• Applied Biological Chemistry
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• v.17 no.4
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• pp.247-256
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• 1974

The Merit variety of soybean (Glycine max L.), harvested in 1971 was germinated in the dark at $21{\sim}25^{\circ}C$ for 10 days. The soybean sprout were divided into cotyledons and seedling axis and subjected to the determination of lipoxygenase activity and fatty acid composition of triglycerides, free fatty acids, phosholipids and crude fat fractions at two-day intervals during the germination periods. The results are summarized as follows 1) The lipoxygenase activity in cotyledons declined sharply after second day, but the activity in seedling axis inclined slightly after second day. However, the decrease of lipoxygenase activity in cotyledons coincided with decrease of linoleic and linolenic acids in cotyledons and increase of lipoxygenase activity in seedling axis coincided with increase of those acids in seedling axis. 2) The iodine value of neutral fat in cotyledons decreased continuously, but the iodine value of the neutral fat in seedling axis remained almost constant. iodine value in cotyeldons was greater than in seedling axis. 3) In the fatty acid composition of triglycerides in cotyledons, palmitic acid did not changes significantly, stearic acid increased continuously, oleic acid changed irregularly, linoleic and linolenic acids continuously decreased significantly. But in the fatty acid composition of triglycerides in seedling axis, palmitic acid remained unchanged, linoleic and linolenic acids slightly increased continuously, stearic and oleic acids changed irregularly. 4) Composition of free fatty acids in cotyledons and seedling axis changed irregularly, suggesting that all fatty acids produced by hydrolysis of triglycerides by lipase are used(or either biosynthetic Purpose or energy Production at random. 5) Fatty acids with odd-numbered carbon chain were not detected in the triglycerides and free fatty acid fractions during the germination periods, suggesting that all fatty acids are utilized as $C_2$-unit in degradation and biosynthesis. 6) The changes of fatty acids composition of Phospholipid in cotyledons and seedling axis during the germination were similar to these of triglyceride fraction.

• Food Science and Biotechnology
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• v.18 no.6
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• pp.1398-1403
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• 2009

Present study deals with variations of physicochemicals including $\gamma$-aminobutyric acid (GABA), $\gamma$-oryzanol, free sugar, lipoxygenase activity, fat acidity, and germination rate from Korean brown rice cultivars. With increase of storage time and temperature, GABA, $\gamma$-oryzanol, lipoxygenase activity, and fat acidity increased, whereas free sugar and germination rate was reduced. Among cultivars, 'Gopumbyeo' exhibited the highest contents in GABA and $\gamma$-oryzanol during 12 weeks storage at $25^{\circ}C$ (GABA: $28.6{\pm}5.6{\rightarrow}170.4{\pm}4.6\;mg/100\;g$, $\gamma$-oryzanol: $6.1{\pm}0.7{\rightarrow}6.7{\pm}0.4\;mg/g$) and 'Ilpumbyeo' significantly decreased in free sugar during 12 weeks storage at $10^{\circ}C$ ($1,423.7{\rightarrow}1,058.4\;mg/100\;g$). Moreover, 'Taebongbyeo' exhibited the highest quality owing to low lipoxygenase activity, low fat acidity, and high germination rate. In free sugar compositions, sucrose exhibited the highest content (>70%), followed by fructose (>7%), raffinose (>5%), glucose (>3%), and maltose (>2%) during storage. Based on our results, changes of physicochemicals in stored brown rice may be important information in processing food and functional properties.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.10
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• pp.1629-1637
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• 2013

The properties of non-GM soybeans with lipoxygenase (LOX) free genotypes, such as Gaechuck#1 (black, LOX2,3-free), Gaechuck#2 (yellow, LOX2,3-free) and Jinyangkong (yellow, LOX1,2,3-free), were compared to Taekwangkong (yellow, LOX1,2,3-present) as control. Length and weight of soybeans were significantly longer in Gaechuck#1, but LOX free genotypes of yellow beans was smaller than Taekwangkong, in terms the size and weight. After soaking for 12 hr, increased ratios of soybean weight were 217.07~226.55%, and they were significantly higher in Gaechuck#2. The total color difference (${\Delta}E$) to Taekwangkong was the highest in Gaechuck#1, but another yellow soybean were similar. Crude lipids content was significantly higher in Taekwangkong (17.30%), and these LOX free genotypes (13.71~14.66%) did not show significant difference. Crude protein contents were significantly higher in Gaechuck#1 (34.79%) compared to the other soybeans (32.93~33.47%). Contents of glutamic acid among the detected composition amino acid were highest, and its total contents were highest in Gaechuck#1 (32.42 g/100 g), and the total content of Gaechuck#2 was similar to Taekwangkong. Contents of total isoflavone were higher in LOX free genotypes than Taekwangkong, especially significantly higher in Gaechuck#1 (1672.54 ${\mu}g/g$). Contents of total phenol were highest in Gaechuck#1 (276.91 mg/100 g), and flavonoids content of Gaechuck#1 (26.93 mg/100 g) was 2.6~2.8 times higher than the other samples. DPPH, ABTS radical scavenging activities and reducing power were significantly higher in Gaechuck#1. The yield of soybean curd from tested samples was the highest in Gaechuck#2. Gaechuck#2 as LOX free genotypes was similar to Taekwangkong with regard to physicochemical properties and antioxidant activities. Therefore, we propose that Gaechuck#2 is a more suitable genotype for soybean curd products.

• Journal of Life Science
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• v.5 no.2
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• pp.14-14
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• 1995

The effect of lipoxygenase (LOX) on the oxidation and co-oxidation of lipid fraction was studied in the model system of rainbow trout. For the reaction in model system 1 g of lipid fraction and 50mL of enzyme extract(LOX, 140 unit in 50mL phosphate buffer solution at pH 7,4)), which were obtained from rainbow trout, were homoginized in the presence of Tween 20 and kept at 23$\circ$C for 3 days. The activity of LOX was decreased to 43% of initial level during the reaction in the model system. The initial composition of rainbow trout lipid was showed to be consisted of trigliceride(TG;82%) and free fatty acid(FFA;0.1%), while this converted to 59% of TG and 20% of FIFA, respectively after reaction in model system. Change of fatty acid composition was also observed and the content of linoleic acid, one of the major fatte acids, was decreased to 13% from 54% in the content of total fatty acids after reaction. The carotenoids in rainbow trout were composed of 0.4% $\alpha$-carotene, 1.6% $\beta$ -carotene, 80% canthaxanthin, 7% lutein and 11% zeaxanthin, thus the canthaxanthin was the major component. This canthaxanthin was the most degraded carotenoid by lipoxygenase catalyzed co-oxidation during the reaction. On the other hand the tocopherol isomers found in the rainbow trout were $\alpha$ and $\beta$ -tocopherol, and $\alpha$-tocopherol had a higher degradation rate by the lipoxygenase catalyzed co-oxidation than of $\beta$-tocopherol in the reaction of model system.

• Food Science and Preservation
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• v.21 no.2
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• pp.215-223
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• 2014

The quality characteristics and antioxidant activity of three kinds of tofu made from lipoxygenase (LOX)-free genotypes soybeans were compared to the Taekwang (LOX-present) tofu as the control. The mineral contents of Jinyang tofu were significantly higher than those of the control. The hardness and gumminess of tofu made from LOX-free genotypes were significantly higher than those of the control. Gaechuck#2 tofu showed higher sensory evaluation results than the other kinds of tofu in terms of taste, flavor and overall acceptability. The total isoflavone contents were higher in the LOX-free genotypes than in the control. The total phenol content was similar for the Gaechuck#1, #2 and Taekwang tofu. The flavonoid content was higher in Gaechuck#1 and #2 tofu than in the control. The antioxidant activities were the highest in Gaechuck#1 tofu, followed by the Gaechuck#2. During the 15-day storage at $4^{\circ}C$, the turbidity of the immersing water tended to increase, but Gaechuck#1 and #2 tofu were significantly lower than in the control after 15-day storage. Therefore it is suggested that Gaechuck#2 tofu could be the suitable genotype for tofu products because it is the most effective in terms of overall acceptability, antioxidant activity, and storage stability.

• Food Science of Animal Resources
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• v.41 no.6
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• pp.923-935
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• 2021

Fresh grass carp was used to produce surimi samples that were supplemented with 50 g/kg, 100 g/kg, or 150 g/kg pork back fat. The lipid composition, lipase activity, lipid oxidation index, and lipoxygenase activity of samples subjected to repeated freezethaw process were determined to assess the effects of the added fat on lipolysis and lipid oxidation of grass carp surimi. Freeze-thaw treatment increased free fatty acid content, mainly due to the decomposition of phospholipids and some neutral lipids by lipase. With repeated freeze-thaw treatment, the levels of free fatty acids and phospholipids were correlated with the lipid oxidation indexes and lipoxygenase activity, indicating that lipid degradation can promote lipid oxidation. In the same freeze-thaw cycle, surimi products with high fat content are more vulnerable to oxidative damage, neutral lipids are the main source of free fatty acids in the early stage of freeze-thaw, and phospholipids are the main source of free fatty acids in the late stage.

• BMB Reports
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• v.40 no.1
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• pp.100-106
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• 2007

The wound-inducible lipoxygenase obtained from maize is one of the nontraditional lipoxygenases that possess dual positional specificity. In this paper, we provide our results on the determination and comparison of the kinetic constants of the maize lipoxygenase, with or without detergents in the steady state, and characterization of the dependence of the kinetic lag phase or initial burst, on pH, substrate, and detergent in the pre-steady state of the lipoxygenase reaction. The oxidation of linoleic acid showed a typical lag phase in the pre-steady state of the lipoxygenase reaction at pH 7.5 in the presence of 0.25% Tween-20 detergent. The reciprocal correlation between the induction period and the enzyme level indicated that this lag phenomenon was attributable to the slow oxidative activation of Fe (II) to Fe (III) at the active site of the enzyme as observed in other lipoxygenase reactions. Contrary to the lagging phenomenon observed at pH 7.5 in the presence of Tween-20, a unique initial burst was observed at pH 6.2 in the absence of detergents. To our knowledge, the initial burst in the oxidation of linoleic acid at pH 6.2 is the first observation in the lipoxygenase reaction. Kinetic constants (Km and kcat values) were largely dependent on the presence of detergent. An inverse correlation of the initial burst period with enzyme levels and interpretations on kinetic constants suggested that the observed initial burst in the oxidation of linoleic acid could be due to the availability of free fatty acids as substrates for binding with the lipoxygenase enzyme.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.1
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• pp.35-43
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• 2016

To evaluate processing suitability of lipoxygenase (LOX)-free genotype soybeans (Jinyang, 05C4 and LS), quality characteristics and antioxidant activities of their Doenjang products were compared to those of Doenjang made from Taekwang soybean (LOX-present) as the control. Moisture and crude protein contents of Doenjang were significantly higher in LS than the control. Crude lipid content was not significantly different and was in the range of 7.92~8.22% in all samples. Carbohydrate content was significantly lower in LS than Taekwang. Content of reducing sugar in Doenjang was significantly higher in Jinyang than Taekwang. Contents of amino-type nitrogen were significantly higher in LOX-free cultivars than Taekwang. Colors of 05C4 and LS Doenjang were not different compared to that of Taekwang, whereas Jinyang Doenjang showed a noticeable color difference. Taekwang Doenjang had a slightly stronger savory taste than another sample. LOX-free cultivars had a strong salty taste. Flavor was the strongest in LS, whereas overall acceptability showed little difference among all samples. The total amino acid content was slightly higher in Jinyang and 05C4 than Taekwang, and content of essential amino acids was higher in Doenjang from LOX-free cultivars than Taekwang. Isoflavon content was significantly higher in Doenjang ($522.16{\sim}684.46{\mu}g/g$) made from LOX-free cultivars than in Taekwang ($374.79{\mu}g/g$). Total phenol content was significantly higher in 05C4 and LS, and flavonoid content was significantly higher in LS than Taekwang. Antioxidant activities were highest in Jinyang based on DPPH radical scavenging and reducing power. ABTS radical scavenging activity was significantly higher in Doenjang made from LOX-free cultivars than Taekwang. These results suggest that Doenjang from LOX-free cultivars could have a suitable genotype for Doenjang processing since it is more effective in terms of amino acids, isoflavone contents, and antioxidant activity.

• Korean Journal of Food Science and Technology
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• v.22 no.3
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• pp.332-336
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• 1990

Antioxidative characteristics of freeze dried soybean sauce powder (SSP) on the oxidation reaction of linoleic acid mixture(LA) were evaluated by the determinations of peroxide formation, synergistic property, hydrogen donation and lipoxygenase activity. SSP was found to possess a considerable potentiality of antioxidant activity on the formation of hydroperoxides in the LA oxidation reaction system at $50^{\circ}C$ for 144hrs. This antioxidative effect was increased by the concentration from 0.02% to 0.5% of SSP in the reaction system. Under the condition of presence of ferric chloride (10 ppm) in the reaction system. appreciable effect of SSP on the synergistic antioxidation were observed. On the other hand, hydrogen donation property of SSP onto ${\alpha},\;{\alpha}'-diphenyl-{\beta}-picrylhydrazyl$ was found and inhibitory ability of SSP on LA oxidation was also shown in the reaction system of lipoxygenase-catalized oxidation.

• Proceedings of the Ginseng society Conference
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• 1990.06a
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• pp.49-57
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• 1990

It has been well known that extended exposure to reactive oxygens causes severe damage to susceptible biomolecules. In this study, the effects of flavonoids including trifling and kaempferol from Ginseng leaves on single oxygen induced photohemolysis of erythrocytes and free radical scavenging activities were investigated . Each flavonoid aglycone (5-50UM) such as kaempferol, quercetin or baicalein exhibited a high protective effect against the photohemolysis. They protected the cells by scavenging 102 and free radicals. Although the free radical scavenging activities of the flavonoid glycosides were not much lower than those of their corresponding aglycones, their insolubility into lipid bilayers of membrane made them less effective in preventing the photohemolysis induced by 1O2. The 102 and free radical scavenging activities of flavonoids were estimated by the decomposition of the flavonoid by 1O2 and the bleaching of free radicals by the flavonoid, respectively. The solubilization of the flavonoid into micelle or erythrocytes was deduced from spectrophotometric and microscopic observations. The cooperation of L-ascorbic acid and a flavonoid, and a possible involvement of lipoxygenase or cyclooxygenase in the photohemolysis mechanism were discussed. Keywords Panax ginseng C.A Meyer, ginseng leaves, flavonoids, singe1 oxygen, Photohemolysis.