• Korean Journal of Food Science and Technology
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• v.47 no.5
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• pp.593-598
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• 2015

This study determined the thermal resistance of Bacillus cereus, Escherichia coli O157:H7, and Listeria monocytogenes in multi-grain soymilk and proposes processing conditions that meet the national standard for retort food products in Korea. D and z values were calculated from thermal inactivation kinetic curves after heating at 55, 60, and $65^{\circ}C$. The D value for B. cereus at $55^{\circ}C$ was the highest (22.8 min), followed by that for E. coli O157:H7 (18.8 min) and L. monocytogenes (17.6 min). At $60-65^{\circ}C$, the order was L. monocytogenes ($D_{60-65^{\circ}C}=3.4-0.9min$), E. coli O157:H7 (3.0-0.3 min), and B. cereus (1.2-0.3 min). The z values for these species were 5.2, 5.5, and $7.7^{\circ}C$, respectively. The Korean national standard for retort food products was achieved by thermal processing at $124{\pm}2^{\circ}C$ for 0.3-2.2 min. This study provides useful data for ensuring both the microbiological safety and product quality of multi-grain soymilk products.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.3
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• pp.388-394
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• 2001

This study was conducted ton investigate the mineral contents of commercial baby foods. Samples were classified into 4 groups; powdered formula, baby juice product (domestic), juice and paste products (imported) and soymilk-based formula. We analyzed Ca, P, Mg, Na, K, Fe, Cu, Zn contents by atomic absorption spectrophotometer after dry-ashing. The difference of analyzed value versus labeled value and Ca/P ratio of analyzed value were calculated. The difference (%) of analyzed value on the labeled value was Ca: 98.6, P: 121.8, Mg: 146.1, Na: 87.4, K: 104.3, Fe: 104.8, Cu: 120.2, Zn: 109.8 in powdered formula, Mg showed the highest difference among the elements. The Ca/P ratio of powdered formula was 1.41 (1.70-1.99). Baby juice products (domestic) were fortified Ca, Fe and the difference (%) of analyzed value on labeled value of Ca and Fe contents was 131.8, 110.2, respectively. The Ca/P ratio of these was 2.36 (1.64-3.71). Differently the domestic products, imported juice and paste products were not fortified Ca, Fe and its Ca/P ratio was 0.38(0.14-0.59). The difference (%) of analyzed value on the labeled value was Ca: 110.2, Mg: 179.5, Na: 83.7, K: 87.8, Cu: 107.8, Fe: 219.8, Zn: 100.5, P: 126.6 in soymilk-based formula, Fe showed the highest difference among the elements. The Ca/P ratio of soymilk-based formula was 1.17 (1.04-0.39).

• Journal of Microbiology and Biotechnology
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• v.20 no.11
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• pp.1546-1554
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• 2010

A bacterial strain capable of producing extracellular ${\alpha}$-galactosidase was isolated from a sample of sugarcane industrial waste. Microbiological, physiological, and biochemical studies revealed that the isolate belonged to Bacillus sp. Furthermore, based on a 16S rDNA sequence analysis, the new isolate was identified as Bacillus megaterium VHM1. The production of ${\alpha}$-galactosidase was optimized based on various physical culture conditions. Guar gum and yeast extract acted as the best carbon and nitrogen sources, respectively. The optimum pH was 7.5 and the enzyme remained stable over a pH range of 5-9. The enzyme was optimally active at $55^{\circ}C$ and thermostable with a half-life of 120 min, yet lost 90% of its residual activity within 120 min at $60^{\circ}C$. One mM concentrations of $Ag^2$, $Cu^2$, and $Hg^{2+}$ strongly inhibited the ${\alpha}$-galactosidase, whereas the metal ions $Fe^2$, $Mn^{2+}$, and $Mg^{2+}$ had no effect on the ${\alpha}$-galactosidase activity, and $Zn^{2+}$, $Ni^{2+}$, and $Ca^{2+}$ reduced the enzyme activity slightly. When treated with the B. megaterium VHM1 enzyme, the flatulence-causing sugars in soymilk were completely hydrolyzed within 1.5 h.

• Korean Journal of Food Science and Technology
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• v.17 no.2
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• pp.95-100
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• 1985

Effects of number of washings with solvents on drying rates and physicochemical properties of dried soymilk residues(SMR) were investigated. The dried soymilk residue was prepared by washing the residue with acetone or ethanol, followed by drying at $60^{\circ}C$. Increase of number of washings with a residue/solvent ratio of 1/1.5 resulted in an increase in drying rate and in protein content of the residue while the lipid content decreased. The brightness of the dried residue and the properties of water and oil absorption were also improved by washing with acetone which was advantageous to ethanol for all of the properties measured. Washings more than 3 times with acetone or 2 times with ethanol were found to be less effective in terms of quality improvement. The more addition of dried residue into the mixture of SMR-wheat flour resulted in a linear increase of water and oil absorption characteristics.

• Korean Journal of Food Science and Technology
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• v.16 no.4
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• pp.423-428
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• 1984

Changes in viscosity of soymilk were evaluated as affected by solid concentration, temperature, pH and sugar addition. Soybeans were soaked, ground with boiling water, and filtered followed by boiling for 30 min for soymilk preparation. It was found that viscosity increased exponentially as solid concentration increased while the raise of temperature caused exponential decrease in it. A minimum viscosity was ovserved at pH 6.5 in the range of pH 5.0-8.0. The effects of solid concentration and pH on viscosity were reduced as the measuring temperature increased. Addition of sucrose up to 9% showed little effect on viscosity with showing a tendency of increase.

• Korean Journal of Food Science and Technology
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• v.20 no.3
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• pp.426-432
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• 1988

This study was undertaken to investigate for the possible use of enzymes with ${\alpha}-galactosidase$ and protease activities to remove flatulence factors as well as to improve the yield and protein digestibility in soymilk preparation. The volume and protein yield were not increased significantly by enzyme treatment. The solids yield increased by raising treatment pH 6 to 10, the temperature $30^{\circ}C\;to\;60^{\circ}C$ Enzyme treatment brought about a remarkable increase in TCA-soluble nitrogen compounds and a decrease in the contents of flatulence factors raffinose and stachyose.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.8
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• pp.1270-1277
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• 2003

The extrusion conditions of the soymilk residue and corn grits mixtures were optimized. The experiment was designed according to the D-optimal design of response surface methodology (RSM), which shows 18 experimental points including 4 replicates for three independent variables (screw speed, water content and die temperature). The responses variables such as bending force, expansion ratio, bulk density, water solubility index (WSI), water absorption index (WAI), and color values (L＊, a＊, b＊) were evaluated using response surface analysis. Expansion ratio and WSI decreased with increasing water content, whereas bulk density tended to increase with increasing water content. While greater screw speeds enhanced WSI and yellowness, higher moisture contents decreased the expansion ratio and WSI value. However, die temperature did not influence upon the response variables. The optimum extrusion conditions by numerical and graphical methods were similar: the screw speed, water content, and die temperature were 250 rpm, 22.43% and l28.16$^{\circ}C$ by the numerical method; 250 rpm, 22.43%, and 128.02$^{\circ}C$ by graphical method.

• Korean Journal of Food Science and Technology
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• v.19 no.4
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• pp.355-360
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• 1987

Among the several lactic acid bacteria, Lactobacillus acidophilus showed the highest acid production when it was cultured mixed with Sacchasomyces uvarum in soymilk. The highest acid production was obtained in 16 hrs of cultivation when the inoculation ratio of L. acidophilus and S. uvarum was 2:1 and the temperature was $30{\sim}37^{\circ}C$. The acid production was greatly enhanced by the addition of 2.0% sucrose. However, skim milk was not stimulatory in mixed culture. During mixed culture in soymilk, acid production was affected by the enzymatic reaction of yeast.

• Korean Journal of Food Science and Technology
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• v.16 no.3
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• pp.358-362
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• 1984

Soybeans were soaked in water for 3 hrs and germinated at $25^{\circ}C$ for 5 days followed by hot water extraction and boilding for 30 min. The prepared soymilk was analyzed for chemical composition, phytic acid and soluble minerals. Germination resulted in a slow decrease in total solids while protein recovery increased to a maximum of 92.5% after 2 days. Carbohydrate content was reduced to 65% by the 5th day of germination. The intial phytic acid content in soymilk of 1.26g recovered from 100g dry soybean was decreased by 41.3% while inorganic phosphorus increased more than four times from 31.3mg to 135.0mg. Total soluble minerals was also steadily increased.

• Korean Journal of Food Science and Technology
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• v.15 no.1
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• pp.12-18
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• 1983

Changes in the quality and amino acid composition of soymilk prepared from soaked and germinated soybeans were investigated. Soybeans were soaked in water for 3 hrs and germinated at $18{\pm}1^{\circ}C$ for 5 days followed by water extraction at room temperature, and then the soymilk was boiled for 30 min. The initial yields of total solid and protein after soaking were 80.7% and 88.6%, respectively and decreased slowly during germination. A slow decrease in lipids and a rapid reduction in total sugar content were found during germination. The change in protein fraction content of soymilk showed an initial increase followed by a gradual decrease. The intrinsic viscosity increased rapidly after 3 days of germination to maximum value at 4th day, then decreased. The amino acid composition of protein fraction of soymilk showed little change while that of nonprotein fraction changed significantly. After 4 days of germination, aspartic acid and alanine increased more than twice, and methionine and tyrosine decreased to half of their initial composition in soymilk prepared from soaked soybean.