• Korean Journal of Food Science and Technology
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• v.20 no.4
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• pp.569-575
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• 1988

Storage stabilities of ramyons fried in palm oil and beef tallow with added antioxidants and their synergists were investigated by comparing the changes in physicochemical parameters and n-hexanal concentrations of oils extracted from ramyons during storage. Ramyons fried in palm oil and beef tallow with added ${\delta}-tocopherol$ $({\delta}-toc)$ showed an enhanced storage stabilities when compared to those fried in the oils with ${\alpha}-tocopherol$ $({\alpha}-toc)$. Ascorbyl palmitate was found to be a better synergist than citric acid for the antioxidant activity of both ${\delta}-toc\;and\;{\alpha}-toc$. Phenolic antioxidants gave a better storage stability than tocopherol when ramyon was fried in beef tallow, while a mixture of BHA and BHT gave an inferior storage stability than${\alpha}-toc$ when ramyon was fried in palm oil. The effectiveness of the antioxidants tested on storage stability of stored ramyon had a close relationship to the n-hexanal concentration. On the other hand, the paramenters such as peroxide value, carbonly value, and conjugated diene concentration showed inconsistency during the course of the storage experiment.

• Korean Journal of Food Science and Technology
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• v.20 no.4
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• pp.493-497
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• 1988

Peroxide value (POV), acid value (AV), color and flavor of soybean oil packaged with polyethylene (PE) bottle and Tetra-pack were periodically checked at $60^{\circ}C,\;40^{\circ}C$ for 33 days. POV more quickly increased when the storage temperature became higher. Kinetics of POV was followed the zero-order reaction rate. $Q_{10}$ values of those were in 1.8 in PE bottle and 2.1 in Tetra-pack at $20-40^{\circ}C$. Sensory scores were stable in PE bottle and Tetra-pack $20-40^{\circ}C$ and in Tetra-pack at $60^{\circ}C$, but those reached to the critical sensory point of 5 in PE bottle at $60^{\circ}C\;after\;30^{\circ}C$ days storage. Therefore, shelf-life of soybean oil could be predicted as 14.1 months and 7.8 months in PE bottle and 32.6 months and 22.5 months in Tetra-pack at $15^{\circ}C\;and\;25^{\circ}C$ by reaction rates of POV, $Q_{10}$ values and sensory scores.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.3
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• pp.231-238
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• 1983

An investigation on optimum condition for processing of salted-dried sardine and quality change of the product during the storage was carried out. The fillets of sardine were salted in 5, 10 and $15\%$ NaCl solution for 12, 24 and 36 hours at $9-10^{\circ}C$, respectively and air-blast dried at $24-25^{\circ}C$ with a velocity of 3 m/sec and then stored at room temperature for 30 days. The results were as follows : The optimum condition for the product was salting in $15\%$ NaCl solution for 36 hours as VBN and histamine contents were 27.5 mg/100g and 42.5 mg/100g, respectively, and also showed a good result in sensory evaluation. Histamine, VBN and TMA-N content of the dried fillets immediately after salting in $15\%$ NaCl solution for 36 hours increased to 47.8 mg, 29.5 mg and 5.4mg per 100g of the sample, respectively and increased slowly during the storage. The peroxide value and acid value of the lipid extracted from the product increased from 15.9 meq/kg to 114.0 meq/kg, and 12.6 to 30.5 during the storage. In the fatty acid composition, $C_{22:6}\;and\;C_{20:5}$ acids were decreased during the storage period.

• Polymer(Korea)
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• v.33 no.3
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• pp.224-229
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• 2009

The dielectric properties of semi-IPN poly(phenylene oxide)(PPO) blend/$BaTiO_3$(BT) composites are investigated. The composites are fabricated via melt-mixing of crosslinker and peroxide in precursor PPO composite obtained by precipitating the suspension consisted of PPO, BT and toluene into methylethyl ketone, poor solvent of PPO. The permittivity of the precursor PPO composites shows higher value than that of integral-blended PPO composites by extruder and coincides with the theoretical value calculated by logarithmic rule of mixture. The blend of PPO and cross-linked triallyl isocyanurate is most effective for lowering the permittivity and loss tangent owing to the suppression of the orientation polarization of matrix. In contrast, 4,4'-(1,3-phenylene diisopropylidene) bisaniline, which has amine unit in its structure, increases the permittivity as well as loss tangent of the composite, but it has the ability to densify the matrix resin and the interfacial adhesion between the matrix and filler to improves flexural strength and modulus.

• Korean Journal of Food Science and Technology
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• v.29 no.4
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• pp.722-729
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• 1997

The study was undertaken to extend the shelf life of filleted and salted fishes such as mackerel and jacopever. These filleted and salted fishes were dehydrated by dewatering sheet containing sodium polyacrylate resin at $5{\pm}1^{\circ}C$, wrapped with low density polyethylene film, and then stored at $-18{\pm}2^{\circ}C$. During the frozen storage, the change of brown pigment formation, peroxide value, carbonyl value, drip formation content in the cold-osmotic dehydrated fishes after salt dipping were much lower than those of non-dehydrated ones. Moreover, the proteins and Ca-ATPase in the cold-osmotic dehydrated fishes after salt dipping were more stable than those of non-dehydrated ones during frozen storage. It was supposed that the cold-osmotic dehydration pretreatment processing for filleted and salted fishes was useful in improvement of the frozen storage stability.

• Korean Journal of Food Science and Technology
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• v.33 no.6
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• pp.728-736
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• 2001

Effects of packaging material and oxygen absorbant on physical and chemical properties of Yukwu were studied during storage to develop packaging conditions. The packaging materials used were PET/EVOH $(16\;{\mu}m)/PL$ : P1 and PET/EVOH $(24\;{\mu}m)/PL$ : P2 with or without oxygen absorbent (E1A : P1 and E2A : P2 for w/ $O_2$, absorbent, E1EA : P1 and E2EA : P2 for w/o $O_2$, absorbent). Color values for Yukwu indicated that L values of E1A, E1EA, E2A and E2EA were decreased during storage while those b values were increased. Hardness and chewiness of Yukwa were generally decreased, however those of E1A and E1EA were rather increased after 6 weeks of storage. Acid value of E2A had maintained less than 2.0 during 12 weeks of storage. E1A, E2A had the below of 20 in peroxide during 12 weeks. Aroma data by using electronic nose showed that there was no difference after 6 week storage time in different packaging materials. Sensory evaluation (Yukwa odor and rancid odor) showed very similar results with electronic nose one. E2A had the highest value of overall acceptability for sensory evaluation. Hardness and cheweness in physical measurement results had the highest correlation with hardness, crispness, overall-acceptability in sensory evaluation results.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.889-892
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• 2002

Barley bran and germ fractions were collected during pearling process. Barley polyphenol extract (BPE) was separated from the pearling fractions, and its antioxidative activity was determined through linoleic acid model system and lipid autoxidation model using corn oil as a substrate. At 0.02% addition level, thiobarbituric acid (TBA) value of BPE from bran fraction III appeared to be similar to that of ${\alpha}-tocopherol$, and bran fraction I and germ extract exhibited similar antioxidative activities to that of BHT. Peroxide value was measured to estimate antioxidative activity of BPE upon lipid autoxidation. As BPE concentration increased, higher antioxidative activity was observed compared to ${\alpha}-tocopherol$ and BHT until 10-15 day storage, whereas no effect was shown after 20-day storage. Relative antioxidant effectiveness (RAE) of $0.02{\sim}0.1%$ BPE from bran fraction I and germ were $128{\sim}135$ and $126{\sim}133$, respectively, and appeared to be higher than that of BHT (126), suggesting that these BPE fractions could be used as natural antioxidants.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.4
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• pp.551-557
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• 2009

The effects of feeding citrus byproducts on the quality of Korean native chickens were investigated during cold storage. Two samples of Korean native chickens (39 weeks old, $1.30{\pm}0.5$ kg) were used for the study: T0 (chickens not fed citrus byproducts) and T1(chickens fed a 4% citrus byproduct diets since from age 17 weeks until 39 weeks old). The breast and thigh meat of each sample were vacuum-packed, and then used for experiments on change in Hunter's color values, acid values (AV), peroxide values (POV), thiobarbituric acid (TBA) values, electron donating ability (EDA), volatile basic nitrogen (VBN) and total plate count during storage for two weeks at 3C. Changes in $L^*$, $a^*$ and $b^*$ values were slower in T1 than in T0. T1 showed slower increment rates for AV, POV, and TBA values during storage, as well as better antioxidant activity, than T0. T1 showed slower increment rates for VBN and total plate counts during storage than T0. Thus, feeding citrus byproducts suppressed change in Hunter's color value, rancidity, and freshness in breast and thigh meat during storage, and resulted in higher EDA value (p<0.05), which implies that the diet has positive effects in maintaining high meat quality.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.7
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• pp.948-952
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• 2005

The antioxidative and antimicrobial properties of the solvent extracts of 3 parts (leaf, stem, root) of Crotalaria sessiflora L. were investigated, in order to find out new natural food additives. The antioxidative activities of the extracts were determined by peroxide value (POV) and the conjugated diene value (CDV) of corn oil stored for 30 days at $60\pm2^{\circ}C$. Each part of the extracts were added as $0.02,\;0.05\%$ and then compared with BHT. The anti oxidative activities were as follows in decreasing order: BHT > LeafEX > StemEX > RootEX > control. The induction period showed that the part of the Crotalaria sessifloria L. group added with solvent extract showed a longer induction period compared with the control group. The part of Crotalaria sessiflora L. solvent extract were shown to have antimicrobial effects on the microorganism such as Bacillus subtilis, Staphylococcus aureus, Listeria monocytogenes, Salmonella Enteritidis, Pseudomonas flrourescens and Escherichia coli. Especially the effect on the Pseudomonas flrourescens was remarkable.

• Journal of the Korean Society of Food Science and Nutrition
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• v.18 no.3
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• pp.247-254
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• 1989

In deep-fat frying, the fats and oils are used over and over again, and moisture and air are mixed in to the hot oil. Many reports related to these fats and oils have been established that thermal and oxidative decomposition products and polymers formed under the conditions of deep fat frying are harmful to health. This work was carried out with 3 domestic frying oils and 6 used oils commercially, and that there were difficulties in finding a good definition between fresh oil and used oil with adding unheated oil. As starting materials, commercially used soybean oil and rapeseed oil already passed over induction period in the lipids oxidation standard. From the qualitative point of view, they were inferior to domestic frying oils. Free fatty acid and peroxide value of heated oils were increased gradually by the time pass whereas iodine value were decreased. After adding unheated oil to the heated oil, these values were restored to that of initial levels. On the other hand, content of polar components in the heated oil were directly related to the heating time. This result showed that polar compounds may be a clear indicator of used oils. Fatty acid composition in the used oils, unsaturated fatty acids such as linoleic and linolenic acid decreased while saturated fatty acid content increased with heating.