• 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 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.

• Korean Journal of Food Science and Technology
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• v.30 no.4
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• pp.751-758
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• 1998

Lipoxygenase-deficient soybeans, Jinpumkong (lipoxygenase-2, 3 lacking) and Jinpumkong 2 (lipoxygenase-1, 2, 3 lacking), were breeded for the improvement of beany flavor problem. The objectives of this study were to characterize and to examine the storage stability of two lipoxygenase-deficient soybeans by comparing with Hwangkeumkong having high lipoxygenase activity. The crude protein and crude lipid content of Jinpumkong 2 were lower than those of Hwkangkeumkong and Jimpumkong. All soybean samples were middle-sized and yellow-coated seeds. The rate of water uptake and trypsin inhibitor activity of Jinpumkong were greater than those of others. The cooking rate of Hwangkeumkong was the highest among all. The lipoxygenase activity of Hwangkeumkong was decreased when the soybeans were stored at $40^{\circ}C$ for 96hrs at 90% RH which is the condition of accelerated aging. After accelerated aging, the germination ratio of Hwangkeumkong was not changed but the ratio and speed of germination dropped rapidly in Jinpumkong and Jinpumkong 2.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.4
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• pp.294-303
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• 2023

Lipoxygenase gives soybeans their grassy flavor, which can disrupt food processing efficiency. This study aimed to identify soybean genotypes with lipoxygenase deficiency among 1,001 soybean accessions and to develop kompetitive allele specific PCR (KASP) markers that can detect lipoxygenase mutations. Three lipoxygenase isozymes (Lox1, Lox2, and Lox3) were analyzed using a colorimetric assay based on a substrate-enzyme reaction. Among the 1,001 accessions examined, two (IT160160 and IT276392) exhibited a deficiency solely in Lox1, and one (IT269984) lacked both Lox1 and Lox2. IT160160 had a 74-bp deletion in exon 8 of Lox1 (Glyma13g347600), whereas IT276392 displayed a missense mutation involving the change of C to A at position 2,880 of Lox1. Moreover, we successfully developed four KASP markers that specifically target Lox1, Lox2, and Lox3 mutations. To validate the Lox1 KASP markers, we used two F_2:3 populations generated through a cross between Daepung 2 (lipoxygenase wild type, maternal parent), IT160160, and IT276392 (null Lox1, paternal parent). The results revealed that the Daepung 2 × IT160160 group followed the expected 3:1 ratio according to Mendel's law, whereas the Daepung 2 × IT276392 group did not. Furthermore, a comparison between the colorimetric and KASP marker analyses results revealed a high agreement rate of 96%. KASP markers offer a distinct advantage by allowing the distinction of heterozygous types independent of other variables. As a result, we present an opportunity to expedite the lipoxygenase-deficient cultivar development.