• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.3
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• pp.294-300
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• 2006

This study was carried out to evaluate the possibility of citron seed as industrial resource by analyzing chemical properties and the antioxidant activity. Crude lipid content of citron seed was $35.29{\pm}0.18%$. Total mineral content in citron seed was 1171.64 mg/100g and the potassium content ($637.99{\pm}5.38mg/100g$) was the highest. The contents of total phenols and flavonoids in citrus seed were $24.44{\pm}1.10mg/100g$ and $2.27{\pm}0.18mg/100g$, respectively. The electron donating ability using DPPH, hydroxy radical scavenging activity and SOD-like activity were increased significantly by increased the sample concentration in the reaction mixture. The nitrite scavenging ability was dependent on pH of reaction mixture and sample concentration. It was higher activity at pH 1.2 than pH 4.2. During the storage of soybean oil, the peroxide and acid values of the oil were significantly increased regardless of addition of citron extract. But antioxidant activity of soybean oil added with ethanol extract from citron seed was superior to that of control (sample with no addition) at 16 days of storage.

• Journal of the Korean Society of Food Science and Nutrition
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• v.15 no.1
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• pp.15-21
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• 1986

This study was conducted to research the industrial utilizaion of the maize germs separated in the manufacture of the cornstarch. The maize germs contained crude protein (25.3%) and crude fat (19.2%), with the 512 Kcal/100g of determined food energy values. It was found to have the valuable amounts of essential minerals, such as the content of calcium and phosphorus were low (53.0, 12.3mg%), while those of potassium (495.4mg%), magnesium (95.0mg%), zinc (48.3ppm) and manganese (45.2ppm) were plentiful. It was noted that the iodine value was 44.0, saponification value 292.3, acid value 1.5 and peroxide value about 3.3. The lipid fractions obtained by silicic acid column chromatography were mainly composed of neutral lipid, whereas, the contents of glycolipid and phospholipid were scarcely. The major fatty acids in total lipids were linoleic $(60{\sim}62.5%)$, oleic $(20{\sim}22.5%)$ and palmitic $(10{\sim}13.5%)$ acids. The content of the unsaturated fatty acids was more predominant than that of the saturated fatty acids. The content of the insoluble proteinous nitrogen (32.5%) was the most abundant. whereas, the contents of soluble proteinous nitrogen (12.7%) and peptide proteinous nitrogen (3.3%) were low. The major amino acids of the maized germs were glutamic, glycine, alanine and aspartic. It has been identified by the SDS-disc electrophoresis that the protein of maized germs had $5{\sim}6$ bands. Compared with standard substances, the molecular weight of the main protein was estimated to be $14,500{\sim}24,500$.

• Food Science and Preservation
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• v.30 no.5
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• pp.885-895
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• 2023

This study aims to investigate the production and characteristics of protein hydrolysates derived from tuna byproducts (TP) using various proteolytic enzymes and to compare the antioxidant activity of the resulting hydrolysates. The TP were subjected to enzymatic hydrolysis using five different proteases: alcalase, bromelain, flavourzyme, neutrase, and papain, and the antioxidant activities of the hydrolysates were evaluated. Subsequent analysis of the available amino group contents and sodium dodecyl sulfate-polyacrylamide gel electrophoresis patterns indicated a high degree of hydrolysis in TP after treatment with all the enzymes, except for papain. Based on the RC₅₀ values obtained from four different antioxidant analyses, all the hydrolysates exhibited similar antioxidant activity, except for the flavourzyme hydrolysate, which showed significantly higher scavenging activity against ABTS radicals and hydrogen peroxide than the other hydrolysates. These findings suggest that protein hydrolysates derived from TP hold promise as potential sources of natural antioxidants.

• Food Science and Preservation
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• v.31 no.3
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• pp.444-451
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• 2024

This study aimed to investigate the characteristics of protein hydrolysates derived from defatted egg yolk using various proteolytic enzymes and compare the antioxidant activity of the resulting hydrolysates. The defatted egg yolk powder was subjected to enzymatic hydrolysis using four different proteases (alcalase, bromelain, flavourzyme and neutrase), and the resulting hydrolysates were evaluated for their antioxidant properties. Through analysis of available amino group contents and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, it was observed that the defatted egg yolk powder treated with alcalase, flavourzyme, and neutrase for 12 h exhibited a high degree of hydrolysis value. Based on the RC₅₀ values obtained from two different antioxidant analyses, all hydrolysates showed comparable antioxidant activity, except for the alcalase hydrolysate, which demonstrated notably higher scavenging activity against hydrogen peroxide than the other hydrolysates. These findings suggest the potential of protein hydrolysates from defatted egg yolk, a by-product of lecithin extraction, as natural antioxidants.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.1
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• pp.81-86
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• 2002

The present study was conducted to investigate the effect of dietary supplementation of vitamin A or $\beta$-carotene on oxidative damage induced by acute ethanol administration. Sprague-Dawley rats were fed on the experimental diets supplemented with retinyl acetate (2.86 mg/kg diet) or $\beta$-carotene (15.2 mg/kg diet) for 5 weeks. After fed the diet, rats were administered 20% ethanol solution (3g/kg B.W.) acutely. Lipid peroxide values in hepatic tissue, hepatic antioxidative enzyme activities and contents of antioxidative nutrient such as vitamins A and E in serum and hepatic tissue were measured. Hepatic level of malondialdehyde decreased in $\beta$-carotene group compared to the control group. However, there was no significant difference between retinal acetate and $\beta$-carotene groups. Superoxide dismutase activity was higher in retinal acetate group than in the control group. Hepatic glutathione-S-transferase activity of retinal acetate and $\beta$-carotene groups significantly decreased as compared with that of control group. The hepatic content of retinol increased in retinal acetate and $\beta$-carotene groups, especially, in retinyl acetate group. But there was no significant difference in serum content of retinol among the groups. Hepatic content of $\alpha$-tocopherol was significantly increased in retinyl acetate and $\beta$-carotene groups. In conclusion, acute ethanol administration might induce lipid peroxidation, and the dietary supplementation of retinyl acetate or $\beta$-carotene improve partly the antioxidative system through activation of superoxide dismutase and retention of hepatic $\alpha$-tocopherol in ethanol-treated rats.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.5
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• pp.542-549
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• 1999

The hydrothermal extracts were produced from fish head and their functional properties were investigated. The extracts exhibited an antioxidative effect and synergistic effect with $\alpha$-tocopherol by measuring peroxide values. The $5\%$ solution showed more antioxidative effect than $1\%$ solution. The extracts showed cryopropective effect, but the effect was less than sucrose. The solubility of the extracts was over $70\%$ in the all range of pH, and its lowest solubility was shown in pH 3.0. The extracts exhibited an emulsifying activity less than sugar ester (EAI=34.72) and little higher than or similiar to egg white (EAI= 14.69). The extracts showed a relatively high foam activity. The osmolality of the hydrothermal extracts at $1.0\%$ concentration were 23$\~$31 mOsmole which were much lower than 317 mOsmole at $1\%$ NaCl.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.5
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• pp.723-730
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• 2011

Soybean oil used to fry French fries, chicken nuggets, and donuts was exposed to high temperature at $180^{\circ}C$ for 72 h. The effects of frying foods on the thermooxidative stability of soybean oil were evaluated by determining the contents of free fatty acids, peroxides, total polar compounds, and conjugated dienoic acids, and by analyzing dielectric constant, refractive index, iodine value, smoke point, and fatty acid composition. The contents of free fatty acids, total polar compounds, conjugated dienoic acids, dielectric constant, and refractive index increased, whereas iodine value, smoke point, and U/S ratio of fatty acids composition decreased with frying time. All samples of frying oils after 72 h presented free fatty acid contents of below 2.0% and total polar compounds of below 25%, which were within the legal limits. However, peroxide values of frying oils were not directly correlated with frying time. The type of fried food affected the thermooxidative stability of the frying oils, with chicken nuggets being more stable in thermooxidation than French fries and donust. Among physiochemical indicators of frying oil quality, a rapid method including dielectric constant and refractive index can be used in quantity food production.

• Korean Journal of Food Science and Technology
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• v.29 no.2
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• pp.379-382
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• 1997

The effects of different concentrations of ${\alpha}-tocopherol,\;{\delta}-tocopherol$, BHA, BHT and TBHQ on the oxidative stability of perilla oils undergoing autoxidation during storage at $50^{\circ}C$ were studied. ${\alpha}-\;and,\;{\delta}-tocopherols$ were added as concentrations of 100, 200, 300 and 400 ppm to the perilla oils from the unroasted seeds or the roasted seeds at $190^{\circ}C$ for 20 min. BHA, BHT and TBHQ were also added to the perilla oils described above as concentrations of 50, 100, 150 and 200 ppm, respectively. The oxidative stability of perilla oils was estimated by the antioxidative index (AI: the induction periods of oils with antioxidants/the induction periods of oils without antioxidants) on the basis of the peroxide values. The roasted perilla seed oil was more stable than the unroasted seed oil in autoxidation. The addition of ${\alpha}-\;and,\;{\delta}-tocopherols$ accelerated the autoxidation of perilla oils. BHA did not show antioxidant effects, but BHT showed very weak antioxidant effects. The autoxidation of perilla oils, however, was effectively prevented by the addition of TBHQ. TBHQ showed activity in preventing 5 times on the autoxidation of perilla oils. Therefore, the oxidation stability of perilla oils seemed to be depend both on the roasting process and the kind of antioxidants.

• Food Science and Preservation
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• v.16 no.2
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• pp.246-252
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• 2009

Diacylglycerol(DAG) was produced by enzymatic esterification of glyceryl mono-oleate(GMO) and conjugated linoleic acid(CLA) in a stirred-batch type reactor. The reaction was catalyzed by lipozyme RMIM(an immobilized lipase from Rizomucor miehei). DAG was isolated by a short-path distillation process and decolorized. DAG oil was composed of 87.3% DAG, 11.4% triacylglycerol(TAG), and 1.5% monoacylglycerol(MAG)(all w/w). Major fatty acids in DAG oil were oleic acid(54%), CLA(31.1%), and linoleic acid(7%). DAG oil iodine,and acid values were 108.8, 2.57, and 1, respectively. The DAG oil solid fat index(SFI) and thermograms were obtained using differential scanning calorimetry.

• Korean Journal of Food Science and Technology
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• v.24 no.1
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• pp.86-91
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• 1992

To develop an effective utilization method of skipjack tuna viscera, fish meal by an improved fermentation method(FFMA) was prepared by fermentation of the solid materials separated from autoclaved viscera with Aspergillus oryzae for 72 hours and by adding the concentrated soluble extracts separated from autoclaved viscera to the fermenting solid materials during fermentation, and FFMA fish meal was compared with the fish meals prepared by Kato mathod(FFMN) and conventional nonfermenting method(NFM). FFMN fish meal was prepared by fermenting the solid materials separated from autoclaved viscera with Aspergillus oryzae for 17 hours without adding the soluble extract. The extracts from FFMA fish meal(FFMA-E) and raw viscera(RM-E) were also prepared respectively after digestion with proteases obtained from Bacillus subtilis and Aspergillus oryzae and compared with each other on the contents of free amino acids. The peroxide values decreased greatly in contents of $Vitamin\;B_{1},\;B_{2}\;and\;C$ significantly increased in FFMA fish meal compared with those of other fish meals. The total free amino acid content of FFMA-E was significantly higher then that of RM-E. The total free essential amino acid content also greatly increased in FFMA-E in which threonine, methionine and lysine showed remarkable increments. Almost all individual nonessential amino acids were higher in FFMA-E then in RM-E. The content of taurine, a nonprotein amino acid, greatly increased compared with other nonprotein amino acids in both extracts.