• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.2
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• pp.156-162
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• 1990

Antimutagenic effect of doenjag (Korean fermented soy paste) on mutagenesis induced by aflatoxin B1 (AFB1) in Salmonella typhimurium strains TA98 and TA100 was studied. AFB1 revealed maximum mutagenicity at dose level of 1 $\mu$g/plate with metabolic activation system in both strains. Strong antiutagenic activity toward AFB1 was completely inhibited at the level of 50% of the doenjang extract. At the same concentration 64-66% and 39-53% of the AFB1 induced mutageneses were blocked when the methanol extracts of raw and cooked soybeans were added in the system respectively Raw soybeans showed higher ihhibition rate to the mutagenicity than cooked soybeans but the fermented soybeans(doenjang) was the most effective (p<0.05) Other soybean fermented foods such as commercial doenjang natto and miso were also exhibited some antimutagenic activities however the traditional doenjang was the most effective and then commercial doenjang. Natto and miso were less effective.

• Korean Journal of Food Science and Technology
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• v.15 no.3
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• pp.307-313
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• 1983

Soybeans ans black-eyed peas, chosen as test samples of dry beans, were subjected to soaking and cooking treatments to develop quick cookig methods and study their effects on quality of cooked products. The results of the study are summarized as follow: 1. Of the soaking methods tested, soaking soybeans in 3% sodium bicarbonate (SBC) solution and black-eyed peas in 0.5-1% SBC solution followed by cooking them in water at $95-100^{\circ}C$ required 40 minutes and 10 minutes of cooking time, respectively. When compared to 180 minutes of cooking time for soybeans and 40 minutes of that for black-eyed peas by conventional cooking method (Control), soaking dry beans in optimum SBC solutions reduced cooking time by over 80%. 2. Among cooking methods tested, steam cooking at $121^{\circ}C$ was the most effective one in reducing cooking time of soybeans (15 min.). Black-eyed peas sacked in water required 6 minutes of cooking time in 1% SBC solution at $95-100^{\circ}C$, and 5 minutes of that in steam at $121^{\circ}C$. 3. Quality of cooked beans with optimum texture was evaluated by sensory panel and Gardner Color Difference Meter. Beans cooked in steam at $121^{\circ}C$ had better overall quality than those cooked by other methods. Beans soaked in optimum SBC solution had quality as good as control, whereas beans cooked in SBC solution had worse quality than control. 4. These results indicated that cooking time of soybeans could be drastically reduced by either steam cooking at $121^{\circ}C$ or soaking in 3% SBC solution followed by cooking in water at $95-100^{\circ}C$. Cooking time of black-eyed peas could be significantly shortened by either steam cooking at $121^{\circ}C$ or soaking in 0.5-1% SBC solution followed by cooking in water at $95-100^{\circ}C$.

• Korean Journal of Food Science and Technology
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• v.16 no.4
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• pp.403-407
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• 1984

The purpose of this study was to investigate the changes of phytic acid content and phytase activity and the interactions between phytic acid and minerals in the preparation of Meju (fermented steamed soybean mash with molds). Meju contained significantly lower phytic acid and higher phytase activity than both raw and cooked soybeans. This seems to be the result of degradation of phytic acid by phytase produced during preparation of Meju by Aspergillus oryzae. Fe, Zn, Ca contents of soybeans were not changed either by cooking or fermentation. However, these minerals in the retentate of ultrafiltration were significantly lower in Meju than in raw and cooked soybeans. This result indicated that there are lower mineral-phytic acid complex in Meju than in raw and cooked soybeans, which might contribute to higher bioavailability of these minerals in Meju.

• Journal of the Korean Home Economics Association
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• v.30 no.3
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• pp.119-129
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• 1992

Black soybeans were gamma-irradiated at dost levels of 0, 2., 5, 10 and 20 kGy, and stored at room temperature for the experiments associated with cooking quality. The degree of cooking of soybeans in boiling water at 98-10$0^{\circ}C$ has been determined by measuring the maximum cutting force of cotyledon. The cutting force to reach a complete cooking was about 120~130g/g. Irradiation at 2.5~20kGy caused the reduction of cooking time in black soybeans by 30~60% compared to the nonirradiated control, and the cooking rate constant of the irradiated samples was higher than that fo the nonirradiated control sample. These results were similarly found in the stored samples for one year at room temperature after irradiation. Color characteristics of cooked samples showed no significant difference between the nonirradiated control and 5 kGy-irradiated sample. After complete cooking of black soybeans, there were not significant in the organoleptic qualities between the nonirradiated and irradiated samples.

• Preventive Nutrition and Food Science
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• v.3 no.2
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• pp.105-110
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• 1998

Color characteristic of thawed samples of frozen cooked soybean pree of selected cultivar (Gomultong) depending upon cooking temperature an dtime as well as freezing conditions were evaluated . Samples were either cooled in 4$^{\circ}C$ refrigerator (control), or frozen at - 4$0^{\circ}C$ deep freezer for 12 hrs and then stored in 4 $^{\circ}C$ refrigerator , or immersed in liquid nitrogen (LN2) and then each samples were cooked for 5, 10, 20 and 40 min at 65, 80 and 95$^{\circ}C$, respectively. Freezing effect was not significant for all color characteristics except for b. Significant cooking temperature by cooking time interacts were found for all characteristics excepts for L.

• Journal of Nutrition and Health
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• v.16 no.4
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• pp.281-286
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• 1983

The interactions of phytic acid with protein and minerals has been blamed to decrease the bioavailability of protein and minerals in soybean products. Tempeh, the traditional Infonesian fermented soybean product, was prepared to investigate the changes of phytic acid contents nesian fermented soybean product, was prepared to investigate the changes of phytic acid contents and its interactions with protein and minerals in the fermentation. The acceptability of tempeh were also studied by conducting sersory evaluation. 1) Phytic acid contents of cooked soybeans and of tempch were significantly lower than that of raw soybeans, indicating that cooking and fermentation resulted in the decrease in phytic acid content of soybeans. In tempeh the fraction of phytic acid retained after ultrafiltration was significantly lower than that in raw soybeans. 2) The total protein contents were not significantly different between raw soybeans and tempeh. Phytic acid contents per gram of protein retained ultrafiltration were significantly higher in raw soybeans than in tempeh. This result is interpreted as that raw soybeans contain higher amounts of phytic acid- protein complexes than tempeh. 3) Both of calcium and zinc contents were not significantly different among raw, cooked soybeans and tempeh. However, the retained Ca and Zn fraction after ultrafiltration were significantly lower in tempeh comparing with that in raw soybeans. Lower retention of Ca and Zn after ultrafiltration in tempeh may be the result of lower phytate content of tempeh, thereby less chance of forming mineral- phytate complexes. 4) Tempeh received the sensory evaluation scores between good and fair and the addition of garlic to tempeh significantly improved the odor, general desirability and total score.

• Korean Journal of Food Science and Technology
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• v.21 no.2
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• pp.229-234
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• 1989

Cooked soybeans were fermented with B. subtilis and B. natto for 48 hrs and 74 hrs. The odor concentrates of during these Chungkookjang fermentation were obtained with a simultaneous distillation and extraction system. The seperation and identification were carried out by GC and GC-MS. The main components of the cooked odor concentrate of soybeans were 3-methyl-1-butanol, 1-pentanol and 1-octen-3-ol etc.. In Chungkookjang (B. subtilis inoculation), 3-methyl-1-butanol, 1-pentanol and 1-octen-3-ol remained but alkyl pyrazines such as 2,5-dimethyl pyrazine, trimethyl pyrazine and tetramethyl pyrazine increased and those increased during the fermentation. In Chungkookjang(B. natto inoculation), 3-methyl-1-butanol, 1-pentanol and 1-octen-3-ol, main components of cooked soybeans decreased and alkyl pyrazines increased, especially, tetramethyl pyrazine remarkably increased during fermentation. From the result, it seems that alkyl pyrazines caused the characteristic odor of Chungkookjang and mask the beany odor.

• Food Science and Biotechnology
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• v.18 no.1
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• pp.213-217
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• 2009

In this study, the effects of processed small black soybeans on the intestinal morphological characteristics of rats were examined. Adult male rats were fed diets containing raw, cooked, or acidified small black soybean powders for 4 weeks. The total short chain fatty acid (SCFA) level was significantly higher in the acidified small black soybean supplemented group than in the raw and cooked soybean diet groups. The major SCFAs found in the experimental groups were acetate, followed by propionate and butyrate. The duodenal villus height and colonic mucosal thickness were also significantly higher in the acidified small black soybean supplemented group than in the raw and cooked soybean diet groups. The acidified small black soybean supplemented group showed the densest colonic mucosa by staining with alcian blue (AB), as compared to the raw and cooked soybean diet groups. The acidified small black soybean supplemented group exhibited strongly stained $CD4^+$ in the mucosal lamina propria, while cooked and acidified diet groups were more strongly stained $CD8^+$ in the submucosal lamina propria than the raw diet group. These results suggest that acidified small black soybeans may help improve intestinal function.

• Applied Biological Chemistry
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• v.32 no.3
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• pp.216-221
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• 1989

Soaking of soybeans and the subsequent effect on cooking kinetics were investigated by the means of puncture test and shear press with Instron universal testing machine. Soaked soybeans were water cooked at temperatures of $90{\sim}135^{\circ}C$ adjusted with oil bath. Instron puncture force of 0.15kg and shear force of 1.2kg/g-soybean were appeared as the eating soft texture by sensory evaluation. Softening activation energies of yellow soybeans for puncture and shear force were 14,540cal/g-mole and 21,374cal/g-mole. z-values were calculated as $42.1^{\circ}C$ and $37.4^{\circ}C$, respectively.

• Food Science and Biotechnology
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• v.15 no.4
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• pp.643-646
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• 2006

Cheonggukjang, a popular Korean traditional fermented soyfood, was manufactured by fermenting steamed soybeans in a temperature-controlled room by traditional methods in which steamed soy was exposed to rice straw naturally rich in Bacillus species. B. subtilus and B. licheniformis were found to be the major microorganisms present in cheonggukjang made by the traditional method. We analyzed the composition of 12 kinds of isoflavones and their glycosides present in cheonggukjang collected at various fermentation times. Total isoflavone content in raw soybeans was 2,867 mg/kg and this decreased by about 50% during cooking prior to cheonggukjang preparation. However, total isoflavone content changed slightly during 45 hr of fermentation. Total content of isoflavone glycosides, consisting mainly of daidzin, glycitein, and genistin, decreased by about 40% during 45 hr of fermenting cooked soybeans. The contents of tree isoflavones including daidzein, glycitein, and genistein showed a dramatic increase during fermentation in cheonggukjang preparation, with a 2.9-, 54.0-, and 20.6-fold increase in concentration, respectively, by the end of fermentation (45 hr). In conclusion, short-term fermentation of cooked soybeans with Bacillus species caused conspicuous changes in the composition of isoflavone derivatives, and its implication in terms of health benefits deserves further study.