• Journal of the East Asian Society of Dietary Life
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• v.14 no.2
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• pp.135-144
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• 2004

A total of 40 Korean and Japanese rice varieties were evaluated for their main chemical components, physical properties, cooking quality, pasting properties, and instrumental measurements. Based on their quality evaluations, it was concluded that Korean and Japanese rice varieties were not significantly different in the basic components of NIR (Near Infra Red) data and the chemical analysis from the uncooked brown and milled rices. Korean rice had a little bit higher protein and amylose contents but much lower fat acidity than those of Japanese rice from the chemical analysis. From all the data of three different kinds of NIR methods, Korean and Japanese milled rice were very similar except the taste score. Japanese rice showed a slightly higher taste score, a little bit higher lightness and whiteness, but lower yellowness and redness than Korean one. From all those data of NIR and the chemical analysis, Korean and Japanese rices had very similar components except the fat content.

• Food Science and Preservation
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• v.31 no.4
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• pp.579-589
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• 2024

To compare the cooking methods (boling, steaming) for broccoli, the extracts from water or 80% ethanol were used to determine total polyphenols, total flavonoids, and antioxidant activities. The total polyphenol and flavonoid contents of both fresh and boiled or steamed broccoli were found to be higher in the 80% ethanol extract compared to the water extract. Nine glucosinolates were identified in broccoli using high-performance liquid chromatography. The glucosinolate content was found to be higher in steamed broccoli compared to fresh broccoli; however, in boiled broccoli, the glucosinolate content decreased by 5.74-18.64% compared with fresh broccoli. It was confirmed that antioxidant activity decreased through heat treatment such as boiling or steaming compared to unheated broccoli. In particular, the decrease in antioxidant activity was higher in boiled broccoli than in steamed broccoli. The results suggested that it would be preferable to use raw or steamed broccoli rather than boiling it in water to minimize the loss of bioactive substances when consuming broccoli.

• Journal of Environmental Health Sciences
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• v.40 no.2
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• pp.88-97
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• 2014

Objectives: The aim of this study was to evaluate the occurrence of microbiological contamination of kitchen utensils and environments of food service operations at university located in Seoul, Korea. Methods: We collected swab samples from the surfaces of knives, chopping boards, floors, and drains, as well as drinking water and airborne bacteria samples from 20 food service operations. Three bacterial indicators and five food poisoning bacteria were measured quantitatively and qualitatively, respectively. We used selective culture media and the PCR assay targeting 16S rRNA gene for the microbiological analysis. Results: We detected bacterial indicators on knives or chopping boards in eight different food service operations and, three food service operations (I, M, and O) showed more than 3 log colony forming units $(CFU)/100cm^2$ on their knives, significantly higher than the others. The levels of bacterial indicators on the floors and drains in the cooking areas were much higher than those on the cooking utensils. S. aureus was detected on 10 floors and 8 drains. Culturable bacteria were identified in 5 drinking water samples, and food service operation B ($431.1CFU/m^3$) and C ($551.2CFU/m^3$) showed more than $400CFU/m^3$ of total airborne bacteria. Conclusions: These results suggest that some of food service operations in this study may require additional investigation to secure the microbial safety of cooking environments. In addition, further actions including hygiene education for employees and proper guidelines to maintain clean cooking environments should be prepared.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.5
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• pp.701-710
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• 2019

Objective: This study investigated the effect of different acute heat stress (HS) levels on chicken meat quality and ultra-structure. Methods: Chickens were randomly divided into 7 groups to receive different HS treatments: i) $36^{\circ}C$ for 1 h, ii) $36^{\circ}C$ for 2 h, iii) $38^{\circ}C$ for 1 h, iv) $38^{\circ}C$ for 2 h, v) $40^{\circ}C$ for 1 h, vi) $40^{\circ}C$ for 2 h, and vii) un-stressed control group ($25^{\circ}C$). Blood cortisol level, breasts initial temperature, color, pH, water holding capacity (WHC), protein solubility and ultra-structure were analyzed. Results: HS temperatures had significant effects on breast meat temperature, lightness ($L^*$), redness ($a^*$), cooking loss and protein solubility (p<0.05). The HS at $36^{\circ}C$ increased $L^*{_{24h}}$ value (p<0.01) and increased the cooking loss (p<0.05), but decreased $a^*{_{24h}}$ value (p<0.05). However, as the temperature increased to $38^{\circ}C$ and $40^{\circ}C$, all the values of $L^*{_{24h}}$, cooking loss and protein denaturation level decreased, and the differences disappeared compared to control group (p>0.05). Only the ultimate $pH_{24h}$ at $40^{\circ}C$ decreased compared to the control group (p<0.01). The pH in $36^{\circ}C$ group declined greater than other heat-stressed group in the first hour postmortem, which contributed breast muscle protein degeneration combining with high body temperature, and these variations reflected on poor meat quality parameters. The muscle fiber integrity level in group $40^{\circ}C$ was much better than those in $36^{\circ}C$ with the denatured position mainly focused on the interval of muscle fibers which probably contributes WHC and light reflection. Conclusion: HS at higher temperature (above $38^{\circ}C$) before slaughter did not always lead to more pale and lower WHC breast meat. Breast meat quality parameters had a regression trend as HS temperature raised from $36^{\circ}C$. The interval of muscle fibers at 24 h postmortem and greater pH decline rate with high body temperature in early postmortem period could be a reasonable explanation for the variation of meat quality parameters.

• Culinary science and hospitality research
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• v.7 no.3
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• pp.45-56
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• 2001

The HPC(High Pressure Cooking) method and the traditional method of brown stock preparation are compared in terms of gelatin, free amino acid and sensory evaluation. The HPC outperform the traditional method. In addition, free amino acid content of brown stock increased when HPC method is applied. In traditional method, however, the contents of free amino acids gradually increased in proportion to the length of heating times. When the HPC method is used for brown stock, the level of alanine and methionine were relatively higher than that of traditional method. In order to measure the quality of brown stock made from different methods, the highly qualified chefs were selected. They favoured the taste and smell made from HPC while they preferred traditional approach to HPC in terms of stickiness and appearance(colour). It is turned out that five hours is the most appropriate heating time for HPC method to obtain the maximum extraction of amino acid. The results suggest that the quality of brown stock from HPC method is not at all inferior to that of traditional brown stock while the HPC approach can improve the level of productivity by saving the labour cost, food cost and time.

• Food Science of Animal Resources
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• v.38 no.1
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• pp.180-188
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• 2018

The market size of home meal replacement (HMR) products has been gradually growing worldwide, even in Korea. In Korean HMR products, meat is the most important food ingredient compared with rice and vegetables. Therefore, this study aimed to evaluate changes in physiochemical and sensory aspects of beef under different preparation processes. For preparing four treatments, beef eye of round (ER) added with salt and sugar (treatment 1) and that without salt and sugar (treatment 2) were mixed with rice and frozen at $-50^{\circ}C$. Beef ER without salt and sugar was also topped onto the rice and frozen (treatment 3), and that was topped onto the rice and precooled before freezing (treatment 4). Physiochemical analyses included cooking and drip losses, shear force, color, salt soluble protein, and sensory attributes were tested. The results showed significantly higher drip loss and total loss in beef ER samples 1 and 2, which were mixed with rice, compared to beef ER samples 3 and 4, which were not mixed with rice. A significantly higher discoloration was also observed in beef ER samples 1 and 2, compared to that in samples 3 and 4. In the partial least squares regression (PLSR) analysis, beef ER sample 4 (precooled before freezing) was highly related to sensory attributes, such as flavor, overall acceptability, and juiciness, and far from non-preferred shear force. As a result, beef ER in HMR sample 4 was the most preferable to the sensory panel, and it had the most desirable physicochemical analysis outcomes.

• Food Science of Animal Resources
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• v.41 no.5
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• pp.869-882
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• 2021

Sodium chloride (NaCl) replacement with calcium chloride (CaCl₂) effect on protein solubility, proteolytic enzyme and quality characteristics of a chicken soup prepared from spent hen (SH) chicken were investigated. By means of immerse marination prior to cooking, a total of 60 skinless SH breast meat were randomly allocated into ten groups admitted to treatments with marinade solution containing sodium tripolyphosphate (STPP) and reduced percentage of NaCl with CaCl₂ at 0%, 25%, 50%, 75%, and 100% at 4±2℃ for 20 h. STPP was adjusted to 0.5% for all treatments and NaCl replacement at 0% was used as control. The different methods, particularly boiling at 100℃ and retorting at 121℃, 1.5 kgf/cm² for 60 minutes, were applied following marination. An upregulation of cathepsin-B and caspase-3 enzymes were a consequences from a higher percentage of CaCl₂ within meat environment. Accordingly, modified the protein solubility in particular the myofibrillar and total protein solubility. In addition, a significant increase in water holding capacity (WHC), pH value, myofibril fragmentation index (MFI), and moisture content was obtained due to salt replacement (p<0.05). Limited effect was observed for shear force value, collagen content and cooking yield. Eventually, this study implied that although protelytic enzyme and protein solubility was upregulated by the replacement of NaCl with CaCl₂ at >75%, extensive effect on texture properties was not observed. Therefore, NaCl replacement at 75% could be a promising strategy for quality improvement of SH chicken soup.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.2
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• pp.96-104
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• 2017

This study was carried out to compare the cooking and antioxidant characteristics of rice containing varying amounts of glutinous rice and cooked by two methods. Rice containing glutinous rice was cooked by general and high-pressure cooking methods with and without fermented alcohol. Pasting characteristics of cooked rice were decreased with increasing amounts of glutinous rice. The water binding capacity and swelling power were significantly decreased with increasing amounts of glutinous rice; however, water solubility indices were significantly increased. Palatability characteristics of cooked rice containing glutinous rice were similar to those of cooked rice without glutinous rice. Total polyphenol contents of cooked rice containing glutinous rice and fermented alcohol were quite different, but this difference was not significant. Total flavonoid contents were increased with increasing amounts of glutinous rice. Total flavonoid content by general cooking method for rice containing 20% glutinous rice and fermented alcohol was $23.20{\pm}0.61{\mu}g\;CE/g$. DPPH radical-scavenging activities for samples with and without glutinous rice were 2.97-5.19 and 3.19-5.45 mg TE/100 g, respectively. ABTS radical-scavenging activity by high-pressure cooking method for rice containing 20% glutinous rice and fermented alcohol was $19.48{\pm}0.63mg\;TE/100g$. In this study, cooking and antioxidant characteristics of cooked rice containing glutinous rice generated data useful for manufacturing processed products.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.1
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• pp.143-155
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• 2014

The purpose of this study was to analyze adaptation for Korean foods and satisfaction for university foodservice by nationality and residence period of Chinese and Japanese university students in Daejeon, Republic of Korea. Among 330 questionnaires distributed to Chinese and Japanese students, 294 complete questionnaires (89.1%) were analyzed. The questionnaire included two 5-point scales for measuring levels adaptation of for Korean food and satisfaction with university foodservice, respectively. Japanese students' level of adaptation for Korean food (3.16) was significantly higher than that of Chinese students (2.96). As the length of residence in Korea increased, the frequency of using university lunch service per week significantly decreased. The main factor when selecting a menu item was food taste (39.8%, 22.8%) in both Chinese and Japanese students, whereas the next main factor was preference (16.4%) in Chinese students and nutrition (18.7%) in Japanese students. The preferred cooking methods for meat were stir-frying (31.6%) and roasting (25.9%). For fish, Chinese students preferred braising (32.7%), whereas Japanese students preferred roasting (26.8%). Both Chinese and Japanese students preferred sukchae (45.6%, 43.1%) for vegetables. Factor analysis grouped 17 items measuring university foodservice into four factors, 'sanitation & employee service', 'physical environment', 'food' and 'customized menu & information' and the mean scores were 3.56, 3.30, 3.20 and 3.00, respectively. Chinese students were significantly more satisfied than Japanese students with the 'physical environment', 'sanitation & employee service' and 'customized menu & information'. These results suggest that efforts such as developing a greater variety of menu items with mild tastes and somewhat less flavor, applying preferred cooking methods, offering special menus for foreign students, providing nutrition information on menus, and offering a description of menu items in the foreign languages could improve Chinese and Japanese students' levels of satisfaction with university foodservice.

• Journal of the Korean Society of Food Culture
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• v.14 no.1
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• pp.1-15
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• 1999

A survey was conducted in 591 college students using 8 different cafeterias serving 31 meals. The information was obtained about the name and amount of dishes they consumed from the menu offered by college foodservice. Mean nutrient contents per meal in offered menu were higher than 1/3 of RDA for their age, sex in offered menu. The mean energy content was 466kcal from rice, 113kcal from soup, 141kcal from side dish and 21kcal from kimchi. When side dishes were classified by cooking methods, side dishes using grilling, frying, roasting methods had high energy content and fat percent above 200kcal, 40% per dish. By main ingredients, side dishes with animal food were higher energy than with plant food. Students consumed 94% of the energy provided in offered menu. When compared to proportion of foods consumed by sex, there was 43% of female and 22% of male consumed less than half in soup and 31% of female and 12% of male in kimchi. The most prevalent menu patterns of subjects included rice, soup, 2 side dishes, kimchi and were the same in both sexes. Mean energy intakes per meal were 989kcal for males and 842kcal for females which were enough to meet 1/3 of RDA for their age and sex. Most nutrient intake except fat and vitamin B1 were higher in set menu than in cafeteria. Nutrient adequacy ratio(NAR) were above 0.9 except calcium and vitamin A. The mean energy intake was 542kcal from rice, 70kcal from soup, 164kcal from side dish and 20kcal from kimchi. In conclusion, intake of most of the nutrients of students obtained from males in college foodservice were sufficient but calcium intake was insufficient and fat content was above 20% of energy. High fat consumption was due to side dishes from frying, grilling, roasting with animal food. To provide desirable meals in college foodservice, use of fat in cooking must be decreased.