Progress 10/01/98 to 09/30/04
Outputs
A total of 6 commercial protein products including fish gelatin, whey, pea, potato, lupin and wheat proteins were evaluated for protein content, molecular size, viscosity, hydrophobicity, nitrogen solubility, emulsifying and thermal properties. The protein content ranged from 70.1-99.5%. SDS-PAGE electrophoresis revealed that pea protein had the largest molecular size that ranged from 14-115 kDa, followed by wheat (15-97 kDa), whey (less than14-93 kDa), potato (24-48 kDa) and lupin (14-17 kDa). Fish gelatin and wheat protein had lower molecular sizes (less than14 kDa). The viscosities at a shear rate of 400 per sec and concentration of 15% were 99.4, 21.7, 12.6, 8.9, 7.9, and 7.9 for wheat, fish, potato, lupin, pea and wheat proteins respectively. Fish and wheat proteins had lower surface hydrophobicities of 232.6 and 261.3 respectively, and both of these products showed very close pattern with a maximum solubility of almost 100%. Whey protein dispersion had the
highest emulsifying properties. Fish gelatin demonstrated excellent thermal stability. Overall, fish, whey, lupin, and potato proteins had higher functional properties in terms of solubility and emulsification, while fish, lupin, whey, and wheat protein had good thermal stabilities. In another study, cow pea proteins demonstrated lower emulsifying and foaming properties compared with soy protein. Carbohydrases and proteases were screened for maximum protein extraction from heat-stabilized defatted rice bran (HDRB). The conditions for maximum extraction were optimized with RSM using a second order model of central composite design. Amylase, pectinase, protease, protex, and multifect extracted 36%, 40%, 52%, 52%, and 52% protein respectively. Combination of pectinase and protease extracted the maximum amount of protein extracted (80%). The optimum conditions for pectinase and protease were 20:1 (water/HDRB), pH 3.55, 3,346 units, and 3.1 h, respectively.
Impacts
The results on commercial proteins demonstrated their potential application in various products that require specific functional properties. The cow pea protein requires modification to enhance its functional properties. Enzymatic treatment is an efficient method for protein extraction from HDRB. Combined use of pectinase and protease can benefit protein extraction from HDRB.
Publications
- Horax, R., N.S. Hettiarachchy, P. Chen, M. Jalaluddin. 2004. Preparation and characterization of protein isolate from cowpea (Vigna unguiculata L. Walp.). J Food Sci 69(2):114-118.
- Horax, R., N.S. Hettiarachchy, P. Chen, M. Jalaluddin. 2004. Functional properties of protein Isolate from cowpea (Vigna unguiculata L. Walp.). J Food Sci 69(2):119-121.
- Hettiarachchy, Navam, S. Tang, and R. McNew (2004) Protein extraction from heat-abilized defatted rice bran: Screening enzymes and optimizing extracting conditions. AACC/TIA Annual Meeting, Book of Abstracts, San Diego, CA, # 382, p.159. October.
- Eswaranandam, S. and N. S. Hettiarachchy. 2004. Textural properties of tomatoes coated with soy, whey protein and cellulose films. IFT Annual Meeting and Food Expo, Las Vegas, Nevada, July 12-16. Book of abstracts. 49F-36, p.128.
- Ronny Horax. M.S., August, 2003. Preparation, Characterization and Functional Properties of Protein isolate from Cowpea (Vigna unguiculata L. Walp.). P. 73. Department of Food Science, University of Arkansas, Fayetteville
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Progress 01/01/03 to 12/31/03
Outputs
Molecular size, thermal properties, hydrophobicity, nitrogen solubility, and emulsifying and foaming properties were determined for protein products from heat-stabilized defatted rice bran (HDRB). The freeze dried, and spray-dried proteins had molecular sizes between 6.5 and 66.2 kDa; denaturation temperatures of 84.1 and 84.6 degrees Celsius, enthalpies of 2.5 and 2.37 J/g, hydrophobicities of 20677 and 22611, maximum solubilities of 66.3% and 66.1% at pH 12.0, emulsifying capacities of 0.19, and 0.18, emulsion stabilities of 16.5 and 17.3, foam capacities of 4.0 mL, and 4.2 mL, and negligible foam stabilities. In another study, 58.4% protein was extracted from HDRB using amylase, viscozyme and celluclast. Protein isolate (PI) was prepared from three cowpea and two soybean varieties. Electrophoretograms showed that cowpea protein isolate (CPI) was concentrated at 60 and 40 kDa, whereas SPI showed bands at 95, 65, 60, 40, and 35 kDa. The CPI had higher lysine
(49.3-51.8) than SPI (41.9-43.4). The CPI and SPI had surface hydrophobicities ranging from 387.8 to 572.9 and 640.6 to 643.1 respectively. Denaturation temperature (85.2 - 88.4 degrees Celsius), and enthalpy (8.42-10.33 J/g) of CPI were similar to the 7S fraction of SPI (82.6 degrees Celsius, and 96.0-96.3 J/g). Both CPI and SPI showed U-shaped curve for solubility with minimum solubility at pH 4.5. The CPI had lower emulsifying activity than SPI but was similar in stability. Foaming capacity and stability ranged form 58.6 to 60.2 mL, and 63.7-64.4 min for CPI and from 31.9-33.0 mL and 43.4 to 45.0 min for SPI, respectively. Gels were formed at 70 degrees Celsius for 40 min and 30 min for CPI (12%) and SPI (10%) respectively. Soy meal and Soy Life isoflavone glycosides(bio-inactive) were effectively converted to aglycones (bio-active)using beta glycosidase enzyme.
Impacts
The results on rice bran protein demonstrate its potential as a nutraceutical ingredient in food applications. The cowpea protein isolate needs modification to enhance functional properties for potential application in food products. The bio-active isoflavones in soymeal (containing approximately 55% protein) and SoyLife will find numerous applications in nutraceuticals food products.
Publications
- Tang, S., Hettiarachchy, N.S., Horax, R., and S. Eswaranandam. 2003. Physicochemical properties and functionality of rice bran protein hydrolyzate prepared from heat-stabilized defatted rice bran with the aid of enzymes. J. Food Sci. 68(1):152-157.
- Tang, S. Hettiarachchy, N.S., Eswaranandam, S. and P. Crandall. 2003. Protein extraction from heat-stabilized defatted rice bran: II. The role of amylase, celluclast, and viscozyme. J.Food Sci. 68(2):471-475
- Xie, L., N.S. Hettiarachchy, R. Cai, K. Tsuruhami, and S. Koikeda. 2003. Conversion of isoflavone glycosides to aglycones in soylike and soymeal using beta-glucosidase. J. Food Sci. 68(2):427-430
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Progress 01/01/02 to 12/31/02
Outputs
Rough rice was subjected to 25 or 60 degree C drying with or without 3 h tempering at 19.5% relative humidity. Proteins extracted from these rice flours were evaluated for surface hydrophobicity, molecular size, and protein cross-linking via lysine-carbohydrate interaction and S-S bond. Drying at 60 degree C with 3 h tempering significantly increased glutelin surface hydrophobicity (P<0.05), but did not affect moisture, protein glutelin components and their molecular sizes, and cystine and available lysine contents. These results suggest that drying rough rice at 60 degree C with or without 3 h drying is ineffective to cause protein cross-linking and glutelin changes in molecular size in rough rice. Physical processing with or without enzyme treatments on protein extraction from heat-stabilized defatted rice bran (HDRB) was evaluated. Freeze-thaw, sonication, high-speed blending, and high pressure extracted 12, 15, 16 and 11% protein respectively. Sonication, 0-100%
750W, followed with amylase, and combined amylase and protease treatments extracted 25.6-33.6, and 54.0-57.8% protein respectively. Blending followed with amylase and protease and without enzyme treatments extracted more protein than the non-blended enzymatic treatments. High-pressure treatments, 0-800 Mpa, with water or amylase-protease combinations, extracted 10.5-11.1 or 61.8-66.6% protein. These results suggest that physical processing in combination with enzyme treatments can be effective in extracting protein from HDRB. The effectiveness of 3 carbohydrases for protein extraction from HDRB was evaluated. Amylase, viscozyme, and celluclast extracted a maximum of 45.4, 12.1, and 28.5 % protein, respectively. A combination of selected enzymes extracted 86% protein from HDR. This protein is rich in all essential amino acids, including lysine.
Impacts
Rough rice can be heated up to 60 degree C during drying without loss of rice quality. This information will be useful to the farmers in shortening the time of drying at a higher temperature. This is the first time that a higher percentage of protein has been extracted from HDRB. This established technology to produce rice bran protein from HDRB will be useful for the rice processors to develop and produce new nutraceutical and functional products from rice bran. The rice bran protein will be in demand by the consumer due to its health benefit. Rice bran protein isolate will add value to a low priced co-product of rice.
Publications
- Tang, S., N.S. Hettiarachchy, Z. Ju and A. Cnossen. 2002. Surface hydrophobicity and protein cross-linking in rice subjected to varying drying and tempering conditions. J. Food Sci. 67(8):2930-2933.
- Tang, S., N.S. Hettiarachchy, Z. Ju, and T.H. Shelhammer. 2002. Protein extraction from heat-stabilized defatted rice bran. I. Physical processing and enzyme treatments. J. Agric. Food Chem. 50:7444-7448.
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Progress 01/01/01 to 12/31/01
Outputs
Rice proteins were extracted from defatted rice flour. Turbidity measurement of supernatants revealed isoelectric points of albumin (pH 4.1), globulin (pH 4.3 and pH 7.9) and glutelin (pH 4.8), at which they were precipitated with 82.3 to 93.2% efficiency. Denaturation temperatures (73.3, 78.9, and 82.2 degrees C) as well as enthalpy values (2.88, 3.14, and 3.79 J/g), of albumin, globulin and glutelin were different. Heat denaturation of globulin and glutelin resulted in progressive increases in their surface hydrophobicities. Evaluation of protein denaturation in rice subjected to varying varying drying and tempering conditions showed that high drying temperature (60 degrees C, RH +60%) and tempering (3 h) can denature rice and rice bran proteins. Therefore gentle drying is recommended to maintain rice quality. Edible films were prepared from solutions of soy protein isolate (SPI) with calcium salts and gluconono-delta-lactone (GDL).Tensile strength (TS) of calcium
sulfate treated SPI film (8.6 Mpa) was higher than the TS of calcium chloride treated films (6.4 Mpa) and the control SPI films. SPI film formulated with GDL had larger elongation at break (39.4%) than that of SPI control films (18.2%). A shelf -life stability of isoflavones in soy meal and soy protein concentrate (at 4/25/37 degrees C and 50/65/85% RH) demonstrated that these products can be stored at least for 6 months without appreciable loss in isoflavones. The results demonstrated that 99.56% soy meal (SM), and 98.94% SoyLife (SL) of genistin glycoside, 89.84% SM and 99.66% SL of glycitin glycoside, 98.69 SM and 98.2% SL of daidzin glycosides were converted to their corresponding aglycones by diglucosidase at pH 5.0, 50 degrees C, 5 hours incubation. Almost all isoflavones were converted to their corresponding aglycones.
Impacts
Measurement of surface hydrophobicity would be an effective parameter to evaluate rice protein denaturation. Soy protein films formulated with calcium salts or glucono-delta-lactone afford potential as moisture barrier for food systems and as coating agents for food applications or intermediate-moisture foods. The stable isoflavones in soy meal and soy protein concentrate can used as nutraceutical and functional ingredients in a variety of health food products. Diglycosidase can be very effective in the conversion of glycosides to aglycones (bioactive compound) in various isoflavone enriched soy products.
Publications
- Ju, Z.Y., Hettiarachchy, N.S., and Rath, N. 2001. Extraction, denaturation and hydrophobic properties of rice flour proteins. J. Food Sci. 66(2):229-232.
- Park, S.K., Rhee, C.O., Bae, D.H. and Hettiarachchy, N.S.. 2001. Mechanical properties and water-vapor permeability of soy-protein films affected by calcium salts and glucono-delta-lactone. J. Agric. Food Chem. 49:2308-2312.
- Anderson, A., Hettiarachchy, N.S., and Ju, Z.Y. 2001. Physicochemical properties of pronase-treated rice glutelin. J. Am. Oil. Chem. Soc. (78):1. 1-6.
- Ju, Z.Y., Hettiarachchy, N.S., Siebenmorgen, T. and Cnossen, A. 2002. Evaluation of protein denaturation in rice subjected to varying drying and tempering conditions. IFT Annual Meeting and Food Expo. Book of Abstracts. 59D-5, p. 134.
- Xie, L. Hettiarachchy, N.S., Ju, Z.Y., Meullenet, J., Wang, H., Slavik, M., and Janes, M.E. 2001. Edible film coating to minimize eggshell breakage and reduce post-wash bacterial contamination measured by dye penetration in eggs. J. Food Sci. (In press).
- Hettiarachchy, N.S. and Armitage, D. 2001. Edible film coatings as carriers of antioxidants. AOCS Annual Meeting and Expo. Minneapolis, MN, INFORM (11) # 5, Abstract, p.S98.
- Xie, L., Hettiarachchy, N.S., Ju, Z.Y, Crandall, P.G., and McNew. 2002. Shelf-life stability of isoflavone in soymeal and soy protein concentrate. IFT Annual Meeting and Food Expo. Book of Abstracts. 44E-2, p.96.
- Xie, L., and Hettiarachchy, N.S. 2001. Isoflavone content in hull, germ, and cotyledon in soybean. IFT Annual Meeting and Food Expo. Book of Abstracts. 44E-3, p. 97.
- Xie, L., Hettiarachchy, N.S., Kazutaka Tsruhami Koikeda. 2001. Effectiveness of diglucosidase for the conversion of isoflavone glycoside to aglycones. IFT Annual Meeting and Food Expo. Book of Abstracts. 44E-4 p.97.
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Progress 01/01/00 to 12/31/00
Outputs
Soybean variety with high genistein and genistin contents was used to evaluate the 3 basic soy protein concentrate (SPC) production methods for genestein and genistin retention . The acid leach method gave the highest total genestein+genistin content compared to other methods. Conversion of genistin in the glucoside form to genestein in the aglycone form by beta glucosidase hydrolytic activity during SPC was evaluated. The optimum conditions for the conversion of genistin to genestein were pH 5.0, 50 degrees Celsius, 2 units of enzyme/g soy flour, I h incubation, and 1:10 (w/v) defatted soy flour to water ratio. Under these conditions 1.214 mg/g genestein were obtained. Combined beta glucosidase and pectin treatment in SPC preparation resulted in higher genestein in SPC (1.551 mg/g). Films containing soy protein and wheat gluten were exposed to simulated farmland soil mix over a period of 30 days and monitored for degradation. The film rapidly degraded with 50% weight
loss in about 10 days and with up to 95% weight in about 30 days. The adhesiveness of meat and bone meal protein at various pH values was investigated. Highest adhesiveness was observed at pH 6.0-8.0. Improved adhesiveness and water resistance were observed with 0.05% glutarldehyde treatment.
Impacts
Isoflavone enriched soy protein concentrate as a nutraceutical can find a variety of uses in numerous food products. The soy protein-wheat gluten films are biodegradable and can be an alternative source for some types of synthetic plastic films. The inedible meat and bone meal protein can be a good source of adhesive.
Publications
- Park, S.K., Hettiarachchy, N.S and L. Were. 2000. Degradation behavior of soy protein-wheat gluten films in simulated soil conditions. J. Agric. & Food Chem. 48:3027-3031.
- Park, S.K., Bae, D.H., and N.S. Hettiarachchy. 2000. Protein concentrate and adhesives from meat and bone meal. J. Am. Oil Chem. Soc. 77(10):1223-1227
- Park, S.K. and Hettiarachchy. 2000. Extending shelf life of fuji and golden delicious apples using soy protein film coatings. IFT Annual Meeting and Food Expo, Dallas, TX. June 10-14. Abstract 78E-6, p.186.
- Ju, Z.Y., Hettiarachchy. N.S., Siebenmorgen, T. and N. Rath. 2000. Surface hydrophobicity as a tool to detect rice protein denaturation. IFT Annual Meeting and Food Expo. Dallas, TX. June 10-14. Abstract 78A-3, p. 166.
- Pandjaitan, N., Hettiarachchy, N.S., Ju, Z.Y., Crandall, P., Sneller, C and D. Dombek. 2000. Evaluation of genestein and genistin contents in soybean varieties and soy protein concentrate prepared with three basic methods. J. Food Sci. 65(3):399-402
- Pandjaitan, N., Hettiarachchy, N.S., and Ju, Z.Y. 2000. Enrichment of genestein in soy protein concentrate with beta glucosidase. J. Food Sci. 65(3):403-407
- Pandjaitan, N., Hettiarachchy, N.S., Ju, Z.Y., Crandall, P., Sneller, C, and D. Dombek. 2000. Enrichment of genestein in soy protein concentrate with hydrocolloids and beta glucosidase. J. Food Sci. 65(4):591-595
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Progress 01/01/99 to 12/31/99
Outputs
Rice bran protein isolate (RBPI), containing approximately 92% protein with about 75% yield was prepared from unstabilized, defatted rice bran using phytase and xylanase enzymes. Nitrogen solubilities of RBPI were 53.2, 62.4, 77.6 and 82.4% at pHs 2.0, 6.0, 8.0 and 10.0 respectively. RBPI had an emulsifying activity of 33% and emulsion stability of 11% compared to standard bovine serum albumin. The foaming capacity and stability were 92%and 90% compared to egg white. Soy protein-gluten films were prepared and evaluated as affected by soy protein:gluten (S;G) ratio, pH (3.0, 7.0 or 9.0) and cysteine (0% or 1.0%). Cysteine increased tensile strength (TS) of most films. Gluten addition decreased water vapor permeability, but increased oxygen permeability. Specific functional and nutritional properties of alkali-and heat-treated soy protein isolate (AHSPI) were evaluated. High pH (12.0) and temperature (100 degrees C) increased protein solubility from 47% to 99.5%, and
emulsifying index from 74 to 1842/g. The values for in vitro protein digestibility (IVPD), computed-protein efficiency ratio, and IVPD-corrected amino acid score of AHSPI were not significantly (p>0.05) afffected at pH 8.0 or 10.0, but were reduced at pH 12.0. Aggregation of 10% whey protein solution was induced by addition of calcium salt, acidification, or proteolysis at 45 degree C. Aggregates induced by calcium salt (74 degrees C) and protease (73 degrees C) had intermediate denaturation temperatures. The pH -induced aggregates had high denaturation temperatures (80 degrees to 91 degrees C)at low pH (3.5-5.7). Flexible plastic foams using soy protein isolate (SPI), soy protein concentrate (SPC), and defatted soy flour (DFS) were produced by interacting protein proteins with glycerol-propylene oxide polyether triol (polyol), surfactant, triethanolamine (cross-linking agents), tertiary amine (catalyst), and water (blowing agent).
Impacts
(N/A)
Publications
- Wang, M., Hettiarachchy, N.S., Qi. M., Burks, W., and Siebenmorgen, T. 1999. Preparation and functional properties of rice bran protein isolate. J. Agric. & Food Chem. (47):2, 411-416.
- Were L., Hettiarachchy, N.S., and Coleman, M. 1999. Properties of cysteine add soy protein-wheat gluten films. J. of Food Sci. 98:
- Yildirim, M., and Hettiarachchy, N.S. 1999. Films from pickle fermentation brines. J. of Agric. and Food Chem. 46 (12):4969-4972.
- Wu Wu, Hettiarachchy, N.S. Kalapathy, U., and Williams, W.P. 1999. Functional properties and nutritional quality of alkali and heat treated soy protein isolate. J. Food Quality (22):2, 113-119.
- Zhi Yong Ju, Hettiarachchy, N.S., and Kilara, A. 1999. Thermal properties of whey protein aggregates. J. Dairy Sci. 82:1882-1889.
- Mott, C.L., Hettiarachchy, N.S., and Qi, M. 1999. Effect of xanthan gum on enhancing the foaming properties of whey protein isolate. J. Am. Chem. Soc. 76 (11):1383-1386.
- Park, S.K., and Hettiarachchy, N.S. 1999. Physical and mechanical properties of soy protein-based plastic foams. J. Am. Oil Chem. Soc. 76(10):1201-1205.
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Progress 01/01/98 to 12/31/98
Outputs
Transglutaminase (TG) was used to produce films from whey protein isolate, soybean 11S globulin and a mixture of the two (1:1, wt/wt). Mean thickness of films ranged from 69 to 77 um and there were no differences among thicknesses. Average tensile strength (TS)values of TG cross-linked films were two times greater than those of homologous controls. Solubility of TG cross-linked films was lower than that of control films at pH 3, 4, 6, and 8. In another study, a proteinaceous fibrous material formed during commercial fermentation of cucumbers was used to produce films. Film thickness ranged from 58 to 74 um. Protein solubility of films in water increased with increasing pH and temperature. The tensile strength (TS) of pH 7.0 films was higher than the TS of pH 9.0 films (p<0.05). Alkaline pH and temperature caused a decrease in both the TS and puncture strength of films. The foaming properties of soy protein isolate (SPI) in the presence of xanthan gum (XG) were
investigated. The optimal foaming properties were obtained from the SPI-XG dispersion that contained 0.1% SPI and 0.2% XG. The SPI-XG foams were stable over wide ranges of ionic strength (0.1 to 1.0 M NaCl) and pH (4.5 to 9.0), and when heated (85 degrees C, 1 h). In another study, SPI was pre-denatured at pH 10, heated at 50 degrees C and subjected to papain hydrolysis. The hydrolysates were fractionated by ultrafiltration. Significant increases (p<0.0001) in functional properties were observed in the hydrolysates. The effectiveness of SPI, soy proteins hydrolysate (SPH) or blends with three detergents and their influence in prototype products on foaming and emulsifying properties were investigated. Products in which SPI or SPH were used to partially replace detergents not only retained excellent foaming properties but also exhibited enhanced emulsifying properties.
Impacts
(N/A)
Publications
- Hettiarachchy, N.S., Yildirim, M., and Buescher, R. 1998. Composition and functional properties of an unusual proteinaceous fibrous material from cucumber fermentation. J. of Agric. and Food Chem. 46(3):825-828.
- Yildirim, M. and Hettiarachchy, N.S. 1998. Properties of cast films from pickle fermentation brine protein. J. Agric. Food Chem. 46(12):4969-4972.
- Xie, R. and Hettiarachchy, N.S. 1998. Effect of xanthan gum on enhancing the foaming properties of soy protein isolate. J. of Am. Chem. Soc. 75(6)729-732.
- Xie, R. and Hettiarachchy, N.S. 1998. Xanthan gum effects on solubility and emulsification properties of soy protein isolate. J. of Food Sci. 62(6):1101-1104.
- Wu, M.W. and Hettiarachchy, N.S. 1998. Foaming and emulsifying properties of soy protein isolate and hydrolysates in skin and hair care products. 1998. J. of Am. Oil Chem. Soc. 1(2):241-246.
- Xie, R. and Hettiarachchy, N.S. 1998. Effect of xanthan gum on enhancing the foaming properties of soy protein isolate. J. of Am. Chem. Soc. 75(6):729-732.
- Wu, M.W. and Hettiarachchy, N.S. 1998. Enhancing storage stability of emulsions by binding detergents with soy protein isolate and hydrolystates. J. of Am. Oil Chem. Soc. 1(3):387-392.
- Wang, M., Hettiarachchy, N.S., Burks, W. and Siebenmorgen, T. 1998. Preparation and functional properties of rice bran protein isolate. J. of Agric. Food Chem. "In press".
- Were, L., and Hettiarachchy, N.S. 1998. Properties of Cysteine-added soy-protein wheat gluten films. J. of Food Sci. "Accepted for Publication".
- Yildirim, M. and Hettiarachchy, N.S. 1998. Properties of films produced by cross-linking whey proteins and 11S globulin using translutaminase. J. Food Sci. 63(2):248-252.
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Progress 01/01/97 to 12/31/97
Outputs
Biopolymers with MW>2,000 kDa were prepared by cross-linking whey protein isolate (WPI) and soybean 11S using transglutaminase. Biopolymer solubility was >90% at pH 3.0 and below, and at pH 7.0 and above. Emulsifying properties of biopolymers were lower than those of WPI. The foaming capacity of the biopolymers (23.6 ml) and WPI/11S mixture (22.7 ml) were similar to that of egg albumin (20.3 ml). The foaming stability of the biopolymers (122 min) was higher than that of WPI/11S mixture (33.7 min) and was similar to that of egg albumin (132 min). Biodegradable films were prepared from rice bran, and their barrier and mechanical properties and solubilities were studied. Rice bran films had higher (WVP) and oxygen permeability when compared to a polyvinylidene chloride film. Puncture strength, tensile strength, breaking factor, and protein solubility of rice bran protein film at pH 9.5 were higher than those of rice bran film at pH 3.0. Rice bran protein isolate (RBPI),
containing approximately 92% proteins (with about 75% yield) was prepared from unstabilized, defatted rice bran. The molecular weight of RBPI ranged from 6.5 to 66 kda, with a majority being 45 kDa. Differential scanning calorimetry showed a denaturation temp. at 83.4 degrees C with a denaturation enthalpy of 0.96 J/g. Nitrogen solubilities of RBPI were 52.2, 62.4, 77.6, and 82.4% at pHs 2.0, 6.0, 8.0, and 10.0, respectively.
Impacts
(N/A)
Publications
- XIE, R. AND N.S. HETTIARACHCHY. 1997. XANTHAN GUM EFFECTS ON SOLUBILITY AND EMULSIFYING PROPERTIES OF SOY PROTEIN ISOLATE. J. OF
- YILDIRIM, M. AND N.S. HETTIARACHCHY. 1997. PROPERTIES OF FILMS PRODUCED BY CROSS-LINKING WHEY PROTEINS AND 11S GLOBULIN USING TRANSGLUTAMINASE. DEC. 16, 1997. "ACCEPTED FOR PUBLICATION".
- YILDIRIM, M. AND N.S. HETTIARACHCHY. 1997. BIOPOLYMERS PRODUCED BY CROSS-LINKING SOYBEAN 11S GLOBULIN AND MILK WHEY PROTEINS USING TRANSGLUTAMINASE. J. FOOD SCI. 62(2):270-275.
- GNANASAMBANDAM, R., N.S. HETTIARACHCHY, AND M. COLEMAN. 1997. MECHANICAL AND BARRIER PROPERTIES OF RICE BRAN FILMS. J. OF FOOD SCI.
- WERE, L., N.S. HETTIARACHCHY, AND U. KALAPATHY. 1997. MODIFIED SOY PROTEINS WITH IMPROVED FOAMING AND WATER HYDRATION PROPERTIES. J. OF FOOD SCI. 62(4):821-823 & 850.
- KALAPATHY, U. AND N.S. HETTIARACHCHY. 1997. EFFECT OF DRYING METHOD ON MOLECULAR PROPERTIES OF FUNCTIONALITIES OF DISULFIDE BOND CLEAVED SOY PROTEINS. J. AM. OIL CHEM. SOC. 74:195-199.
- QI, M. AND N.S. HETTIARACHCHY. 1997. SOLUBILITY AND EMULSIFYING PROPERTIES OF SOY PROTEIN ISOLATE MODIFIED BY PANCREATIN. J. OF FOOD
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Progress 01/01/96 to 12/30/96
Outputs
Soy protein based ingredients with enhanced functional properties were produced using structural modification of soy proteins by enzymatic and chemical methods. Papain hydrolysis enhanced both foaming and emulsifying properties. Papain modified soy proteins (PMSP) had enhanced foaming stability (63.3) compared to that of egg white (40.8) and unmodified soy proteins (26.7). Papain modification also resulted in a two fold increase in emulsifying activity of soy proteins (102 to 228 m2/g). The stability of cosmetic emulsion produced by 1% sodium dodecyl sulfate(SDS) enhanced from 1.25 % to 35% when 1% PMSP was included in the emulsion formulation. The stability of the SDS-soy protein complex was 28%. Protein based films with improved mechanical strength were produced from protein polymers obtained by cross-linking wheat gluten with disulfide cleaved soy proteins in the presence of 1% cysteine. Cleavage of disulfide bonds have been used to produce low viscosity adhesive
from soy proteins, and the effect of drying methods on viscosity of soy protein adhesive was investigated. Spray dried product had higher viscosity (2,200 cP) compared to freeze dried product (100 cP). A natural iron carrier with enhanced digestibility was produced by binding iron to peptides obtained by pancreatin hydrolysis of low phytate soy protein isolate (LPSPI). A three fold increase in iron content (140 ppm vs 40 ppm of native soy protein isolate) of peptides was achieved by binding iron to peptides from LPSPI.
Impacts
(N/A)
Publications
- HETTIARACHCHY, N. S., LEE, M. H., AND GNANASAMPNDAM, R. 1996. CALCIUM FORTIFICATION OF RICE: DISTRIBUTION AND RETENTION IN THE GRAIN. J. FOOD SCI. 61:195.
- HETTIARACHCHY, N.S. GRIFFIN, V. K., AND GNANASAMPANDAM, R. 1996. FUNCTIONAL PROPERTIES OF PROTEIN ISOLATE FROM WHEAT GERM. CEREAL CHEM. 73:363.
- KALAPATHY, U., HETTIARACHCHY, N. S., MYERS, D., AND RHEE, K. C. 1996. ALKALI MODIFIED SOY PROTEINS: EFFECT OF IONIC SALTS AND DISULFIDE BOND CLEAVAGE ON ADHESION AND VISCOSITY. J. AM. OIL CHEM. SOC. 73:1063.
- YILDIRIM, M., HETTIARACHCHY, N. S., AND KALAPATHY, U. 1996. PROPERTIES OF BIOPOLYMERS BY CROSS-LINKING WHEY PROTEIN ISOLATE AND SOYBEAN 11S GLOBULIN. J. FOOD SCIENCE. 61:1129.
- KALAPATHY, U., HETTIARACHCHY, N. S. 1996. EFFECT OF DRYING METHODS ON MOLECULAR PROPERTIES AND FUNCTIONALITIES OF DISULFIDE BOND CLEAVED SOY PROTEINS. J. AM. OIL CHEM. SOC. "IN PRESS".
- GNANASAMPANDAM, R., HETTIARACHCHY, N. S. AND COLEMAN, M. 1996. MECHANICAL AND BARRIER PROPERTIES OF RICE BRAN FILMS. J. FOOD SCI. "IN PRESS".
- WERE, L., HETTIARACHHCY, N., AND KALAPATHY, U. 1996. FOAMING AND WATER HYDRATION PROPERTIES OF PAPAIN MODIFIED SOY PROTEINS. J. FOOD SCIENCE. "IN REVIEW".
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Progress 01/01/95 to 12/30/95
Outputs
Soy proteins were modified using enzymatic and chemical methods to improve theirfunctionalities. High molecular weight (>200 kDa) biopolymers were prepared by cross-linking whey proteins and soybean 11s proteins using transglutaminase. Biopolymer solubility was higher than 90% below pH 3 and above pH 7. The foaming capacity (24 ml) and stability (122 min) of biopolymers were similar to that of egg albumin (20 ml, and 132 min, respectively at 0.1% protein concentration). Disulfide bonds in soy proteins were cleaved using 0.1 M Na2SO3. Modified soy proteins obtained by 14% disulfide cleavage had enhanced adhesive strength (1013 N), low viscosity (110 cP at 14% protein concentration) and improved water resistive property. Films having thickness of 150 #M were produced using 10% disulfide cleaved soy proteins and 2.5% plasticizer. Modified soy protein films had higher puncture strength (1294 g) compared to unmodified film (739 g). Water vapor permeation of modified soy
protein films (2.6 x 10-10 g/mPa) was similar to that of unmodified soy protein films (2.1 x 10-10 g/mPa). Films from modified soy proteins were smoother and more transparent compared to unmodified soy protein films.
Impacts
(N/A)
Publications
- NO PUBLICATIONS REPORTED THIS PERIOD.
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Progress 01/01/94 to 12/30/94
Outputs
Soy protein isolates were modified using enzymes (trypsin) and chemical methods (alkali treatment). Alkali treatment under varying conditions of pH/temperature included 9.0/70oC, 10.0/50oC, 11.0/50oC, and 12.0/40oC. The products obtained by trypsin hydrolysis and alkaline treatment exhibited improved adhesive and water resistive properties. A two-fold increase in adhesive properties were observed due to modification process. A moderate alkaline treatment (10.0/50oC) may be useful for producing wood adhesives from soy proteins. Protein concentrates were prepared from unstabilized and stabilized rice bran by alkaline extraction procedures. Studies concluded that qualitative and quantitative attributes of rice bran are influenced by stabilization process as indicated by decreased protein content and total yield, and changes in the amino acid make-up in the concentrates prepared from stabilized rice bran. Protein concentrates from both sources had appreciable amounts of
lysine the first limiting amino acid in cereal proteins. Degradable protein films were prepared from rice bran. Proteins extracted from rice bran were mixed with a plasticizer at levels ranging from 1 to 5% and heated to temperatures from 50oC to 80oC, and dried to produce films with thickness ranging from 0.2 to 0.4 mm. Protein ingredients from rice bran and soybeans can be used for several novel food and non-food applications including in infant formulations, as edible coatings and degradable films, and adhesives for wood industry.
Impacts
(N/A)
Publications
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