• Food Science and Preservation
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• v.19 no.2
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• pp.178-184
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• 2012

The physiochemical property, nutrient composition, and functionality of apple juice sterilized at a low temperature (LT, $70^{\circ}C$, 30 min) or a high temperature (HT, $100^{\circ}C$, 20 min) were analyzed. The pH of the apple juice that was sterilized at LT (pH 4.72) was higher than that of the apple juice that was sterilized at HT (pH 4.57), and the acidity of the apple juice that was sterilized at HT (8.90%) was higher than that of the other sample. The sugar content of the two apple juice samples was 15 $^{\circ}Brix$, and the apple juice samples had high potassium, malic acid, and glutamic acid contents. The total polyphenol contents of the apple juice samples that were sterilized at LT and HT were 27.39 mg/100 mL and 23.24 mg/100 mL, respectively. The apple juice that was sterilized at LT had a significantly stronger DPPH radical scavenging activity than the apple juice that was sterilized at HT ($p$ <0.01), and the apple juice that was sterilized at LT had a lower hydroxyl radical scavenging activity level than the other apple juice. Finally, the apple juice that was sterilized at LT showed significantly stronger activities that inhibit enzyme-related oxidation than the apple juice that was sterilized at HT ($p$ <0.05).

• Food Science and Preservation
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• v.31 no.2
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• pp.235-244
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• 2024

A nonthermally sterilized raw apple vinegar was manufactured using an ultra-fine filtration process (0.2 ㎛ membrane filter) and its quality was comparable to commercially available vinegar products. First, using apple concentrate as a raw material, it was possible to produce non-thermal sterilized Using a two-stage fermentation process of alcohol and acetic acid fermentations, a non-thermally sterilized raw apple vinegar with pH 2.94 and an acidity of 6.20% was produced from an apple concentrate. The fermentation process increased the browning index significantly. However, the fundamental quality parameters of the non-thermal sterilized raw apple vinegar (A) with sterilized apple vinegar (B) did not differ significantly. The pH (2.92-2.95) of apple vinegar (A and B) was higher than that (pH 2.65-2.70) of commercial vinegar (C and D), and the total acidity, which is in the range of 6.20-6.21% and 6.53-6.90%, respectively, was higher in samples C and D than in samples A and B. However, four kinds of organic acids were detected in non-thermal sterilized raw apple vinegar (A), and its total organic acid content (6,245.00 mg%) was significantly higher than that of other samples (B, C, D) (p<0.05). In particular, malic acid content, as a main organic acid in apples, was very high in sample (A) (244.83 mg%) and sample (B) (210.21 mg%), compared to commercial products C (125.78 mg%) and D (86.90 mg%). The total polyphenol content and antioxidant activity of fermented apple vinegar (A, B) were more than twice as high as those of commercial products (C, D). Vinegar A had higher total polyphenol content than vinegar B. The above results suggest it is possible to manufacture and commercialize non-thermal sterilized raw apple vinegar with higher organic acid content and antioxidant properties using ultra-fine filtration.

• Journal of the Korean Society of Food Culture
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• v.4 no.3
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• pp.265-269
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• 1989

Korean traditional fermented foods have been diversely developed to enhance taste and flavor while preserving them on a long term basis. For those furthur utilization and development, more efforts to commercialize these products focusing to the consumer's needs should be proceded. In that sence, the fermented foods might be classified into the bioproduct (biofood) and the sterilized. The former defines the non-sterilized such as Kimchi, Jeotkal (fermented fishes), and Jang (fermented soybean products) so as to include various kinds of microorganisms, enzymes and the unknown bioproducts, while the latter defines the sterilized such as soysauce and vinegars proper to the commercialization. In this paper, present R & D status has been reviewed laying stress on Kimchi, Jeotkal and Jang and the mixed fermentation system by the microflora was suggested as a Korean style model for the future R & D direction in these fields.

• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1134-1139
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• 1998

Quality changes of filter-sterilized Yakju were examined by filtration of Yakju through membranes followed by storing at $25^{\circ}C$ for 50 days. To evaluate quality changes of filter-sterilized Yakju, pH, titratable acidity, turbidity, and viable cell numbers of total bacteria, lactic acid bacteria, and yeast were measured. Titratable acidity, turbidity and viable cell numbers of non-sterilized Yakju increased, but pH profile decreased during the storage. In filter-sterilized Yakju, titratable acidity and turbidity did not change, while viable cells of total bacteria, lactic acid bacteria, and yeast were not detected during the storage. Addition of chitosan at the concentration of 0.1% (w/v) decreased the viable cell numbers significantly showing similar pH and titratable acidity profiles with non-sterilized Yakju.

• Korean Journal of Food Science and Technology
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• v.41 no.6
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• pp.652-656
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• 2009

A cylindrical ultraviolet (UV) sterilization system was developed for decreasing microorganisms in takju. The takju was passed through 110 strips of honeycomb-type teflon tubing with 9 UV lamps (1,395 W) set between the teflon tubes. Thus, during passage, the takju was effectively exposed to the UV rays without loss. In terms of the overall quality aspects of the takju, the optimum sterilization condition was set for 4 min at 2 L/min. A 2-3 log cycle decrease in viable cell numbers of total bacteria and fungi was observed at this operating condition. Quality changes in the UV-sterilized takju were examined via UV irradiation of samples followed by storage at 30oC for 8 days. To evaluate the quality changes, pH, amino nitrogen content, acidity, reducing sugar content, and viable cell numbers of total bacteria and fungi were measured. Increases in pH, acidity, and amino nitrogen content were observed in both the takju control and UV sterilized takju with increasing storage time. However, reducing sugar content was decreased in both samples. The L, a, and b values of the control takju and UV sterilized takju showed similar trends over the storage period. Viable cell numbers of fungi did not change in the control or UV sterilized takju during storage, showing approximately $10^8\;CFU/mL$ and $10^4-10^5\;CFU/mL$, respectively. In addition, viable cell numbers of total bacteria remained lower in the UV sterilized takju over 4 days compared to the non-sterilized takju.

• Journal of the FoodService Safety
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• v.2 no.2
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• pp.59-66
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• 2021

The results of the inspection based on the sanitation checklist and the measurement of refrigerator/freezer temperature, illuminance, and ATP were conducted at 12 school foodservices in Daiyue-district, Taian-city, Shandong Province, China, at the same time, and the results were as follows. Five items of 'Use sterilized cutting boards', 'Use sterilized knives', 'Use worktable after sterilization', 'Use sink after sterilization', 'Sterilize the interior/exterior of the refrigerator regularly' in the checklist inspection were found not to be performed (0%). Two items of 'Disinfect hands after washing', 'Equipped with hand sterilizer' and 'Sterilize the kitchen areas regularly' were investigated as being performed only in one foodservice (8%). The average illuminance of the receiving stand were 373.08±106.35 Lux, 8% when the standard (540 Lux or higher) was complied with, the average refrigerator temperature were 7.06±0.82℃, 38.9% when the standard (-2 to 5℃) was observed 8% of cases complying with the standard (below -18℃) at -8.56±0.76℃ were investigated. As a result of ATP measurement, the surfaces of knife edge, cutting board, refrigerator door handle, worktable, and sink, which are not sterilized at all, were not suitable (accept ratio 0%), sterilized food plate (accept ratio 54.2%) and utensil for preserved food (accept ratio 75%) had a relatively high accept ratio. China's hygiene regulations should be revised in the direction of strengthening disinfection practices for facilities, equipment, and the environment, and hygiene measures such as education on disinfection and preparation of economical disinfection methods should be established.

• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1327-1332
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• 1998

The optimum thermal condition of retort Biji product was determined by heat penetration curve, aerobic bacteria count and sensory test. Retort Biji showed a simple logarithmic heating curve regardless of solid content. Heating time was a $26{\sim}27$ min until Fo value reached 9 min and the amount of microorganism in the Biji product sterilized for 26 min at $121^{\circ}C$ were decreased to $10^{-4}\;CFU/g$, indicating the safe range for retort product. The rate of heat penetration was reduced as solid content and size of product were increased, whereas sterilization temperature and initial temperature of product influenced the heat penetration curve. Sensory scare indicated that there was no significant difference in color, flavor, and appearance among different thermal processes. However, Biji product sterilized at $121^{\circ}C$ showed the highest score in overall preference value.

• The Korean Journal of Food & Health Convergence
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• v.5 no.3
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• pp.35-40
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• 2019

In this study, general bacterial counts and coliform counts, which are hygienic indicator microorganisms, were tested for candy, chocolate, and jelly which are easily available and enjoyed around. After dropping each sample on the desk, indoors, and outdoors, it is immediately collected, or washed and collected to confirm the myth of the 3-second rule. Immediately after removing the wrapping paper, each sample was dropped on the desk, indoors, and outdoors, and after 3 seconds from the moment of contact with the surface, and then collected in a sample bag using sterilized sanitary gloves. After the same operation, each sample was rinsed for 5 seconds using sterilized sanitary gloves and sterilized distilled water, and then collected in a sample bag. The number of bacteria detected in non-washing candies was 41 CFU/g at outdoor and the number of bacteria detected in non-washing chocolate was 76 CFU/g at outdoor. The number of bacteria detected in non-washing jellies was 79 CFU/g at outdoor. Coliform group was not detected in all samples. This showed good results at the level of m = 10,000 or less, which is an allowable value suggested in the Food Code. Also, effect of washing on contaminated food was confirmed. This result is remarkably low compared with the microorganism specimens shown in Food Code, and it is confirmed that contamination occurs but not high value. Therefore, the myth of the 3-second rule is true compared to the figures based on Food Code. However, it showed the characteristics of bacteria that could survive and cross-contaminate on dry food surfaces and emphasized the importance of hygiene through food contact to unsanitary surfaces to minimize the risk of food poisoning.

• Applied Biological Chemistry
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• v.48 no.2
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• pp.140-149
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• 2005

In order to examine the changes of commercial value during storage conditions and shelf-life of Chungkookjang, response surface methodology of SAS program was applied to monitor orgenoleptic properties and color changes to determine optimum storage conditions. Lightness (L) value of vacuum-packed Chungkookjang showed under the 1% significance probability with high influence in all conditions such as sterilized temperature, storage time and storage temperature. Redness (a) value of vacuum-packed Chungkookjang was increased during highly sterilized and storage temperatures, and was individually influenced. One of the generally packed sample also showed that significance value was influenced under 10%, during high storage temperature. Yellowness (b) value of vacuum-packed Chungkookjang showed the significance probability under 1% during storage time and temperature, and under 5% during sterilized temperature. Also, stational point showed saddle type in both packaging samples. In case of vacuum-packed Chungkookjang, compatibility of odor was influenced by sterilized temperature under 10% significance probability. But generally packed samples have an effect on storage time under 1% significance probability effect on storage time, and sterilized temperature under 5%. In case of vacuum-packed Chungkookjang, compatibility of taste was highly concerned with storage time under 1% significance probability, whereas generally packed samples were concerned with storage temperature under 5% significance probability. Overall palatability of vacuum-packed samples showed maximum value of 5.15 on sterilized temperature ($61.92^{\circ}C$), storage temperature ($6.79^{\circ}C$) and storage time (56.48 days) during storage.

• Preventive Nutrition and Food Science
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• v.9 no.4
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• pp.312-316
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• 2004

Sterilized raw ground pork was inoculated with Pseudomonas aeruginosa (PA) and Lactobacillus casei (LC) to investigate the relationship between microbial growth and 2-thiobarbituric acid reactive substances (TBARS) values. The analyses including microbial growth, pH, and TBARS values were performed during 3 weeks of storage at room temperature $(20^{\circ}C)$. The radiation-sterilized control sample did not show any microbial growth, but the samples inoculated at different levels (diluted twice vs non-diluted) exhibited differences until 1 week. However, the difference disappeared at weeks 2 and 3. The pH of raw ground pork inoculated with PA increased, but that of LC decreased. The pH of non-inoculated samples increased slightly after storage. The TBARS values in non-inoculated and LC inoculated with pork increased, but TBARS remained unchanged in samples inoculated with PA after 1 week. Results indicated that the microbial growth level and strains can influence the TBARS value of raw ground pork. Thus, it is important to use samples exposed to the same microbial conditions to compare the oxidation of lipids in meat samples.