Effects of glutamic acid (Glu) and monosodium glutamate (MSG) on oxidative stability of oil-in-water (O/W) emulsions with different emulsifier charges during riboflavin (RF) photosensitization were evaluated by analyzing headspace oxygen content and conjugated dienes. Cetyltrimethylammonium bromide (CTAB), Tween 20, and sodium dodecyl sulfate (SDS) were used as cationic, neutral, and anionic emulsifiers, respectively. Glu acted as an antioxidant in CTAB- and Tween-20-stabilized O/W emulsions during RF sensitization, whereas Glu acted as prooxidants in SDS-stabilized O/W emulsions in the dark. However, adding MSG did not have a constant impact on the degree of oxidation in O/W emulsions irrespective of the emulsifier charge. In RF-photosensitized O/W emulsions, the emulsifier charge had a greater influence on antioxidant properties of Glu than on those of MSG.

The purpose of this study was to investigate the antioxidant activities, quality characteristics, and storage stability of perilla oil mayonnaise (PM) with different levels of onion powder (OP) from 0 to 3%. As the amount of OP increased, the L, a, and b values increased, but pH decreased (p<0.05). The addition of OP raised viscosity (p<0.05). The addition of OP to PM proportionally increased the total phenolic content, and antioxidant activities as measured by DPPH and ABTS radical scavenging activity, and FRAP assay. When compared to PM without OP, PM that contained OP had a peroxide value that was almost 1.94 times lower. The emulsion stability was between 97.62 to 94.92% in the PM without OP and PM with OP groups was 99.60% for 12 weeks. This study showed that the inclusion of OP in PM has the potential to inprove its quality, antioxidant activities, and storage stability.

This study was carried out to investigate the effects of supercritical carbon dioxide (SC-CO2) extracts from sweet potatoes (SP) and watermelon (WM) on the oxidative stability of perilla seed oils (POs) over the existing ones. A comparison was done between the oxidative stability of perilla oil (PO) after the addition of 0.1% of SP, and WM extracts and PO without extract. The oxidative stability was measured based on the viscosity, acid value (AV), peroxide value (POV), antioxidant (DPPH) activity, p-anisidine value (p-AV), and fatty acid composition. The viscosities ranges were: PO without extract, from 53.99±0.99 to 74.38±1.61 cps, PO with SP extract, from 53.99±0.10 to 58.73±0.8 cps, and PO with WM extract, from 53.98±0.10 to 56.00±0.70 cps. While the PO containing the SC-CO2 extracts had significantly lower AV, POV, and p-AV, their antioxidant activity was approximately 10 times higher than that of the PO without extract. There were no significant differences in fatty acid composition between SC-CO2 extracts added groups and PO without extract (p<0.05). The findings of this study confirmed that the SC-CO2 extracts from sweet potatoes and watermelon enhanced the oxidative stability of perilla seed oils, and are potential natural antioxidants for use in the food industry.

육제품에 사용되는 합성 항산화제를 대체할 천연물질에 관한 관심이 높아지고 있다. 본 연구는 냉장 저장 중 아스타잔틴(AX)의 첨가가 유화형소시지의 산화 안정성 및 품질 특성에 미치는 영향을 조사하기 위해 무첨가구인 대조구, 500 mg/kg BHT (Butylated hydroxytoluene), 및 80 mg/kg AX으로 처리하였다. AX의 첨가는 유화형소시지의 pH, 유화 안정성 및 가열 수율에 유의적인 영향을 미치지 않았다(p>0.05). 그러나 육색의 경우 아스타잔틴 첨가구의 초기(day 1) 색상유지력은 합성 항산화제인 BHT와 동일하였고, 적색도는 높게 나타났다(p<0.05). 항산화 능력에서, 처리구간 단백질 산화는 유의 적인 차이가 없었다. 지질 산화의 경우 저장 종료시(day 14) BHT 처리구에서 가장 낮은 값을 나타냈으나 AX 첨가구 또한 무첨가구인 대조구보다 매우 낮게 나타났다(p<0.05). 한편, 경도는 저장 초기에 비해 저장 종료시 BHT와 AX 처리구들에서 대조구에 비해 낮게 나타났다(p<0.05). 그러므로 천연물질인 아스타잔틴은 기존에 사용되는 합성 항산화제인 BHT를 대체하여 항산화제의 역할뿐만 아니라 육제품의 색상 증진제로도 활용 가능할 것으로 판단된다.

The purpose of this study was to investigate the quality characteristics of roasted peanuts and the antioxidative effect of peanut oil added with sesame oil. Saltiness of roasted peanut increased with increasing salt content. In terms of color value, L and b values decreased as increasing concentration increased, whereas a value increased with increasing salt content. Overall, sensory evaluations proved that roasted peanuts with 15% added salt was preferred over other samples. For peanut oil added with sesame oil, acid values increased during the storage period, whereas samples made with sesame oil had lower values than the control group. Peroxide values increased rapidly for 21 days and then decreased. The acid and peroxide values were lower in peanut oil added with 50% sesame oil compared to peanut oil added with 30%, 10%, and 70% sesame oil, as well as the control. The TBA values of peanut oil made with 50% and 30% sesame oil were lower than those of the control and 70% and 10% sesame oil. According to the Rancimat method, PS-50% (524 min) and PS-30% (453 min) demonstrated longer induction periods as compared to the control (280 min), PS-70% (445 min), and PS-10% (291 min) samples.

Vegetable seed oils (VSOs) have been extracted and used not only as ingredients in food and as sources of dietary lipids, but also as sources of nutraceuticals used to overcome the various oxidative stresses that contribute to the development of diseases, including cancer and other chronic conditions. The chemical compositions and oxidative stabilities of various VSOs were therefore investigated; samples were stored for 35 d, with each oil having been tested under O2 exposure, sealed from O2 exposure and sealed from O2 exposure while containing O2 scavengers. Oxidative stability was evaluated by peroxide value (POV), p-anisidine value (p-AnV), iodine value (IV), and thiobarbituric acid (TBA) value. Perilla seed and flaxseed oil were mostly composed of linolenic acid (45.5% and 59.7%, respectively), whereas pine seed oil was mostly composed of linoleic acid (48.3%). Meanwhile, camellia seed and olive oils contained 80% oleic acid, which correlated strongly with oxidative stability. The POV, p-AnV, and TBA values were the highest under O2 exposure, and the lowest in the presence of O2 scavengers. These results indicate that VOS oxidative stability depends not only on storage conditions, but on unsaturated fatty acid profiles as well.

Surface-active substances in defatted rapeseed cake were obtained using a supercritical fluid extraction method. Then, it was purified by removing sinapine in the extract through a series of steps using a mixed solvent: diethyl ether and ethyl acetate (1:1, v/v). Emulsifying properties of purified surface-active substances were investigated, including fat globule size, zeta potentials and creaming stability and its antioxidant activity in emulsion systems were also studied by peroxide value and 1H-NMR spectrum. It was found that fat globules in emulsions with purified surface-active substances were much smaller than ones with the unpurified. In addition, as pH of the emulsion lowered and with increasing NaCl concentration in the emulsion, they were observed to increase, which led to worse creaming stability. These properties were reflected in changes of zeta potentials of emulsions. The oxidative stability was better in emulsions with purified surface-active substances than ones with Tween 20 or commercial lecithin, possibly resulted from the existence of sinapic acid in the extract. It was concluded that purified surface-active substances from defatted rapeseed cake could be simultaneously used as emulsifier and antioxidant agent in emulsion system.

This study aimed to investigate the changes in antioxidant activities, quality characteristics, and storage stability of mayonnaise prepared with perilla oil with the addition of mulberry powder ranging from 0 to 5%. The antioxidant activities of perilla oil mayonnaise (PM), as determined by DPPH and ABTS radical scavenging activity, as well as FRAP and total phenolics content were improved by the addition of mulberry powder compared with the control sample. Antioxidant activities were dependent on the amount of mulberry powder added. Lipid oxidation of PM decreased with a higher amount of mulberry powder, based on measurements of peroxide value. The emulsion stability of PM increased with decreases in the amount of mulberry powder level. The a-value in PM color increased with increasing amount of mulberry powder. Sensory evaluation showed that the highest score in overall acceptability of PM was achieved with 4% mulberry.

들기름 및 미강유를 베이스로 개발한 혼합 식용유는 오메가-3 지방산인 리놀렌산 함량이 약 20% 정도로 매우 높다. 이는 기존의 일반 식용유 중 오메가-3 지방 함량이 매우 높은 콩기름과 카놀라유의 리놀렌산 함량이 각각 6% 및 10% 내외인 점을 감안하면, 이들 식용유에 비하여 새로 들기름과 미강유를 혼합한 식용유는 2~3배 높은 비율로 오메가-3 지방산을 제공할 수 있어서, 오메가-3 지방산 섭취가 부족한 현대인의 식단에서 중요한 오메가-3 지방산 급원으로서의 역할을 할 수 있을 것이다. 뿐만 아니라, 토코페롤 함량도 약 46.77 ㎎/ 100 g oil 정도인데, 가장 주목할 일은 토코페롤 동족류 중 비타민 E의 활성이 가장 강한 알파-토코페롤(31.71 ㎎/100 g oil)이 가장 많이 존재하여, 총 토코페롤의 64%를 차지하고 있어서 비타민 E로서의 기능이 높다. 혈중 콜레스테롤 함량을 낮추는 기능성이 알려진 파이토스테롤 함량이 들기름과 미강유를 혼합한 식용유에 약 7,200 ppm 함유되어 있어, 일반적인 식용유의 3,000 ppm의 약 2.3배에 달한다. 본 연구에서 개발한 들기름과 미강유를 혼합한 식용유는 일반적인 식용유인 콩기름과 거의 유사한 산화안정성을 갖는 것으로 확인되어, 일반 들기름에 비하여 현저히 높은 산화안정성이 확보되었다.

본 연구는 수준별 압력(760, 560, 360, 160 mmHg)에 따른 튀김유의 산화안정성에 미치는 영향에 대하여 실험하였다. 본 연구에서는 상압(760 mmHg) 및 감압(560 mmHg, 360 mmHg, 160 mmHg) 상태에서 튀김유를 일정한 온도(180℃)로 유지하고, 8시간 간격으로 튀김반죽을 교체하면서 채취한 튀김유를 이용하여 상압과 감압 상태에 따른 튀김유의 산패 정도를 acid value(AV), peroxide value(POV) 및 지방산 측정, 색도, 갈변도를 통해서 알아보았다. 산가의 경우, 네 압력 모두 튀김의 시간이 증가할수록 유지의 산가 또한 증가하였다. 48 시간 튀긴 후 채취한 유지의 산가에서는 760, 560, 360, 160 mmHg 각각 1.28, 1.58, 1.34, 0.40으로 160 mmHg가 다른 압력들과 비교하면 확연히 더디게 증가한다는 것을 알 수 있었다. 48시간 동안 튀긴 후 채취한 식용유지의 과산화물가는 160 mmHg가 0.81 meq/㎏으로 760 mmHg의 1.52 meq/㎏에 비해 50%로 낮은 수치를 보였다. 지방산 조성에서는 네 압력 모두 스테아르산, 올레산, 리놀렌산(오메가 6)은 증가하였고, 리놀레산과 리놀렌산(오메가 3)은 각각 감소하는 경향을 나타냈다. 색도에서는 명도를 나타내는 L값은 유의적인 차이가 나타나지 않았지만, 적색도를 나타내는 a값에서는 네 압력 모두 튀김 시간이 길어질수록 감소하는 경향을 나타냈고, b값은 시간이 지남에 따라 증가하는 경향을 보였다. 갈색도의 결과는 네 압력 모두 시간이 지날수록 증가하는 경향을 보였지만, 160 mmHg는 다른 압력들보다도 가장 낮은 증가를 보였고, 급속하게 갈색도가 증가하는 40시간에서도 다른 압력들 만큼 큰 증가를 보이지 않았다. 본 연구 결과, 감압상태에서 식품을 튀겼을 때 튀김유의 산패도를 감소시킬 수 있었다. 이 결과에 따라 튀김유 산패로 인한 빈번한 튀김유 교체를 줄여 비용적인 절감효과와 튀김유의 장시간 사용이 가능할 것으로 생각된다. 이로 인해 튀김유 사용량을 절감할 수 있어 업체의 경제성 향상 및 발생되는 폐유를 줄여 환경보호를 겸할 수 있을 것이다.

This study was conducted to investigate the effect of age on the oxidative stability of Hanwoo (Korean cattle) cow beef. The samples of M. longissimus dorsi from 65 and 133 months-old-Hanwoo cows (4 and 3 heads, respectively) were stored at 4±0.2℃ for 9 days. The proximate composition, total myoglobin content, pH value, water-holding capacity and drip loss were not significantly affected by age. At day 9 of storage, the lipid oxidation (2-thiobarbituric acid reactive substances) was significantly (p<0.05) higher in beef from 133 months-old-cows than 65 months-old-cows. Lower (p<0.05) oxymyoglobin concentration and R630-R580 value and higher (p<0.05) metmyoglobin concentration were observed in beef from 133 months-old-cows at day 9 of storage than 65 months-old-cows. The CIE a*, b* and C* values were significantly (p<0.05) lowered in beef from 133 months-old-cows at day 9 of storage than 65 months-old-cows. It could be concluded that old age decreased the lipid oxidation stability and myoglobin oxidation stability in Hanwoo cow beef.

This study was carried out to investigate the effect of amino acids complex and choline supplementation on the antioxidant enzyme activities and oxidative stability of Hanwoo (Korean cattle) beef. Fifteen months-old-Hanwoo steers were assigned into two groups and fed on a basal diets with or without amino acids complex (≥25% L-lysine monohydrochloride+≥8% DL- methionine)+choline (≥25% choline chloride) for 12 months. After slaughter, the M. longissimus from carcasses were stored at 4℃ for 7 days. Catalase, glutathione peroxidase and total superoxide dismutase activities were found to be unaffected by supplementation of amino acids+choline. After 2 days of storage, significant decline (p<0.05) in lipid oxidation (2-thiobarbituric acid reactive substances, TBARS) was observed when supplemented with amino acids+choline. However, supplementation of amino acids+choline maintained meat color as indicated by higher CIE L* (Lightness), a* (Redness), b* (Yellowness) and C* (Chroma) values during storage. It was therefore concluded that supplemental amino acids+choline could stabilize the lipid oxidation stability and meat color in Hanwoo beef.

Camellia sinensis L. (green tea) seed oils were prepared by roasting at 213℃ and pressing (RP), pressing (P), and nhexane extraction (H). The physico-chemical properties of the RP, P, and H samples, including fatty acid composition, color, and sensory characteristics were analyzed. RP, P and H samples were thermally oxidized at 180℃, and oxidative stability was determined by DPPH, CDA, and p-AV at 0, 20, 40, 60, and 80 min. Compared to the P and H samples, RP resulted in significantly higher thermal oxidative stability according to the DPPH, CDA, and p-AV results (p〈0.05). The ratio of unsaturated fatty acids to saturated fatty acids among RP, P, and H samples were significantly different (p〈0.05). The oleic acid and linoleic acid contents in green tea seed oils were 58 and 23%, respectively. Hunter's color value of lightness (L) for the RP, P, and H samples was not significant. Redness (a) of RP was 3.47±0.119 and yellowness (b) of H was 60.10±2.483, which were significantly different. Compared to RP samples, H and P samples had the highest color and off-odor values in the sensory evaluation. RP samples showed the highest taste value and were significant overall (p〈0.05). The thermal stability of RP extraction was more stable than any other method. Camellia sinensis L. seed oil extracted by RP had better sensory characteristics than other edible oils, including soybean oil, grape seed oil, and extra virgin olive oil.

This experiment was conducted to investigate the effect of wa-song (Orostachys japonicus A. Berger) extracts on the oxidative stability of edible oil. Wa-song was dried from hot air (HWE) and freeze (FWE), and then they were extracted by hot water. The different levels (0.1, 0.5 and 1.0 g/100 mL) of HWE and FWE were added to soybean oil and lard. The chromaticity of edible oils was generally increased with prolonged heating time and HWE was higher than FWE. The anisidine value showed significant increase during heating for 48 hrs. After heating for 48 hrs, it was lower than control, except for HWE added sample of 0.5 and 1.0 g/100 mL, FWE added sample of 1.0 g/ 100 mL. In lard, it was lower in sample added wa-song extract than control. The acid value was not significant by added amount of wa-song. Its value in HWE added sample was lower than FWE, after heating for 48 hrs. POV was lower HWE than FWE, also. After heating for 24 hrs, TBA values in soybean oil containing HWE and FWE added sample was lower than control. In lard, its value in HWE and FWE added sample was lower than control during heating for 12~48 hrs. Therefore, those results suggested that HWE has higher antioxidant activity than FWE added sample, and then oxidative stability of HWE in edible oil was more potential for lard during its heating.

: In this experiment, three samples of oils were used. These oils were hydrated soybean oil, pure soybean oil and regular soybean oil. Oil was used after heating at 235-240℃ every four hours term and total heating hours was 16 hours. The physio-chemical analysis and sensory evaluation were performed on these oils. The hydrated soybean oil showed lower acid, peroxide and carbonyl value than the other two oils (p〈0.05 or p〈0.001). The other two oils were more affected in rancidity than the hydrated soybean oil. In color test, whereas L value lowed during the heating time, a and b value increased during the heating time. The tendency of high L value and low b value in a long-time heating was more apparant on the pure soybean oil and the regular soybean oil than on the hydrated soybean oil (p〈0.05). In sensory evaluation, color and rancidity order increased during the heating time. The hydrated soybean oil showed color and rancidity order than the other two oils. In overall quality test, the pure and regular soybean oil that had been used for 12 and 16 hour were not preferable. The hydrated soybean oil that had been used for 16 hour were not preferable. In sensory evaluation, the hydrated soybean oil, the pure and regular soybean oil did not show a apparent difference, although the hydrated soybean oil had a little better scores on the overall quality.

In this study, we examined the effects of egg yolk powder added to flour dough on the lipid oxidation of fried products during storage. The flour dough containing the egg yolk powder (0, 5, and 10%) was fried in sunflower oil at 180℃ for 90 sec. The fried products were then stored at 60℃ for 9 days in the dark. The lipid oxidation of the fried products was evaluated by fatty acid composition, peroxide values (POV), conjugated dienoic acid (CDA) contents, and thiobarbituric acid (TBA) values. The color and phospholipids (PL) contents of the fried products were also determined by colorimetry and high performance liquid chromatography, respectively. The addition of egg yolk powder to the dough decreased the POV, CDA contents, and TBA values of the fried products during storage. Although POV, CDA contents, and TBA values significantly increased in the products without egg yolk powder during storage, little change was observed in the products with egg yolk powder. The PL contents remained relatively constant in the fried products added with egg yolk powder during storage. The lightness and greenness of the fried products decreased, and the yellowness increased, as the storage time increased. The results clearly indicate that the addition of egg yolk powder to the dough improved the lipid oxidative stabiliy of the fried products during storage in the dark, and the PL in the egg yolk might have contributed to the improvements in lipid oxidative stability.

비불소계 스티렌 고분자 전해질 막의 산화안정성을 개선하기 위해 p-methyl styrene, t-butyl styrene, α-methyl styrene과 같은 스티렌 유도체를 단독 또는 복합으로 도입하고 모노머 흡수법을 이용하여 막을 제조하였다. 제조된 막의 특성분석으로 중합무게비, 함수율, 이온교환용량, 수소이온 전도도 및 가속조건에서의 산화안정성을 조사하였다. 사용된 스티렌 유도체의 구조 및 특성에 따라 모노머 흡수, 중합 및 술폰화 단계가 영향을 받는 것으로 나타났다. 산화적으로 안정한 고분자를 형성하는 α-methyl styrene은 중합 단계가 어렵기 때문에 스티렌 또는p-methyl styrene과 공중합하여 제조하였고 p-methyl styrene과 공중합된 α-methyl styrene 막은 스티렌과 공중합한 막보다 높은 전도도 및 안정성을 나타내었으나 낮은 분자량으로 인해 안정성의 개선을 크게 보이지 못하였다. 벤젠 고리에 큰 치환기를 갖는 t-butyl styrene은 모노머 흡수 및 술폰화과정이 용이하지 않기 때문에 제조된 막의 성능이 감소하였으며 이를 p-methyl styrene과 공중합할 때 우수한 성능과 스티렌막보다 크게 개선된 안정성을 보였다.