• 한국식품조리과학회지
• /
• 제21권5호
• /
• pp.742-758
• /
• 2005

Lipid-based functional components present in foods undergo chemical changes during cooking. Useful n-3 and n-6 fatty acids, phytosterols, tocopherols, and carotenoids are degraded by thermal cooking such as frying, resulting in loss of their physiological functions. However, conjugated linoleic acid and diacylglycerols can be formed during heating, which would be beneficial to the health. Degree of degradation and formation of the functional components depends on the cooking method, cooking temperature and time, lipid matrix containing the components, and the presence of other materials. Although it is clear that the content of each functional component varies during long-heating in a model system consisting of small numbers of components, the real foods cooked in a small scale for a limited cooking time do not show highly significant differences in the functional components contents from raw food materials.

• KSBB Journal
• /
• 제17권4호
• /
• pp.396-402
• /
• 2002

바이오디젤(지방산 메틸 에스테르)은 생분해성, 무독성, 그리고 재생연료로서 지난 10여년간 많은 관심을 끌고 있다. 바이오디젤을 생산하기 위해 다양한 방법들이 개발되었는데, 그 중 알칼리 촉매를 이용한 에스테르화 반응이 짧은 시간동안 높은 수율을 얻을 수 있다. 따라서 본 연구에서는 알칼리 촉매하에 에스테르화 반응의 최적조건을 찾기 위하여 response surface method를 사용하였다. 결과적으로 바이오디젤 생산 공정에 영향을 주는 7개의 변수 중 반응온도, 반응시간, 그리고 교반속도가 중요했는데 이들의 최적 값은 각각 67$^{\circ}C$, 68분, 94 rpm이었다. 이와같은 최적인 조건하에서 실험한 결과 바이오디젤로의 전화율은 99.7%이었다.

• 한국식품영양과학회지
• /
• 제43권12호
• /
• pp.1881-1888
• /
• 2014

본 연구는 당근을 열처리법 중에서 열수침지, 과열증기 및 볶음 처리에 따른 이화학적 및 영양학적 특성을 분석한 논문으로 열처리가 당근에 미치는 영향을 비교하고자 하였다. 상품을 구매할 때 1차적인 구매요소인 색도 및 경도 측정과 추가적으로 pH와 조직 관찰 결과로 최적 조건 선정 후 영양학적 및 관능검사를 실시하였다. 열처리를 하지 않은 대조구에 비해 짧은 시간의 열처리에서는 더 진하고 선명한 색을 띠었으나, 장시간 동안 처리한 열처리 시료는 색의 침착을 보였다. 원물과의 색은 열처리 후 차이를 나타냈지만 열수 및 과열증기 2분 처리까지가 원물과 가장 유사한 색을 나타냈으며, 경도는 열처리 시간에 따라 감소 경향을 나타냈고 볶음 처리는 짧은 시간으로도 물성이 연화됐으며, 열수침지 및 과열증기 처리는 2분까지 원물에 가까운 경도를 유지했으나 처리 시간이 길어질수록 경도가 확실히 감소하였다. 비타민, 유리당 및 유기산의 경우 열수침지 처리에서 가장 큰 손실을 보였고, 과열증기, 볶음 처리 순으로 손실된 결과를 보였다. 특히 유기산에서 succinic acid는 열수침지 처리 시 큰 손실률을 보이며 감소된 결과를 나타냈다. Peroxidase activity 변화는 열수침지 및 과열증기 처리에서 볶음 처리보다 높은 불활성화를 보였다. 당근의 열처리 조건은 과열증기 처리법으로 2분 동안 처리하는 것이 다른 처리법에서 처리한 시간들에 비해 최적으로 나타났다. 식품마다 열처리 방법 별 각각의 최적 처리 시간을 가지고 있어, 높은 효율성이나 산업적으로 이용하려면 최적의 전처리 방법과 처리 시간을 산정하는 것이 중요하다.

• 한국식품조리과학회지
• /
• 제14권3호
• /
• pp.241-249
• /
• 1998

The purpose of this study was to develop a recipe for high quality Yackwa (fried cake made of wheat flour) by adjusting the mixing ratio of flours, frying temperature and time. Yackwas were prepared by using 3 kinds of flour mix (3：7, 4：6, and 2：8 of weak to medium ratio), fried at various temperatures and times, and evaluated by mechanical characteristics and sensory evaluation. It was found that Yackwa prepared with 3：7 mixing ratio of flour and fried at 160$^{\circ}C$ for 9 min was most preferred. Yackwas with the same flour mixing ratio and fried at 150-155$^{\circ}C$ for 12∼16 min were also within the range of acceptance. The characteristics of desirable Yackwa were suggested to be soft, crispy, and to have little taste of oil.

• Journal of Microbiology and Biotechnology
• /
• 제33권9호
• /
• pp.1238-1249
• /
• 2023

In this study, we sought to investigate the production and optimization of biosurfactants by soil fungi isolated from petroleum oil-contaminated soil in Saudi Arabia. Forty-four fungal isolates were isolated from ten petroleum oil-contaminated soil samples. All isolates were identified using the internal transcribed spacer (ITS) region, and biosurfactant screening showed that thirty-nine of the isolates were positive. Aspergillus niger SA1 was the highest biosurfactant producer, demonstrating surface tension, drop collapsing, oil displacement, and an emulsification index (E₂₄) of 35.8 mN/m, 0.55 cm, 6.7 cm, and 70%, respectively. This isolate was therefore selected for biosurfactant optimization using the Fit Group model. The biosurfactant yield was increased 1.22 times higher than in the nonoptimized medium (8.02 g/l) under conditions of pH 6, temperature 35℃, waste frying oil (5.5 g), agitation rate of 200 rpm, and an incubation period of 7 days. Model significance and fitness analysis had an RMSE score of 0.852 and a p-value of 0.0016. The biosurfactant activities were surface tension (35.8 mN/m), drop collapsing (0.7 cm), oil displacement (4.5 cm), and E₂₄ (65.0%). The time course of biosurfactant production was a growth-associated phase. The main outputs of the mathematical model for biomass yield were Yx/s (1.18), and µ_max (0.0306) for biosurfactant yield was Y_p/s (1.87) and Y_p/x (2.51); for waste frying oil consumption the So was 55 g/l, and Ke was 2.56. To verify the model's accuracy, percentage errors between biomass and biosurfactant yields were determined by experimental work and calculated using model equations. The average error of biomass yield was 2.68%, and the average error percentage of biosurfactant yield was 3.39%.

• 동아시아식생활학회지
• /
• 제20권6호
• /
• pp.888-895
• /
• 2010

Riceyeotgangjung (RYG) with added spirulina was prepared with citron juice for masking of odor. Oil temperature for puffing was found to be $220^{\circ}C$ for frying dry rice based upon the results of expansion rate and color. RYGs with added spirulina (1, 2, and 3%) were prepared under the above conditions, and their physicochemical and sensory properties were examined under storage at $60^{\circ}C$ for 15 days. Moisture content of RYG decreased proportionally with the spirulina content and storage time. The hardness levels of the freshly made RYGs with spirulina were higher than that of control. During storage, the hardness of the control gradually increased, but those of the RYGs with spirulina gradually decreased, although no significant differences existed between the spirulina containing RYGs. Lightness and redness values in the Hunter color system decreased according to the spirulina content and storage time. Yellowness value also increased with the spirulina content and storage time. Phycocyanin and total phenolic content increased with spirulina content, but decreased with the storage period. Sensory evaluation results showed that RYG with 2% added spirulina received the highest scores for color, taste, overall acceptability, and intention of purchase. As a result, the optimal addition amount of spirulina to RYG is recommended to be 2%.

• 한국식품조리과학회지
• /
• 제18권4호
• /
• pp.461-469
• /
• 2002

In order to develop a better food preparation method in terms of vitamin retention in food service establishments, the retention rate of riboflavin in two kinds of Korean dish (stir-fried sausage with vegetables, stir-fried garlic young stems) were examined during various cooking stages, holding temperature and duration time. Riboflavin content of the sample was analyzed using by using a HPLC with a fluorescent detector at various holding durations and temperatures. Also the changes in the pH and water contents of the samples were measured during holding at various temperatures to find any relation among the pH, water contents and riboflavin content. In the results, there were significant differences in riboflavin contents at various cooking processes such as washing, slicing, blanching, soaking, etc. Also, the retention rates of riboflavin at various holding methods and temperature were significantly different from one another. Especially 50% reduction of riboflavin content occurred during blanching of young garlic stem and only 38% of riboflavin was left after slicing carrots for stir-frying of sausage.

• 동아시아식생활학회지
• /
• 제10권4호
• /
• pp.274-280
• /
• 2000

The effect of heated oil on human nutrition has recently become of great interest to nutritionists and food chemists. However, the detrimental effect of heated oil has been hardly studied extensively and many problems have still remained unsolved. This study was carried out to investigate the storage stability of the heated oils at room temperature (25$\pm$5$^{\circ}C$), with the variation in storage conditions (addition of spices and herbs) for 7 weeks period. The rancidity of the oils according to storage time and condition was measured and compared with TBA, ferric thiocyanate, and DPPH method. For fresh oil, when stored for 7 weeks at room temperature, her was no significant change in the degree of oxidation. But for the heated oil with frying materials, the degree of oxidation significantly increased at 5 weeks(p<0.05). When stored with spices and herbs, the degree of oxidation significantly decreased with storage period(p<0.05). Antioxidative activity of herbs, especially sage group was higher than that of any other group.

• 한국응용과학기술학회지
• /
• 제6권2호
• /
• pp.11-19
• /
• 1989

In order to fractionate sardine oil by different solvents for an effective use of fish oil being subjected to the limit of use, an attempt was to investigate the proper solvents, ratios and fractionation time. The results of the study were as follows: 1. The proper solvent of fractionation using ethanol, isopropyl alcohol, acetone, and hexane was ethanol, and its optimum ratio was 2:1 (ethanol: oil, v/w). The proper time of ethanol fractionation by the ratio (2:1) was 4hr at $10^{\circ}C$, 6hr at $5^{\circ}C$, 8hr at $0^{\circ}C$and 8hr at $-5^{\circ}C$, respectively. 2. In the fractionation by stages using the ratio (2:1) at each temperature, the yield of stearine was 8％ at $10^{\circ}C$ (Fraction I), 32％ at $5^{\circ}C$ (Fraction II), 7％ at $0^{\circ}C$ (Fraction III) and 10％ at $0^{\circ}C$ (Fraction IV), respectively. When ethanol fractionation was undertaken at $5^{\circ}C$ by stages, the yield of stearine (Fraction II) was high. 3. Iodine value of Fraction II was 96.8. This result indicated that the hydrogenation process would be simplified by fractionation. 4. The percentage of the decrease of polyenoic acids from original sardine oil to Fraction II oil was from 30.5％ to 13.5％. The major fatty acids of Fraction II were palmitic and oleic acids and these fatty acids were about 52％ of total fatty acids. Therefore, Fraction II, which remained liquid oil at room temperature because solid fat content was 6.9％ at $20^{\circ}C$, would be used as frying oil.

• Applied Biological Chemistry
• /
• 제24권1호
• /
• pp.29-39
• /
• 1981

삶은 스파게티를 10%, 20%와 40% 글리세린 수용액에 10분간 담가둔결과 차후의 건조 과정에서 가소화(可塑化)시키는데 충분한 글리세린을 흡수했다. 글리세린의 가소화작용으로 높은 건조온도와 건습구온도의 큰차에서도 스파게티가 균열되고 표면에 주름지는 것이 방지되었다. 그러한 보호가 가능한 건조온도와 건습구온도차는 글리세린의 농도가 높을수록 높아졌다. 건조속도의 감소에도 불구하고 스파게티의 수분활성도를 0.65로(저장안정성에 필요한 수준) 내리는데 필요한 건조시간은 글리세린양이 증가함에 따라 짧아졌다. 글리세린의 첨가로 늪은 건조온도에서 스파게티의 갈변화 정도가 심해졌고 갈변화를 유도하는 기간이 짧아졌으나 갈 변화는 모든 경우에 스파게티의 수분활성 가 건조완성에 필요한 0.65에 도달한 훨씬 후에 시작되었다. 글리세린의 첨가로 건조시간을 단축하고 더 높은 온도에서 건조할 수 있기 때문에 약간의 글리세린을 (0.15 kg glycerine/ kg dry spaghetti) 첨가함으로써 스파게티의 건조시간을 약 80%에서 93%까지 단축시킬 수 있다.