• Journal of the Korean Society of Food Science and Nutrition
• /
• v.21 no.1
• /
• pp.29-35
• /
• 1992

Total lipids of Korean black soybean (Glycine man Merr) during soaking in water were extracted, purified and fractionated into three lipid classes, and then lipid contents and their fatty acid compositions were investigated. The lipids of the beans consisted of 89.1% neutral lipids, 1.5% glycolipids and 9.4% phospholipids, and these fractions did not change significantly during the soaking period. The neutral lipid fraction of the beans contained 92.1% triglyceride, 3.0% sterol esters and hydrocarbons, 2.8% diglyceride, 1.5% free fatty acids, 0.3% free sterols and 0.3% monoglyceride, and no significant changes were found in the composition of neutral lipid fraction from the soaked beans. Major components of the glycolipid fraction were esterified steryl glycosides (43.6%), steryl glycosides (26.6%) and digalactosyl diglycerides (14.5%), and these fractions did not change significantly during the soaking period. On the other hand, phosphatidyl choline (41.6%) and phosphatidyl ethanolamine (39.5%) were most abundant components found in the phospholipid fraction, and the contents of phospholipids changed a little during the soaking period. Linoleic acid, oleic acid and palmitic acid were the major fatty acids found in total lipids, neutral lipids, glycolipids and phospholipids. A few changes in the major fatty acid compositions of phospholipids were observed during the soaking period.

• Journal of the East Asian Society of Dietary Life
• /
• v.15 no.6
• /
• pp.752-758
• /
• 2005

This study examined growth and sensory characteristics of soybean sprout cultured at $25\pm1^{\circ}C$ for 4 days with distilled water(control) and green tea extract(0.03 and $0.05\%$). Initial germination rate was higher when soaking in green-tea extract than in the control. The proper concentration of green-tea extract was $0.03\%$. The growth of soybean sprout in $0.05\%$ green-tea extract was better than the control for the hypocotyl thickness and mot hair. Soybean sprout grown with green-tea extract were better than that with control inappearance, flavor, texture and over-all acceptabilitty.

• Korean Journal of Food Science and Technology
• /
• v.35 no.6
• /
• pp.1098-1103
• /
• 2003

Soybeans released proteins when immersed in water at $50{\sim}60^{\sim}C$. We investigated the changes in the characteristics of soybean when soaked in water at different temperatures and studied the electrophoretic properties of soy proteins in recommended Korean soybean varieties after heat treatment. Soybean seeds were heated in soaking water at temperatures of 30, 40, 50, 60, $70^{\circ}C$ for 90 min, and also from 10 to 150min at $60^{\circ}C$. The pH value of the water decreased with heating time at $60^{\circ}C$, and the amount of soluble solids increased with temperature and heating time. The protein concentration of the solution increased with temperature and time. From SDS-PAGE of the proteins in soaking water, we detected two new bands of 16 kDa- and 31 kDa-proteins from the Korean soybean varieties on heat treatment.

• Korean Journal of Food Science and Technology
• /
• v.22 no.2
• /
• pp.116-122
• /
• 1990

In order to improve the shelf life of Tofu, the effect of calcium chloride or acetic acid as coagulants were investigated for microbial and physicochemical changes during the storage in different kinds of soaking solution. The soaking water of Tofu prepared from calcium chloride was found to be spoiled after 15-17 hours of storage at $30^{\circ}C$, by reaching the bacteria count to 10million per ml. The shelf life of the Tofu prepared from acetic acid was better than those prepared by calcium chloride. For the effect of soaking solution on storage life, soaking Tofu in 0.1% acetic acid was found to be more effective than soaking in other solutions of 3% NaCl or 0.1% K-sorbate. The optical density of soaking solution of Tofu increased in proportion to spoilage, and in case of soaked Tofu in 3% sodium chloride and 0.1% K-sorbate solution, it greatly increased. Titratable acidity, and amino nitrogen contents in soaking solution increased as spoilage of Tofu progressed, but pH decreased the early period, one or two days, of stored Tofu and then increased.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.25 no.5
• /
• pp.796-803
• /
• 1996

Gamma irradiation was applied to soybean(Glycine max.), Hwangkeum, at dose levels of 0, 5, 10 and 20 kGy to improve the physical properties of soybeans. The time to reach a fixed moisture content was reduced depending on the increment of soaking temperatures and applied irradiation dose levels. Irradiation at 5~20 kGy resulted in reduction in soaking time of the soybeans by about 3~6 hrs at soaking temperature of $20^{\circ}C.$ The degree of cooking of soybeans in boiling water was determined by measuring the maximum cutting force of cotyledon. The cutting force to reach complete cooking was about 145g/g. Irradiation at 5~20 kGy resulted in a reduction of cooking time of soybeans by 55~75% as compared to the nonirradiated soybean. In electron microscopic observation of seed coat inner, the parenchyma of nonirradiated soybean showed tight fibrillar structure, whereas that of irradiated soybeans showed loosened and deformed structure. The microstructure of compressed cells and cotyledon epidermis was also deformed by gamma irradiation. In subcellular structure of cotyledon, the roundness of protein body was deformed and changed to spike shape at 20 kGy. Also, the size of lipid body decreased as the irradiation dose levels increased.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.33 no.3
• /
• pp.603-608
• /
• 2004

Traditional Jeju tofu with a hard texture was manufactured by traditional method with a compounded coagulant. The processing condition for industrial production was optimized by determining soaking of soybean, extraction and heat treatment of soymilk as well as concentration and composition of coagulant. Maximum yield of soymilk was obtained by grinding one part of soaked soybean with eight parts of water, and the soluble solid of soymilk was about 8$^{\circ}$Brix. The free thiol group in soymilk was maximally exposed by heating at 10$0^{\circ}C$ for 2 min. A vacuum cooker for heating soymilk was effective for the improvement of yield and texture properties of tofu. The hardness of traditional Jeju tofu was obtained by increasing pressing time and drying by a fan instead of soaking in cold water. Optimization of a traditional tofu production resulted in the increase of total yield and improvement of quality control. Texture of traditional Jeju tofu prepared in industrial production scale was analyzed by instrumental analysis and sensory evaluation. Traditional Jeju tofu showed higher score in the hardness, roasting taste and overall preference compared with a commercial tofu, showing significant difference in 5% significant level..

• Korean Journal of Food Science and Technology
• /
• v.18 no.5
• /
• pp.398-405
• /
• 1986

The food quality of lupin seed, i.e. soaking, cooking, sprout growing and mold growing for fermentation, was investigated by using the seed of Lupinus angustifolius harvested in Western Australia. A method to produce lupin seed protein concentrate (LPC) was developed, and the wage of LPC in Korean food system was investigated. The water soaking rate of lupin seed was faster than that of soybean, but the cooking rate of lupin seed was much slower compared to soybean. The thermal softening time, $D_{100}$, was 345 min for lupin seed and 84 min for soybean. A two-phase solvent extraction system consisting of haxane-alcohol-water could effectively remove the residual bitter taste, lipid and yellow pigments of lupin seed flour, and the resulting LPC contained over 50% protein and had bland flavor and milky white color. Treatment of LPC with carbohydrate decomposing enzymes resulted in a product of more soluble and higher concentration of protein. Methods to produce lupin seed vegetable milk and lactic beverages from LPC products were discussed.

• Journal of the Korean Society of Food Culture
• /
• v.13 no.1
• /
• pp.9-17
• /
• 1998

The objective of this study is to provide a fundamental data to improve meals of the college foodservice operations serving more than 300 meals per day through evaluating changes in; total vitamin C contests, water contents, and pH, in the process of handling such foods as soybean sprout cooked and of fresh vegetable salads. This study, also, tried to identify nutrition reduction, step by step, to minimize nutrition loss. 1. In handing COOKED SOYBEAN SPROUTS, total vitamin C contents were higher after wash(1.54%mg%) than other cooking methods adopted in university meals(1.08mg%), however, total vitamin C contents was significantly lost during boiling step. 2. Significant loss of total vitamin C and water content in the FRESH VEGITABLE SALADS was detected in the process of washing and cutting vegitables. Especially,'cabbage' lost 20% of total vitamin C in the process of 'soaking in water', which was one of preparation process 3. Significant loss of vitamin C was observed after 6 hours of HOLDINC AFTER COOKING but it can be reduced through holding under lower temparature, in case of soybean sprouts and fresh vegitable salads. pH became acidic as holding time expanded. WATER CONTENT of cooked soybean sprouts decreased up to 4 hours holding time, however, it increased when we checked at after 6 hours' of holding time. Water content continuously decreased up to 6 hours of holding time in case of FRESH VESITABLE SALADS with the statistically significance level.

• The Korean Journal of Food And Nutrition
• /
• v.32 no.6
• /
• pp.643-650
• /
• 2019

The purpose of this study was to investigate the quality of dehulled soybean (DHSB), and the rapid preparation possibility of soybean milk with DHSB (SM-DHSB), and then the quality of SM-DHSB. In DHSB, the moisture content decreased, the crude protein, crude fat, minerals, and carbohydrate contents increased, and the isoflavone (daidzein, genistein and glycitein) content was similar to that of soybean (SB). The water absorption rate of DHSB for soybean milk preparation was higher than that of SB. In the results of SM-DHSB and soybean milk (SM) qualities, the crude protein content, total solid content, and the viscosity of SM-DHSB were higher, the yield and the proximate composition (except crude protein) were similar, and the Biji production rate, and total dietary fiber content of SM-DHSB were lower compared to the SM. In terms of the isoflavone contents of SM-DHSB, daidzein and genistein content were similar, and glycitein content was lower compared with the SM. Consequently, these results suggest the possible use of DHSB for rapid SM-DHSB preparation, because the soaking time was decreased by the high water absorption rate of DHSB in the SM preparation, and the quality of SM-DHSB improved compared to those of the SM.

• Korean Journal of Food Science and Technology
• /
• v.49 no.4
• /
• pp.415-420
• /
• 2017

Soybean sprouts are the third-most consumed vegetable in Korea. Several studies on cultivation techniques, including use of medicinal plants extracts, have been performed to enhance the quality and yield of soybean sprouts. The objective of the present study was to investigate the effect of lacquer, a medicinal plant extract, on the yield and nutritional value of soybean sprouts. Linolenic acid content was significantly (p<0.05) increased in the sprouts produced by soaking seeds in lacquer extract diluted with equal volume of water. Lacquer extract significantly increased the flavonoid and phenolic contents (p<0.05). The content of total free amino acids, including ${\gamma}$-aminobutyric acid, was higher in lacquer extract-treated sprouts than in the untreated control. Results of this study suggest that lacquer extract could be used for enhancing the yield and nutritional values of soybean sprouts.