable antioxidants along with gums in suitable food products. PARTICIPANTS: Navam Hettiarachchy, Arvind Kannan, Srinivas Rayaprolu, Vijayalakshmi Ganesh, Patrick Rodgers, Divya Sharma, Ruiqi Li. Provided hands on experience for graduate students and training for their professional career development. TARGET AUDIENCES: Food scientists, food companies, ingredient manufacturers, Wal-Mart, Ozark natural foods. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
<br/>PROGRESS:
<br/>2011/01/01 TO 2011/12/31
<br/>OUTPUTS: Green teas and a rice co-product have been investigated for the presence of phenolics with potential antioxidant properties. Extracts of two green tea varieties from Sri Lanka, designated as GTK and GTP, were tested for antioxidant activities. Dried leaves from both the varieties were ground, passed through sieve (60 mesh) and methanolic extracts (10% w/v with sonication for 20min), were prepared to determine the total phenolic contents expressed as Chlorogenic Acid Equivalents (CAE), using the Folin Ciacalteu reagent method. Aqueous extracts were prepared to test for antioxidant activity using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity assay. The extract from the GTP green tea variety showed maximum total phenolics (125.5mg CAE/g of tea leaves) in comparison to extract from GTK (87.6mg CAE/g
of tea leaves). Commercial green tea extracts have total phenolic contents in the range of 83 to 92mg CAE/g of leaf material. The aqueous phenolic extracts at 300ppm concentration from GTP demonstrated high antioxidant activity (83%), compared to a positive control (BHT, 200ppm - a commercial antioxidant) with 89% antioxidant activity signifying good antioxidant potency of phenolic extracts obtained from green tea extracts. In another ongoing resarch utilizing a co-product of rice processing, the rice bran, extraction of phenolics from heat-treated rice bran was conducted using fermentation with food-grade B. subtilis culture (8 log CFU/ml, 24 h incubated culture) in a bioreactor. The fermentation bioprocess of rice bran with B. subtilus resulted in the extraction of total phenolics with maximum amounts extractable after 72h of fermentation. The total phenolic acid contents in the
ferments (supernatants after centrifuging fermented rice bran extracts with time) were found to increase from approximately 40mg/100g bran to nearly 80mg/100g bran phenolics after 72 h fermentation. A total of nearly 82mg phenolics/100g of bran was extracted from the bran by B. subtilus fermentation. The total phenolics were separated in a HPLC and the major phenolic compounds that were identified corresponding to standard phenolic acid peaks were protocatechuic acid, coumaric acid, ferulic and sinapinic acid. The antioxidant potential of these total phenolics were determined by the DPPH assay, and was found to be approximately 3.5 mg/mL, compared to unfermented rice bran showing minimum degree of antioxidant activity (~1.3 mg/mL). PARTICIPANTS: Navam Hettiarachchy, Arvind Kannan, Srinivas Rayaprolu, Patrick Rodgers. Provided hands on experience for graduate students and training for
their professional career development. TARGET AUDIENCES: Food scientists, food companies, ingredient manufacturers, Wal-Mart, Ozark natural foods. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

<br/>PROGRESS:
<br/>2011/01/01 TO 2011/12/31
<br/>OUTPUTS: Green teas and a rice co-product have been investigated for the presence of phenolics with potential antioxidant properties. Extracts of two green tea varieties from Sri Lanka, designated as GTK and GTP, were tested for antioxidant activities. Dried leaves from both the varieties were ground, passed through sieve (60 mesh) and methanolic extracts (10% w/v with sonication for 20min), were prepared to determine the total phenolic contents expressed as Chlorogenic Acid Equivalents (CAE), using the Folin Ciacalteu reagent method. Aqueous extracts were prepared to test for antioxidant activity using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity assay. The extract from the GTP green tea variety showed maximum total phenolics (125.5mg CAE/g of tea leaves) in comparison to extract from GTK (87.6mg CAE/g
of tea leaves). Commercial green tea extracts have total phenolic contents in the range of 83 to 92mg CAE/g of leaf material. The aqueous phenolic extracts at 300ppm concentration from GTP demonstrated high antioxidant activity (83%), compared to a positive control (BHT, 200ppm - a commercial antioxidant) with 89% antioxidant activity signifying good antioxidant potency of phenolic extracts obtained from green tea extracts. In another ongoing resarch utilizing a co-product of rice processing, the rice bran, extraction of phenolics from heat-treated rice bran was conducted using fermentation with food-grade B. subtilis culture (8 log CFU/ml, 24 h incubated culture) in a bioreactor. The fermentation bioprocess of rice bran with B. subtilus resulted in the extraction of total phenolics with maximum amounts extractable after 72h of fermentation. The total phenolic acid contents in the
ferments (supernatants after centrifuging fermented rice bran extracts with time) were found to increase from approximately 40mg/100g bran to nearly 80mg/100g bran phenolics after 72 h fermentation. A total of nearly 82mg phenolics/100g of bran was extracted from the bran by B. subtilus fermentation. The total phenolics were separated in a HPLC and the major phenolic compounds that were identified corresponding to standard phenolic acid peaks were protocatechuic acid, coumaric acid, ferulic and sinapinic acid. The antioxidant potential of these total phenolics were determined by the DPPH assay, and was found to be approximately 3.5 mg/mL, compared to unfermented rice bran showing minimum degree of antioxidant activity (~1.3 mg/mL). PARTICIPANTS: Navam Hettiarachchy, Arvind Kannan, Srinivas Rayaprolu, Patrick Rodgers. Provided hands on experience for graduate students and training for
their professional career development. TARGET AUDIENCES: Food scientists, food companies, ingredient manufacturers, Wal-Mart, Ozark natural foods. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

<br/>PROGRESS:
<br/>2010/01/01 TO 2010/12/31
<br/>OUTPUTS: Many studies have shown that plant phenolic extracts could serve as effective antioxidants in food system as well as against disease states involving oxidative damage to tissues. Bitter melon (Momordica charantia) used as traditional medicines for various diseases in Asia can be a potential source of phenolic compounds having antioxidant activities. The objectives of this study were to extract phenolics from the pericarp and seed of immature, mature, and ripe bitter melons using ethanol at varying levels as the extracting solvent, determine total phenolic contents, phenolic constituents of the extracts, and investigate antioxidant activities of the extracts. Total phenolic assessment demonstrated 80% of ethanol to be the optimal solvent level to extract phenolics either from pericarp or seed. Main phenolic constituents in
the extracts were catechin, gallic acid, gentisic acid, chlorogenic acid, and epicatechin. Free radical scavenging assay using 2,2-diphenyl-1-picrylhydrazyl (DPPH) demonstrated the bitter melon extracts as slow rate free radical scavenging agents. There were low correlations between the total phenolic contents and antiradical power values of the extracts. In another study, boneless, skinless chicken breasts were infused with grape seed extract (GSE) and green tea extract (GTE), tertiary butylhydroxyquinone and a combination of GSE and GTE. Samples were irradiated and their physicochemical properties were assessed over nine months of frozen storage. The extent of lipid oxidation was determined by thiobarbituric acid reactive substances (TBARS) and carbonyl content methods. Irradiation increased both TBARS and carbonyl content in both raw and cooked chicken. Infusion with plant extracts
decreased TBARS and carbonyl content compared with controls. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Food scientists, food microbiologists, food safety personnel, food companies, Walmart, Ozark natural foods PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

<br/>PROGRESS:
<br/>2009/01/01 TO 2009/12/31
<br/>OUTPUTS: Many studies have shown that plant phenolic extracts could serve as effective antioxidants in food system as well as against disease states involving oxidative damage to tissues. Bitter melon (Momordica charantia) used as traditional medicines for various diseases in Asia can be a potential source of phenolic compounds having antioxidant activities. The objectives of this study were to extract phenolics from the seed of bitter melon fruits harvested at two maturation stages (mature/green, and ripe/yellow) using ethanol and water solvent system, and determine their total phenolic contents, phenolic constituents, and antioxidant activities. Phenolics were extracted from seeds of mature or ripe bitter melon fruit using water or 0, 20, 40, 60, 80, or 95% ethanol. Total phenolics, phenolic constituents, and antioxidant
activities of the extracts were determined using Folin-Ciocalteau method, high performance liquid chromatography, and free radical (2,2-diphenyl-1-picrylhydrazyl/DPPH) scavenging assay, respectively. Total phenolics in the extracts of 40, 60 and 80% ethanol from mature and ripe fruit seeds were 17.7, 17.9, and 18.0 mg/g extracts (dry basis) and 19.1, 20.7 and 20.9 mg/g extracts, respectively and significantly higher (P-valueIMPACT: 2009/01/01 TO 2009/12/31Seeds of bitter melon fruit can be a good source of phenolics and these phenolic extracts have the potential to minimize lipid oxidation in suitable foods.
<br/>
PROGRESS:
<br/>2008/01/01 TO 2008/12/31
<br/>OUTPUTS: Irradiation increased both TBARS and carbonyl content in both raw and cooked chicken. Infusion of green tea and grape seed extracts (GSE) decreased lipid oxidation. In another study, phenolics were extracted from the seeds of bitter melon fruits harvested at two maturation stages (mature/green and ripe/yellow) using ethanol (20, 40, 60, 80 or 95%) and water systems. Total phenolics in the extracts of 40, 60 and 80% ethanol from mature and ripe fruit seeds were 17.7, 17.9, and 18.0 mg/g extract (dry basis) and 19.1, 20.7, and 20,9 mg/g extracts respectively, and significantly higher (P value less than 0.0001) than those from the other solvents. The main phenolic acid constituents in the extracts were gentisic acid, catechin, and epicatechin. The extracts that showed the best free radical scavenging activities were the
extracts derived from 40, 60 and 80% ethanol. The E50 values of the ethanolic extracts from mature and ripe fruit seeds were 16.7 (40%), 15.6 (60%), and 17.4 (80%) g extract/DPPH; and 20.6 (40%), 19.4 (60%), and 18.0 (80%) g extract/g DPPH respectively. Antilisterial activity of green tea and grape seed extracts and their phenolic compounds were investigated. Phenolic contents in grape seed extract and green tea extracts ranged from 15.4-158.5, and 18.3-108.0 mg/100 grams of extracts respectively. Caffeic acid and epicatechin were the main phenolics in green tea extract (GTE), while in grape seed extract (GSE) epicatechin, catechin, and gentisic acid were the major phenolics. The phenolic compound treatment at concentrations of more than 200 microgram/ml resulted in 80% growth inhibition. Meat studies inoculated with L. monocytogenes showed a 3.6 log reduction in the sample containing
GSE combined with nisin at 4 degrees Celsius, and 2.1 log reduction at 10 degrees Celsius. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

<br/>PROGRESS:
<br/>2008/01/01 TO 2008/12/31
<br/>OUTPUTS: Irradiation increased both TBARS and carbonyl content in both raw and cooked chicken. Infusion of green tea and grape seed extracts (GSE) decreased lipid oxidation. In another study, phenolics were extracted from the seeds of bitter melon fruits harvested at two maturation stages (mature/green and ripe/yellow) using ethanol (20, 40, 60, 80 or 95%) and water systems. Total phenolics in the extracts of 40, 60 and 80% ethanol from mature and ripe fruit seeds were 17.7, 17.9, and 18.0 mg/g extract (dry basis) and 19.1, 20.7, and 20,9 mg/g extracts respectively, and significantly higher (P value less than 0.0001) than those from the other solvents. The main phenolic acid constituents in the extracts were gentisic acid, catechin, and epicatechin. The extracts that showed the best free radical scavenging activities were the
extracts derived from 40, 60 and 80% ethanol. The E50 values of the ethanolic extracts from mature and ripe fruit seeds were 16.7 (40%), 15.6 (60%), and 17.4 (80%) g extract/DPPH; and 20.6 (40%), 19.4 (60%), and 18.0 (80%) g extract/g DPPH respectively. Antilisterial activity of green tea and grape seed extracts and their phenolic compounds were investigated. Phenolic contents in grape seed extract and green tea extracts ranged from 15.4-158.5, and 18.3-108.0 mg/100 grams of extracts respectively. Caffeic acid and epicatechin were the main phenolics in green tea extract (GTE), while in grape seed extract (GSE) epicatechin, catechin, and gentisic acid were the major phenolics. The phenolic compound treatment at concentrations of more than 200 microgram/ml resulted in 80% growth inhibition. Meat studies inoculated with L. monocytogenes showed a 3.6 log reduction in the sample containing
GSE combined with nisin at 4 degrees Celsius, and 2.1 log reduction at 10 degrees Celsius. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

<br/>PROGRESS:
<br/>2007/01/01 TO 2007/12/31

<br/>OUTPUTS: Phenolics are phytochemicals extensively distributed among plants that have been receiving great deal of attention as antioxidants. Rice bran is a good source of phenolics. This study was conducted to optimize a procedure to isolate phenolics from rice bran using sonication as a preextraction treatment. Sonication was optimized by varying output, time, and temperature. Extraction was optimized by varying solvent, extraction time, temperature, and sample-to-solvent ratio. The optimum conditions for extracting phenolics from rice bran were sonication with water (1:100 sample -to-solvent ratio) for one min.; output intensity of 10; holding at ambient temperature; and autoclave treatment for 20 min. at 121 degrees Celsius. This procedure extracted approximately 9.0 milligrams of phenolics per gram of dry rice bran. In another study, cow pea protein obtained from alkali treatment
was hydrolysed with various proteolytic enzymes followed by fractionation using ultrafiltration with different molecular size cut off. Peptide fraction with molecular size cut off of 30-50 kDa and 5-10 kDa had significantly higher free radical scavenging activities than those from cow pea protein without hydrolysis.
PARTICIPANTS: Navam Hettiarachchy, PI James Dickson, Iowa State University -Collaborator
TARGET AUDIENCES: Government, industry, academics, consumer, producers and processors
.
<br/>PROGRESS:
<br/>2006/01/01 TO 2006/12/31
<br/>Lipid oxidation as well as off-odors and flavors produced during and after irradiation can reduce the quality of meats. Antioxidants can reduce lipid oxidation in irradiated meat Due to a concern with synthetic antioxidants, there is an increasing demand for identifying plant extracts to minimize lipid oxidation in food products. A previous study has shown that grape seed and green tea extracts had the highest antioxidant activities among the plant extracts that were investigated. This study was conducted on irradiated (at a dosage of 3.0 kGy) fresh boneless and skinless chicken breast meats infused with plant extracts: green tea (GT), grape seed (GS) extracts alone / in combination to evaluate their effectiveness on sensory properties of non-irradiated and irradiated chicken meats. Chicken breast meats were vacuum infused with
green tea, grape seed extracts (singly or in combination), or tertiary butylhydroquinone. After irradiation at a dosage of 3.0 kGy, these samples were stored at -20 degrees Celsius for 0, 3, 6, and 9 mo. Nonirradiated samples were included for comparison. Infusion of plant extracts increased lightness and decreased redness.
<br/>IMPACT:
<br/>2006/01/01 TO 2006/12/31
<br/>Infusion of chicken breasts with GT extracts is effective in preventing and minimizing lipid oxidation caused during irradiation. These extracts can find application as antioxidants in food products including meat and poultry.
<br/>
PROGRESS:
<br/>2005/01/01 TO 2005/12/31
<br/>This study was conducted on irradiated (at a dosage of 3.0 kGy) fresh boneless and skinless chicken breast meats infused with plant extracts: green tea (GT), commercial grape seed (GS) extracts alone / incombination to evaluate their effectiveness on sensory properties of non-irradiated and irradiated chicken meats. Descriptive results showed that irradiation did not affect the sensory flavor attributes (P > 0.05) except that of brothy flavor, and irradiation increased texture attributes of hardness, cohesiveness, and hardness and cohesiveness of mass. Consumer results showed that GT and water control gave the best color.
<br/>IMPACT:
<br/>2005/01/01 TO 2005/12/31
<br/>Infusion of chicken breasts with GT extracts at 3000 ppm is effective to prevent and minimize major sensory changes of the meat during irradiation. The antioxidant capacity of cow pea extracts can be harnessed for nutraceutical and functional applications. Bitter melon extract can be a potential source of antioxidant and antimutagen. These extracts can find application in food products, and
dietary supplements.<br/>PROGRESS:
<br/>2011/01/01 TO 2011/12/31
<br/>OUTPUTS: Results from this period have been disseminated through 6 poster presentations at 5 international and regional conferences, and 7 referred publications. The results demonstrated that health-promoting starch fractions, i.e. slowly digestible starch and resistant starch, in parboiled rice can be increased by varying the rice cultivar and parboiling conditions, including feedstock, autoclaving duration and storage treatment. The storage treatment promoted the formation of slowly digestible starch and decreased rapidly digestible starch content in parboiled rice. It is possible to increase the health benefits of parboiled rice by choosing cultivars and the combinations of parboiling conditions that promote the formation of retrograded amylopectin and amylose-lipid complex and the interactions among rice components. In
addition, parboiled rice was used to prepare rice pasta with the addition of various types of starch to improve the processibility. The effect of starch addition on the textural properties of rice pasta varied with the type of starch. The addition of waxy starch or tapioca starch resulted in rice pasta with a significant increase in hardness, stickiness, and adhesiveness compared to the rice flour control; whereas the addition of common corn and high amylose corn starches resulted in a decrease in hardness, stickiness, and adhesiveness. Knowing how starch affects the properties of rice pasta will help the improvement and future development of hypoallergenic pastas and cereal products, thus expanding the foods available to those suffering from gluten intolerance. The changes of starch and protein during nixtamalization as related to corn masa properties were studied. The results show that
the combined effects of lime on starch cross-linking and the formation of zein polymers and calcium-zein interactions during cooking, yielded a stronger and more elastic gel structure. In order to elucidate the roles of starch molecular structures on its pasting properties, beta-amylase and isoamylase were employed to modify two waxy mutant maize starches in a controlled manner. The results suggest that the pasting viscosity of waxy maize starch is primarily governed by gyration of radius than by molar mass and/or long B chains among amylopectin structural characteristics. Any modification resulting in significant changes in gyration of radius would have a strong impact on the pasting properties of waxy starch.
<br/>PARTICIPANTS: Dr. Ya-Jane Wang, the PI of this project. Dr. Maria Guadalupe Mendez-Montealvo participated in characterizing the structure and rheological properties of starch and
starch derivatives using HPLC and dynamic rheometer, respectively. Dr. Mark Campbell of Truman State University collaborated on corn mutant project. Adriana Quintanar-Guzman from Instituto Politecnico Nacional, Mexico participated in studying interaction of protein and starch in masa. Youngbum Lee, a master student, worked on characterizing rice starch changes during rice ageing.Curtis Luckett, a master student, characterized the resistant starch formation from retrograded debranched starch with the addition of an enzymatic treatment. Emily Arijaje, a Ph.D. student, worked on preparation of amylose-lipid complex as controlled release agents. Alexandria Mertz, an undergraduate student, developed rice pasta using parboiled rice and starch from various botanical sources.Kyle Mattal, an undergraduate student, helped with the development of method to measure the degree of gelatinization in
parboiled rice.
<br/>TARGET AUDIENCES: The understanding of starch structure, functionality, and modification will provide a scientific basis for the food industry to select appropriate starch and modification for specific application, and to adjust processing conditions to increase health-promoting starch fractions in products. The results can also serve as guidelines for breeders and biotechnologists to produce novel starch based on end applications. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

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