热处理及植酸与脂肪对豆浆中大豆蛋白凝胶体系的影响研究进展

豆浆由于其优异的特性已经成为大豆食用的重要形式。热加工处理在豆浆加工工艺中起到至关重要的作用,不同程度的热处理会使豆浆中大豆蛋白发生不同程度的变性,从而会影响豆浆加工后产品的品质与特性。本文综述了近年来豆浆加工工艺中不同热处理条件对大豆蛋白结构、组分及其凝胶特性的影响规律,钙、镁、植酸盐、脂肪与大豆蛋白的互作对豆浆混合体系解离缔合行为的影响,并对豆浆及其产品加工行业和相关领域发展提出展望,以期为我国当前豆浆加工行业的发展提供参考。     

Effect of soy protein subunit composition and processing conditions on stability and particle size distribution of soymilk

The influence of soy protein subunit composition on the particle size distribution and solid content of soymilk and various supernatant fractions was investigated. A well-established seed variety (Harovinton), containing all protein subunits, and eleven null soybean genotypes lacking specific glycinin and β-conglycinin subunits were investigated, to determine the effect of protein composition on the physico-chemical characteristic of soymilk. Soymilk made from Harovinton and soybean lines null in glycinin showed significantly higher total solid yields than the other genotypes evaluated. Soymilks prepared from soybeans null for glycinin or lacking glycinin's group I (A₁, A₂) showed a smaller particle size distribution compared to soybean lines containing glycinin. In general, unheated soymilk made from lines having glycinin showed a bimodal size distribution with large particles, with a decrease in the particle size distribution after heating and heating with homogenization. The results of this work will help in the evaluation of breeding lines with a specific protein composition tailored to a specific processing functionality.     

Selected odor compounds in cooked soymilk as affected by soybean materials and direct steam injection

ABSTRACT:  Soy odor is a major concern in the consumption of soymilk by Western consumers. The objectives of this study were to determine selected soy odor compounds as affected by soybean materials and direct steam injection and to determine if the steam-injection method affected overall cooked soy aroma of the soymilk and compared to the soymilk cooked by a traditional indirect method. Five varieties of soybeans with or without lipoxygenases were processed by direct-steam injection for up to 20 min at 100 °C. Eight selected odor compounds were analyzed by gas chromatography after extraction using a solid-phase micro-extraction (SPME) method. Hexanal, hexanol, 1-octen-3-ol, 1-octen-3-one, and trans-2-nonenal decreased whereas 2-pentylfuran and trans-2, trans-4-decadienal increased by boiling up to 20 min. The results showed that soybean variety was a significant factor to affect odor compositions. Direct steam injection cooked soymilk resulted in lower odor contents than a traditional indirect cooking method. The advantage of having a low odor composition in the heated soymilk products made from lipoxygenases-null soybean varieties could be attained by using normal soybean materials with direct steam injection.     

发酵豆制品的抗氧化活性研究

采用测定抗氧化活性值(AOV值)的方法,比较了市售几种豆制品的抗氧化活性。用不同的乳酸菌和霉菌菌株发酵豆乳,在不同的发酵温度和时间下,研究发酵豆乳的抗氧化活性变化。结果表明,豆制品水溶性组分的AOV值高于醇溶性组分的AOV值;发酵豆制品的抗氧化活性明显高于非发酵豆制品;乳酸菌和霉菌发酵都能够使豆乳的抗氧化活性提高,不同菌株提高的程度不同,霉菌发酵提高的程度更大。温度对总状毛霉和乳酸菌发酵豆乳的抗氧化活性变化有影响。     

增稠剂和乳化剂对豆浆稳定性的影响

为增加豆浆的稳定性,采用测定豆浆稳定系数、表面张力及进行感官评分的方法筛选适合用于豆浆样品的增稠剂和乳化剂,确定了最适宜的豆浆增稠剂和乳化剂的种类及其用量。经过黄原胶、刺槐豆胶、卡拉胶、结冷胶和海藻酸钠的单因素实验,黄原胶和刺槐豆胶的复配实验及黄原胶、刺槐豆胶和乳化剂(单硬脂酸甘油酯和蔗糖脂肪酸酯)的正交实验得出以下结果:黄原胶和刺槐豆胶对增加豆浆稳定性有着较好的效果,当它们的质量浓度分别为0.2g/L时,其稳定系数分别为0.737、0.742。单硬脂酸甘油酯和蔗糖脂肪酸酯复配后HLB=8、质量浓度为2g/L时,豆浆样品的稳定性最好,表面张力为41.7mN/m。当黄原胶、刺槐豆胶、乳化剂质量浓度(单硬脂酸甘油酯质量∶蔗糖脂肪酸酯质量=7∶4)分别为0.14、0.14、2g/L时豆浆的稳定性最好,此时豆浆样品的稳定系数为0.879,表面张力为41.6mN/m,感官评分为96。     

RELATIONSHIPS BETWEEN SOYBEAN COMPONENTS AND TOFU TEXTURE1

Tofu was prepared from samples of Amsoy 71 and Vinton or Vinton 81 soybeans grown in different environments. Relationships between soybean, soymilk and tofu protein, lipid, phytic acid, calcium, copper and iron were examined. All components except lipid in soybeans were significantly correlated with the same component in soymilk, but only phytic acid, copper and iron were significantly correlated in soybeans and tofu (moist basis). When relationships were examined on a dry basis, soybean and tofu protein were significantly correlated (r = 0.93). Soybean phytic acid was significantly correlated with tofu calcium (r = 0.90). Tofu calcium and hardness (r = 0.73) and springiness (r = 0.83). were significantly related, and tofu protein was significantly related to fracturability (r = 0.75). The higher-protein varieties (Vinton/Vinton 81) generally produced tofu that had a higher protein content and a firmer, more springy texture than that of the Amsoy 71 beans. Phytic acid may preferentially bind the calcium coagulant, altering the curd structure and the yield, composition and texture of the resulting tofu.     

The effects of freezing on soybean microstructure and qualities of soymilk

This study was to investigate the effects of freezing on soybean microstructure and the qualities of soymilk made from the soybean by direct grinding in water without soaking. Transmission electron microscopic (TEM), particle size distribution determination and SDS–PAGE were used for the examination. TEM images showed that freezing treatment could induce the coalescence of protein storage vacuoles (PSVs) and oil bodies. Particle size distribution showed a trend that prolonging of freezing could decrease the average particle size of soymilk and increase the extraction efficiency of soybean. SDS–PAGE showed that extractable proteins were mainly composed of glycinin and β-conglycinin even after freezing. After freezing, soybean could be easily stored and could be used to make soymilk without soaking. The soymilk had a higher solid content and better stability than the soymilk from soybean without treatment. Thus, this study provided a convenient and short-time way to process soymilk at home.     

摄食不同来源磷脂对大鼠脂质代谢及脑内磷脂脂肪酸组成的影响

研究了摄食不同来源磷脂对大鼠脂质代谢及其脑内磷脂脂肪酸组成的影响。雄性SD大鼠按体重随机分为大豆油对照组(添加9%)、牛乳磷脂组(添加5%)、大豆磷脂组(添加5%)、蛋黄磷脂组(添加5%),喂食3周。检测了血清总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)、游离脂肪酸(FFA)及肝脏TC、TG、磷脂(PL)的含量,并用气相色谱法测定了脑内磷脂脂肪酸的组成变化。结果显示:与大豆油对照组相比,3种磷脂均不同程度提高了大鼠体重、脏器指数,蛋黄磷脂效果显著;3种磷脂不同程度降低了血清TC、TG和FFA含量,牛乳磷脂降低血清FFA显著,大豆磷脂降低血清TC、TG显著,蛋黄磷脂降低FFA显著,大豆磷脂显著提升了血清HDL-C含量;3种磷脂不同程度降低了肝脏TC、TG、PL含量,牛乳磷脂与大豆磷脂降低肝脏TG、TC显著,而蛋黄磷脂降低肝脏TG显著;3种磷脂对脑内磷脂脂肪酸组成的影响各不相同,牛乳磷脂显著提高了脑内磷脂饱和脂肪酸含量,而大豆磷脂和蛋黄磷脂提高了DHA等多不饱和脂肪酸含量。研究表明,3种磷脂均有降血脂、肝脂作用,以大豆磷脂作用尤为明显,大豆磷脂和蛋黄磷脂的益智作用可能优于牛乳磷脂。     

豆浆制备过程中大豆脂肪氧化酶的抑制与豆腥味量的关系

探讨大豆加工制备豆浆的过程中,有效抑制大豆脂肪氧化酶对降低豆腥味量的影响,为生产低含量豆腥味的豆浆提供理论与技术支持.通过抑制大豆脂肪氧化酶实验,即热水研磨大豆、热处理或化学处理大豆原料后再沸水研磨、大豆脱皮后隔氧研磨,对得到的豆浆样品采用静态顶空气相色谱质谱法测定13种豆腥味物质,比较定量数据获得最佳抑制脂肪氧化酶的...     

DEVELOPMENT AND PROPERTIES OF SOYBEAN SPREADS

Soybean spreads were developed by concentrating soymilk with the addition of sugar, sorbitol, sodium citrate, carrageenan and refined bleached and deodorized (RBD) palm olein. Soymilk was prepared by 3 extraction methods: soaking in water (control), blanching at 85C with sodium bicarbonate (NaHCO₃) solution and acid treatment using HCl. Three different types of soybean spreads were developed using these soymilks. The spreads were evaluated for their proximate composition, pH, water activity (A_w), color, spreadability, sensory characteristics and storage stability. Sensory and spreadability results showed that soybean spread from blanched and alkali-treated soymilk was most acceptable and showed better spreadability than the others. It was more yellowish in color, possessed lower A_w and firmer texture. The shelf-life of all three types of spreads at refrigerated temperature were at least 30 days.