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.     

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.     

蛋白及脂肪含量对腐竹差异成膜的影响

腐竹是我国历史悠久的传统的大豆制品之一。本文以提升腐竹产量、改善其机械性能及提升其营养价值为目标,使用大豆分离蛋白及大豆油为原料,采用人工模拟豆浆体系进行成膜实验,研究蛋白含量、脂肪含量、蛋白变性程度及蛋白组分对腐竹成膜的影响。结果表明:脂质含量的提高能提升成膜速度、增加膜弹性、提高成膜的蛋白和脂肪含量,但是脂质的含量过高又会对以上指标产生一定的抑制作用。随着蛋白添加量的增加,成膜速度会随之加快、膜的硬度增大、膜的蛋白含量增高、膜的脂质含量先增后减。蛋白变性程度提高能提升成膜速度,改善膜的机械性能和营养价值。尽管蛋白组分的改变对成膜速度影响不大,但是11S/7S直接影响膜的机械性能,11S/7S越高,膜的机械性能越优秀。     

Reduction of Levels of Volatile Components Associated with the "Beany" Flavor in Soymilk by Lactobacilli and Streptococci

ABSTRACT: Methanol, acetaldehyde, ethanol, and hexanal were the 4 major volatiles detected in unfermented soymilk. Eight of the cultures of lactobacilli or streptococci completely eliminated hexanal in the soymilk during fermentation. However, there were considerable variations in the effects of the cultures on the other 3 compounds. All 8 caused significant reduction in levels of methanol. Streptococcus thermophilus OSU-2 was the only culture that significantly lowered the concentration of ethanol in the soymilk. All except Lactobacillus acidophilus C19 and Lactobacillus casei E5 significantly lowered the level of acetaldehyde. Of the cultures tested, L. acidophilus L1 offered the best potential for producing fermented soymilk with an improved volatile profile.     

Effect of Soybean Varieties and Growing Locations on the Flavor of Soymilk

ABSTRACT: The volatile compounds of soymilk prepared from 5 soybean varieties grown in 2 locations were isolated and separated by a dynamic headspace analyzer and capillary gas chromatography. The coefficient of variation for the quantitative analysis of volatile compounds of soymilk by dynamic headspace analysis was less than 3.0%. Soybean varieties and growing locations had significant effects on the volatile compounds of the batches of soymilk at α= 0.05. The higher the soybean protein, the higher was the volatile compounds of soymilk. Correlation coefficient between the protein content and the volatile compounds of the milk was 0.99. Thirty-eight volatile compounds of soymilk were identified by a combination of mass spectrometry and gas chromatographic retention times of standard compounds. Most of the identified compounds were formed by the lipid oxidation of soymilk. However, 2-pentylfuran, dimethyl disulfide, and dimethyl sulfide were formed by singlet oxygen. The beany or green flavor that makes the soymilk unpleasant or unacceptable to Westerners may be due to 2-pentylfuran, which is formed from linoleic acid by singlet oxygen. The beany flavor can be eliminated by processing the soymilk with a minimum exposure to light and air.