• Food Science of Animal Resources
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• v.30 no.5
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• pp.730-738
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• 2010

We developed predictive growth models for Staphylococcus aureus and Bacillus cereus on various food matrices consisting primarily of ready-to-eat (RTE) foods. A cocktail of three S. aureus strains, producing enterotoxins A, C, and D, or a B. cereus strain, were inoculated on sliced bread, cooked rice, boiled Chinese noodles, boiled bean sprouts, tofu, baked fish, smoked chicken, and baked hamburger patties at an initial concentration of 3 log CFU/g and stored at 8, 10, 13, 17, 24, and $30^{\circ}C$. Growth kinetic parameters were determined by the Gompertz equation. The square-root and Davey models were used to determine specific growth rate and lag time values, respectively, as a function of temperature. Model performance was evaluated based on bias and accuracy factors. S. aureus and B. cereus growth were most delayed on sliced bread. Overall, S. aureus growth was significantly (p<0.05) more rapid on animal protein foods than carbohydrate-based foods and vegetable protein foods. The fastest growth of S. aureus was observed on smoked chicken. B. cereus growth was not observed at 8 and $10^{\circ}C$. B. cereus growth was significantly (p<0.05) more rapid on vegetable protein foods than on carbohydrate-based foods. The secondary models developed in this study showed suitable performance for predicting the growth of S. aureus and B. cereus on various food matrices consisting of RTE foods.

• Journal of the East Asian Society of Dietary Life
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• v.26 no.1
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• pp.1-10
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• 2016

The purpose of this study was to investigate the need to develop foods for the elderly based on their food preferences. A one-to-one survey method was used for data collection, and the survey was conducted on 165 elderly people (male: 47, female: 118) attending senior welfare centers in Seoul. The results of this study show that the preferred cooking method was steaming rather than stir-frying. Vegetables (4.24), fruits (4.22), Kimchi (3.87), fish (3.83), tofu (3.81), rice-cakes (3.65), dairy products/eggs (3.47), meat (3.45), noodles (3.44), seafood (3.44), poultry (3.23), bread/cookies (3.10) showed high preferences in order (p<0.05). The respondent's chewing & swallowing degree were "Not uncomfortable chew" 31.5%, "Hard food, and a big food is a little difficult to intake". 37%, "Hard food, and a big food is difficult to intake" 11.5%, "Small food, and soft foods can intake" 11.5%, and "It is difficult to intake solid food" 1.2%. Foods that were difficult to chew were meat 28.3%, seafood 15.2%, vegetables 15.2%, nuts 14.1%, fruits 12.0%, Kimchi 8.7%, and other 6.5%. For respondents, the most important factors affecting choice of elderly foods were flavor (48.5%), hygiene (43.0%), and nutrition (36.4%). The elderly wanted "Ready to eat (RTE)" 53.9%, "Ready to heat (RTH)" 15.8%, "Ready to cook (RTC)" 21.2%, and 'Fresh cut product" 9.1%.

• Korean journal of food and cookery science
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• v.25 no.1
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• pp.45-54
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• 2009

Contamination levels of aerobic colony counts, coliforms and pathogenic bacteria were tested in fried rice dishes to monitor quality for risk management. The prevalence of Bacillus cereus in dishes from 8 Chinese-style restaurants and 2 institutional foodservices was 10%, and the bacteria's contamination levels was 3.47 log CFU/g. Echerichia coli, Staphylococcus aureus, and Salmonella were not detected in any of the 10 samples. However, for their aerobic colony counts and numbers of isolated coliforms, the samples were 30% and 70% over the microbial criteria, respectively, for ready-to-eat foods presented in the Korean Food Code. This suggests that fried rice dishes, although cooked with oil at high temperature, require special care. For the prediction of the growth curve of B. cereus spp. in the fried rice samples, an experiment design of 3 storage temperatures ($7^{\circ}C$, $35^{\circ}C$, $57^{\circ}C$) x 5 storage times (0 h, 2 h, 4 h, 6 h, 24 h) was applied. The sample exposed to $35^{\circ}C$ showed no B. cereus spp. at 0 h; however, there was a tendency of slow growth (1.0 log CFU/g) after 4 hours of storage and then faster growth at 6 h (3.7 log CFU/g) and 12 h (4.7 log CFU/g), showing a growth rate of 0.56 log CFU/g/hr. These results indicate that fried rice, despite being heat-treated, can become heavily contaminated with B. cereus spp. when held over 2 hours at room temperature. However, the samples stored at $7^{\circ}C$ and $57^{\circ}C$ over 24 hours were not contaminated with B. cereus. Based on these results, management guidelines for controlling B. cereus are suggested.

• Korean Journal of Community Nutrition
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• v.17 no.1
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• pp.81-90
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• 2012

This study is to research the use and the demand of the elderly generation that pursue economic ability and active lifestyle. The composition of the meals were "homemade meals" 65.3%, "homemade & convenience meals" 26.7% overall. For the "never miss a meal" category, 70-74 years old was 48.3%, over 80 years old was 60.0%. The elderly under 70 years old showed a high frequency in the use of alternative meals (p < 0.05) and the elderly with higher education used the alternative meals more frequently (p < 0.01). The rice-cakes, bread, tuna cans, Korean side-dishes, beverages, meat, cup-noodles and seafood as alternative meals are in the order of most frequency. Also, 96.0%, 59.0% and 46.5% of the elderly had experience in using "Ready to eat (RTE)", "Ready to heat (RTH)" and "Ready to cook (RTC)". The oldest group surveyed, the elderly at the age of 80 years old and above showed lower preference for "completely cooked state" but showed highest results in the "half-cooked state". This shows the difference between people's perception and the behavior that showed high frequency of 96.0% in the experience with "RTE". This can be inferred that the elderly needs the development of convenience food that is moderately packaged according to the newer lifestyle where the elderly live independent from their children. Moreover, there is a higher demand in the healthy convenience food, which means that there is a need for development in the quality of the convenience food that will allow more faith in convenience food by the elderly.

• Korean Journal of Food Science and Technology
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• v.43 no.1
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• pp.39-44
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• 2011

This study was carried out to examine microbiological contamination of ready-to-eat products and to propose a draft-standard and specifications according to food types. RTE foods were classified into 6 groups including fish products, meat products, breads, rices, salads, and fresh cut foods. The prevalence rates of pathogens detected from all samples were compared among food categories. The pH ranges for all RTE samples were between 3.8 and 7.3. Total aerobic cell counts ranged from 2 to 6 log CFU/g. Bread, rice and fresh-cut foods showed significantly higher counts, which ranged above 4.0 log CFU/g among the samples. Two kinds of rice were above the level of the KFDA Food Code standard for Eschrichia coli. The prevalence rate of E. coli in the rice was 6.7%. For Staphylococcus aureus, one fish product and one bread-product had levels above 2 log CFU/g. Bacillus cereus counts for all samples were below the level of 3 log CFU/g. Listeria monocytogenes was not detected in the samples. Therefore, these data suggest that the primary microbial hazard factors for ready-to-eat foods and risk assessments should focus on E. coli, S. aureus, and B. cereus.

• Journal of the Korean Dietetic Association
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• v.5 no.2
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• pp.205-214
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• 1999

Nutrition fortification of processed foods with microelements is a popular practice in many countries to improve nutritional status of target population. In this study the current food fortification in Korea was evaluated and the regulations and guidelines for food fortification in other countries were presented. Most commonly added nutrients were calcium, vit.C, fiber, vit.Bs and iron. The level of fortified nutrients and the vehicle foods were variable. vit.C and fiber appeared to be overfortified in some foods and the necessity of fortification of these nutrients needs to be examined since the intakes of these elements appears to meet the RDA. Most of other nutrients such as vit.A, vit. $B_1$, vit. $B_2$, and iron were added at the level of 10~25% RDA per serving size. The vehicle foods for fortification were snacks, milk, ramyun, breakfast cereal, juices, candies and ready-to-eat retort pouch foods but not rice which is a staple food in Korea. The guideline and regulation for food fortification is required to ensure safe and proper supplementation of needed nutrients in processed foods.

• Food Engineering Progress
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• v.14 no.1
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• pp.54-59
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• 2010

Instantized thin gruels have been popular to supplement patients who want nutritional, ready-to-eat, and easy-to-use products. In this study, rice-based thin gruels were developed by use of gelatinized rice powder which was manufactured by extrudating rice in a twin-screw extruder. Subsequently, the rice paste from the extruder were dried and ground into fine powder. The gelatinized rice powder was mixed with the powders of various grains, soy beans, nuts, oil seeds, and vegetables to formulate the instantized thin rice gruel with well-balanced nutrients (mixed powder). The mixed powder was granulated to improve reconstitution capability in a fluid bed spray granulator (granulated powder). Lipid and protein contents were higher by 0.9 and 1.9%, respectively, in the granulated powder whereas carbohydrate content was higher by 3.2% in the mixed powder. The calculated dispersibility was 93.7 and 77.0% for the granulated and the mixed powders, respectively. The reconstitution time was 122.3 and 305.3 for the granulated and the mixed powders, respectively. In conclusion, the granulation of the mixed powder improved the dispersibility. This study will be helpful to develop a variety of processed rice products and promote rice process industry.

• Korean Journal of Food Science and Technology
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• v.48 no.5
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• pp.521-524
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• 2016

This study aimed to examine variations in the texture profile analysis (TPA) of cooked rice in relation to the instrumental parameter conditions. The TPA of four types of ready-to-eat, white rice products was conducted in two levels of compression ratio (30 and 70%) and cross-head speed (0.5 and 1.0 mm/s). The properties of the four rice products significantly or non-significantly differed, depending on the instrumental parameter condition. Agglomerative hierarchical clustering, based on the five TPA properties such as hardness, adhesiveness, cohesiveness, chewiness, and springiness, revealed that clustering of the four rice products varied with the instrumental parameter condition. Additionally, the ratio of adhesiveness to hardness, an index of rice texture quality, showed a variation depending on the two instrumental parameter conditions. In conclusion, our findings demonstrate that the texture profile, texture-based sample clustering, and the ratio of adhesiveness to hardness vary with the compression ratio and cross-head speed in the TPA.

• Applied Biological Chemistry
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• v.51 no.4
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• pp.329-333
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• 2008

This study was designed to estimate the shelf-life of the popular chilled foods kimbab (rice rolled in dried laver), samgak kimbab (triangular rice rolled in dried laver), eomook (fish surimi, boiled fish paste) mook (acorn-starch jelly), and tofu (soybean curd) in large discount markets and convenience stores. Different types of chilled foods were stored at 5, 7, and 10 for 7 and 28 days, and changes in the total numbers of the aerobic bacteria were monitored. Values of 6 and 7 log cfu/g were used as the standard. Ready-to-eat foods stored at 5 showed a much longer shelf-life compared to storage at 10. The respective percentage increases in the shelf-life observed at both 7 and 5 were kimbab (70%, 171%), samgak kimbab (87%, 143%), soybean curd (46%, 95%), fish surimi (46%, 99%), and mook (45%, 87%). To reduce the microbiological contamination, storages at 7 and 5 are recommended for the increases of 45-88 and 87-171% in the shelf-life of these chilled foods.

• Korean journal of food and cookery science
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• v.26 no.2
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• pp.165-170
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• 2010

Although the demand of ready-to-eat (RTE) foods such as Kimbab is growing, large quantities and wide distribution of these foods is difficult due to their short shelf-life, exposed packaging with hygienic risk, and decreased quality at refrigerator temperatures. This study was undertaken to develop preservation and storage methods to extend the shelf-life of RTE rice products using microwave and packaging methods such as vacuum and modified atmosphere packages. RTE rice ball samples inoculated with Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes, Staphylococcus aureus or Bacillus cereus were microwave treated for 0, 30, 60, 90 and 120 seconds. Populations of pathogens on the rice balls were significantly reduced with an increase in treatment time. There were more than 5 log reductions of all pathogens when the samples were microwave treated for 60 seconds. RTE rice balls inoculated with two pathogens (S. aureus and B. cereus) were packaged via air, vacuum, $N_2$ gas, and $CO_2$ gas following microwave treatment for 90 seconds. The initial S. aureus and B. cereus concentration before treatment was 7.60 and 6.59 log CFU/g, and these levels were reduced by 3.37 and 2.18 log CFU/g after microwave treatment. The levels of pathogens were significantly increased during storage time at room temperature. $CO_2$ packaging was the most effective at inhibiting microbial growth among the tested packaging methods. The levels of total mesophilic count, S. aureus and B. cereus after 5 days of storage were 7.7, 8.8 and 9.3 log CFU/g in air packaged samples and 2.4, 3.2 and 8.3 log CFU/g in $CO_2$ gas packaged samples, respectively. However, after 3 days of storage higher levels of B. cereus were observed in all samples, indicating that the samples were not safe to be consumed. Base on these results, microwave treatment and MAP packaging methods using $CO_2$ gas could be used as a potential method for extending the shelf-life of RTE foods.