Concentration of soy protein isolate affects starch-based confections' texture, sensory, and storage properties

The effects of increasing soy protein isolate concentration on the physico-chemical properties of starch-based grape confectionery gels were investigated using thermal, textural, and sensory analyses. Soy protein isolate decreased hardness, cohesiveness, and gumminess, demonstrating potential as a texture modifier. Increasing soy protein concentration progressively decreased the elastic properties of the starch network demonstrated by a lower G'-G" crossover frequency. High levels of soy protein also created a more homogeneous water population, one which was lost at lower temperatures compared to standard confections. An improvement in taste and texture acceptability of the confections upon addition of soy protein isolate was found by sensory analysis. Finally, physico-chemical properties were compared up to 20 d of storage at ambient temperature. Soy-containing confections demonstrated lower gumminess and cohesiveness during the entire storage period but a significant increase in hardness after 20 d of storage. PRACTICAL APPLICATION: Soy protein isolate imparted soft texture to starch-based confections on a concentration-dependent basis. Increasing soy protein isolate concentration decreased elastic properties of the starch network in starch confections and significantly improved flavor and texture. Gumminess and cohesiveness of soy protein isolate confection was lower during 20 d of storage.     

猪肉丸主要原料对其凝胶性质和感官品质的影响

研究主要原料玉米淀粉、大豆分离蛋白、肥肉、水,在不同添加量时,对猪肉丸凝胶性质中硬度、弹性、黏聚性、咀爵性、蒸煮损失率和感官品质的影响.通过质构分析和感官评价,结果表明:玉米淀粉的不同添加量对猪肉丸的硬度、弹性、黏聚性、咀嚼性、蒸煮损失率有显著差异,在添加量22％时感官评分最高;大豆分离蛋白的不同添加量对猪肉丸的硬度、弹性、咀嚼性、蒸煮损失率有显著差异,在添加量为2.0％时感官评分最高;肥肉的不同添加量对猪肉丸的硬度、咀嚼性、蒸煮损失率有显著差异,在添加量30％时感官评分最高;在水的不同添加量对猪肉丸硬度、黏聚性、咀嚼性、蒸煮损失率有显著差异,在添加量35％时感官评分最高.     

Food Powder Characteristics Important to Nonelectrostatic and Electrostatic Coating and Dustiness

ABSTRACT: Corn starch, maltodextrin, powdered sugar, cellulose, soy flour, corn flour, wheat flour, cocoa, nonfat dry milk, and salt were coated at 0, 19, and 25 kV using corona particle charging. Particle size, powder charge, density, and flow characteristics (flow index, cohesiveness, angle of repose, Hausner ratio) were correlated to coating efficiency and dustiness. Nonelectrostatic coating efficiency improved with large particle size, small powder charge, and low cohesiveness. Electrostatic coating at 25 kV improved with small particle size, low flow index, and high particle density. Dustiness decreased with large particle size-particle density interaction, high flow index, and low cohesiveness. Electrostatics improved coating efficiency 68% and decreased dustiness 65% (excluding largest salt).     

Optimization of Gluten-Free Bread Prepared from Cornstarch, Rice Flour, and Cassava Starch

ABSTRACT: The proportions of cornstarch, cassava starch, and rice flour were optimized for production of gluten-free bread (with 0% and 0.5% soy flour) to maximize specific volume (Y₁,Y₁'), crumb-grain score (Y₂,Y₂'), and bread score (Y₃,Y₃'). A central composite design involving cornstarch/cassava starch ratio (X₁) and rice flour/cassava starch ratio (X₂) was used, and 2nd-order models for Y₁ and Y₁' were employed to generate response surfaces. The maxima of response surfaces for crumb-grain score and bread score indicate that optimal gluten-free bread can be prepared from 74.2% cornstarch, 17.2% rice flour, and 8.6% cassava starch. Addition of soy flour at the 0.5% level also improved bread texture.     

κ-卡拉胶对大豆分离蛋白乳浊凝胶特性的影响

研究了κ 卡拉胶在不同pH的条件下对大豆分离蛋白乳浊凝胶质构特性和流变特性的影响。研究结果表明 ,pH 7 3条件下的乳浊体系比 pH 6 8的体系更易形成凝胶。卡拉胶质量分数为 0 0 5 %时 ,因与大豆分离蛋白发生静电吸引相互作用形成连接型凝胶而显著提高了凝胶的质构特性和流变特性。 0 2 %时则形成相分离型凝胶 ,降低了凝胶的弹性和内聚性。     

Evaluation of Corn Protein Concentrate: Extrusion Study

Functional properties of corn protein concentrate were evaluated after extrusion with a laboratory Brabender and a Wenger X-25 extruder. Bulk density, water content and hardness after rehydration were used as criteria for textural comparison among extrudates. Results indicated that corn protein concentrates resulting from either aqueous (CPC-A) or ethyl acetate (CPC-E) extraction were more suitable for extrusion applications than the one resulting from hexane extraction. A blend containing corn protein concentrate and soy flour at the ratio of 15:85 was good for chunks and granules extrusion in the pH range 7.0 - 7.3. In a dry spinning process which requires a dough with high cohesiveness for fiber formation, a blend containing 21% of corn protein concentrate, 20% soy isolate, and 59% soy concentrate at a natural pH was satisfactory.     

Effect of Relative Humidity on Coating Efficiency in Nonelectrostatic and Electrostatic Coating

ABSTRACT:  Fifteen food powders were coated on aluminum targets at 0, + 25, and –25 kV using corona electrostatic coating at 20% to 80% relative humidity (RH). The effect of RH on 3 losses, that is, targeting loss, coating loss, and transportation loss, which contribute to coating efficiency, was studied. RH had no effect on targeting loss in either nonelectrostatic or electrostatic coating. In nonelectrostatic coating, increasing RH increased coating loss for powders with particle size ≥ 297 μm, but had no effect on powders ≤ 227 μm. Large powders were free-flowing and clumped with increasing RH, and then rolled off the targets, resulting in high coating loss. RH had no effect on nonelectrostatic transportation loss for all powders, except for very high absolute humidity when capillary forces dominated. Electrostatic charging efficiency and powder resistivity decreased with increasing RH. Electrostatic coating loss for salts increased with increasing RH. At high RH, powder resistivity decreases, increasing the charge decay rate, which decreases electrostatic adhesion. Electrostatic coating loss for powders other than salts, whose resistivities are much higher than salts, was not affected by RH until 80% RH. Electrostatic transportation loss for powders other than proteins was not affected by RH. There was no significant difference between positive and negative electrostatic transfer efficiency and adhesion, except for transfer efficiency of soy protein and pork gelatin, whose high positive tribocharging values cause higher positive electrostatic transfer efficiency. A 20% to 60% RH is recommended for both nonelectrostatic and electrostatic coating.     

RHEOLOGICAL AND CALORIMETRIC PROPERTIES OF HEATED CORN STARCH-SOYBEAN PROTEIN ISOLATE DISPERSIONS

Differential scanning calorimetric (DSC) data on 10% (w/w) corn starch dispersion showed one endothermic peak and on soybean protein (SP) isolate dispersions two peaks attributed to 7S and 11S globulins. In corn starch-SP isolate mixtures, thermal transitions appear to occur independently of one another. Dynamic rheological data over 0.63–62.9 rad s^-1 revealed weak gel-like behavior of both 10% corn starch and SP isolate dispersions with magnitudes of storage modulus (G') being significantly higher than those of loss modulus (G") and both exhibiting slight frequency-dependence; G' of corn starch dispersion was higher than that of SP isolate and in mixed dispersions its magnitude decreased with increase in proportion of protein. The Maxwell model described creep-compliance data on dispersions high in corn starch, while the Burgers model described dispersions high in SP isolate. Plots of protein/starch ratio versus G' and instantaneous elastic modulus showed similar trends in phase separation and inversion.     

柠檬酸钙和大豆分离蛋白对大米淀粉质构分级的影响

目的 探究柠檬酸钙和大豆分离蛋白对大米淀粉液体食品质构分级的影响。方法 本研究通过国际吞咽障碍饮食标准(International Dysphagia Diet Standardisation Initiative, IDDSI)质构测试、物性分析、快速黏度分析及扫描电镜等技术方法分析柠檬酸钙(0.1%、0.2%和0.3%)和大豆分离蛋白(5%、10%和15%)对大米淀粉质构分级的影响。结果 IDDSI质构测试结果表明,柠檬酸钙使大米淀粉质构等级呈上升趋势(添加量为0.3%时,质构等级由2级变为3级),而大豆分离蛋白使大米淀粉质构等级呈下降趋势。物性分析(A/BE模式)结果表明,添加比例为0.3%的柠檬酸钙的淀粉样品黏度升高51.4%,添加比例为15%的大豆分离蛋白的淀粉样品黏度下降19.4%。快速黏度分析淀粉样品的终值黏度结果与物性分析的黏度结果趋势一致。粒径分析结果表明,柠檬酸钙提高了淀粉颗粒的尺寸,促进了淀粉颗粒的膨胀。大豆分离蛋白减小了淀粉颗粒的尺寸,抑制了淀粉颗粒的膨胀。红外光谱分析表明,钙盐和蛋白的添加量越大,淀粉分子之间的氢键数量减少的越明显。此外,通过扫描电镜观察到柠檬...     

蛋白质和淀粉对肉制品品质影响的研究

选取了三种蛋白(谷朊粉、花生分离蛋白和大豆分离蛋白)和三种淀粉(玉米淀粉、红薯淀粉和绿豆淀粉)作为肉制品的脂肪模拟品,经比较分析可知,大豆分离蛋白和绿豆淀粉均为肉制品的最佳脂肪模拟品.通过单因素试验和正交试验,结果表明,当大豆分离蛋白和绿豆淀粉的比例为1:4,添加量为15%(占鲜肉质量分数),水分添加量为20%时,肉制...     

Rheological study of layer cake batters made with soybean protein isolate and different starch sources

The study of new gluten-free foods suitable for celiac people is necessary since people allergic to wheat proteins are more and more frequent. This study examined the effect of using different starch sources (rice, corn, potato and wheat) and protein types (soy protein isolate, wheat protein) at different percentages (0%, 10%, 20%), on the rheological properties of batters (flow, viscoelastic and stickiness behaviour) and on batter density and cake volume. The highest consistency, viscous and elastic moduli, and adhesive force corresponded to batters made of rice starch and soy protein isolate, which showed the most similar rheological behaviour to wheat flour batters. The batters obtained showed adequate characteristics in processing and in achieving high quality products. However, the percentages of starches and proteins should be experimentally optimized in each case.     

Isolation and characterization of proteins from soymilk residue (okara)

Protein was extracted from okara at pH 9.0 and 80 °C for 30 min, giving a recovery of 53% protein. The extracted protein was isolated by isoelectric precipitation at pH 4.5, and the dried, defatted protein isolates (prepared at 25 and 80 °C) had over 80% protein.

The okara protein isolates have essential amino acid profiles similar to the FAO scoring pattern, and high in vitro protein digestibility, with methionine and cysteine as the limiting amino acids. Polyacrylamide gel electrophoresis in sodium dodecyl sulfate showed that okara protein isolates had a large quantity of high molecular weight components suggesting protein aggregation. Differential scanning calorimetry and hydrophobicity data suggested extensive protein unfolding in the okara products.

Okara protein isolates had lower solubility than a commercial soy protein isolate at both acidic and alkaline pH, probably due to protein aggregation. Other functional properties, including emulsifying, water and fat binding, and foaming properties, were found to be comparable to the commercial soy isolate.     

Viscoelastic Changes of Rice Starch Suspensions During Gelatinization

Dynamic rheometry was utilized to characterize viscoelastic changes during heat-induced gelatinization of 2 domestic rice starch suspensions, 1 from waxy and the other from indica rice. Gelatinization included 4 stages: suspension into sol, sol transition to gel, network destruction, and network strengthening. Increase in storage modulus (G') was observed as early as about 47°C. For indica rice, the maximum value (G'_max) was higher, and the decrease afterwards was slower, owing to its higher amylose content. The effects of heating time and temperature were found additive. Sealing samples with oil affected the accuracy of measurement. Finally, the network of starch gels had a larger fractal dimension than that of soy protein isolates previously investigated, suggesting firmer food texture.     

三种蛋白在青团中的复配应用研究

本研究以糯米粉、小麦淀粉、粘米粉、红薯粉、葛根粉、艾叶粉为基础配方,将大豆分离蛋白粉、乳清蛋白粉、荞麦蛋白粉分别添加其中制作青团,研究其对青团品质的影响。通过单因素实验,以3种蛋白的添加量为实验因素,研究其对葛薯糯米团的感官指标、质构指标的影响。在单因素实验的基础上,进行3因素4水平的正交实验,优化青团的配方。实验结果表明三种蛋白粉对青团的黏附性值相关系数较高,其因素影响从主到次的顺序为大豆分离蛋白、乳清蛋白、荞麦蛋白,通过Minitab软件优化得出青团最优配方为:大豆分离蛋白占混合粉的6%、乳清蛋白占混合粉的5%、荞麦蛋白占混合粉的5%。此条件下的青团蛋白质含量为17.42%,通过验证得出其黏附性较低,色泽纯正。本研究结果为工业化生产提供参考数据。     

Isolation of Tomato Seed Meal Proteins with Salt Solutions

Salt solutions were used in isolating tomato seed meal proteins. Na₂SO₃ and NaCl solutions at different concentrations, and pH were included in a central composite design to find optimum conditions of protein isolation. The highest total protein yield was achieved with water extraction (no salt present). Salt extraction at pH 7.5 produced isolates with protein content of 93.4% (NaCl 5% w/v) and 77.1% (Na₂SO₃ 0.5% w/v). Observed values were in good agreement with predicted values. Isolates extracted with different salt solutions ranged from less soluble but very resistant to heat and Ca²⁺, to very surface active with functional properties comparable to commercial soy isolates.     

Cold plasma hydrophilization of soy protein isolate and milk protein concentrate enables manufacturing of surfactant-free water suspensions. Part I: Hydrophilization of food powders using cold plasma

In this study, we found that treatment with cold plasma influenced the wetting properties of soy protein isolate and milk protein concentrate powders. Cold plasma treatment significantly decreased the apparent contact angle of the powders, indicating hydrophilization of the powders. Cold radiofrequency low-pressure plasma treatment had a larger effect on powder wettability than corona atmospheric plasma discharge. In addition, cold plasma treatment had a more noticeable effect on the wettability of the hydrophobic milk protein concentrate than on the inherently hydrophilic soy protein isolate. Both the soy protein isolate and milk protein concentrate demonstrated zero hydrophobic recovery over time. Scanning electron microscopy showed that cold air plasma treatment of food powders caused minor surface oxidation, though these changes were not observed using FTIR spectroscopy. We suggest that cold plasma treatment has important implications for the production of stabilizer-free food suspensions.     

Solubility and Foaming Properties of Phytate-Reduced Soy Protein Isolate

A pilot scale ion exchange process was developed to produce a 75 - 77% phytate-reduced soy protein isolate. The solubility and foaming properties of this isolate were compared to those of control and commercial soy protein isolates as a function of protein concentration (5 and 10%, w/v), pH (3, 6 and 9) and preheat temperature (25, 60 and 80°C). Phytate-reduced soy protein extract exhibited minimum solubility at pH 4.8 - 5.0, compared to 4.2 - 4.5 for control soy extract. Phytate-reduced soy protein isolate was most soluble and functional at pH values below its isoelectric point (pH 3), whereas control and commercial soy isolates were generally most soluble and functional at pH values above their isoelectric point (pH 6 and 9).     

Effect of powder and target properties on wrap around effect during coating

Tapioca starch, NaCl (28, 135, and 378 μm), corn starch, cocoa powder, soy protein isolate, cheese powder, wheat protein, modified starch, nacho cheese, and sugar were coated at 0 kV for nonelectrostatic and at 25 kV for electrostatic coating onto metal, wood, unoiled paper, oiled paper, unoiled plastic, oiled plastic, fresh bread, and dry bread. Powders and targets were allowed to naturally tribocharge, or all charge was removed before coating. Powder particle size, flowability, resistivity, and target resistivity were reported. Electrostatic coating produced the same or better wrap around, or percent side coverage as nonelectrostatic coating for every powder and target. The greatest electrostatic improvement was found when using powders that had the worst nonelectrostatic side coverage: large particle size (>135 μm), low resistivity, and low cohesiveness, especially on targets that had high-surface resistivity (2 × 10(5) Ωm). Tribocharging had a similar effect as electrostatic coating. In both nonelectrostatic and electrostatic coating, percent side coverage increased as powder particle size decreased, cohesiveness increased, or target resistivity decreased. In electrostatic coating, percent side coverage increased as powder resistivity increased; however, in nonelectrostatic coating, as powder resistivity increased, percent side coverage increased on only oiled plastic and dry bread. Practical Application: The evenness of powder coating on food is very important for consumer acceptability, since consumers judge food from its appearance before they have a chance to taste it. If thick food targets, such as cakes, donuts, and marshmallows need to be coated, the side coverage, due to the wrap around effect, is important. Choosing powders with small particle size, high cohesiveness and high-powder resistivity, and using electrostatic coating can produce food targets coated on all sides.     

STABILIZATION OF CALCIUM SENSITIVE PLANT PROTEINS BY κ-CARRAGEENAN

The stabilizing effect of κ-carrageenan on 0.15% solutions of coconut, glandless cottonseed, peanut and soy protein isolates was investigated at neutral pH ranges. Addition of 0.01 M calcium decreased protein stability by 75–88% in carrageenan-free solutions and only by 30% in solutions containing 0.2g carrageenan per g protein. The order of mixing carrageenan, Ca⁺⁺, and protein solutions adversely affected stability only when carrageenan was added last. Electron microscopy of stable fractions revealed the presence of many 100—500Å protein globules, both complexed with κ-carragecnan and free in solution. Protein stabilization appeared to be related to the formation of double helix junction zones by κ-carrageenan.     

添加淀粉和蛋白质对挂面力学特性的影响

通过向小麦粉中分别添加玉米淀粉、红薯淀粉、马铃薯淀粉以及大豆分离蛋白,制作挂面并对挂面的弹性模量、抗弯能力进行分析.结果表明:无论添加何种淀粉,挂面的弹性模量都会随添加量的增大而减小;添加大豆分离蛋白能使挂面弹性模量明显上升,若添加量超过0.6％弹性模量会有所回落但仍明显高于对照组.添加3种淀粉和大豆分离蛋白都会使挂面的抗弯能力下降.用断裂应力评价挂面抗弯能力比使用端部轴向位移量可靠度更高.综合考虑挂面的弹性模量及抗弯能力,挂面中玉米淀粉、马铃薯淀粉、红薯淀粉以及大豆分离蛋白的添加量分别不宜超过10％、5％、5％和0.8％.