• 한국식품과학회지
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• 제30권1호
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• pp.77-81
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• 1998

쌀눈 및 쌀겨에 함유된 유지를 추출, 온도별 저장 안정성과 지방산조성을 비교하였다. 쌀눈 및 쌀겨유지를 $40^{\circ}C$ 및 $60^{\circ}C$에 31일간 저장 중 유지의 산가는 큰 차이가 없었고 과산화물가는 저장 온도가 높아짐에 따라 크게 상승하였는데, $40^{\circ}C$저장 31일에는 건조처리한 쌀눈의 유지가 가장 높아 146.2 meq/kg이었고 정제유는 15.1 meq/kg 이었으며, $60^{\circ}C$저장 24일에는 정제유는 219.6 meq/kg, 건조쌀눈유지는 151.7meq/kg 이었다. 쌀눈과 쌀겨유지 중 주 지방산은 쌀눈은 linoleic acid (39.0%)와 oleic acid (34.7%)이었고 쌀겨는 oleic acid (40.1%)와 linoleic acid (38.1%)였으며, 저장 중 주 지방산의 조성은 쌀눈의 건조처리나 저장온도에 큰 영향을 받지 않았으나 linolenic acid의 함량은 모든 처리에서 감소하는 경향이었다.

• 한국가스학회지
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• 제23권3호
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• pp.40-45
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• 2019

인화점은 가연성 액체 혼합물의 화재와 폭발의 위험성을 특징짓는 중요한 인화성 지표이다. 본 연구에서는 Seta flash 장치에 의해 water+formic acid 계와 water+acrylic acid 계의 인화점을 측정하였다. 측정한 인화점을 라울의 법칙과 경험식을 이용한 인화점 예측값과 비교하였다. 라울의 법칙을 이용한 예측 결과의 절대평균오차는 water+formic acid 계의 경우 $10.7^{\circ}C$ 였고, water+acrylic acid 계의 경우 $4.8^{\circ}C$ 이었다. 경험식을 이용한 예측 결과의 절대평균오차는 water+formic acid 계의 경우 $1.0^{\circ}C$ 였고, water+acrylic acid 계의 경우 $0.5^{\circ}C$ 이었다. 결과적으로 라울의 법칙에 의한 예측값에 비해 경험식에 의한 예측값이 측정값을 보다 잘 모사하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제30권6호
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• pp.872-877
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• 2017

Objective: In order to utilize fat from broiler byproducts efficiently, it is necessary to develop an appropriate rendering procedure and establish quality information for the rendered fat. A study was therefore undertaken to evaluate the influence of rendering methods on the amounts and general properties of the fat recovered from broiler skin. Methods: The yield and quality of the broiler skin fat rendered through high and lower energy microwave rendering (3.6 W/g for 10 min and 2.4 W/g for 10 min for high power microwave rendering (HPMR) and high power microwave rendering (LPMR), respectively), oven baking (OB, at $180^{\circ}C$ for 40 min), and water cooking (WC, boiling for 40 min) were compared. Results: Microwave-rendered skin exhibited the highest yields and fat recovery rates, followed by OB, and WC fats (p<0.05). HPMR fat had the highest $L^{\star}$, $a^{\star}$, and $b^{\star}$ values, whereas WC fat had the highest moisture content, acid values, and thiobarbituric acid (TBA) values (p<0.05). There was no significant difference in the acid value, peroxide value, and TBA values between HPMR and LPMR fats. Conclusion: Microwave rendering at a power level of 3.6 W/g for 10 min is suggested base on the yield and quality of chicken fat.

• Food Quality and Culture
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• 제1권1호
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• pp.6-12
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• 2007

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 $180^{\circ}C$ for 90 sec. The fried products were then stored at $60^{\circ}C$ 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 flied 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 stability 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.

• Journal of Biosystems Engineering
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• 제31권5호
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• pp.443-448
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• 2006

For development of an on-line monitoring unit of fermentation process, an auto dilution unit based on traditional chemical and biological analytical method was developed and the performance was evaluated. The dilution unit was constructed with two syringe pumps and flow direction change valves and fully automated. Total delivery volume of two pumps using distilled water was measured to confirm the operating stability And diluted concentrations of three substrate solutions (glucose, lactic acid, ethanol) were compared with a standard method with a high performance liquid chromatograph (glucose, lactic acid) and gas chromatograph (ethanol). Relative error values of total delivery volume of the pumps were below 3% and standard deviation values were 0.003 (n=5). Relative error values of diluted concentration of the dilution unit measurements were below 2% with 1/10 of dilution ratio and 70, $80{\mu}{\ell}$ of sample volume conditions for glucose and lactic acid, 1/30 of dilution ratio and $70{\mu}{\ell}$ of sample volume conditions for ethanol, respectively. In case of the ethanol, cause of the evaporative characteristics, the relative error values showed over 5% whole experimental conditions.

• 생약학회지
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• 제52권1호
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• pp.49-54
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• 2021

As the consumption of avocado fruits and avocado oils is steadily increasing, the amount of avocado seeds which are thrown away as by-products is also inceasing. Thus, the possibility of use of avocado seeds as natural preservatives was studied focused on the antioxidant effect. The extraction of avocado seeds and seed husks with 100% ethanol by maceration showed highest antioxidant activities and lowest IC50 values compared to 80% ethanol extract. Furthermore, 100% ethanol extract of avocado seeds and seed husks included significantly higher amount of polyphenols than 80% extract. However, total flavonoid content of 100% avocado seed extract was not signigicantly different from 80% seed extract, whereas that of 100% avocado seed husk extract was significantly higher than 80% seed husk extract. In case of acid values, heating of oil alone for 120 and 180 min significantly increased the acid values, whereas the treatment of oil with seed and seed husk extract signficantly decreased the acid values. These results suggest that antioxidant effects of avocado seeds and seed husks protected the oil against heat-induced acidification. Thus, avocado seeds and seed husks have a potential to be developed as an natural antioxidant and natural preservative which could be used commercially.

• 한국가금학회지
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• 제22권3호
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• pp.155-160
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• 1995

To evaluate the nutritive values of outdoor mass cultivated Spirulina platensis both chemical analysis and bioassay were carried out using adult cockerels. Blue-green algae, Spirulina platensis contained about 71g /l00g DM of crude protein with balanced amino acid profiles although methionine is liable to he limiting to animals. Compared to fish meal, calcium content and calcium : phosphorus ratio of the Spirulina were not suitable in terms of animal requirements. Reasonable amount of y-linolenic acid(C18: 3 $\omega$6) in Spirulina platensis draws a clinical attention due to its historically recognized pharmacotheraputic functions. Metabolizable energy contents of Spirulina were 3.67 and 3.11 mcal /kg DM for TMEn and AMFn, respectively, which therefore, can he a reliable energy source for poultry. True amino acid availabilities of essential amino acids of Spirulina platensis were higher than 90% for poultry, which is better than comparative ingredient like fish meal. Overall data from both chemical analysis and bioassay demonstrated that the Spirulina platensis could he a favorable protein feedstuffs for poultry.

• 대한화학회지
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• 제9권1호
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• pp.37-40
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• 1965

8-Hydroxyquinoline-5-sulfonic acid 를 alkali 媒質에서 $10^{\circ}C$以下로 維持하여 nitroso 化시켜 7-nitroso-8-hydroxy-quinoline-5-sulfonate (NHQS)를 合成하였으며 그 酸解離定數를 分光光度法과 pH滴定法에 依하여 測定하였다. 두 方法에 依하여 近似하게 같은 값은 얻어졌고 이것들은 8-hydorxyquinoline의 該當 pK값에 比해 작다. 8-hydroxyquinoline에 比해 NHQS의 낮은 鹽基性은 導入된 電子吸引性基들의 影響으로 생각되며 特히 nitroso 基는 ortho位의 phenol性 OH基의 酸性度의 增加에 많은 影響을 주는 것으로 생각된다.

• 한국식품영양과학회지
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• 제19권1호
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• pp.61-64
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• 1990

The influence of extraction time on the fatty acid profile and the contents of calcium and magnesium in pig's shank were examined. The 9 kinds of fatty acid were identified in water extracts from pig's shank by GLC. The profiles of fatty acids from different extraction were similer to each other,. The content of linolenic acid was increased after two-hours extraction however the amounts of MUFA, PUFA and p/s ratio were decreased by the longer extraction time. The amount of calcium was 124.7mg% in raw materials but water extracts and bone powder samples showed higher values. in case of magnesium it was 138.4mg% in raw materials, but the extracts showed lower amount and bone powder exhibited higher values.

• Mass Spectrometry Letters
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• 제10권3호
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• pp.79-83
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• 2019

Horse heart myoglobin (MYG) and bovine serum albumin (BSA) were hydrolyzed by microwave-assisted weak-acid hydrolysis for 10, 20, 30, 40, 50, and 60 min using 2% formic acid (FA) at $100^{\circ}C$. Generally, the number of identified peptides increased with increasing irradiation time, indicating that the duration of microwave irradiation is linked to the efficiency of hydrolysis. For MYG, irradiation for 60 min provided the highest number of identified peptides, the greatest sequence coverage values and the highest MASCOT score values among the investigated irradiation times. Irradiation of BSA for 50 min, however, yielded a greater number of peptides than irradiation for 60 min due to the generation of miscleaved peptides after microwave irradiation for 50 min.