Functional Properties of Soy Protein Isolates Produced from Ultrasonicated Defatted Soy Flakes

This study aimed to determine the effect of pretreating defatted soy flakes with ultrasound on soy protein isolate (SPI) yield and functionality. Defatted soy flakes dispersed into water (16%, w/w) were sonicated for 30, 60 and 120 s at ultrasonic amplitudes of 21 and 84 μm_pp (peak to peak amplitude in μm), representing low and high power, respectively. The power densities were 0.30 and 2.56 W mL⁻¹, respectively. The SPI yield increased by 13 and 34%, after sonication for 120 s at low and high power, respectively. The sonication of defatted soy flakes for 120 s at the higher power level improved the SPI solubility by 34% at pH 7.0, while decreasing emulsification and foaming capacities by 12 and 26%, respectively, when compared to control SPI. Rheological behavior of the SPI was also modified with significant loss in consistency coefficient due to sonication. Some of these results could be explained by the loss of the protein native state with increased sonication time and power.     

Functional Properties of Soy Protein Isolates Prepared from Gas-Supported Screw-Pressed Soybean Meal

White flakes (WFs) are obtained from dehulled flaked soybeans by extracting oil with hexane and flash- or downdraft-desolventizing the (defatted) flakes, and WFs are the normal feedstock used to produce soy protein ingredients. Gas-supported screw pressing (GSSP) is a new oilseed crushing technology in which traditional screw pressing is combined with injecting high-pressure CO₂, thereby producing hexane-free, low-fat, high-PDI soybean meal. The objectives of the present study were to evaluate yields, compositions, and functional properties of soy protein isolates (SPIs) produced from GSSP soybean meal and to compare these properties to those of SPIs produced from WFs. GSSP meals produced SPIs in significantly higher yields (59.7–63.1% vs. 51.6–61.1%), with greater free (0.05–0.40%) and bound fat (3.70–4.92%) contents than did WFs. There were no significant differences in protein contents of the SPI; all exceeded 90% protein content (db). SPIs prepared from GSSP meals had similar or slightly lower water-solubilities compared to SPIs prepared from WFs. SPIs prepared from GSSP meals had higher water-holding capacities and viscosities, and significantly better emulsifying and fat-binding properties compared to SPIs prepared from WFs. SPIs prepared from WFs had significantly better foaming properties compared to SPIs prepared from GSSP meals, which were attributed to the lower fat contents of SPIs prepared from WFs.     

Extraction and Functional Properties of Non-Zein Proteins in Corn Germ from Wet-Milling

This study was conducted to evaluate the extractability of wet-milled corn germ protein, characterize the recovered protein and identify its potential applications. Protein was extracted from both wet germ and finished (dried) germ using 0.1 M NaCl as solvent. The method involved homogenization, stirring, centrifugation, dialysis and freeze-drying. Factors evaluated were temperature (40, 50, or 60 °C) and the presence of reducing or denaturing agents. The recovered protein was analyzed for proximate composition and functional properties. Protein recovery was greater from wet germ. For both germ samples, protein recovery was not improved by using higher temperatures; thus, subsequent extractions were done at 40 °C. Addition of 2% SDS and 1% β-mercaptoethanol to the solvent nearly doubled protein yield; but, SDS-PAGE indicated some protein denaturation. The recovered freeze-dried proteins from both germ samples were least soluble at pH 2.0–4.0, but solubility increased at higher pH values. Wet germ protein extract was more soluble than finished germ protein at all pH values; however, the finished germ protein showed much better foaming and emulsifying properties and water-holding capacity.     

氯化钙储槽蒸发器二次蒸汽的回收利用

酸钙法及氨碱废液法生产氯化钙都涉及氯化钙溶液的蒸发增浓,如何合理利用蒸汽是控制成本的关键.本文对升膜、降膜、储槽蒸发工艺的储槽外排常压、有腐蚀蒸汽的合理利用,降低了产品的蒸汽单耗,收到较好的经济效益.     

Comparison of Flavor Volatiles and Some Functional Properties of Different Soy Protein Products

Flavor volatiles profiles and some functional properties of soy protein products produced by five different extraction methods were studied. A method, consisting of Ethanol Washing and a Hydrothermal cooking Treatment, was proposed to produce a soy protein product (EWHT). Flavor volatiles profiles, emulsifying ability and whiteness of EWHT were improved in comparison with those of Acid Precipitated soy protein product (AP), soy protein product with Oil-Body Associated proteins and Polar Lipids removed (OBA/PL-less), soy protein product obtained from Countercurrent Extraction (CE) and Oil-Body Associated protein product with Polar Lipids (OBA/PL). The GC-MS and sensory analysis showed that the flavor volatiles content of EWHT was lower than that of the other soy protein products. The results from high performance size exclusion chromatography and dynamic light scattering showed that proteins with larger molecular weights and larger hydrodynamic radii were contained in EWHT, suggesting that EWHT formed soluble larger protein aggregates with a more flexible structure, thus the solubility of EWHT was similar to that of AP, OBA/PL-less and CE. The surface hydrophobicity of EWHT (994.8) was higher than that of the other soy protein products. Therefore the process for preparing EWHT can be an ideal processing method to produce soy protein with good quality relative to flavor and functionality.     

Profile and Functional Properties of Seed Proteins from Six Pea (Pisum sativum) Genotypes

Extractability, extractable protein compositions, technological-functional properties of pea (Pisum sativum) proteins from six genotypes grown in Serbia were investigated. Also, the relationship between these characteristics was presented. Investigated genotypes showed significant differences in storage protein content, composition and extractability. The ratio of vicilin:legumin concentrations, as well as the ratio of vicilin + convicilin: Legumin concentrations were positively correlated with extractability. Our data suggest that the higher level of vicilin and/or a lower level of legumin have a positive influence on protein extractability. The emulsion activity index (EAI) was strongly and positively correlated with the solubility, while no significant correlation was found between emulsion stability (ESI) and solubility, nor between foaming properties and solubility. No association was evident between ESI and EAI. A moderate positive correlation between emulsion stability and foam capacity was observed. Proteins from the investigated genotypes expressed significantly different emulsifying properties and foam capacity at different pH values, whereas low foam stability was detected. It appears that genotype has considerable influence on content, composition and technological-functional properties of pea bean proteins. This fact can be very useful for food scientists in efforts to improve the quality of peas and pea protein products.     

大豆蛋白质流变性能的研究

采用毛细管流变仪和布拉本得转矩流变仪研究了大豆蛋白质的流变性能。结果表明，在通常的挤出加工条件下，大豆蛋白质是典型的假塑性流体，其非牛顿指数在0．2－0．6之间。粘度随剪切速率、含水量的增大而减小，随蛋白质含量的增大而增大。温度对粘度的影响十分复杂，在蛋白质变性前，粘度随温度的升高而减小；蛋白质变性后，粘度明显增大；在120℃左右，粘度的动态变化剧烈。该研究结果有助于指导蛋白质基生物高分子材料的挤出加工和功能改性。     

环己醇生产中的废油回收

分析了神马集团尼龙六六盐公司环己醇装置废油回收的状况；介绍通过分罐贮存，废油分离精制的方法，大大提高环己醇装置的废油回收率。     

Effects of Tween 20 and Transglutaminase Modifications on the Functional Properties of Peanut Proteins

The effects of Tween 20 on the emulsification and gelation properties of peanut protein isolates (PPI) were investigated. The functional properties of different peanut protein products, including PPI, Tween 20-assisted aqueous extraction peanut proteins (TPP), and their transglutaminase-modified products (TG-TPP), were then compared. The results indicate that the addition of Tween 20 to the PPI resulted in higher emulsifying activity index (EAI) and emulsion stability index (ESI) values than PPI without Tween 20; however, the emulsions produced by the PPI–Tween 20 mixtures were easier to destabilize during storage. As the amount of Tween 20 was increased, both the surface hydrophobicity and gel strength of the PPI–Tween mixtures significantly decreased. TPP (containing approximately 11% Tween 20) exhibited significantly different functional properties from PPI. Compared with PPI, TPP had higher EAI and ESI values but a weaker heat-induced gelation ability. The protein solubility of TPP was markedly higher than that of PPI. Modification of TPP with transglutaminase (TGase) significantly enhanced their gelation and oil-binding properties but reduced the protein solubility and ESI value. The remarkable improvement in the gelation ability of TG-TPP was mainly attributed to the formation of high-molecular-weight protein aggregates and their conformational changes.     

Separation and Recovery of Proteins by Elution-Convection

Abstract

The design, construction, and operation of an apparatus for preparative electrophoresis is described. This apparatus employs high-resolution gel electrophoresis to separate protein components with subsequent electro-convection to effect their elution and concentration.     

CLA-Rich Soy Oil Margarine Production and Characterization

A heterogeneous catalysis method to produce 20 % conjugated linoleic acid (CLA)-rich food-grade soy oil in 2 h without solvents or gases was recently developed. The objective of this study was to produce and characterize CLA-rich soy oil margarine relative to a soy oil control and commercial margarine. CLA-rich soy oil was used to prepare margarine. The samples were characterized for firmness, rheology, thermal behavior, solid fat content (SFC) and microstructure and compared with a soy oil control and commercial margarine. The CLA-rich oil margarine firmness and rheological properties were similar to commercial margarine and provided a better texture relative to the soy oil control margarine. However, SFC, droplet size distribution and melting behavior of CLA-rich oil margarine were similar to control soy oil margarine and dissimilar to the commercial product. This suggests that hardness and rheological properties of margarine are not solely dependent on SFC and melting behavior. Lipid composition, polymorphism and microstructure differences in CLA-rich oil margarine may play an important role on the texture and rheological properties. A 7-g typical serving of the CLA-rich oil margarine will provide 0.6 g CLA. Thus five servings will provide 3.2 g/day of CLA and 185 calories/day, which is well within the maximum recommended 700–980 fat calories/day.     

Highly Thermal-Resistant and Biodegradable Textile Sizes from Glycols Modified Soy Proteins for Remediation of Textile Effluents

Poly(vinyl alcohol) (PVA) sizes are widely used in textile industry due to their excellent sizing properties on synthetic fibers and their blends. However, PVA contains non-biodegradable chemicals and is a major contributor to environmental pollution related to the textile industry. To overcome this problem, an environmental-benign and highly thermal-resistant yarn coating is fabricated from soy proteins, an agricultural byproduct. The soy proteins are chemically modified by glycols having varying chain lengths and number of hydroxyl groups. Compared with the physically modified soy proteins and their sized yarns, coating made from the soy proteins esterified by 1,4-butanediol show 91.38% increment in work of rupture at 120 °C and cotton/polyester (65/35) yarns sized by 1,4-butanediol esterified soy protein sizes have 39.91% decrease in coefficient of friction. In addition, 1,4-butanediol esterified soy sizes have a five-day biochemical oxygen demand/chemical oxygen demand of 0.476, indicating that the chemically modified soy sizes have high biodegradability in activated sludge. Successful utilization of modified soy sizes can promote large-quantity applications of soy byproducts, impelling high value addition to agricultural byproducts and sustainability of textile industry.     

Ultrafiltration of Wastewater from Isolated Soy Protein Production: Fouling Tendencies and Mechanisms

Membrane separation processes appear to be a good alternative in wastewater treatment systems. One of the biggest limitations is the decrease in permeate flux, which is caused mostly by concentration polarization and fouling phenomena. The extent of these phenomena are dependent on the interactions between the different solution compounds, membrane-solution interactions, and the operating conditions. The fouling tendencies of three different commercial tubular ceramic membranes (5, 20, and 50 kDa) during the ultrafiltration of an isolated soy protein (ISP) wastewater were evaluated through determination of the water permeate flux before and after the wastewater ultrafiltration and using Hermia's Model. The wastewater from ISP production is a complex solution characterized by a very high organic load: reaches COD values greater than 18,000 mg · L^?1. The wastewater proteins are small molecules (8 to 50 kDa) that could not be removed during the industrial processing. The recovery of these small proteins and their return to the ISP production process would result in both economical and environmental benefits by increasing the final product yield and reducing significantly the wastewater organic load. All the membranes tested presented a large fouling tendency: 65% (5 kDa membrane), 69% (20 kDa membrane) and 76% (50 kDa membrane). The best fit to Hermia's Model for all of the UF membranes was obtained by the complete blocking model.     

聚碳酸酯生产中三乙回收胺的研究

采用盐酸洗涤聚碳酸酯的二氯甲烷溶液,有机相中的三乙胺转化为盐酸盐溶于水中。盐酸洗液套用后,蒙脱土吸附处理套用后盐酸洗液中富集的三乙胺盐酸盐,再对该蒙脱土进行碱化、精馏回收三乙胺。该工艺增加了盐酸洗液的套用次数,减少了酸洗液总废水量。三乙胺回收率达70%。     

Production and Removal of Assimilable Organic Carbon Under Pilot-Plant Conditions Through the Use of Ozone and PEROXONE

Pilot-plant studies were conducted in two source waters to determine the effects of predisinfection with ozone alone and with a combination of hydrogen peroxide and ozone (PEROXONE) on the production of assimilable organic carbon (AOC) compounds. Colorado River water (CRW) and State project water (SPW) from Northern California were treated with ozone alone at applied dosages ranging from 1 to 4 mg/L and with PEROXONE at hydrogen peroxide/ozone (H₂O₂/O₃) ratios of 0.05, 0.10, 0.20, and 0.30. Ozonation of CRW with applied dosages of 1.0,2.0, and 4.0 mg/L increased AOC concentrations from 70μg C/L to 275, 350, and 224 μg C/L, respectively. Ozonation of SPW with an applied dosage of 4.0 mg/L elevated AOC concentrations from 70 to 522μg C/L.     

大豆蛋白质塑料加工和力学性能的研究

采用HAAKE扭矩流变仪研究了增塑型、还原剂和润滑剂等对大豆蛋白质塑料扭短流变性能的影响,并在此基础上,对经HAAKE密炼并模压制得的大豆蛋白质塑料力学性能作了测试。     

从生产农药的废渣中回收碳酸钾

介绍了离子交换法从生产农药三唑酮、多效唑的废渣中回收碳酸钾的新工艺。     

人造金刚石废水中锰的回收

分析了人造金刚石废水的水质,提出了用含氧氧化剂氧化法去除人造金刚石废水中Mn2+的方法。同时分析比较了在不同温度下KMnO4和NaClO两种氧化剂的投加量对Mn2+的去除率的影响。实验证明,采用KMnO4氧化酸性废水中的Mn2+,不但去除率高,而且具有很高的经济效益。     

中试原液着色特黑海岛纤维的性能及应用评估

基于前期超纤用特黑色母粒的研究基础,中试生产了原液着色特黑海岛纤维,并对其物理性能和后道应用性能进行测试与评估。16岛和37岛COPET/PA6特黑海岛纤维的断裂强力均2.9 cN/dtex,断裂伸长率均55%;纤维制备成非织造布,经过开纤后,黑度L值13,a、b值在0左右;制成超纤革后,黑度L值在12左右,与市面上染整工艺制备的超纤革的色度接近。该原液着色超细特黑海岛纤维纺丝工艺稳定,适宜进行规模化工业生产,可用于环保制革。     

Physicochemical Properties and ACE-I Inhibitory Activity of Protein Hydrolysates from a Non-Genetically Modified Soy Cultivar

Arkansas‐grown non‐genetically modified soybean cultivar, R08‐4004, was selected to prepare a protein isolate, which was treated with Alcalase for limited enzymatic hydrolysis. The objective was to optimize the Alcalase hydrolysis condition to produce soy protein hydrolysate (SPH) with high protein yield, low bitterness, and clarity for beverage applications. The degree of hydrolysis ranged between 14 and 52 % during the study at varying incubation times using two different concentrations of Alcalase enzyme. Recovery of soluble protein, between 21 and 53 %, was achieved with a decrease in turbidity. There was an increase in surface hydrophobicity (S₀) which is correlated with bitterness of SPH treated with 1.0 AU (3.2 µL/g) of Alcalase 2.4 L. The sodium dodecyl sulfate‐polyacrylamide gel electrophoresis analysis showed a distinct hydrolysis pattern in which 7S globulin and the two acidic sub‐units of 11S globulin were hydrolyzed extensively in comparison to the two basic sub‐units of 11S globulin. Limited enzymatic hydrolysis produced low molecular weight peptides <17 kDa. Among these SPHs, the one derived after 120 min incubation had the highest soluble protein yield (43 %), low S₀ value (35.4), low turbidity (0.88), and highest angiotensin‐I converting enzyme (ACE‐I) inhibition activity (66.6 %). This hydrolysate has potential use as protein rich nutraceutical for developing many non‐genetically modified food product applications.