• Title/Summary/Keyword: Soy protein isolate

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Effects of ${\alpha}$-Chymotrypsin Modification on the Functional Properties of Soy Protein Isolates

  • Ahn Tae-Hyun;Lee Sook-Young
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.51 no.2
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    • pp.148-153
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    • 2006
  • Effects of ${\alpha}$-chymotrypsin modification on degree of hydrolysis (DH), solubility, emulsifying capacity and thermal aggregation of laboratory-purified soy protein isolate (SPI) using a lipoxygenase-defected soybean (Jinpum-kong) and commercial soy protein isolate (Supro 500E) were compared. SPIs were hydrolyzed by ${\alpha}$-chymotrypsin at pH 7.8 and $37^{\circ}C$ for 30 min. DHs of Supro 500E and Jinpum-kong SPI were increased by ${\alpha}$-chymotrypsin modification, and DH of Supro 500E was higher than that of Jinpum-kong SPI. DH of ${\alpha}$-chymotrypsin treated Jinpum-kong SPI was similar with untreated Supro 500E and DH of treated Supro 500E was the highest. Solubility, emulsifying capacity and thermal aggregation of SPIs were increased by ${\alpha}$-chymotrypsin modification, and these changes were highly related to changes in DH. Functional properties of Supro 500E were higher than Jinpum-kong SPI in both of untreated and ${\alpha}$-chymotrypsin treated SPIs.

The effects of soybean oil and cyclodextrin on the quality characteristics and storage of frozen soy yogurt prepared from proteolytic soy protein isolate (콩기름과 cyclodextrin 첨가량이 효소처리한 분리대두단백으로 제조한 frozen soy yogurt의 품질특성 및 저장성에 미치는 영향)

  • Lee Sook-Young;Park Mi-Jung
    • Korean journal of food and cookery science
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    • v.21 no.1 s.85
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    • pp.18-23
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    • 2005
  • The effects of soybean oil and cyclodextrin were studied on the quality characteristics and storage of frozen soy yogurt prepared from proteolytic soy protein isolate. The viscosity and overrun of frozen soy yogurt were improved by the addition of soybean oil and cyclodextrin. Upon the addition of cyclodextrin, there was a decrease in the peroxide value of yogurt with subsequent increase by the addition of soybean oil during frozen storage. During the process of storage, there was an increase in the acetone and diacetyl contents, but methanol, ethanol and butanol contents decreased. However, the value of hexanal content was not consistent in the obtained results. Sensory characteristics of frozen soy yogurt such as mouth feel, and overall quality were improved by the addition of cyclodextrin and remained the same frozen storage at $-20^{\circ}C$ for 30 days.

The quality characteristics of frozen soy yogurt prepared with soy protein isolate, industrial proteases and commercial mixed cultures (산업용 단백분해효소로 처리한 분리대두단백과 혼합균주의 종류가 frozen soy yogurt의 품질특성에 미치는 영향)

  • Lee Sook-Young;Park Mi-Jung
    • Korean journal of food and cookery science
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    • v.20 no.6 s.84
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    • pp.658-666
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    • 2004
  • In order to develop and commercialize high quality frozen soy yogurt, the effects of industrial proteases and commercial mixed cultures were examined on the functional properties and the sensory attributes of frozen soy yogurt. For quality improvement, soy protein isolates were primarily hydrolyzed by either Flavourzyme or Neurtrase, industrial Proteases, to reduce the beany flavor and increase the functional properties of the protein. The viable cell count of lactic acid bacteria was higher in the soy protein hydrolysates than whenuntreated. ABT-5 (L. acidophilus, Bifidobacterium lactis, and S. thermophilus) resulted in higher acid tolerance, bile acid tolerance and melt-down percent values than those with YC-X11 (Lactobacillus bulgaricus and Streptococci thermophilus). The overrun of frozen soy yogurt was improved by both Flavourzyme $(193.3\%)$ and Neurtrase $(156.7\%)$ treatments. With regard to thesensory characteristics, Flavourzyme improved the beany flavor, astringency taste, mouth feel and overall quality of frozen soy yogurts fermented with ABT-5. Further studies onproduct formulation will be needed to commercialize the frozen soy yogurt for the market.

Quality Characteristics of Soy Ice Creams as Affected by Enzyme Hydrolysis Times and Added Calciums (효소처리시간과 칼슘의 종류를 달리한 칼슘강화 콩아이스크림의 품질특성)

  • 김지영;이숙영
    • Korean journal of food and cookery science
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    • v.19 no.2
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    • pp.216-222
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    • 2003
  • The effects of hydrolysis times and calcium source additions (calcium lactate, calcium carbonate), on the qualify characteristics of soy ice cream prepared with soy protein isolate(SPI), were studied. Increasing the hydrolysis time decreased the viscosity and overrun of soy ice creams, but increased the melt-down property. The addition of calcium lactate increased the viscosity of the soy ice cream mix, but no changes were observed from the calcium carbonate addition. The overrun of calcium lactate samples was higher than on addition of calcium carbonate. The addition of calcium lactate and calcium carbonate resulted in decreased melt-down properties, although these effects were more evident in the calcium lactate samples. However, calcium carbonate addition resulted in higher scores in the overall quality of the soy ice creams. In conclusion, better soy ice cream could be prepared by treating the SPI with Flavorzyme for 50 min, along with calcium fortification in the form of calcium carbonate.

Characterization of Cinnamaldehyde-Supplemented Soy Protein Isolate Films

  • Kim, Ki-Myong;Hanna, Milford A.;Weller, Curtis L.;Cho, Sung-Hwan;Choi, Sung-Gil
    • Food Science and Biotechnology
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    • v.15 no.4
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    • pp.631-634
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    • 2006
  • Soy protein isolate (SPI) films were supplemented with cinnamaldehyde (CA) at concentrations of 0.1-0.5 mL/5 g SPI. The effects of CA on film color, tensile strength (TS), percent elongation at break (E, %) and water vapor permeability (WVP) of SPI films were investigated. Generally, total color difference (${\Delta}E$), WVP, and TS of SPI films increased gradually, while E and TSM decreased significantly (p<0.05) as the amount of cinnamaldehyde in the SPI films increased. Cinnamaldehyde can be used as a potential cross-linking agent for preparing SPI films by improving mechanical strength and water resistant properties.

Bio-film Composites Composed of Soy Protein Isolate and Silk Fiber: Effect of Concentration of Silk Fiber on Mechanical and Thermal Properties

  • Prabhakar, M.N.;Song, Jung Il
    • Composites Research
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    • v.27 no.5
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    • pp.196-200
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    • 2014
  • A novel, simple and totally recyclable method has been developed for the synthesis of nontoxic, biocompatible and biodegradable bio-composite films from soy protein and silk protein. Bio films are defined as flexible films prepared from biological materials such as protein. These materials have potential application in medical and food as a packaging material. Their use depends on various parameters such as mechanical (strength and modulus), thermal, among others. In this study, prepare and characterization of bio films made from Soy Protein Isolate (SPI) (matrix) and Silk Fiber (SF) (reinforcement) through solution casting method by the addition of plasticizer and crosslinking agent. The obtained SPI and SPI/SF composites were subsequently subjected to evaluate their mechanical and thermal properties by using Universal Testing Machine and Thermal Gravimetric Analyzer respectively. The tensile testing showed significant improvements in strength with increasing amount of SF content and the % elongation at break of the composites of the SPI/SF was lower than that of the matrix. Though the interfacial bonding was moderate, the improvement in tensile strength and modulus was attributed to the higher tensile properties of the silk fiber.

Preparation of Seaweed Jelly(Muk) with Sea Mustard (Undaria pinnatifida) and Sea Tangle(Laminaria japonica) -3. Muks Prepared with Soy milk or Soy Protein Isolate- (미역과 다시마를 이용한 해조묵제조 -3. 두유혼합묵과 분리대두단백질 혼합묵-)

  • JUNG Yong-Hyun;COOK Joong-Lyoul;CHANG Soo-Hyun;KIM Jong-Bae;KIM Geon-Bae;CHOE Sun-Nam;KANG Yeung-Joo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.28 no.3
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    • pp.325-330
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    • 1995
  • Seaweed Jellys(Muks) were prepared with sea mustard and sea tangle, Optimum conditions for preparation of seaweed Muks with soy protein were investigated. Gel strength of Muks with sea mustard and soymilk decreased as the quantity of soy milk increased, and increased as the moisture content of soy milk had been decreased. Optimum mixing ratio of seaweed and soy milk was 7 : 1 and optimum temperature of gelation was $65^{\circ}C$. Gel strength of seaweed Muk mixed $5\%$(w/w) of soy protein isolate was higher$(900g/cm^2)$ than those of seaweed Muks with and without soy milk.

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Effect of succinylation on functional properties of soy protein isolate and qualities of soy bean curd (Succinyl화가 대두 단백질의 기능성과 두부의 품질에 미치는 영향)

  • 김수희
    • Journal of the Korean Home Economics Association
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    • v.28 no.4
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    • pp.41-50
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    • 1990
  • Soy protein was isolated from Korean soy bean 'Chang ryub' and chemically modified with succinic anhydride. Functionality of the soy protein isolate(SPI), succinylated SPI(SPPI), and PP590(commercial) at various pH were investigated. The mechanical and sensory properties of soy bean curds made from several mixing ratio of succinylated soy bean milk were observed. The solubility of SPI significantly increased with succinylation. The solubility of PP590 was lower than that of SSPI. The solubility of SPPI increased significantly in 0.03M CaCl2 solution. The emulsifying activity of SSPI increased. On the range of pH above pI the emulsifying activity of PP590 was higher than that of SPI. There was no difference in emulsion stability among the groups. The foam expansion capacity of SPPI increased at higher pH than pI but the foam stability decreased significantly above pH 9. Mechanical texture profile analysis revealed the modified soy bean curds had the lower hardniss, chewiness and cohesiveness with increased modification. The mechanical characteristics of modified soy bean curds revealed generalized Maxwell Model of 7-elements or 5-elements. In sensory evaluation, the hardness, the springiness and acceptability of modified soy bean curds were lower significantly than those of control soy bean curd.

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Effect of ${\gamma}-irradiation$ on the Physicochemical Properties of Soy Protein Isolate and Whey Protein Concentrate (감마선 조사가 Soy Protein Isolate와 Whey Protein Concentrate의 이화학적 성질에 미치는 영향)

  • Cho, Yong-Sik;Song, Kyung-Bin
    • Korean Journal of Food Science and Technology
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    • v.31 no.6
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    • pp.1488-1494
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    • 1999
  • Effect of ${\gamma}-irradiation$ on the SDS-PAGE pattern, secondary structure content, the solubility of commercial soy protein isolate (SPI) and whey protein concentrate (WPC) was investigated. The change in the subunit molecular weight of SPI and WPC irradiated in aqueous solution or dried state was studied using SDS-PAGE. The SDS-PAGE pattern of SPI irradiated in aqueous solution revealed the fragmentation and aggregation of the subunit protein. For WPC irradiated in aqueous solution. fragmentation of the subunit protein up to 10 kGy was observed. In contrast, ${\gamma}-irradiation$ of SPI and WPC in dried state did not cause any significant changes in the SDS-PAGE pattern. The change In the secondary structure of irradiated SPI and WPC solution was studied using circular dichroism. The aperiodic structure content of SPI and WPC solution increased at higher irradiation doses, which suggests that ${\gamma}-irradiation$ caused the disruption of the ordered structure of SPI and WPC solution. Gamma-irradiation also caused the change in solubility of SPI and WPC in dried state.

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Extending Shelf-life of Rice Cake Using Coating Agent Containing Soy Protein Isolate (찹쌀떡의 보존기간 연장을 위한 대두단백질 코팅제의 특성)

  • 박상규;조지미;이유석;이종욱
    • Food Science and Preservation
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    • v.8 no.2
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    • pp.181-186
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    • 2001
  • The objective of this study is to determine the effect of soy protein isolate (SPI) film coating on the color, firmness, viscosity and weight loss of Rice Cake stored at 15, 20 and $25^{\circ}C$ (RH 50%) for 30 days. Raw materials mixed with SPI and cocoa powder (10:0, 7:3, 5:5, 3:7, w/w) were prepared. After adding sugar and shortening to raw materials, the mixture were refined to 25 micron of particle size. Coating of Rice Cake were carried out at $65^{\circ}C$. SPI coated Rice Cake had higher internal and external firmness comparing to the control at $25^{\circ}C$. SPI coated Rice Cake showed smooth surface morphology and had 0.71-1.01 mm of thickness. SPI coated Rice Cake showed less weight loss for 30 days compared to controls. SPI coating solution was successfully coated on Rice Cake and extended shelf-life over 15 days at room temperature.

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