Physicochemical and Sensory Properties of Soymilk-incorporated Bulgur

ABSTRACT Bulgur cooked in soymilk of 6% and 9% solid content had significantly ( P < 0.05) higher bulk density compared with bulgur cooked in soymilk of 3% solid content and control bulgur cooked in water. As the soymilk solid content increased, pilav bulgur yield increased whereas fine bulgur yield decreased. The SDS-extractability of bulgur proteins increases with the increase in soymilk solid content. Water absorption capacity of fine bulgur samples was affected by soymilk incorporation, and variations in oil absorption capacity were not significant ( P > 0.05). Soymilk incorporation improved color and sensory properties of pilav and fine bulgur. The results of this study suggest that soymilk can be successfully applied to bulgur production.     

生物解离对豆乳体系稳定性的研究

本文研究了碱性蛋白酶生物解离0、10、20和30 min条件下豆乳体系的粒径分布、Zeta电位、流变学特性、乳化活性及乳化稳定性的变化.并通过多重光散射稳定性分析考察豆乳体系的稳定性.研究结果表明,当生物解离20 min时,豆乳体系的平均粒径为456 nm,豆乳的粒径主要分布在100-1000 nm,随着生物解离时间的...     

高静压技术对豆浆中脂肪氧合酶的钝化效果及其动力学分析

研究了高静压技术(HHP)对豆浆中脂肪氧合酶(LOX)活性的钝化作用,并进行失活动力学分析。结果表明:HHP处理能显著钝化豆浆中LOX活性。用300～600MPa压力处理5～20min,对LOX活性有显著的钝化效果(P<0.05),并且随处理压力和处理时间的增加,酶的失活率提高。当压力500MPa,保压时间0min时也有一定的钝化LOX效果;当压力600MPa处理10min以上,豆浆LOX活性被完全抑制。用500MPa处理5min,可以达到与传统巴氏杀菌相同的钝酶效果(P>0.05)。HHP技术钝化豆浆LOX的过程可用一级动力学模型拟合(R2>0.900)。随着压力的升高和处理时间的延长,k值逐渐升高,D值逐渐减小;动力学参数ZP和Va分别为125.94MPa和-45.290cm3/mol。HHP技术在钝化豆浆中脂肪氧合酶活性方面比传统巴氏杀菌彻底,效果更好。其在改善豆浆品质方面具有良好的应用前景。     

Bioavailability of Calcium Citrate Malate Added to Microbial Phytase-Treated, Hydrothermally Cooked Soymilk

Effects of microbial phytase on bioavailability of calcium added to corn/soy diets were investigated in chickens. No effect (P > 0.17) of phytase was found for weight gain, feed intake, tibia/body weight, ash%, and ash Ca% when calcium citrate malate (CCM) was added to corn/soybean meal and corn/hydrothermally cooked (HTC) soymilk diets. Using calcium carbonate in corn/HTC soymilk diets, means for weight gain, feed intake, tibia/body weight, and ash% were less (P < 0.05) without phytase. We hypothesize that CCM is less amenable to the formation of calcium phytate complexes than are other calcium salts and, therefore, should be more effective for fortification of soymilk products.     

Formulation and Processing of a Heat Stable Calcium-fortified Soy Milk

Calcium-fortified soy milk (200 mg/100g) was formulated by adding water (85–90°C) full-fat soy flour (10%), sucrose (2.75%) and soy protein isolate (2.25%). Following homogenization, the blend was twice clarified and pasteurized at 65°C/30 min before refrigeration. Samples of the soy milk (45°C) were adjusted to pH 8 before adding calcium lactogluconate (1.55%) and varying amounts of sodium hexametaphosphate or potassium citrate. Samples with 1.25% potassium citrate the best heat stability. For successful calcium fortification, it is recommended to maintain a calcium-to-protein ratio < 38 mg/g and to use an appropriate sequestering agent at a molar ratio of 0.8/mole calcium.     

Growth characteristics of agrowaste‐immobilised lactobacilli in soymilk during refrigerated storage

We aimed at evaluating agricultural wastes as solid supports for the immobilisation of lactobacilli in a liquid media, namely soymilk. Lactobacillus acidophilus FTDC 1331, L. acidophilus FTDC 2631, L. acidophilus FTDC 2333, L. acidophilus FTDC 1733 and L. bulgaricus FTCC 0411 were immobilised on solid supports produced from durian (Durio zibethinus), cempedak (Artocarpus champeden) and mangosteen (Garcinia mangostana). The immobilised cells were inoculated into soymilk and stored at 4 °C over 168 h. Soymilk inoculated with non‐immobilised cells was used as the control. Immobilised cells showed higher survivability over 168 h compared to the control, accompanied by higher reduction of simple sugars and oligosaccharides in soymilk. Higher growth and higher utilisation of substrates also led to the higher production of lactic and acetic acids, which lowered the pH in soymilk compared to the control. Our results illustrated that agrowastes could be used as immobilisers to enhance the growth of lactobacilli in a liquid medium.     

Effect of Soybean Varieties and Growing Locations on the Physical and Chemical Properties of Soymilk and Tofu

ABSTRACT: Soybean varieties and growing location greatly affected the protein content and color of soymilk and the protein content and yield of tofu ( P < 0.05). Protein content of soybeans was the most important affecting factor for the qualities of soymilk and tofu. There were significant correlations between the protein contents of soybeans and soymilks ( P < 0.05). There were also significant correlation between the soybean protein and the total solid content of soymilk (P < 0.05). Tofu moisture content had significant effect on the hardness and yield of tofu (P < 0.05). The correlation between soybean protein and tofu yield was significant at P < 0.05. The protein content and yield of tofu can be predicted by analyzing soybean protein.     

Enzymic Transformation of Isoflavone Phytoestrogens in Soymilk by β-Glucosidase-Producing Bifidobacteria

ABSTRACT: Five strains of bifidobacteria were screened for β-glucosidase activity using p-nitrophenyl-β-D-glucopyranoside as the substrate, and selected strains were used to ferment soymilk. Enumeration of viable bifidobacteria and quantification of isoflavones using HPLC were performed at 0, 12, 24, 36, and 48 h of incubation. Four strains produced β-glucosidase. B. pseudolongum and B. longum -a displayed the best growth in soymilk, with an increase of 1.3 log₁₀ CFU/mL after 12 h. B. animalis, B. longum -a, and B. pseudolongum caused hydrolysis of isoflavone malonyl-, acetyl- and β-glucosides to form aglycones, and transformed daidzein to equol in soymilk. Fermentation of soymilk with Bifidobacterium sp. resulted in a significant increase (p < 0.05) in the concentration of aglycones.