• Preventive Nutrition and Food Science
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• v.21 no.4
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• pp.338-347
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• 2016

The present study investigated the volatile compound, physicochemical, and antioxidant properties of beany flavor-removed soy protein isolate (SPI) hydrolyzates produced by combined high temperature pre-treatment and enzymatic hydrolysis. Without remarkable changes in amino acid composition, reductions of residual lipoxygenase activity and beany flavor-causing volatile compounds such as hexanol, hexanal, and pentanol in SPI were observed after combined heating and enzymatic treatments. The degree of hydrolysis, emulsion capacity and stability, 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, and superoxide radical scavenging activity of SPI were significantly increased, but the magnitudes of apparent viscosity, consistency index, and dynamic moduli (G', G") of SPI were significantly decreased after the combined heating and enzymatic treatments. Based on these results, it was suggested that the enzymatic hydrolysis in combination with high temperature pre-treatment may allow for the production of beany flavor-removed SPI hydrolyzates with superior emulsifying and antioxidant functionalities.

• The Korean Journal of Food And Nutrition
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• v.13 no.2
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• pp.118-124
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• 2000

Lipoxygenase(LOX) in soybeans is responsible for beany flavors which limit the wide utilization of soybeans to foods. This study was conducted to analyze beany flavor compounds of the normal Hwagkeumkong and LOX-deficient soybean cultivars, Jinpumkong which lacks L-2, L-3, and Jinpumkong 2 which lacks all L-1, L-2, L-3. Using the combination of dynamic headspace sampling and gas chromatography-mass selective detector(DHS-GC-MSD) for analyzing volatile compounds, hexanal and hexanol were identified in whole soy flour of all three soybena cultivars. Hwangkeumkong had more volatile compounds than Jinpumkong and Jinpumkong 2 in defatted soy flour. Hexanal and acetic acid were identified in soy milk of all three soybean cultivars but Hwangkeumkong had more volatile compounds than Jinpumkong 2. From the analysis with a static headspace sampling(SHS) and GC-MSD the major compounds were hexanal, acetic acid, 1-hexanol, and 1-octen-3-ol. The content of acetic acid was similar among three cultivars. But contents of hexanal and pentanal in Jinpumkong 2 were less than that of Jinpumkong and Hwangkeumkong. Using GC-FID, Jinpumkong 2 had less contents of hexanal and pentanol than Hwangkeumkong in whole soy flour and defatted soy flour. In this study, LOX-deficient soybean cultivars showed less hexanal, pentanol and other compounds than the normal Hwangkeumkong. However quite amount of beany flavor compounds were identified in Jinpumkong and Jinpumkong 2. So further studies are required to characterize LOX isozymes, to understand the mechanisms of beany flavors production, and to develop some other methods for removing beany flavor.

• Korean journal of food and cookery science
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• v.10 no.4
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• pp.369-375
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• 1994

This study was carried out to investigate the effect of beany flavor elimination and the acceptability of tofu prepared with blanched soybean. The results were as follows: 1. The content and me total protein of soymilk prepared with blanched soybean were decreased comparing with those of soymilk prepared with raw soybean. But the yield of tofu was not changed by blanching the soybean. 2. The beany flavor(hexanal, 1-hexanol, and pentanoI) was decreased but the toasted nutty flavor(ethanol and propanol) were increased by blanching the soybean. 3. By heating of soymilk, most of volatile compounds was disappeared, but ethanol, hexanal and 1-hexanol were remained. The hexanal content of tofu prepared with raw soybean was eleven times higher than that of tofu prepared with blanched soybean. 4. The color of tofu prepared with blanched soybean was more yellower than that of control group. At the lower temperature of blending, the texture of tofu was more smooth and elastic. 5. The tofu prepared with blanched soybean was more tasteful.

• Korean Journal of Food Science and Technology
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• v.5 no.1
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• pp.33-35
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• 1973

If soybeans are presoaked, two minutes heating at $100^{\circ}C$ is sufficient to inhibit production of objectionable green beany flavors, with dry beans, three minutes heating at $100^{\circ}C$ accomplishes the same inhibition, These brief heat treatments are not sufficient to inactivate growth inhibition factors as determined by chick feeding trials. The inhibition of off flavor coincides with loss of lipoxygenase activity, and the inhibition is thought to be due to lipoxygenase inactivation.

• The Korean Journal of Food And Nutrition
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• v.7 no.4
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• pp.353-360
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• 1994

Effect of pH, calcium, sucrose, heating and mixing ratio of soy and cow milk was studied on the viscosity and the sensory characteristics of cow-soy milk. The viscosity of soymilk was significantly affected by pH with showing maximum at 6.0 and the pH effect was decreased as the ratio of cow talk increased. A addition of sucrose or calcium affected little on the viscosity and a negative linear relationship was found be tween viscosity and an increase in cow milk ratio. Sensory characteristics of grassy and beany odor and taste of soymilk were rapidly decreased and nutty flavor and total acceptability were increased during initial 30 min of boiling. A further increase in boiling affected little on tastes and odors of soymilk. The beany odor and taste linearly decreased and milk flavor Increased as the ratio of cow milk increased. The total acceptability of 50 : 50 was found to be maximum for cow and soy mixed milks.

• Korean Journal of Food Science and Technology
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• v.31 no.5
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• pp.1235-1240
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• 1999

The objective of this study was to investigate the application of lipoxygenase(LOX)-deficient soybean to food processing by evaluation of processing and sensory characteristics. LOX activity of some processed products of soybean was decreased as the order of whole soy flour, defatted flour, isolated protein. Particularly the decrement of LOX activity of Hwangkeumkong having all L-1, L-2 and L-3 was so high in defatting and isolation of protein. LOX activities of cotyledon of Jinpumkong sprouts were so high. When soy milks were prepared with LOX-deficient soybeans, its beany flavor was evaluated to be weaker than that of Hwangkeumkong. And soybean sprout of Jinpumkong 2 showed less beany flavor but hypocotyl elongation was poor. The beany flavor of ice cream prepared with defatted flour of Jinpumkong 2 didn't make a significant difference from that of ice cream made with defatted milk powder. We suggest that LOX-deficient soybean may have on relatively good oganoleptic properties of processed foods, so it takes advantage of food processing.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.6
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• pp.1128-1134
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• 1997

Lactobacillus helveticus was inoculated to the fermentation liquid containing skin milk powder(SMT) plus soymilk, SMP plus isolated soybean protein(ISP), SMP plus ISP plus whey powder(WP) to increase the nutritional and economic value of commercial soy yogurt. The yogurt fermented with soymilk and SMP showed the lower acid production than of SMP and had significant beany flavor in the product. The yogurt prepared with ISP and SMP showed the higher cell number and lower acid production than that of SMP. Also, the partial substitution of SMP with ISP over 6%(w/w) produced less acceptable product due to gel production. The yogurt prepared by the partial substitution of SMP with ISP, WP and SMP showed the higher cell number and lower acid production than that of SMP and not bring about gel formation unlike the case of ISP. Sensory properties of yogurt substituted SMP with ISP and WP(38:62 mixture) below 4% were not significantly different from that of SMP and the sample containing the mixture over 6% and 0.067% artificial flavor showed lower sensory score due to beany taste than that of SMP. But increase of yogurt flavor up to 0.1% resulted in significantly high score in organoleptic acceptability. The separation of water occured in yogurt prepared by the combined mixture of ISP, WP and SMP, and this problem could be resolved by addition of Na-alginate and PGA at the concentration of 0.1%(w/w).

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.2
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• pp.85-94
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• 1988

This experiment was carried out to obtain the basic data for removal the astringency and off-flavor in soybean milk, by means of soaking of soybean in NaOH and $NaHCO_3$ solutions. The changes of phenolic compounds in soybean during soaking were investigated with HPLC and also the changes of flavor and sensority of soybean milk, prepared from soaked soybean were studied. Phenolic compounds of soybean were identified as chlorogenic, p-hydroxybenzoic, p-coumaric, ferulic and gentisic acid and, chlorogenic acid content was greater than the others. The chlorogenic acid of soybean was mainly neutral type and the other compounds were almost acidic type. Up to 85% of the chlorogenic acid was removed by soaking of soybean in 0.1% of NaOH solution for 8 hrs. Phenolic compounds of soybean was almost removed by soaking in 0.1% of NaOH solution at $90^{\circ}C$ for 1 hr. Chemical composition of soybean milks prepared from soaking of soybean in water, 0.1% NaOH and 0.5% $NaHCO_3$ solution were similar. Hexanol content of beany flavor in soybean milk was increased by soaking of soybean in NaOH solution, where as hexanal, propanal, pentanal contents were removed up to 60%. Color of soybean prepared from soaking of soybean in NaOH solution at high temperature were deep yellow but were high whiteness in soybean milk prepared from soaking of soybean in water at low temperature. Sensority of soybean milk prepared from soaking of soybean in 0.1% of NaOH solution at $90^{\circ}C$ for 1 hr was more favorable than the others.

• Korean journal of food and cookery science
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• v.20 no.6 s.84
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• pp.658-666
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• 2004

In order to develop and commercialize high quality frozen soy yogurt, the effects of industrial proteases and commercial mixed cultures were examined on the functional properties and the sensory attributes of frozen soy yogurt. For quality improvement, soy protein isolates were primarily hydrolyzed by either Flavourzyme or Neurtrase, industrial Proteases, to reduce the beany flavor and increase the functional properties of the protein. The viable cell count of lactic acid bacteria was higher in the soy protein hydrolysates than whenuntreated. ABT-5 (L. acidophilus, Bifidobacterium lactis, and S. thermophilus) resulted in higher acid tolerance, bile acid tolerance and melt-down percent values than those with YC-X11 (Lactobacillus bulgaricus and Streptococci thermophilus). The overrun of frozen soy yogurt was improved by both Flavourzyme $(193.3\%)$ and Neurtrase $(156.7\%)$ treatments. With regard to thesensory characteristics, Flavourzyme improved the beany flavor, astringency taste, mouth feel and overall quality of frozen soy yogurts fermented with ABT-5. Further studies onproduct formulation will be needed to commercialize the frozen soy yogurt for the market.

• Korean journal of food and cookery science
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• v.31 no.2
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• pp.185-192
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• 2015

This research tried to contribute to the diversification and the high quality of tofu products by adding the natural colors from tomatoes and strawberries, thus providing more attractive colors, greater antioxidative activity, and higher palatability The quality characteristics of tofu with 4%, 8%, and 12% strawberry juice and 5%, 10%, and 15% of tomato juice were analyzed. Tofu with tomato juice was found to be higher in transference number, and pH showed a significant decrease as the rate of the addition increased, The antioxidant activity of tofu with strawberry juice is 37.76~52.12%, and tofu with tomato juice is 41.79~51.51%, with tofu with tomato juice is being higher than tofu with strawberry juice in antioxidant status DPPH radical scavenging ability. In chromaticity, the L-value and b-value showed significant decreases as tomato juice was added and when strawberry juice are was added and the values increased. In texture, the hardness of tofu with tomato juice was found to be significantly more solid than tofu with strawberry juice. For the test of springiness, the order was as follows: control group> tomato juice 5%> tomato juice 10%. The result of the organoleptic test of tofu showed, tofu with tomato juice to be significantly brighter in exterior color than tofu with strawberry juice (p<0.001), in for savory flavor, the result shows that tofu with 12% strawberry juice added and that with 10% tomato juice added had better flavor. For the test of beany flavor, the control group is higher than tofu with strawberry juice and tomato juice, and tofu with 10% of tomato juice added was lowest in beany flavor. In the preference investigation, tofu with 10% tomato juice showed the highest preference after swallowing and in overall status.