• Current Research on Agriculture and Life Sciences
• /
• v.6
• /
• pp.121-127
• /
• 1988

Ramyon(deep fat fried instant noodle with palm oil) preserved in sunlight, room temp. ($20{\pm}5^{\circ}C$), incubator ($30{\pm}2^{\circ}C$) and corrugated fiber board box to investigate the oxidative changes of the Ramyon lipids. In the study, changes in acid value, peroxide value, carbonyl value, TBA value, fatty acid composition, iodine value and panel test were determined with the lipids extracted from the Ramyon samples in intervals for a period of 20 weeks. Acid value, peroxide value, carbonyl value and TBA value of the Ramyon lipid were increased slightly during the storage in aluminum foil package in the corrugated fiber board box in the dark room. They did not appear the oxidative rancid odor at the end of 20 weeks storage. Acid value, peroxide value, carbonyl value and TBA value of the samples under room temp., incubator slightly during storage, while a sharp increase of those values were noticed with the samples of sunlight. Especially, the TBA value of the Ramyon lipid under sunlight markedly increased within 14 weeks and then decreased. Oxidative rancid odor appeared at the end of 10 weeks storage under sunlight, while it took 18 weeks with the sample stored under room temp. and incubator. During the storage under incubator and sunlight for 18 weeks, the content of oleic, linoleic acid decreased, while palmitic and stearic acid increased. However, only small changes were noticed in iodine value of the samples.

• Journal of Nutrition and Health
• /
• v.20 no.6
• /
• pp.395-404
• /
• 1987

A nutritional quality and rancidity of marketed korean traditional foods were assessed. That is, basic chemical analysis were done in Galbi-tang, Sullung-tang, Pibimbap, Pulkogi and Naeng Myon. Ca and P for the Galbi-tang and Sulung-tang and vitamin C for the Pibimbap were analyzed. Chemical analysis were done in Gangjung 4, Sanja 1, Parksan 6, Yoomilkwa, 4 out of korean traditional cookies. Amounts of energy and protein in Galbi -tang and protein and Ca in Sullung -tang are more than the recommended allowance at ta meal. Amounts of Ca in Galbi-tang and energy in SUllung-tang are less than the recommended . The amounts of energy and protein in Pibimbap, Pullkigi and Naeng Myon Except protein in Pullkogi are short of the recommended at a meal. And amounts of vitamin C in Pibimbap are short of the recommended, too. The content of carbohydrate in Korean traditional cookies is the highest one comparing to others. Contents of crude fat in Gangjung Parksan and Dasik which are made up of sesame, black sesame and pine nuts are higher than that of other Korean traditional cookies. Acid value and peroxide value in all Gangjung, Yoomilkwan and Sanja except the peroxide value in one Sanja product, are not in the excess of standard of peroxide value and acid value. The standard are 600meq/kg and 3 for peroxide value and acid value respectively in oil treated foods.

• Food Science and Preservation
• /
• v.17 no.1
• /
• pp.107-116
• /
• 2010

We prepared extracts from Ulmus davidiana (root, Korean source; URK) and Ulmus davidiana (bark, Korean source; UBK). URK extracts obtained with all tested solvents showed the highest antioxidant effects on fish oils. Both treatments containing 0.1% (v/v) extract from URK and UBK each showed that peroxide values of 30 meq/kg were maintained for 6 h and levels of 40 meq/kg were apparent for up to 18 h, indicating that antioxidative activity seemed to sustain during all tested time periods. Compared with commercial antioxidants, butanol and methanol extracts diluted to 0.05% (v/v) had similar antioxidative effects. Water and butanol UBK extracts diluted to 0.1% (v/v) both showed the highest antioxidative activities. After addition of metal ions, methanol and butanol URK extracts diluted to 0.1% (v/v) showed enhanced antioxidative activity. UBK ethanol extracts displayed superior antioxidative activity and a constant peroxide value throughout storage. However, in the case of Perilla oil, $\alpha$-tocopherol which is known as a natural antioxidant did not show any antioxidative activity except in the BHT. Methanol and butanol URK extracts diluted to 0.2% (v/v) showed superior antioxidative activities throughout the experiment. A methanolic UBK extract (0.2%, v/v) also had a similarly increased antioxidative effect. In tests involving addition of metal ions to all extracts, the methanolic UBK extract (0.2%, v/v) showed excellent antioxidative activity. When lard was tested, antioxidant levels did not differ significantly among extracts prepared using four different solvents at either 0.05% or 0.1% concentrations (both v/v). Addition of metal ions at levels of 0.05% or 0.1% (w/v) to these extracts had no significant additive effect on oxidation.

• Journal of Life Science
• /
• v.20 no.2
• /
• pp.161-168
• /
• 2010

White-skinned sweet potato (Ipomoea batatas L.) has been traditionally used for diabetes treatment and management in many countries. In this experiment, methanol extract of white-skinned sweet potato (WSPMe) at a dose of 100 or 200 mg/kg body weight was tested to evaluate its effect on renal damage in streptozotocin (STZ)-induced diabetic rats. Its efficacy was compared with that of insulin secretogogue, glimepiride ($50\;{\mu}g/kg$ body weight). Experimental diabetes was induced by a single dose of STZ (45 mg/kg, i.p.) injection. The WSPMe and glimepiride were administered orally for 14 days and the effects on glucose, renal markers including blood urea nitrogen (BUN), creatinine and lactate dehydrogenase (LDH), lipid peroxide (LPO) level, antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathion-S-transferase (GST) activities in kidney were studied. An increase in BUN, creatinine, LDH, glucose, LPO levels and decrease in SOD, CAT, GPx and GST features were observed in diabetic control rats. Administration of WSPMe at a dose of 200 mg/kg body weight caused a significant improvement in blood glucose, LPO level, renal markers, lipid peroxidation markers and increased antioxidant levels in diabetic kidney. In conclusion, the WSPMe was found to be effective in reducing oxidative stress, thus confirming the ethnopharmacological use of I. batatas L. in protecting diabetes and its complications.

• Journal of Life Science
• /
• v.19 no.9
• /
• pp.1284-1288
• /
• 2009

To produce high quality fish oil products, additional deodorization experiments on purified fish oil from squid using columns filled with citric acid or gluconic acid were performed. A deodorization effect on the fish oil was observed on both the citric acid and gluconic acid columns. These effects were more efficient on the columns packed with 3 g of organic acid than those with 1 g or 2 g of organic acid. In addition, a better effect was observed in the column packed with gluconic acid than that with citric acid. Peroxide value (POV) and acid value (AV) of the sample treated with citric acid was the as same as the non-treated sample. However, POV and AV of the sample treated with gluconic acid were about 10% higher than the non-treated sample. Contents of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) of the samples treated with citric acid or gluconic acid columns were about 0.5% higher than the non-treated sample. In conclusion, deodorization of squid fish oil by organic acid could be an efficient method to produce high quality fish oil products.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.41 no.6
• /
• pp.745-751
• /
• 2012

The purpose of this study was to investigate the quality characteristics and antioxidative effect of Yukwa prepared with Lycii fructus powder (LFP). The Yukwas were stored at $50^{\circ}C$ for 40 days. Yukwa dough prepared with 5% LFP demonstrated higher pH and density value compared to the other groups and control. For color values, as more LFP was added, the L-value decreased, whereas the a-value and b-value increased. The hardness of Yukwa made with 7% LFP was the highest among all samples. The results of a sensory evaluation test showed that Yukwas with 5% LFP was most preferable in terms of overall acceptability compared to the others. The acid, peroxide, and thiobarbituric acid values were lower in Yukwa prepared with 5% LFP compared to Yukwa prepared with 3% or 7% LFP, as well as control Yukwa.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.21 no.5
• /
• pp.484-489
• /
• 1992

The present study was designed to evaluate the effects of dietary coenzyme $Q_{10}$ and vitamin E on hepatic lipid metabolism changes in adriamy cin(ADR)-treated rats. ADR treatment significantly increased the plasma levels of lipid peroxide in rats. But this increase was reduced by dietary supplementation of coenzyme $Q_{10}$ or vitamin E. Catalase and glutathione peroxidase activities were not greatly changed by ADR treatment, but the activities were significantly increased by dietary coenzyme $Q_{10}$. There was a tendency of lower superoxide dismutase activity in ADR-treated rats. However, coenzyme $Q_{10}$ administration induced this enzyme activity. The contents of cholesterol and phospholipid in liver were elevated by ADR-treated. Dietary coenzyme $Q_{10}$ reduced the increased hepatic cholesterol content in ADR-treated rat.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.17 no.4
• /
• pp.376-383
• /
• 1988

The effect of dietary methionine level on lipid peroxidation of rats was studied. Rats were fed vitamin E- selenium- deficient diet or diet supplemented with various levels (0.3, 0.6, 0.9%) of methionine. In rat fed MF diet, body weight gain and feed efficiency ratio were decreased compared with those of control rats, but reversed by supplementation with 0.3 and 0.6% methionine. Lipid peroxide levels in plasma and hepatic mitochondrial fraction of MF group rats were significantly higher than those of control rats. However, supplementation with 0.6% methionine modified this increment. GSH-Px activity was decrased to varying degrees in erythrocyte and hepatic mitochondrial fraction from rats fed MF diet. Methionine supplementation did not affect induction of this enzyme activity. Examination of hepatocytes by electronmicroscopy showed that Influence of vitamin E, selenium, and methionine deficiency was mainly characterized by lipid droplets, swollen mitochondria and microvilli destruction. Supplementation with various levels of dietary methionine modified these changes to some extent. The results of this experiment indicated that MF diet causes significant change in lipid peroxide level, GSH-Px activity and morphology of rats which these changes may lessen by supplementation with 0.6% methionine.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.30 no.5
• /
• pp.714-718
• /
• 1997

The tendency of rancidity in roasted and/or reheated yellowfin sole and yellow croaker was investigated as typical white muscled fish. In fatty acid composition of the total lipid, saturated fatty acid was $27.4\%,\;33.4\%$; monoenoic acid, $36.5\%,\;38.7\%$ and polyenoic acid, $34.5\%,\;26.5\%$ in yellowfin sole and yellow croaker, respectively. The ratio of unsaturated fatty acid (UFA)/saturated fatty acid (SFA) were 2,6, 2.0 and content of total lipid was $1.4\%,\;0.8\%$, respectively. Peroxide content decreased after heating in yellowfin sole while decreased after heating and tended to increase after reheating in yellow croaker. Thiobarbituric acid value increased during roasting and heating in all the samples but decreased after reheating. Acid value increased after roasting, heating and reheating in all samples, particularly higher in yellowfin sole which have a high content of UFA. Conjugated dienes continuously increased during the repeats of heating, showing more increase in the fillet with Skin than the skinless.

• Korean Journal of Food Science and Technology
• /
• v.31 no.3
• /
• pp.600-605
• /
• 1999

Methyl linoleate was oxidized at 60, 90, 120 and $150^{\circ}C$, respectively, with sparging oxygen for different periods of time. On the basis of the peroxide values determined at four temperatures, four heating times were chosen for the analysis of physicochemical parameters, such as peroxide value, total oxidation products, polymer content, viscosity, refractive index and characteristics of thermal degradation by DSC (Differential Scanning Calorimeter). The content of peroxide linkage (C-O-O-C) polymer and ether or carbon to carbon linkage (C-O-C/C-C) polymer were analyzed by High Performance Size Exclusion Chromatography (HPSEC). The polymer formed at four temperatures was qualitatively identified as dimer. The polymer with peroxide linkage (C-O-O-C) were detected from methyl linoleate oxidized at $60^{\circ}C\;and\;90^{\circ}C$, but they were not detected from methyl linoleate oxidized at $120^{\circ}C\;and\;150^{\circ}C$. The enthalpy changes increased as peroxide value increased whereas maximum degradation temperature decreased. The highest correlation coefficients were obtained between maximum degradation temperature $(T_m)$, exothermic enthalpy changes and peroxide value, peroxide linkage (C-O-O-C) polymer content.