• Korean Journal of Food Science and Technology
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• v.26 no.5
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• pp.579-584
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• 1994

Near infrared reflectance(NIR) spectroscopy was used to determine the degree of retrogradation of cooked rice. Cooked rice samples were stored at $4^{\circ}C$ for 120 hours, and the degree of retrogradation was measured at every 6 hour during the storage time. Stored cooked rices were freeze-dried, milled and passed through a 100 mesh sieve. Enzymatic method using glucoamylase was used as reference method for the determination of the degree of retrogradation. Spectral differences due to retrogradation of cooked rice were observed at 1434, 1700, 1928, 2100, 2284 and 2320 nm. 32 samples of which moisture content were below 5% were used for calibration set, and 16 samples were used for validation set. High correlations were achieved between degree of retrogradation determined by conventional enzymatic method and by NIR with multiple correlation coefficient of 0.9753, and a standard error of calibration(SEC) of 3.64%. Comparable results were obtained with 3.91% of standard error of prediction(SEP), when the calibration equation was applied to independent group of samples of which moisture contents were in the range of calibration set. But when the calibration equation was applied to samples of which moisture contents were outer range of calibration set, SEP and bias were increased and correlation coefficient was decreased. The determination of degree of retrogradation was affected by sample moisture content. To determine degree of retrogradation of cooked rice by NIR using this calibration equation, it was suggested that sample moisture content should be controlled to below 5%.

• Proceedings of the Korean Environmental Health Society Conference
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• 2002.04a
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• pp.55-56
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• 2002

Aflatoxin is a secondary fungal metabolite and is a public health hazard because it is a human carcinogenic and has many deleterious effects in men and animals. Rice is one of the better substrates for the fungus which can produce aflatoxins. This study was performed to investigate aflatoxin reduction during the cooking and processing of rice. Aflatoxin was produced by Aspergillus parasiticus ATCC 15517 on well-milled rice(Japonica type) at the level of 13.2 ppb. Cooked rice, rice cakes (baek-sol-gi, plain steamed rice bread), fermented rice (sik-hye, sweet rice beverage), and popped rice were prepared from the aflatoxin-contaminated rice. Aflatoxin content in the samples was determined by high performance liquid chromatography. The total aflatoxin level was decreased to 46.9％ in the cooked rice, 85.6％ in the rice cakes, 11.4％ in the fermented rice, and 7.6％ in the popped rice, respectively (p＜0.05). This reduction brought the level of aflatoxins down to below the Standard and Specification of Korea (10 ppb), except for the rice cakes. These results indicate that washing, steaming, fermentation, and popping of rice was helpful in reducing the aflatoxin level in the rice and the most helpful factors were high temperature & high pressure. More research is needed to understand why the preparation of rice cakes did not reduce the level of aflatoxin as much as the other cooking methods.

• Food Science of Animal Resources
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• v.18 no.4
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• pp.301-306
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• 1998

Four low fat ground beef groups containing 10% fat plus 0, 5, 10 and 20% additional cooked lod rice and a control ground beef containing 30% fat were prepared and the analysis for microbiological and oxidative stability were conducted. During 6 days of storage at 4$^{\circ}C$ microbial analysis including total plate count and coliform groups were performed and 2-thiobarbituric acid reactive substance (TBARS) absorbances were measured. The growth rate of total aerobic bacteria and coliform groups tended to increase with the increase in fat content and the amount of added cooked lod rice. Development of oxidative rancidity were not significantly different between 10 and 30% fat ground beef but among the 10% ground beef the rancidity development significantly(p<05) decreased with the in-crease in the amount of added cooked old rice. Low fat ground beef groups were not stable over 3 days during storage at 4$^{\circ}C$.

• Korean Journal of Food Science and Technology
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• v.14 no.1
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• pp.80-81
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• 1982

Staling rates of cooked rice from Akibare (Japonica) and Milyang 23 (Indica) stored at $21^{\circ}C$ and $72^{\circ}C$ were analyzed using the expression ${\theta}={\exp}\;(-kt^n)$, where ${\theta}$ in the fraction of uncrystallized material remaining after time t. The values for the rate constant (k) indicated that the firming process for both rices was not dependent on the variety, but was dependent on the storage temperature. The Avrami exponent (n) was found to be unity at two temperatures, suggesting that the staling of cooked rice is characterized by instantaneous nucleation followed by rod-like growth of starch crystals.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.2
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• pp.281-285
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• 1998

For the purpose of improving the qualities of carrot, spinach and cooked rice, the effects of food height(0mm: H0, 5mm: H5, 10mm: H10, 15mm: H15) for microware blanching and reheating on physicochemical properties were investigated. In carrot blanching, color values of each treatment were not different, and cutting forces of microware blanching carrots were decreased as carrot height increased. In spinach blanching, the shape of orignal form was changed as height increased. In cooked rice reheating, H10 had the highest overall acceptance score. Physicochemical properties were changed by food hight of microwave blanching and reheating on food.

• Journal of the Korean Society of Food Culture
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• v.8 no.1
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• pp.1-9
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• 1993

This study was carried on the preferences for food intake pattern of Korean industrial workers. The survey was conducted from Feb 17, to March 31, 1992 by questionnaires which was composed of 21 items. The subjects of this study were composed of 426 clerical workers, and 439 physical workers. The results were obtained as follows. 1. In the educational background, clerical workers was almost of highschool or collage graduates, and physical workers was almost of highschool graduates. Marginal food cost of per person for lunch a day was from 500 Won to 1,000 Won. They replied that amount of staple food and side dishes were appropriate, and the type of preferable foods was Korean style cooked rice. Also it was known that physical workers thought their nutritive condition more badly than that of clerical workers. So the physical workers considered their health very much when they had meal. It was represented that unbalanced diet, without diet and drinking alcohol effected badly to food intake and taste of food was the most important point in food intake. 2. Preferences for staple foods; Cooked rice was preferred the most by the subjects. Cooked rice with redbean was preferred by clerical workers and cooked rice with soybean was preferred by physical workers and cooked rice with soybean was preferred by physical workers. Also clerical and physical workers liked Kalkooksoo (hot noodle), Nangmyun (cold noodle), bread, vegetable bread and disliked Sphagetti, Ramyun (Instant noodle) in same rate. In the next, cooked rice covered with raw fish pieces (Sushi) was preferred by clerical workers and Mandu-kook was preferred by physical workers. Also they disliked Curriedrice and Hashrice in same pattern. 3. Preference for side-dishes; The Acceptances for side-dishes were high soybean paste soup (clerical workers:43.7%, physical workers:34.4%), Kim chi stew, fried potatoes, crab steaming (37.8%, 36.9%), broiled fish (34.6%, 33.9%), fried green pepper, Ham, Chinese cabbage Kim chi, and pickled garlic by clerical and physical workers all together. But in clerical workers, Wooghugi beef-rib tang, Deodeok muchim, spinach namul, beef jangjeorim, fried shrimp were shown to have high preference in physical workers, beef-rib tang, wild onion and shepherd's purses muchim, soybean sprout, fish jeorim, fried sweet potatoes were high preference. 4. Preference of Snacks; The preferences for snacks were high in strawberry (clerical:36.3%, physical:34.3%), milk (49.9%, 44.4%), waxy rice Doek (30.7%, 30.2%), coffee (40.1%, 38.9%) by two groups in same order.

• Korean Journal of Food Science and Technology
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• v.52 no.3
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• pp.310-315
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• 2020

The aim of this study was to investigate the texture change of cooked rice within a short time after cooking. Using four instant rice brands, the texture change within 30 min after cooking was measured by the texture profile analysis (TPA) method for hardness, adhesiveness, cohesiveness, chewiness, and springiness with different compression ratios (30, 70%) and cross-head speeds (0.5, 1.0 mm/s). In the case of cohesiveness, adhesiveness, and chewiness, there were significant differences in the rice textures at 20 to 30 min after cooking compared to that in the sample immediately after cooking. In particular, adhesiveness showed significant differences at 10 min after cooking. However, there were little significant differences within 30 min for springiness. In conclusion, when measuring cooked rice texture, it is desirable to measure it, if possible, within 10 to 20 min after cooking.

• The Korean Journal of Food And Nutrition
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• v.25 no.4
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• pp.762-769
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• 2012

In order to study the cooking characteristics of four rice cultivars of Seolhyangchal, Baegjinju, Ilpum and Haiami, we investigated the relationship between the textures of cooked rice and their physicochemical properties. Different levels in grain weight. length/width ratio and amylose content were observed among the four rice cultivars. There was no significant difference in the amylopectin chain length distribution among the cultivars. Water absorptions of rice grains during soaking were completed between 30 and 40 min, with Haiami showing the slowest absorption. Significant differences in the viscosity properties of rice flour were found by a Rapid Visco Analyser. Baegjinju with low amylose content had the highest viscosity in paste breakdown. According to the DSC results of rice starches, there were significant differences in the onset, peak and conclusion temperatures of the endothermic peak. Gelatinization enthalpy showed energy content changes between 4.20 and 6.97 J/g, with the lowest change in Haiami. Texture properties of cooked rice were assessed using a Texture Analyzer, which showed that the hardness of cooked rice was decreased with soaking than without soaking. However, this finding was not applicable for Haiami rice.

• Korean Journal of Food Science and Technology
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• v.27 no.4
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• pp.449-457
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• 1995

Aseptic packaged cooked rice without oxygen absorber and EVOH material was not suitable for good quality during long storage at room temperature. Quality change of aseptic packaged cooked rice with OPP/EVOH/EPL(P-1), PET/EVOH/EPL(P-2) and OPP/EVOH/LLDPE(P-3) for lid material and FX and TSQ for oxygen absorber was observed during storage(60 days) at $20^{\circ}C,\;30^{\circ}C\;and\;40^{\circ}C$. To evaluate quality change of aseptic packaged cooked rice, water content, color, pH, acidity, hardness, and total plate count were measured periodically. The results showed that moisture content was decreased as storage time increased while storage temperature showed no significant effect. P-2 and FX combination had the lowest evaporation of water. L value was decreased as storage time increased while a value increased in all treatment. P-2 and FX combination had the best result for color value. Titratable acidity and pH of P-3 increased up to 20, 5.5, respectively at the end of storage while the other treatment showed no significant effect. Hardness of aseptic packaging of cooked rice was decreased as temperature of storage increased while lid materials and oxygen absorber types showed no significant effect. Result of total plate count showed that there was no detection for $20^{\circ}C\;and\;30^{\circ}C$ storage temp. while more than $1{\times}10^6\;CFU/g\;for\;40^{\circ}C$ storage temp. at the end of storage. In conclusion, aseptic packaged cooked rice could be stored and distributed for 6 month at room temp. and effect of lid materials on quality change of aseptic packaged cooked rice was more significant than oxygen absorber.

• Korean journal of food and cookery science
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• v.7 no.2
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• pp.1-6
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• 1991

The sensory properties and the change of lipid content of cooked rice were investigated to evaluate the effects of cooker (electric and pressure cooker) and variety ($Japonica and Indica\timesJaponica variety$). Overall preference of cooked rices were higher in the pressure cooker than the electric cooker. In the case of electric cooker, Japonica variety was prefered than $I\timesJ$ variety. Free lipid contents were reduced and bound lipid contents were increased after cooking. The bound lipid contents had a correlation with shiness of cooked rice(r=-0.69).