• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.4
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• pp.730-735
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• 2004

The effects of cook-chill and sous-vide upon the vitamin retention and acceptance of soybean sprout muchim and soybean sprouts soup were evaluated. When the sous-vide packaged soybean sprout muchim was stored at 3$^{\circ}C$ for 1, 3, and 5 days, the contents of thiamin, riboflavin, and ascorbic acid were not changed. However, the nutrient contents were changed in sous-vide packaged soybean sprouts soup stored at the same conditions at each storage time up to 5 days. The contents of thiamin, riboflavin, and ascorbic acid showed the lowest level at 5 days after storage. Regarding customer's acceptance of sous-vide packaged soybean sprout muchim compared to the freshly cooked one, the former had a higher score in taste and color than the latter. Overall acceptability of the sous-vide soybean sprout muchim had a lower score than that of the freshly cooked one, but the sensory characteristics did not show any significant difference between them. The freshly cooked soybean sprout soup had higher scores in taste, flavor, color, texture, appearance, and overall acceptability than the son-vide packaged soybean sprout soup. The former, however, had a significantly higher score in color (p＜0.05) and the overall acceptability (p＜0.01) than the latter.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.6
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• pp.944-950
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• 1996

The purpose of our study is to investigate the changes of physico-chemical properties according to packaging methods(vacuum packaged with polyamide/polyethylene, air packaged with polyvynyl-chloride) and illumination on the properties of Hanwoo beef. pH value in vacuum packaged beef tended to be decreased, but pH value in air packaged beef tended to be increased during storage for 21 days, irrespective of illumination. Contents of volatile basic nitrogen(VBN) and thiobarbituric acid(TBA) values were increased, regardless of packaging methods. However, vacuum packaged beef showed lower VBN, TBA values than those of air packaged beef. Red color(CIE a value) was also decreased. Regardless of packaging method, saturated fatty acids(SFAs) were increased, but unsaturated fatty acids(UFAs) were relatively decreased. And in the ratio of the UFA/SFA, vacuum packaged beef had lower UFA/SFA ratio than that of air packaged beef. In this study, the effect of illumination did not change on physico-chemical properties in Hanwoo beef. In conclusion, the results indicate that the vacuum packaging treatment was more important to prolong the shelf-life of Hanwoo beef than air packaging method.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.12
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• pp.1773-1778
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• 2009

Guava (Psidium guajava L.) contains high amount of vitamins and minerals, and its leaves have been reported to be very effective on reducing blood pressure. In this study, antimicrobial characteristics of extracts from four different parts of guava (fruit, branch, leaf, and seed) with four different solvents (methanol, ethanol, acetone, and water) were evaluated. Four targeted food-borne microorganisms were selected; two Gram negatives (Escherichia coli O157:H7 and Salmonella Typhimurium) and two Gram positives (Staphylococcus aureus and Listeria monocytogenes). By the paper disc method, guava extracts showed stronger clear hollow zone against Gram positive bacteria than Gram negatives in nutrient broth agar plate. Especially, extracts of branches and leaves showed significant antibacterial activity. Guava extracts also showed significant inhibition activity on the growth of Gram positive food-borne bacteria in nutrient broth. For example, S. aureus did not grow at all at 200 ppm of acetone extracts of guava branch and leaf. In the case of L. monocytogenes, the same concentration of acetone extracts of guava branch and leaf inhibited the growth 33.5% and 55.4%, respectively, at 32 hrs of incubation time. The results indicated that extracts of guava branch and leaf showed significant antibacterial activities against food-borne Gram positive microorganisms, and that guava branches, the byproducts of guava, might be a valuable resource for antibacterial materials.

• The Korean Journal of Food And Nutrition
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• v.27 no.4
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• pp.551-557
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• 2014

To improve microbiological quality of Aster scaber during storage and distribution, hurdle technology with the sanitizers and packaging methods was used. After blanching, total aerobic bacteria of Aster scaber treated with 20% ethanol and 10% NaCl were measured at 2 log CFU/g after 6 days. Total aerobic bacteria of blanched Aster scaber at $100^{\circ}C$ were measured at 2 log CFU/g, and the storage at $4^{\circ}C$ effectively inhibited the growth of bacteria. Repeated blanching using water with added NaCl at $80^{\circ}C$ showed similar microbial growth inhibition compared with treatment at $100^{\circ}C$. After vacuum packaging, blanched sample showed 2 log CFU/g of total aerobic bacteria during 10 days (the storage at $4^{\circ}C$). Therefore, repeated blanching using the water with added 10% NaCl improved the microbiological quality of Aster scaber. We also found that repeated blanching after vacuum packaging was an effective way for storage and distribution of Aster scaber. In conclusion, blanching two times in the 10% salt water or in vacuum packaging at $80{\sim}100^{\circ}C$ would be helpful to control the microbes during storage and distribution.

• Korean journal of food and cookery science
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• v.3 no.1
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• pp.20-30
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• 1987

Kyongdan is a kind of Korean rice cake made from glutinous rice powder. This study attempted to clarify the factors which affect the textural characteristics, and to examine the effects on sensory characteristics and texture of Kyongdan in various soaking time, temperature and volume of adding water in the preparation of Kyongdan. Evaluation was conducted through sensory evaluation and objective evaluation. The degree of gelatinization in various storage time and temperature were evaluated by $\beta$-amylase digestibility. The results were summarized as follows. 1. In preparation, the significant factors were the temperature and volume of water, number of kneading, condition of powder, and the relationships between soaking time and temperature of water and between volume and temperature of water and between volume of water and number of kneading and between volume of water and salt. 2. In sensory evaluation on the various soaking time and temperature and volume of water, the most favorite tendency on the overall quality was at the addition level of hot water of 25% with glutinous rice powder made by soaking for 12 hours. This condition corresponded to the low level of hardness, gumminess, chewiness and the high level of springiness and cohesiveness in comparision with Instron measurement. 3. The degree of gelatinization were decreased rapidly during two days of storage. In storage temperature, Kyongdan which was stored at $0^{\circ}C$, showed the most low level of the degree of gelatinization at the same storage time.

• Korean Journal of Food Science and Technology
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• v.17 no.6
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• pp.474-481
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• 1985

Radurization effects on fried fish meat paste with Co-60 gamma irradiation at 0-5 kGy and physicochemical aspects of the stored samples at low ($3{\pm}1^{\circ}C$, LT) and room ($10-20^{\circ}C$, RT) temperatures were investigated. The initial microbial loads of the samples were $2.2{\times}10^3/g$ in total bacterial count, $2.8{\times}10^2/g$ in yeasts & molds, and $1.0{\times}10^2/g$ in coliform group, respectively. An irradiation dose of more than 3 kGy was shown to be effective for the radurization of stored samples and there is no apparent difference between air and vacuum packaging groups. The chemical components related to the quality underwent similar changes in the nonirradiated and irradiated groups; however, as the storage time was prolonged the quality of nonirradiated samples rapidly deteriorated. Textural parameters of the samples were little affected by the applied doses, and sensory evaluations showed that 3 kGy irradiation was the optimum dose level to extend the shelf-life of fried fish meat paste up to 2 times at RT and 3 to 4 times at LT, respectively compared with the nonirradiated control.

• Korean Journal of Food Science and Technology
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• v.49 no.5
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• pp.502-506
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• 2017

To improve the storage and firmness of Tteokbokki tteok Korean-style rice cakes with spicy sauce, steaming of the rice dough, soaking of the rice cake in acidic solution, and heat sterilization were conducted sequentially. The untreated control could be stored for 1 month under cold conditions, but this was extended to 10 months at room temperature ($15-30^{\circ}C$) after immersion in lactic acid solution (pH 4.0) for 20 min and heating to $100^{\circ}C$ for 30 min. The mechanical strength, which was related to firmness, was significantly increased to $11.4kgm/s^2$ compared with the untreated rice cakes ($8.8kgm/s^2$, p<0.05) and the overall descriptions of the sensory evaluation, including texture, was significantly higher than the control (p<0.05). The average size of the pores in the treated rice cakes was smaller than that of the conventional sample and the texture was improved as a result of decreased starch elution from smaller pores.

• Korean Journal of Food Science and Technology
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• v.27 no.3
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• pp.420-427
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• 1995

This study was conducted to investigate the preservative effect of low molecular weight chitosans on kimchi(2% salt concentration) during fermentation at $20^{\circ}C$. The pH and total acidity of control kimchi were lower and higher, respectively than those of kimchi samples containing chitosan. Reducing sugar content tended to be lower in control kimchi than in kimchi samples containing chitosan until 6 days of fermentation. Malic acid content was lower in control kimchi than in kimchi samples containing chitosan until 4 days of fermentation. Succinic acid content was higher in control kimchi than in kimchi samples containing chitosan at the 2 days of fermentation. Content of lactic and acetic acid also was higher in control kimchi than in kimchi samples containing chitosan at the 4 days of fermentation. The number of total microorganisms and those of microorganisms of Leuconostoc genus and Lactobacillus plantarum were higher in control kimchi than in kimchi samples containing chitosan. The number of microorganisms of Leuconostoc genus was lower in kimchi samples containing chitosan with the lower molecular weight chitosan than those with the higher molecular weight chitosan. Intensity of sensory sour taste and staled flavor were higher in control kimchi than in kimchi samples containing chitosan. There was not much difference in sensory firmness among kimchi samples, but control kimchi was evaluated slightly weaker than kimchi samples containing chitosan. Off-flavor was evaluated as weak in all the kimchi samples.

• Korean Journal of Food Science and Technology
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• v.37 no.6
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• pp.861-865
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• 2005

2,4-Dinitrophenylhydrazine (DHP), indophenol, and HPLC methods, which are generally used to analyze vitamin C, were evaluated by comparing changes in vitamin C contents in various samples kept at 10 and $20^{\circ}C$. Amount of total ascorbic acid (TAA) in yoghurt A kept at $10^{\circ}C$, as measured by DNP method, decreased from 26.7mg/100mL for early period to 22.8mg/100mL for final period of storage, whereas, on 3rd and 10th storage days, increased contrary to general results. Using indophenol, TAA measured at 28.6 and 9.5mg/100mL, and 30.5 and 14.6mg/100mL using HPLC far early and final periods, respectively. With indophenol and HPLC, TAA amount showed steady tendency to decrease. In conclusion, HPLC is the most suitable method to analyze vitamin C content, and indophenol method can be also used during early storage stage.

• Korean Journal of Food Science and Technology
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• v.37 no.1
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• pp.11-14
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• 2005

White radish was minimally processed, packed with air, $CO_{2}$ (100%), and $CO_{2}/N_{2}$ (25/75%), and irradiated at 0, 1, and 2 kGy, and its microbiological quality and pH were investigated during storage for 2 weeks at $4^{\circ}C$. Irradiation significantly reduced total aerobic, coli-form, and lactic acid bacteria counts. Modified atmosphere packaging (MAP) enhanced microorganism control during storage. Acidity decreased by MAP but was restored during storage, Irradiation did not affect sample pH. Results show irradiation at 2 kGy combined with MAP can enhance microbiological safety and quality of minimally processed radish.