• Korean Journal of Food Science and Technology
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• v.28 no.1
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• pp.179-183
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• 1996

The objective of this study was to investigate the difference of oxidative stability between DHA (docosahexaenoic acid) added and not added commercial mayonnaise, and then to find out stable condition for maintaining the quality of DHA added mayonnaise. During the storage at room temperature $(25^{\circ}C{\pm}1^{\circ}C)$, it showed that DHA added commercial mayonnaise was more sensitive to oxidation than DHA not added commercial mayonnaise. And sensory quality of DHA added commercial mayonnaise decreased drastically after 5 months from the production date of mayonnaise. During the storage at low temperature $(4^{\circ}C{\pm}1^{\circ}C)$, DHA added mayonnaise was also more sensitive to oxidation than DHA not added mayonnaise, but it showed no apparent and sensory problem with both samples during 8 months of cold storage test periods. In considering the distribution condition of mayonnaise in the country, it was suggested that shelf-life of the DHA added commercial mayonnaise should be shortened 2 or 3 months than that of the DHA not added commercial mayonnaise.

• Preventive Nutrition and Food Science
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• v.6 no.4
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• pp.201-205
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• 2001

As a series of studies on improving the processing suitability of imported Pacific saury, oxidative stability of seasoned-dried Pacific saury treated with liquid smoke (T2 product) was examined during storage, comparing with control (C, seasoning only) and T1 (treatment of 0.05% BHT instead of liquid smoke). The pH of T2 treated with liquid smoke was relatively lower than those of C and T1 during storage. The contents of volatile basic nitrogen in all products increased continuously during storage. In the changes of TBA and POV of products during storage, the POV of T2 was lower than that of T1, and the TBA values of T1 and T2 were lower than that of C product. The major fatty acids were 22 : 1n-11, 20 : 1n-11, 16 : 0, 14 : 0, 22 : 6n-3, 20 : 5n-3, 18 : 4n-3, 16 : 1n-7, 14 : 1n-7 and 18 : 1n-9 in the both C and T2 products. The contents of polyunsaturated fatty acids in hath C and T2 somewhat decreased with increasing storage period, while those of saturated and monounsaturated fatty acids increased.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.2
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• pp.231-234
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• 2000

To evaluate the effect of frying times on the oxidative stability of soybean oil and shortening, they were reused up to 10 times and measured by thiobarbituric acid(TBA) value, acid value(AV), peroxide value(POV) and sensory evaluation. As the reusing time was increased, TBA value of "battered pork" fried with shortening showed more sharply increased than that with soybean oil, while the value of shortening, itself, showed more decreased than that of soybean oil. In frying fat, AV and POV increased with the increase of reusing times. Compared with soybean oil, shortening had rapidly increased for POV as reusing time was increased. Among the sensory analyses TBA of "battered pork" with soybean oil and shortening exhibited the highest correlation with flavor and texture, respectively. For the "batgtered pork" fried with soybean oil and shortening, reusing shelf-lives predicted were approximately 9 and 8 times, respectively.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.212-212
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• 2011

In addition to the catalysts' activity and selectivity, the deactivation of catalysts during use is of practical importance. It is crucial to understand the phenomena of the deactivation to predict the loss of activity during catalyst usage so that the high operational costs associated with catalyst replacement can be reduced. In this study, the activity of Ru catalysts, such as nanoparticles (3~6 nm) and polycrystalline thin film (50 nm), have been investigated under CO oxidation and oxidative/reductive reaction conditions at various temperatures with the ambient pressure X-Ray photoelectron spectroscopy (APXPS). With APXPS, the surface oxides on the catalyst are measured and monitored in-situ. It was found that the Ru film exhibited faster oxidation-and-reduction compared to that of nanoparticles showing mild oxidative-and-reductive characteristics. Additionally, the larger Ru nanoparticles showed a higher degree of oxide formation at all temperatures, suggesting a higher stability of the oxide. These observations are in agreement with the catalytic activity of Ru catalysts. The loss of activity of Ru films is correlated with bulk oxide formation, which is inactive in CO oxidation. The Ru nanoparticle, however, does not exhibit deactivation under similar conditions, suggesting that its surface is covered with a highly active ultrathin surface oxide. Since the active oxide is more stable as nanoparticles than as a film, the nanoparticles showed mild oxidative/reductive behavior, as confirmed by APXPS results. We believe these simultaneous observations of both the surface oxide of Ru catalysts and the reactivity in real time enable us to pinpoint the deactivation phenomena more precisely and help in designing more efficient and stable catalytic systems.

• Korean Journal of Food Science and Technology
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• v.22 no.1
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• pp.7-12
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• 1990

The effect of $Fe^{2+}$ and myoglobin on the oxidative stability of triglyceride molecular species was investigated at $25^{\circ}C$. The molecular species of soybean oil triglycerides were analyzed by capillary column gas chromatography and electron impact ionization mass spectrometry utilizing selected ion monitoring. When $Fe^{2+}$ and myoglobin were added to soybean oil triglycerides, the oxidative stability of each molecular species of triglycerides appeared to decrease in proportion to the increase in the number of double bonds present in the acyl residues, and it was affected by degree of unsaturation of fatty acid when the total degree of unsaturation of triglyceride was the same. But the length of the saturated acyl chain had no influence on the stabilization of unsaturated fatty acid present in the same glyceride when prooxidants were added.

• Korean Journal of Poultry Science
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• v.35 no.1
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• pp.29-37
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• 2008

This study was evaluated the oxidative stability of the breast and leg meat from chicken fed extract of medicinal herb mix (Lonicera japonica Thunberg : Morus alba L. : Coptis chinensis = 48.5 : 48.5 : 3.0%) and antibiotics (Albac G150). Ross chickens were divided into three treatments: basal diet (control), basal diet with antibiotics (0.05%) and basal diet with extract of medicinal herb mix (0.3%). They were fed the experimental diets for 35 days and slaughtered. After that, the breast and leg meat samples were stored at $4^{\circ}C$ for 10 days. Total phenol content of breast meat in Ross chicken fed extract of medicinal herb mix was higher than that of antibiotics treatment and control during storage. DPPH radical scavenging activity was the highest in leg meat of Ross chicken fed extract of medicinal herb mix at 0 day. $ABTS^+$ reduction activity was higher in chicken meat fed extract of medicinal herb mix than antibiotics treatment and control. This results showed that the diet with extract of mixed medicinal herb was more effective in oxidative stability of chicken meat than basal diet and diet with antibiotics.

• Korean Journal of Food Science and Technology
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• v.26 no.2
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• pp.178-183
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• 1994

The fresh perilla seed and tile one-year stored perilla seed were solvent extracted for their oil. On the other hand, the fresh seed and the stored seed were germinated in the dark at $25{\sim}28^{\circ}C\;for\;2{sim}3$ days and then solvent extracted. The above four kinds of perilla oil, that is, the oil from the nongerminated and fresh seed(NFO), the oil from the nongerminated and one-year stored seed (NSO), the oil from the germinated and fresh seed(GFO), and the oil from the germinated and one-year stored seed(GSO) were analyzed with regards to the chemical composition, and the effects of germination of the seed on the oxidative stability of perilla oil were studied. The iodine value and the saponification value were similar in all the perilla oils, but the acid value was increased by germination of the seed. The contents of free fatty acid and diacylglycerol were increased by germination of the seed, while the content of triacylglycerol was decreased. Of the polar lipid components, the content of phosphatidyl ethanolamine was greatly increased by germination of the seed. The contents of total tocopherol of perilla oil from the fresh seed and the one-year stored seed were 494 ppm and 439 ppm, respectively, and by germination of the seed increased to 560 ppm in GFO and 515 ppm in GSO, respectively. Especially a great change in the content of ${\gamma}-tocopherol$ was observed. The oxidative stability of perilla oil was increased by germination of the seed and the increase was distinct in the case of the one-year stored seed compared with that in the case of the fresh seed.

• Food Science of Animal Resources
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• v.32 no.4
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• pp.491-496
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• 2012

The objective of this research was to investigate the effect of the fattening period (18, 21, and 24 mon) on the oxidative stability of Holstein beef patties. The ground Holstein steer beef samples (M. longissimus dorsi) were stored at $4^{\circ}C$ for 12 d and used for lipid oxidation, protein oxidation, myoglobin oxidation, and color measurements. Fat content was significantly (p<0.05) higher in the 24 mon group than in the 18 mon group. 2-thiobarbituric acid reactive substances content and metmyoglobin concentration were the highest (p<0.05) in the 24 mon group from 8 d of storage. Conjugated dienes content was significantly (p<0.05) higher in the 21 and 24 mon groups. Carbonyl content was the highest (p<0.05) in the 24 mon group at 12 d of storage. In surface meat color, the CIE $L^*$ value showed a lower level in the 21 and 24 mon groups from 4 d of storage. Although the CIE $a^*$ value was further lowered, the CIE $b^*$ value maintained a higher value in the 24 mon group during storage, compared to the other groups. Therefore, greater fattening period increased lipid oxidation, protein oxidation, and myoglobin oxidation in Holstein beef patties. Partially, the 24 mon group had the lowest oxidative stability.

• Korean Journal of Food Science and Technology
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• v.32 no.2
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• pp.246-251
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• 2000

This study was investigated to compare the changes of antioxidative compounds in sesame oil with roasting temperature$(110^{\circ}C{\sim}230^{\circ}C)$. Lightness was decreased markedly over $170^{\circ}C$. In the changes of lignan contents, 7 different lignans unchanged up to $170^{\circ}C$ and sesamolin and sesamin decreased markedly, whereas sesamol, unknown1, unknown3 increased drastically at the higher temperatures. In tocopherol contents, ${\gamma}-tocopherol$ decreased from 70.59 mg% in unroasted oil to 33.87 mg% at $220^{\circ}C$, and to 26.73 mg% at $230^{\circ}C$. In the result of AOM(active oxygen method) test carried out at $120^{\circ}C$ for evaluating oxidative stability, the induction period of unroasted oil was 4.12 hrs and that of roasted oils was increased with roasting temperature (induction period at $220^{\circ}C$ was 27.9 hrs.). From the above results, it was confirmed that correlation coefficient between oxidative stability and lightness is -0.993 and that between oxidative stability and sesamol content is 0.934 above $170^{\circ}C$. Therefore its remarkable oxidative stability with the roasting temperature, might be considered to be due to the increase of sesamol, other lignans(unknown 1, unknown 3).

• Animal Bioscience
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• v.36 no.5
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• pp.785-796
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• 2023

Objective: We aimed to evaluate the color and oxidative stability of beef gluteus medius (GM) from cattle raised in organic and non-organic production systems. Methods: The GM samples (n = 10) were obtained from organic (ORG; n = 5) or nonorganic (NORG; n = 5) beef samples, sliced into 2.54-cm steaks, packaged in aerobic conditions, and stored for nine days at 4℃. ORG and NORG steaks were compared regarding myoglobin concentration, pH, instrumental color, delta E (ΔE), metmyoglobin reducing activity (MRA), and lipid oxidation on days 0, 5, and 9. Results: Feeding system did not influence (p>0.05) the myoglobin concentration. ORG steaks exhibited greater (p<0.05) meat pH, yellowness, and MRA, whereas NORG steaks exhibited greater (p<0.05) redness, chroma, R630/580, delta E, and lipid oxidation. ORG and NORG steaks exhibited similar (p>0.05) lightness and hue angle. During storage, ORG and NORG exhibited an increase in muscle pH, hue angle, and lipid oxidation; and a decrease (p<0.05) in redness, yellowness, chroma, and color stability (R630/580). Both samples exhibited a stable (p>0.05) pattern for lightness and MRA. Conclusion: Therefore, the production system can affect beef color and lipid stability during storage.