• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.3
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• pp.211-215
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• 1994

Lipoxygenase is involved in the formation of certain undesirable flavors of soybean products. Three isozymes(L-1, L-2 and L-3) of lipoxygenase have been identified in soybean seeds, and the three types of mutants lacking L-1, L-2 and L-3, respectively, were detected in the 1980's. In this paper, lipoxygenase activity was measured to investigate the response of lipoxygenase in organs and tissues during soybean development. There was no tendency according to genotypes between lipoxygenase lacking mutants and normal soybeans in lipoxygenase activity of leaf at $V_3$ and $V_5$ stage. Likewise, pod wall lipoxygenase was no difference among genotypes tested at R$_{6}$ stage. Seed coat lipoxygenase activity was similar among the lipoxygenase lacking mutants, while normal soybean was lower as compared with that of the lipoxygenase lacking mutants. Embryo and cotyledon lipoxygenase activity in the lipoxygenase lacking mutants was much lower than that of normal soybean, also there was large difference among lipoxygenase lacking mutants. Thus, the lipoxygenase null mutant showed very weak value although the lacking L-3 mutant had a large effect on developing embryo lipoxygenase activity. It was suggested that soybean lipoxygenase isozymes expressed in embryo may be different from those expressed in the pod wall and leaf tissues.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.3
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• pp.209-214
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• 2006

Three lipoxygenase isozymes in soybean seeds are thought to be a major contributor to lipid peroxidation and generation of free radicals which may result in seed deterioration. This study was conducted to get the basic information for changing lipoxygenase activity during seed germination in lipoxygenase-lacking soybeans. Fresh weight of soybean seedling of Jinpumkong 2 and Taekwangkong increased more rapidly than that of Jinpumkong. Hypocotyls of Jinpumkong and Jinpumkong 2 were longer and thicker than that of Taekwangkong. Type I lipoxygenase activity (pH 9.0) in cotyledon of Jinpumkong lacking lipoxygenase-2, 3 showed higher than that of Taekwangkong, and Type I lipoxygenase activity of two cultivars decreased continually. On the other hand, Type II lipoxygenase activity of Taekwangkong began to increase continually two days after germination, reached to the maximum between 4 days and 5 days, and began to decrease continually five days after germination. Type I and II lipoxygenase activity in hypocotyls was not detected in all soybean cultivars.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.2
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• pp.180-186
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• 1994

Lipoxygenase activity of soybean seeds of approximately 507 genotypes as well as its inheritance and selection efficiency in early breeding generation was measured in the Department of Agronomy, Seoul National University to facilitate breeding for low lipoxygenase activity of soybean. Average seed lipoxygenase activity of 507 cultivars and strains was 350 unit (unit: $\Delta$0.01 /min. /mg at 234nm) and ranged from 50 to 670 unit. There was no difference in mean lipoxygenase activity according to apparent seed characters such as seed coat and embryo color. But early mature soybean genotypes had fairly low lipoxygenase activity. Lipoxygenase activity was inherited quantitatively, in which additive effect was greater than dominant one and proportion of gene with positive effects was similar to that with negative ones. Estimated narrow- and broad-sense heritabilities were 0.78 and 0.86 for lipoxygenase activity, respectively. Heritability measured from selection in early breeding lines for high or low lipoxygenase activity was 64~76% or 54~62%, respectively. And selection for high lipoxygenase activity increased by 29.7~44.7%, whereas that for low ones decreased by 21.8~27.3%, respectively, when compared to random population. Clear effect in selecting of lipoxygenase activity was present in early generation.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.576-580
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• 1997

Lipoxygenase activity in Chinese cabbage was measured at various concentrations of brines. Lipoxygenase activity on linoleic acid substrate was determined by changing the rate of dissolved oxygen consumption. The inactivation of lipoxygenase by salting was increased when concentration of sodium chloride and soaking time were increased. About 60% of enzyme activity was reduced after submerging in 13% brine solution for 5 hr. The addition of calcium chloride (0.7%) reduced about $10{\sim}15%$ of lipoxygenase activity rather than without. Residual activity of lipoxygenase in Chinese cabbage submerged in 13% brine was 20% and about 60% of lipoxygenase was also inhibited by addition of garlic extract.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.5
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• pp.808-812
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• 1998

Melania snail(Semisulcopira bensoni) is used as ingredient in Korean traditional soup and nutritional foods. Generally, lipoxygenase in several food products may produce off-flavors during their processing and storage. Therefore, the inactivation of lipoxygenase is required to make the better extracts from Melania sanil. Also, the quality on freshness of Melania snail may be evaluated by lipoxygenase activity. The lipoxygenae activity was the highest at 40~60% saturation among several concentrations in salting-ouot saturated solution of ammonium sulfate. The partial purification of lipoxygenase was successfully obtained by Sephacryl S-200 gel chromatography. The first peak among three peaks for protein determination showed the highest activity of lipoxygenase in 13~16 fractions among 100 fractions. The highest peak of lipoxygenase activity by ion exchange chromatography was shown at 0.1M NaCl. In the purification step, the specific activity was 20.8U/mg and activity yield was 19.8%. The optimum pH and temperature were pH6.0~8.0 and 3$0^{\circ}C$, respectively. Molecular weight of the lipoxygenase was estimated about 35kDa by SDS-PAGE.

• Korean Journal of Food Science and Technology
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• v.19 no.5
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• pp.441-445
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• 1987

The subcellular distribution of lipoxygenase in germinating soybean seeds (Glycine max[L.] AmSoy) was investigated by using differential centrifugation and sucrose density gradient fractionation. Most of lipoxygenase -1 and -2/3 activities was present in the supernatant fraction after differential centrifugation of homogenates prepared from three-day-old seedlings; only 1.5% of lipoxygenase activity remained in particulate fractions. The results of a sucrose density gradient fractionation (three-day-old) showed that the lipoxygenase activity coincided with acid phosphatase at the densities of 1.19, 1.23, $1.25g/cm^3$, even though most of lipoxygenase and acid phosphatase activities appeared in supernatant fractions. There was no indication that mitochondria contained any lipoxygenase activity, and it does not appear that glyoxysomes and ER contained any lipoxygenase activity either.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.spc1
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• pp.112-117
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• 2005

This study was conducted to see the feasibility of breeding for sprout soybean cultivar with minimum benny flavor using lipoxygenase-less lines. Lipoxygenase-less cultivar Jinpumkong2 was crossed by lipoxygenase containing Gwangankong, Sebaeknamulkong, and Pureunkong as paternal parent and 24 lipoxygenase-less lines derived from those 3 combinations were selected and those lines were evaluated with their parental cultivars. Germination rate showed no difference between lipoxygenase-less lines and their parental cultivars, however, rates of normal sprout of those and Jinpumkong2 were 63 and $56\%$, and were lower than that of paternal parents. Hypocotyl length of those was same as Jinpumkong2, however, shorter than paternal parents. Texture characteristics including hardness, cutting force and mastication of 96 hour-cultured sprout of lipoxygenase-less lines showed higher value than that of their parental cultivars. Lipoxtgenase isozyme was not detected in the sprout cotyledon of lipoxygenase-less lines, however it was observed in the sprout hypocotyl of all the used genotypes. Though lipoxygenase activity in the seed of lipoxygenase-less lines was lower than that of Jinpumkong2(0.477, ${Delta}A$ 234 nm min-1 mg meal-1),2 lines revealed more than 0.5 value. Lipoxygenase-activity of 2 day-cultured sprout(both cotyledon and hypocotyl) was the highest, decreased in 3 days after culture and re-increased thereafter. Several lipoxygenase-less lines with lower lipoxygenase activity of sprout than Jinpumkong2 were selected and this suggested the possibility of breeding lines for soy-sprout with low benny flavor.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.115-121
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• 1999

Changes of free sugars, lipoxygenase activity and effects of chitosan treatment were analyzed during cultivation of soybean sprout. Free sugars(sucrose, raffinose and stachyose) were more rapidly decomposed in the cotyledon of soybean sprout. Contents of sucrose and raffinose in control group were decreased more rapidly than those of chitosan treated soybean sprouts (CTSS). But the decreasing rate of stachyose was higher in the CTSS. In the hypocotyl, 82% of L-2/3 activity were decreased, whereas 42% of the activity were decreased in the cotyledon after 132 hours of germination. The effect of chitosan treatment on the lipoxygenase activity was more effective on L-2/3 isozyme than L-1. After the germination period of 132 hours, L-2/3 activity of control group was 82.7unit/mg and that of CTSS was 56unit/mg.

• Korean Journal of Food Science and Technology
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• v.29 no.4
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• pp.710-715
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• 1997

Inactivation of lipoxygenase activity in Chinese cabbage was shown after salting and heat treatments. Crude lipoxygenase was obtained from treatment of $(NH_{4})_{2}SO_{4}$. Lipoxygenase activity in Chinese cabbage was about 50% after 20 hrs of salting in 13% (w/v) concentration. After heating at $90^{\circ}C$ for 15 min, residual activity of lipoxygenase was about 50%. Inactivation of lipoxygenase was highly accelerated by increasing temperature and heating time. Decimal reduction time (D-value) were 42, 20 and 14 min at 70, 80 and $90^{\circ}C$, respectively. When cabbage was soaked in 0.05 M $CaCl_{2}$ and heated at $55^{\circ}C$ for 1.5 hr, higher activity of crude lipoxygenase was found compared with the heat treatment without $CaCl_{2}$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.1
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• pp.29-35
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• 2007

This study was conducted to investigate the germination rate, fat acidity and lipoxygenase activity of brown rice after storage of 6 and 12 weeks at high temperature ($35^{\circ}C$) with fifteen Korean and two Japanese rice varieties. Germination rate in rough rice and palatability value in cooked rice by rice taster were lower with longer storage period, while protein content, fat acidity, and lipoxygenase activity in brown rice were higher with longer storage period. Fat acidify was negatively correlated with germination rate. However fat acidity was positively correlated with lipoxygenase activity. Seventeen varieties were classified into two groups on the basis of germination rate, fat acidity and lipoxygenase activity after 12 weeks' storage at high temperature; Group I including eleven varieties of Odaebyeo, Sangmibyeo, Unkwangbyeo, Ilpumbyeo, Nampyeongbyeo, Ilmibyeo, Donganbyeo, Jungsanbyeo, Koshihikari, Hitomebore and Chucheongbyeo showed high germination rate, low fat acidity and low lipoxygenase activity, while Group II including six varieties of Sindongjinbyeo, Hoanbyeo, Gyehwabyeo, Daeyabyeo, Hopyeongbyeo, and Dongin 1 showed lower germination rate, high fat acidity and high lipoxygenase activity.