• Food Science of Animal Resources
• /
• v.35 no.4
• /
• pp.441-448
• /
• 2015

Blanching beef for use in home meal replacements (HMR) is an important process that determines the final quality of the beef after the cooking process. Thermal pretreatment also minimizes the change in quality during the main cooking process or storage. In this study, beef samples were washed and sliced, then treated by immersion in boiling water (1-10 min), steaming (1-10 min), or pan-frying in oil (30-240 s). The color after each thermal treatment showed higher L* and b* values and lower a* values compared with the raw beef, except for the pan-frying thermal treatment. The total color difference (∆E) and pH value were significantly increased by panfrying (p<0.05). There was no significant difference in the shear force of the beef samples, except for the sample pan-fried for 210 s. The nutritional content of beef was measured as the moisture, protein, fat, and ash contents, which were 69.96, 16.64, 3.49, and 1.13%, respectively, in raw beef. After thermal treatment, the crude protein and fat contents were increased, whereas the moisture and ash contents decreased. The mineral content, including Na, Mg, Fe, and Ca was highest after pan-frying. The heat treatment decreased microorganisms in all the samples. The total bacteria count in raw beef was 4.5-4.7 Log CFU/g, whereas the bacteria count decreased to 2.2-2.8 Log CFU/g after blanching. Thermophilic bacteria, coliform, mold, and yeast not detected in any thermally treated sample.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.23 no.4
• /
• pp.654-659
• /
• 1994

To elucidate the relationship between physical and chemical properties of frying vegetable oils, soybean oil and cottonseed oil were heated in air temperatures from $160^{\circ}C\;to\;220^{\circ}C$ for 60 hours. Acid value, carbonyl value, iodine value, viscosity and content of polymer were remarkably changed as higher heating temperature and/or longer heating time. Correlation coefficient of viscosity to acid value was 0.9843 for soybean oil and 0.9819 for cottonseed oil. In case of viscosity and carbonyl value, viscosity also showed good relationship to carbonyl value as 0.9779 for soybean oil and 0.9797 for cottonseed oil. And correlation coefficient of viscosity to iodine value of soybean oil was 0.9852 and cottonseed oil was 0.9948.

• Korean Journal of Food Science and Technology
• /
• v.6 no.2
• /
• pp.70-74
• /
• 1974

The round muscle of Korean cattle and squid muscle were cooked with various methods which were followed digestibility test by use of pepsin in-vitro, determination of amino nitrogen in the course of digestion procedure by using Formol method (AOAC) and influence of ether treatment for preminary test also examined. The results obtained were summarized as follows: 1. The order of digestibility values were demonstrated as follows: In case of beef, it was autoclaving, frying, raw, freezing, roasting, boiling and in case of squid muscle, it was raw, autoclaving, boiling, freezing, dry heating and roasting. 2. The amounts of amino nitrogen for beef and squid muscle were increased in proportion to digestibility value. 3. There were no significances in the digestibility between treating with ether and none of any treatment of beef and squid muscle in raw condition.

• Korean journal of food and cookery science
• /
• v.21 no.5
• /
• pp.607-615
• /
• 2005

The purpose of this study was to analyze the characteristics of Chinese foods in main ingredients, sauces, and cooking methods, and to assess the applicability of kochujang in Chinese foods. Twenty Chinese foods and commercial kochujang were selected by a Chinese head cook. The main ingredients were 24 kinds such as pork, chicken, shrimp, bok choy, bean curd, Chinese noodles etc., which were generally used in Korean foods. The main Chinese sauces were 11 kinds, and soy sauce was used in 12 foods, shang loo tau soy sauce in 2, wine in 8, oyster sauce in 7, rice wine in 6. The classification of cooking units in all Chinese foods was performed and the cooking frequency was deep frying>pan frying>boiling>stir frying>steaming>roasting. The proper amount of kochujang (weight ratio) was decided by pre-test of the Chinese head cook and Chinese food added kochujang was assessed by a Chinese focus group. The overall preference of Chinese food added kochujang was assessed highly and was related to the kinds of sauces, and to the kinds of main ingredients. The foods which used soy sauce or shang loa tau soy sauce were preferred. Sweetness by using kochujang wasn't preferred in several foods. Saltiness and aftertaste by using kochujang didn't affect the food preference, and the intensity of color and pungency were evaluated as a moderate level. An increased amount of kochujang would be possible in several foods. However, the increase in the amount of kochujang for intensive color and pungency in Chinese foods was directly related to the increase of sweetness, which had been discussed as the main problem in lowering the preference. Therefore, the screening of various Chinese foods harmonized with kochujang and the determination of the proper mixing ratio with Chinese sauces are very important. The results of this study could be used as basic data for the promotion of kochujang consumption in the Chinese market.

• Korean journal of food and cookery science
• /
• v.23 no.6
• /
• pp.824-831
• /
• 2007

This study was conducted to investigate the quality characteristics of low-fat pork patties containing fat replacers. Pectin(PE) and potato starch(PO) were added as fat replacers and physicochemical properties of the patties were evaluated after oven-roasting or pan-frying. Uncooked and cooked pork patties formulated with the fat replacers were higher in moisture and ash content and lower in fat content than those of the control. The cooking yield and reduction in diameter of the patties were significantly improved by the addition of PE or PO and oven-roasting exhibited a higher cooking yield and lower reduction in diameter than pan-frying (p<0.05). Water holding capacity(WHC) and fat retention were highest in the patties formulated with PE, while the control had the lowest WHC when cooked by oven-roasting. The Hunter L (lightness) values were not different among the patties but the Hunter a (redness) and b (yellowness) values of the low fat pork patties were higher than those of the control and oven-roasting produced higher redness values than pan frying. Hardness and brittleness were lowest in the patties with PE, while cohesiveness and springiness showed no difference among the patties (p<0.05). The sensory analysis results showed that the use of PE or PO improved the overall acceptability of the low-fat pork patties. After 30 days of storage at $-20^{\circ}C$, pH and cooking yield decreased slightly, while hardness increased in all the patties.

• Food Science and Preservation
• /
• v.8 no.3
• /
• pp.331-337
• /
• 2001

The oxidative stability of tallow heated was studied by different frying condition (temperature 130, 150, and 180$^{\circ}C$;heating time, each 10hours per day, total 240hrs). Changes of physicochemical parameters such as acid value, peroxide value, iodine value, dielectric constant, content of polar components and polymer, refractive index, smoke point, viscosity and color changes in tallow heated were also measured. Acid value, dielectric constant, refractive index, viscosity, and content of polar component and polymer increased as the tallow was heated longer, whereas iodine value and smoke point decreased and peroxide value was increased and decreased repeatedly. These parameters changed to a greater extent as the heating temperature went up. The color became darkened with the increase of red and yellow values during heating. The decree of coloration was proportional to heating temperature.

• Korean Journal of Food Science and Technology
• /
• v.23 no.2
• /
• pp.241-247
• /
• 1991

The objective of this experiment was to study the effect of dextrin on vacuum frying dried carrots. The concentrations of dextrin solution were 0%, 10%, 20%, 30% and the criteria for quality evaluation were sorption characteristics, rehydration power, color and crispness differences. The sorption characteristics were evaluated by Peleg's equation. Rehydration, color and crispness were determined by rehydration percentage, colorimetry and sensory evaluation, respectively. The dextrin pretreatment of carrot resulted in the reduction of adsorption rate and the equilibrium moisture content of dried carrot at various range of relative humidities, and the adsorption rate of samples pretreated with aqueous dextrin solution at different temperatures($4^{\circ}C,\;20^{\circ}C,\;30^{\circ}C$) were in the following decreasing order : control>10% dextrin>20% dextrin>30% dextrin. As the concentration of dextrin solution and ambient temperature increased, BET monomolecular layer moisture content decreased significantly. In addition, as the concentration of dextrin solution increased, the crispness intensity increased and the color of sample treated with 20% dextrin solution was similar to that of raw carrot.

• Korean Journal of Community Nutrition
• /
• v.25 no.4
• /
• pp.280-290
• /
• 2020

Objectives: This study investigated the menu and nutritional contents of convenience store lunchboxes, and evaluated the nutritional content by meal type, price, and store brand. Methods: In September 2019, 93 convenience store lunchboxes from the top five franchise stores were purchased. Relevant information on price, food weight, food ingredients, cooking methods, and nutrition labeling were subsequently collected. Nutritional content was evaluated based on the daily value (DV) and Index of Nutritional Quality (INQ), and energy contribution of carbohydrate, protein, fat, saturated fat and sugar was compared with the recommended range. Results: Most lunchboxes included the food groups; grains/starches, meats/fish/eggs/legumes, and vegetables. However, none provided fruits, and only a few lunchboxes provided milk/milk products. Stir-frying, deep-frying, and pan-frying were the most frequent methods of cooking. The average energy content of the lunchboxes was 736.6 kcal, whereas the average contents of protein, fat and saturated fat were higher than 40% of the DV, and sodium content was 66.8% of the DV. The contents of most nutrients in traditional type lunchboxes were higher, as compared to nutrients in onedish type lunchboxes. Considering pricing of lunchboxes, protein and sodium contents were higher in the higher-priced lunchboxes as compared to lower-priced lunchboxes, but there were no differences in the INQs. The contents of energy, protein, fat, saturated fat, and cholesterol significantly differed by brand. Conclusions: Our results indicate that convenience store lunchboxes contain high levels of protein, fat, saturated fat, and sodium. The nutritional contents differed by meal type, price, and store brand, and higher price did not imply higher nutritional quality. We propose the need to educate consumers to check nutrition labels and purchase appropriate lunchboxes. Manufacturers also need to make efforts to reduce the amounts of fat, saturated fat, and sodium, and not provide protein in excess.

• Applied Chemistry for Engineering
• /
• v.19 no.2
• /
• pp.214-221
• /
• 2008

The production of biodiesel by transesterification of waste frying oil was conducted on various zeolite catalysts with different acidity and pore structure. $H^+$ ion exchanged MOR, MFI, FAU, and BEA zeolites were employed in the reaction with silicalite which has no strong acid sites. $H^+$ ion exchanged MOR(10) zeolite, which has more acid sites and stronger acid strength than other zeolites, exhibited the highest methyl esters yield as 95%. Dealumination to the HMOR zeolite induced decreasing of acid amount and acid strength. It brought about the decrease of fatty acid methyl esters (FAME) yield. The yield increased linearly with enhancing of acid strength and increasing of amount of strong acid sites. The yields were independent on pore structure of the zeolites.

• Korean journal of food and cookery science
• /
• v.2 no.1
• /
• pp.59-64
• /
• 1986

This study was designed to revive the disappeared Younsa and to investigate the optimum processing condition and characteristics of Younsa nade of the glutinous rice powder. Agitating time of base mixture, thickness of Younsa base, and frying time were examined as the influencing factors in Younsa processings. The textural parameters of Younsa were determined by sensory cvaluation and hardness of Younsa was measured by Rheometer. The results were found as follows; 1. In the sensory evaluation, 1) The Younsa base agitated for 10 minutes by agitating machine was favorable. It, however, did not showed any significant difference among products prepared under varying agitaing time-10 minutes, 20 minutes, and 30 minutes. (p<0.05) 2) The thinnest Younsa base (5 cm$\times$4cm, 1.1-1.5g) showed the most favorable quality and the second quality went to 5cm$\times$4cm, 1.6-2.0g, the third 5cm$\times$4cm, 2.1-2.5g, the fourth 5 cm$\times$4 cm, 2.6-3.0g. (p<0.05) 3) In examination of varying frying time, the optimal time for frying Younsa was 12 minutes was 12 minutes in $150 ^{\circ}C$. However, the quality was found no significant difference between 12 minutes's fried Younsa and 14 minutes's. (p<0.05). 2. The hardness of the most favorable Younsa, agitated for 10 minutes, the thinnest (5 cm$\times$4 cm, 1.1-1.5g), ana fried for 12 minutes in $150^{\circ}C$ was 0.59-0.73 kg/wt measured by Rheometer. The thickest Younsa base (5 cm$\times$4 cm, 2.6-3.0g) is the hardest (1.26 kg/wt). The most optimal conditions in this experiment were found the same ones which was written in historical literature.