• 한국식품조리과학회지
• /
• 제18권4호
• /
• pp.407-412
• /
• 2002

녹차를 첨가한 마요네즈의 신화아정성을 조사하기 위하며 대두유, 난황, 식초, 설탕, 식염과 녹차의 분말을 0~0.5% 첨가하여 마요네즈를 제조한 후, 5$^{\circ}C$, 15$^{\circ}C$, $25^{\circ}C$에 13주간 저장하면서 과산화물가의 변화를 조사한 결과는 다음과 같다. 1. 마요네즈를 5$^{\circ}C$, 15$^{\circ}C$, $25^{\circ}C$에 13주간 저장했을 때, 대조구의 과산화물가는 각각 28, 63.5, 144.4 meq/kg 으로 저장온도가 높을수록 산화가 촉진되었다. 2. 녹차의 마요네즈에 대한 항산화작용은 녹차의 첨가농도에 비례하였으나 저장온도가 높을수록 그 효과는 감소하였다. 3. 녹차의 첨가는 마요네즈 유지 산화에 대한 유도기간을 연장하는 효과가 있었으며 녹차 분말을 0.5% 첨가했을 때 전 저장 온도에서 유의적인 유도기간의 연장효과를 볼 수 있었다(p<0.05). 4. 마요네즈에 0.1%의 녹차를 첨가했을 때의 상대적 항산화효과는 5, 15, $25^{\circ}C$에서 각각 226%, 188%, 143%였으며 마요네즈에 첨가하는 녹차 농도에 비례하여 증가하였다. 이러한 결과는 녹차를 마요네즈의 산화를 방지할수 있는 천연 항산화제로서 이용할 수 있는 충분한 가치가 있는 것으로 판단된다.

• 한국식품영양과학회지
• /
• 제28권6호
• /
• pp.1212-1219
• /
• 1999

The oils were extracted from the mixture of roasted(for 20 min at 190oC) perilla seeds(RPS) and roasted (commercially) peanuts(RPN) by solvent extraction(SE) and mechanical expression(ME). The effects of mixing ratio on physicochemical characteristics and oxidative stability of their oils were investigated. Yields of both SE and ME oils were increased as the RPN ratio in the mixture increased. In all the SE and ME oils, the major fatty acids were oleic, linoleic and linolenic acid, and total saturated fatty acids increased gradually, but total unsaturated fatty acids decreased gradually as the RPN ratio in the mixture was increased. The specific gravity and refractive index of both SE and ME oils decreased as the RPN ratio in the mixture was increased. Acid value, saponification value and iodine value of SE oils decreased as the RPN ratio in the mixture increased, whereas acid value and iodine value of ME oils decreased and saponification value increased. The colors of ME oils were darker brownish than SE oils. The oxidative stability of SE oils was decreased as the RPN ratio in the mixture increased, whereas that of ME oils was increased. Sensory evaluation of all the oils extracted from the mixture with various mixing ratio showed significant differences in flavor, taste, color and overall acceptance(p<0.01). The oil extracted from the mixture of the mixing ratio of 8:2(RPS:RPN) showed slightly higher preference regardless of extraction method.

• 한국축산식품학회지
• /
• 제29권2호
• /
• pp.245-251
• /
• 2009

This study was carried out to investigate the fatty acid composition, aroma pattern, color, and oxidative stability of M. longissimus from 28-mon-old Hanwoo steers with different raising altitude (100, 200, 300, 400, 700, and 800 m above sea level). The samples were stored at $2{\pm}0.2^{\circ}C$ for 9 d. Meat from 700 and 800m had lower palmitic acid, saturated fatty acids and higher oleic acid, monounsaturated fatty acids (MUFA) than that from 100 m (p<0.05). There was no positive discrimination of the aroma pattern of meat among all groups. There were no significant difference in TBARS values of beef among all groups at 6 and 9 d of storage. At 9d of storage, meat from 700m showed the highest MetMb concentration and the lowest a* value among all groups. However, the differences in Mb concentration and color among groups were not linear to the difference in raising altitude. Consequently, the difference in raising altitude at 100-800 m affected the fatty acid composition of meat from Hanwoo steers; the higher the raising altitude, the higher the MUFA concentration. The difference in fatty acid composition among them didn't affect the aroma pattern and oxidative stability.

• 한국축산식품학회지
• /
• 제22권4호
• /
• pp.316-321
• /
• 2002

본 실험 결과를 종합하여 볼 때 전자선의 처리는 돈육의 냉장, 냉동 중 일반세균과 중온균의 증식 억제에 효과가 있는 것으로 밝혀졌으며 전자선의 조사량이 증가할 수록(1.5에서 3.0 kGy로) 그 효과는 더욱 커지는 것으로 나타났다. 본 실험에서 사용한 전자선 1.5와 3.0 kGy는 그 조사량이 매우 낮은 수준이므로 조사량을 증가시키면 살균효과는 증대될 것으로 예상된다. 반면 전자선의 처리가 지방의 산패를 촉진한다는 결과는 충분히 예상한 결과였고 본 실험에서도 전자 건의 조사량이 증가할수록(1.5에서 3.0 kCy로) 산패는 더욱 촉진되었다. 따라서 전자선 처리의 살균 효과를 극대화하기 위하여는 전자선을 조사하여도 돈육의 산패도는 전자선을 조사하지 않은 돈육의 수준으로 유지시킬 수 있는 방법이 필수적으로 연구되어야 할 것이다. 이러한 방법으로는 전자선의 조사 속도를 조절한다든지 공기조절 포장 방법($N_2$, $CO_2$) 과의 병용 등을 들 수 있을 것이다. 전자선을 식품에 활용하는 작업은 그 유용성이 무궁 무진 할 수 있으므로 앞으로도 그 활용이 기대되며 우선적으로 해결해야 할 문제는 전자선 조사에 의 한 지방의 산패를 억제 할 수 있는 방법을 강구하는 것이다.

• Tribology and Lubricants
• /
• 제31권6호
• /
• pp.258-263
• /
• 2015

Biodiesel is an environmentally-friendly fuel with low smoke emission because it contains about 10% oxygen. Biodiesel fuel prepared by transesterification of vegetable oil or animal fats is susceptible to auto-oxidation. The rate of auto-oxidation depends on the number of methylene double bonds contained within the fatty acid methyl or ethyl ester groups. Biodiesel may be easily oxidized under several conditions, i.e., upon exposure to sunlight, temperature, oxygen environment. Maintenance of the fuel quality of biodiesel requires the development of technologies to increase the resistance of biodiesel to oxidation. Treatment with antioxidants is a promising approach for extending the shelf-life or storage time of biodiesel. The chemical properties of various amine-based antioxidants were evaluated after synthesis of the antioxidants by condensation of phenylenediamine with alkylamines at room temperature. In general, the oxidative stability can be assessed based on various experimental parameters. Such parameters may include temperature, pressure, and the flow rate of air through the samples. The Rancimat method (EN14112) was selected because it is a rapid technique that requires very little sample and provides good precision for oxidative degradation analysis. Specifically, the EN 14112 technique provides enhanced efficiency for oxidative stability evaluation when a larger ester head group is utilized. Therefore, this technique was employed for evaluation of the oxidation stability of biodiesel by the Rancimat method (EN14112).

• Asian-Australasian Journal of Animal Sciences
• /
• 제32권1호
• /
• pp.137-143
• /
• 2019

Objective: The aim of this study was to compare male and female geese of two contrasting genotypes in terms of fatty acid composition, indexes related to human health, lipid metabolism and oxidative stability of the meat. Methods: The experiment was carried out on total of 120 geese of two different genotypes; the native breed Czech goose (CG) and commercial hybrid Novohradska goose (NG). One-d-old goslings were divided into 4 groups according to genotype and sex, and 8 birds from each group were slaughtered at 8 weeks of age. Results: The effects of the interactions between genotype and sex were observed on growth performance and carcass traits. Final body weight (p<0.001), daily weight gain (p<0.001), daily feed intake (p<0.001), slaughter weight (p<0.001), and cold carcass weight (p<0.001) were highest in NG males and lowest in CG females. The meat fatty acid composition results showed effects of both genotype and sex on the total n-6 and the total polyunsaturated fatty acid (PUFA) content, as well as the PUFA n-6/PUFA n-3 ratio. Regarding genotype, the total n-6, the total PUFA content and the PUFA n-6/PUFA n-3 ratio were higher in CG, and higher values were found in females. In terms of the lipid metabolism, ${\Delta}^5-{\Delta}^6$ desaturase (p = 0.006) was higher in males. The meat oxidative stability results revealed an interaction between genotype, sex and storage time (p<0.001). The highest (13.85 mg/kg) malondialdehyde content was measured in the meat of CG females after 5 days of storage and was presumably related to a higher PUFA content. Conclusion: NG had a relatively higher growth rate and meat oxidative stability, whereas the advantage of CG meat is its favourable fatty acid profile characterized by a higher PUFA content.

• Journal of Animal Science and Technology
• /
• 제63권5호
• /
• pp.1169-1181
• /
• 2021

We investigated the comparative physicochemical attributes, oxidative stability, and microbial characteristics of 28 days dry-aged meat in between boneless sirloin (gluteus medius) and bone-in T-bone steaks (infraspinatus) muscles from Korean Native Hanwoo Steer (KNHS). Results reveal that regardless of the muscles, dry-aging increased protein content and water-holding capacity (WHC) (p < 0.05). Meat from infraspinatus-aged muscle led to darker meat with higher pH values than un-aged meat (p < 0.05). However, fat content, CIE a^*, and CIE b^* remained unchanged in both muscles at aging. At aged meat, thiobarbituric acid reactive substances (TBARS) values from bone-in infraspinatus muscle was 2.5-fold higher than boneless gluteus medius muscle (p < 0.05). Dry-aging led to an increase in the contents of total unsaturated fatty acids (UFAs), monounsaturated fatty acids (MUFAs), and UFA/saturated fatty acids (SFA) in both muscles (p < 0.05). Furthermore, gluteus medius aged muscle concentrated with olic acid (C18:1) compared to infraspinatus aged muscle. Irrespective of the muscles, dry-aging enhanced the total free amino acids (FAAs) as well as tasty, and bitter amino acid contents whereas decreased the tasty/bitter amino acids (p < 0.05). Aromatic amino acid, tryptophan that converted to serotonin was 2-fold higher in boneless gluteus medius muscle than bone-in infraspinatus muscle at pre and post aging processes (p < 0.05). Aged Infraspinatus muscle increased total bacteria (p < 0.05) while no salmonella spp. was detected in both muscles. Taken together, our study confirms that 28 days dry-aging profiling the quality characteristics of boneless sirloin (gluteus medius) and bone-in T-bone steaks (infraspinatus) distinctly while gluteus medius aged steak performs better owing to oxidative stability and functional compounds than infraspinatus aged steak.

• Journal of Electrical Engineering and Technology
• /
• 제10권6호
• /
• pp.2348-2355
• /
• 2015

Transformer mineral oil which is normally hydrocarbon based is non- biodegradable and pollutes the environment in all aspects. Though vegetable oils are eco-friendly in nature and potentially could be used in transformers as a replacement for the mineral oil, there usage is restricted because of their oxidative instability. The present work focuses on using rapeseed oil and pongamia (pongamia pinnata) oil as effective alternatives for the traditional mineral oil in power transformer. The oxidative stability of the rapeseed oil and pongamia oil is increased by using combinations of the natural and synthetic anti-oxidants as additives. The parameters like breakdown voltage, viscosity, flash point, fire point are measured for the rapeseed oil and pongamia oil with and without the additives as per IEC and ASTM standards. The results shown encouraging changes in the parameter values and ensures the use of the oils as a potential alternative insulation in power transformers.

• 한국식품조리과학회지
• /
• 제5권2호
• /
• pp.27-34
• /
• 1989

In the present study, the oxidative stability of Korean evening primrose oil (EPO) stored in various conditions, i.e., dark, cool, fluorescent light and daylight irradiation were investigated. Furthermore difference between the compositional content of gamma-linolenic acid (GLA) of EPO and that of alpha-linolenic acid of soybean oil (SOY) undergoing various modes of oxidation was observed. The results of the present study were as follows: More rapid autoxidative reations of EPO than that of SOY in vairous conditions increased in order of daylight, fluorescent light, cool and dark. Espectially, autoxidative rates of EPO increased rapidly on exposure to daylight and fluorescent light. This probably was due to chlorophyll functioned as a photosensitizer resulting in rapid oxidation of the EPO during irrdadiation of light. However, there was no difference between compositional content of GLA in EPO and alpha-linolenic acid in SOY undergoing various modes of oxidation. Therefore, theripid oxidative rate of EPO could be due to the catalytic effect of the chlorophyll on the photoxidation and the free radical reaction of PUFA.

• 한국축산식품학회지
• /
• 제18권4호
• /
• pp.301-306
• /
• 1998

Four low fat ground beef groups containing 10% fat plus 0, 5, 10 and 20% additional cooked lod rice and a control ground beef containing 30% fat were prepared and the analysis for microbiological and oxidative stability were conducted. During 6 days of storage at 4$^{\circ}C$ microbial analysis including total plate count and coliform groups were performed and 2-thiobarbituric acid reactive substance (TBARS) absorbances were measured. The growth rate of total aerobic bacteria and coliform groups tended to increase with the increase in fat content and the amount of added cooked lod rice. Development of oxidative rancidity were not significantly different between 10 and 30% fat ground beef but among the 10% ground beef the rancidity development significantly(p<05) decreased with the in-crease in the amount of added cooked old rice. Low fat ground beef groups were not stable over 3 days during storage at 4$^{\circ}C$.