• Food Science and Preservation
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• v.16 no.6
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• pp.884-892
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• 2009

We determined the chemical changes occurring in oil after exposure to high temperatures for various periods of time. Alterations in the chemical parameters of oil after heating for 30, 60, 90, and 120 min at 120C were investigated. The study involved cold-pressed perilla oil (CPPO), virgin perilla oil (VPO), and commercial heat press-extracted perilla oil (CHPEPO), and we assessed quality properties such as Hunter's color values, browning color intensity, acid value, conjugated dienoic acid level, peroxide value, total phenolic content, electron-donating ability, and fatty acid concentration. Hunter L values were higher for CPPO than for VPO or CHPEPO, whereas browning color intensity was greatest for CHPEPO. Peroxide value data showed higher levels of oxidation products in CPPO than in VPO or CHPEPO, whereas conjugated dienoic acid level was most increased in CHPEPO. The content of total phenolics and electron-donating ability were higher in CHPEPO than in CPPO or VPO. After thermal treatment, fatty acid content was most altered in CPPO; in particular, the level of polyunsaturated fatty acids dropped significantly. Hunter L value, acid value, conjugated dienoic acid level, and peroxide concentration also increased whereas Hunter a and b values, browning color intensity, and total phenolic content were decreased in perilla seed oils after thermal oxidation treatment.

• Food Science of Animal Resources
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• v.29 no.5
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• pp.612-618
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• 2009

The objective of this study was to determine the antioxidant and antimicrobial effects of garlic juice and onion juice in emulsified sausage during cold storage. The sausages were into five groups: control, 1% garlic juice (T1), 3% garlic juice (T2), 1% onion juice (T3), and 3% onion juice (T4). Each sausage type was tested in triplicate and assigned to one of four storage periods: 0, 7, 14 and 21 days. As storage time increased, the presence of garlic juice and onion juice resulted in decreased pH, residual nitrite value, and increased peroxide value, TBARS (thiobarbituric acid reactive substance) values, and total plate counts. The pH value, peroxide value, TBARS, residual nitrite and total plate counts were significantly decreased by the addition of garlic and onion juice relative to the control (p<0.05). Especially, T2 was significantly (p<0.05) more effective in delaying lipid oxidation compared to the other treatment groups. However, no significant difference (p<0.05) was found in total plate counts among all the formulations on day 0. Also, the use of garlic juice resulted in much better antioxidant and antimicrobial effects than the use of onion juice and the control. In conclusion, this study demonstrates that the addition of 3% garlic juice (T2) to emulsified sausages tended to improve antioxidative and antimicrobial effects during storage relative to the other treatment groups.

• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1179-1183
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• 1998

Effects of gamma irradiation on beef spoilage were investigated by determination of the peroxide value, TBA value and total volatile basic nitrogen for 10 days at $4^{\circ}C$ or $25^{\circ}C$ after gamma irradiation up to 5 kGy in air or vacuum package. The total lipid contents were $4.4{\sim}4.7%$ and were not significantly changed by gamma irradiation up to 5 kGy. The peroxide value and thiobarbituric acid value increased with the elapse of the storage period. The level of lipid oxidation was higher at $25^{\circ}C$ than at $4^{\circ}C$ and higher in air package than in vacuum package and increased depending on the incremental irradiation doses level. Volatile basic nitrogen showed a lower content in the vacuum packaged samples irradiated at $3{\sim}5\;kGy$ than in non-irradiated samples over the storage period.

• Korean Journal of Food Science and Technology
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• v.23 no.4
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• pp.517-519
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• 1991

The effect of glucose oxidase (GO) and superoxide dismutase (SOD) on the oxidative stability of fish oil was investigated from oxygen content and peroxide value determinations of oil samples stored in vial. GO could inhibit the oxidation of the oil by removing headspace oxygen. When SOD was solubilized in the oil, peroxide value was slightly lower than that of a control, indicating that the enzyme also had an effect on retarding the oxidation.

• Journal of Food Hygiene and Safety
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• v.16 no.1
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• pp.41-47
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• 2001

The purpose of this study was to elucidate the effects of green tea catechins (GTC) on the lipid peroxidation and superoxide dismutase (SOD). GTC showed the high SOD activity, while sitgnificantly inhibited the peroxide value of linoleic acid (93%) and lipid peroxidation (84%) from rat liver microsomal fraction induced by Fe$^{2+}$ascorbate system. The effects of GTC on the SOD and catalase activities, and lipid peroxidation after oral administration were investigated. GTC (50 mg/kg) significantly increased SOD (62%) and catalase activities (75%), while significantly inhibited the lipid peroxidation (52%) of rat liver microsome in a dose-dependent manner. These results suggest that GTC has the antioxidative effect which is rotated to the prevention of aging and cancer.r.

• Fisheries and Aquatic Sciences
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• v.13 no.3
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• pp.231-235
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• 2010

The effects of various natural antioxidant sources on oxidation of olive flounder (Paralichthys olivaceus) and fish diet during storage was determined. Juvenile fish were distributed among 18 flow-through tanks (40 fish per tank). Six experimental diets were prepared in triplicate: control (CT), antitox (AT), green tea extract (GE), fig extract (FE), Haeroc product (HP) and by-product of green tea (BG). The experimental diets were stored at two temperatures: room temperature ($26.8^{\circ}C$) for 14 days and frozen ($-30^{\circ}C$) for 16 weeks. Thirty fish were sampled from each tank at the end of the 8-week feeding trial. Whole bodies of fish were homogenized and stored in a home freezer ($-9.6^{\circ}C$) for 24 weeks. Acid values (AVs) and peroxide values (POVs) of the diets and frozen fish during storage were monitored. AVs of the experimental diets tended to increase with the storage period except for that of the HP diet at room temperature. POVs from FE, CT, and BG diets peaked at day 7 and then decreased through the remainder of the experiment. AVs of the experimental diets and fish increased with time at $-30^{\circ}C$ and $-9.6^{\circ}C$. Results of this study show that by-products of green tea and Haeroc product seem to have potential as antioxidants in fish feed to inhibit oxidation of both the feed and fish during storage.

• Korean Journal of Food Science and Technology
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• v.44 no.3
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• pp.287-292
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• 2012

Light effects on temperature dependence of safflower oil oxidation and tocopherol degradation were studied. Safflower oil was oxidized at 20, 40, 60, or $80^{\circ}C$ for 30, 30, 15, and 6 days, respectively, in the dark or under light. Oil oxidation was evaluated with peroxide value (POV) and conjugated dienoic acid (CDA) value, and tocopherols were monitored by HPLC. Safflower oil consisted of palmitic, stearic, oleic, and linoleic acids at 7.3, 2.0, 14.2, and 76.6%, respectively, with tocopherols at 1157.1 mg/kg. Peroxide and CDA values of safflower oil increased while tocopherol contents decreased with the oxidation time and temperature. Light increased and accelerated the oil oxidation and tocopherol degradation. Temperature dependence of the oil oxidation and tocopherol degradation was higher in the dark rather than under light. The results suggest that temperature control could be more essential in the dark rather than under light with regard to the oxidative stability of safflower oil.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.526-532
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• 2009

Quenching mechanisms and kinetics of $\alpha$-, $\beta$-, $\gamma$-, and $\delta$-tocopherol in photosensitized oxidation of lard were studied. Lard at 0.03, 0.07, 0.11, and 0.3 M in methylene chloride containing $4.4{\times}10^{-6}\;M$ chlorophyll and 0, 0.1, 0.3, and 0.6 mM $\alpha$-, $\beta$-, $\gamma$-, and $\delta$-tocopherol were stored under light for 4 hr, respectively. Oxidation was determined by headspace oxygen and peroxide value. Tocopherols prevented the photosensitized oxidation of lard (p<0.05). Steady state kinetic study showed that $\alpha$-, $\beta$-, $\gamma$-, and $\delta$-tocopherol prevented the photosensitized oxidation of lard by quenching singlet oxygen. Singlet oxygen quenching rates of $\alpha$-, $\beta$-, $\gamma$-, and $\delta$-tocopherol by headspace oxygen depletion were 1.86, 2.39, 2.47, and $2.11{\times}10^7/M/sec$, respectively. The quenching rates of $\alpha$-, $\beta$-, $\gamma$-, and $\delta$-tocopherol by peroxide value were 1.42, 1.11, 0.97, and $0.42{\times}10^7/M/sec$, respectively. The quenching rates of tocopherols were slightly different depending on the measurements of oxidation.

• Korean journal of food and cookery science
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• v.33 no.3
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• pp.275-284
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• 2017

Purpose: This study was performed to evaluate the effects of sannamul or herb extract addition to a soybean oil-in-water emulsion during photooxidation in the presence of chlorophyll. Methods: The emulsion mainly consisted of purified soybean oil and citric acid buffer (pH 4.0) at a weight ratio of 4 to 6, with chlorophyll a addition at 6 mg/kg. Ethanol extract of daraesoon, samnamul, basil, or peppermint was selectively added to the emulsion at 400 mg/kg, and emulsions in glass serum bottles were oxidized at $5^{\circ}C$ under 2,600 lux light for 48 hours. Lipid oxidation of the emulsions was evaluated based on determination of headspace oxygen content, peroxide value, and p-anisidine value. Pigments and antioxidants were also monitored. Results: The emulsion with added samnamul extract with high contents of polyphenols and low chlorophyll content showed lower oxygen consumption, peroxide values, and p-anisidine values, whereas basil and peppermint extracts with high chlorophyll contents increased photooxidation. Chlorophylls were degraded during photooxidation of the emulsions, and the degradation rate was highest in the emulsion with added samnamul extract. Conclusion: The high antioxidant activity of samnamul extract in the photooxidation of soybean oil-in-water emulsion could be due to low chlorophyll content, high concentrations of polyphenol compounds in the extract, as well as rapid degradation of chlorophylls during oxidation.

• Food Science of Animal Resources
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• v.40 no.5
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• pp.785-794
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• 2020

Food Codex regulations have set freshness limits for oils used to fry food, such as potato and fish products, and fried food itself; however, no such freshness limits have been set for meat products, such as sweet and sour pork. The freshness standard suggest that acid values (AVs) and peroxide values (POVs) for frying oil should be less than 2.5 and 50, respectively, whereas AVs and POVs for common fried food should be less than 5.0 and 60, respectively. Therefore, in this study, we investigate the effect of the number of frying cycles on oxidation-promoted changes in the oils used to fry sweet and sour pork and fried food itself during repeated frying over 10 d by determining their AVs and POVs, which were found to be highly correlated. Soybean, canola, palm, and pork lard oils could be reused approximately 37, 32, 58, and 87 times, respectively, to fry sweet and sour pork based on oil freshness, and 78, 78, 81, and 286 times, respectively, based on the freshness of fried food. Our data may help establish food-quality regulations for oils used to fry animal-based foods.