• The Korean Journal of Community Living Science
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• v.26 no.3
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• pp.489-498
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• 2015

This study investigates the effects of a China root (Smilax china L.) extract on the chemical and microbiological characteristics and antioxidant activity of the sausage stew sauce and the soft-tofu stew sauce over a 5-week storage period. Commercial sauces were obtained from the market, and samples were prepared using four different concentrations of the China root extract (0% (control), 0.5%, 1.0%, and 1.5%) and stored at $5^{\circ}C$ and $20^{\circ}C$. Over the 5-week storage period, pH and salinity showed slight changes in both the sausage and soft-tofu stew sauces, but there was no significant difference (p<0.05) regardless of the extract amount and temperature. At 5 weeks, there were significant decreases in the total microbial count in groups with the China root extract (p<0.05) for both the sausage and soft-tofu stew sauces at $5^{\circ}C$. Over the whole storage period, no coliform, yeast, and mold were detected in any sample. S. aureus counts were not detected in 1.0% and 1.5% China root groups at $5^{\circ}C$, but 1.00-1.60 log CFU/g was found in the control and 0.5% groups. DPPH radical scavenging activity at 5 weeks showed an increase with an increase in the amount of the China root extract in both sauces. These results indicate that the China root extract inhibited microbial growth during storage as well as scavenging activity and thus that it can be considered to prolong the shelf life of commercial sauces.

• Journal of the Korean Society of Food Culture
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• v.24 no.3
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• pp.295-307
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• 2009

The principal objective of this study was to develop and standardize a preparation method for low-sodium tomato jangachi (traditional Korean pickle) via short-term fermentation with immature green cherry tomatoes. In order to determine the preferred concentrations of soy sauce and soaking temperatures of immature cherry tomato pickles in different stages of storage, we conducted an analysis of physico-chemical characteristics and microbiological properties, and also performed a preference test on samples of immature green cherry tomato pickles. Immature cherry tomatoes were prepared in three different soy sauce concentrations --20, 40, and 60%-- and three different soaking temperatures --60, 80, and 100$^{\circ}C$-- and then stored for 28 days at 5$^{\circ}C$. As a result, the pH increased significantly with increases in the amount of soy in the dipping solution (p<0.05). The saltiness was maintained at levels of approximately $0.17{\sim}0.28%$ (20% group), $0.32{\sim}0.67%$% (40%group), $0.48{\sim}1.00%$ (60% group) during storage periods. These results show that the saltiness of immature cherry tomato pickles was substantially lower than that of commercial pickles. The contents of reducing sugar and lightness decreased significantly with increasing concentrations of soy dipping solution. The redness and yellowness values of the tomatoes decreased significantly with increasing concentrations of soy sauce. Additionally, the lower the concentration of soy sauce used, the more rapidly the hardness of the immature cherry tomato pickles was reduced at 100$^{\circ}C$. PME activity moved within a narrow range, and then stabilized during the storage period. With regard to the results of the consumer preference test, 20%-100$^{\circ}C$ was the most preferred condition overall, 40%-80$^{\circ}C$ was the condition in which the texture was most preferred, and 40%-80$^{\circ}C$ was the condition that yielded the highest color scores.

• Food Science and Preservation
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• v.31 no.1
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• pp.1-14
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• 2024

The utilization of coatings composed of bio-based materials in the processing and preservation of meat presents an environmentally conscious, secure, cost-effective, and superior method for prolonging the storage life of meat while also preserving its nutritional value. In this study, changes in physical, chemical, and microbiological characteristics of freshly cut beef coated with distilled water (control) and keratin-starch composites (K-S) functionalized with 0.0-, 0.2-, 0.6-, and 1.0-mL avocado peel polyphenolic-rich extract (APPPE) kept at 4℃ for 12 days were evaluated periodically at 3-day interval using standard techniques. Keratin was extracted from waste feathers, while starch was obtained from ginger rhizomes. Following a 12-day storage period, beef coated with APPPE-enriched K-S composites exhibited a significant (p<0.05) improvement in shelf life by minimizing deteriorative changes in pH and color (as determined by metmyoglobin level) in addition to inhibiting oxidative changes in lipids (as determined by TBARS level) and proteins (protein carbonyl level) in comparison to control and K-S composite without APPPE. Furthermore, microbial growth was significantly (p<0.05) suppressed in meat coated with K-S composite functionalized with APE at 0.6 and 1.0 mL compared to the control. The study suggested that APPPE-enriched K-S composite could offer an eco-friendly and safe food preservation technique for fresh meat.

• Korean Journal of Food Science and Technology
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• v.19 no.2
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• pp.107-112
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• 1987

Comparative effects of ethylene oxide and gamma radiation treatment of the microbiological and physicochemical qualities of ground garlic and onions were investigated. The standard ethylene oxide cycle employed was substantially less effective in reducing microbial counts than were 7 and 10 kGy of gamma radiation, and was roughly comparable to 5 kGy. Effects of gamma radiation on pungency, nutrient and color were relativey small in comparison with ethylene oxide which adversely affected physicochemical properties. Sensory evaluation indicated that no significant difference was observed between the nontreated control group and 10 kGy irradiated smaples.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.4
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• pp.312-320
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• 1993

Low-salted and fermented squid products, squid jeotkal was prepared and fermented at $10^{\circ}C$. During fermentation of squid, microbiological and chemical changes were examined. Sensory evaluation was also carried out. After 20 days of fermentation, taste and flavor of the squid jeotkal containing $10\%$ NaCl were proven to be the best; in contrast, the jeotkal with $7\%$ NaCl exhibited the highest sensory score. At the period showing the best flavor and taste, viable cell count reached to $10^8/g$. Throughout the fermentation period, types of microorganisms isolated were significantly different in squid jeotkal of different salinity. In general, protease producer and bacteria producing components of jeotkal-flavor and organic acids more likely contributed to producing the jeotkal of the best quality. pH of the squid jeotkal with $10\%$ salinity maintained under pH 7.0 throughout the fermentation periods; however, in the case of the jeotkal with $7\%$ salinity, pH increased over pH 7.0 after day 25. Similar tendency was observed in the results from VBN and hypoxanthine formation. Total nitrogen was decreased as fermentation proceeded; in contrast, total free amino acids were increased.

• Journal of Food Hygiene and Safety
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• v.10 no.2
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• pp.111-131
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• 1995

Quality changes of sausages in refrierated storage for 60 days were investigated. Nine types of sausages produced in Korea were stored at 4$^{\circ}C$(3~5$^{\circ}C$), and then chemical, microbiological, and sensory characteristics were evaluated on every 10 days. The proximate analysis showed considerable variation in fat (23.97%, 17.10~30.20%) with less variation in moisture (51.96%, 48.10~56.30%) and protein (12.96%, 11.40~13.95%), pH value decreased over time averaging from 6.31 to 6.22 with no significant difference. Water activity was consistent over refrigerated storage averaging 0.95. Volatile basic nitrogen (VBN) values were still within 20 mg% though VBN for all types significantly increased over time (p<0.05). Thiobarbituric acid (TBA) values were well below 1.0 though TBA showed significant differences among storage periods (p<0.05). Standard plate counts (SPCs) significantly increased during storage (p<0.05) while coliform group was not counted in all cases. SPCs reached 104 CFU/g in two types after 50 days' storage and were below 105 CFU/g in all types after 60 days' storage. Instrumental texture analysis showed that springiness, adhesiveness, and hardness signficantly decreased over time (p<0.05) while no change was observed in external color. significantly decreased over time the 60-day storage period (p<0.05) while cohesiveness, chewiness and gumminess did not change. Lightness, redness and yellowness of the internal Hunter color significantly decreased over time (p<0.05) while no change was observed in external color. Sensory profile showed that flavor, taste, texture and overall acceptable after 60 days' storage at 4$^{\circ}C$. However, the shelf-life of the samples should be decided in the consideration of the growth rate other spoilage flora coupled with the bacterial growth after 50 days' storage.

• Nuclear Engineering and Technology
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• v.1 no.1
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• pp.23-31
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• 1969

Whole cure shrimp, eviscerated common squid and little squid meats were irradiated with gamma radiation from 60Co using varying dose up to one Mrad. Changes in quality were assessed by organoleptic, chemical (VRS and TMA-N), biochemical (hypoxanthine) and microbiological tests； and the effect of radiation on prolonging of the storage life at 2-4 C was studied. With the cure shrimp, 0.12-0.20 Mrad appears to be optimal with 8 days of storage life, whereas the unirradiated control samples had a storage life of 3 days. With the common squid meat, 0.20-0.30 Mrad appears to be optimal with 14-21 days of storage life, where-as the unirradiated control samples had a storage life of 8 days. And for the little squid meat, 0.12-0.20 Mrad appears to be optimal with 10 days of storage, where-as the unirradiated control samples had a storage life of 5 to 6 days.

• The Plant Pathology Journal
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• v.27 no.3
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• pp.207-224
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• 2011

Diseases caused by plant pathogenic bacteria constitute an emerging threat to global food security. Xanthomonas is a large genus of Gram-negative bacteria that cause disease in several host plants leading to considerable losses in productivity and quality of harvests. Despite the ranges of controlling techniques available, the microbiological safety of economically important crops and crop plants including fruits and vegetables continues to be a major concern to the agriculture industry. On the other hand, many of the currently available antimicrobial agents for agriculture are highly toxic, non-biodegradable and cause extended environmental pollution. Besides, the use of antibiotics has provoked an increased resistance among the bacterial pathogens and their pathovars. Thus, novel efficient and safe remedies for controlling plant bacterial diseases are necessary. There has been an increasing interest worldwide on therapeutic values of natural products such as essential oils, hence the purpose of this review is to provide an overview of the published data on the antibacterial efficacy of essential oils that could be considered suitable for application in agriculture as biocontrol measures against plant pathogenic bacteria of Xanthomonas species. The current knowledge on the use of essential oils to control Xanthomonas bacteria in vitro and in vivo models has been discussed. A brief description on the legal aspects on the use of essential oils against bacterial pathogens has also been presented. Through this review, a mode of antibacterial action of essential oils along with their chemical nature and the area for future research have been thoroughly discussed.

• Food Science of Animal Resources
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• v.43 no.6
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• pp.1170-1182
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• 2023

The aim of this study was to determine the effect of chitosan (CH)-based nanocomposite coating applications [chitosan+TiO₂ (CHT) and chitosan+TiO₂+rosmarinic acid (CHTRA)] on changes in quality attributes of rainbow trout fillets during cold storage (4℃). Fish fillets were randomly divided into four groups and subjected to treatments (CH, CHT, CHTRA, and control). After treatments, the groups were packaged under a modified atmosphere (40% CO₂+30% O₂+30% N₂) and stored at 4℃ for 18 days. During cold storage, the samples were subjected to physico-chemical and microbiological analyses. During storage, CH, CHT, and CHTRA treatments showed lower aerobic mesophilic and psychrotrophic bacteria counts than the control. However, the differences between coating treatments were not significant. The highest mean pH value was determined in the control group. As the storage time increased, the thiobarbituric acid reactive substances value increased. At the end of the storage period, no significant differences were observed between the treatments, including in the control group. The total volatile basic nitrogen (TVB-N) level in the control group was above 25 mg/100 g on day 15 of storage. However, the TVB-N level in the treatment groups was below 20 mg/100 g on day 18. It was also determined that coating application×storage period interaction had a significant effect on all color parameters (p<0.01). At the end of storage, the highest CIE L* was observed in CHTRA treatment. However, the value of this treatment did not differ from that of the CH treatment.

• Journal of the Korean Society of Food Culture
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• v.20 no.4
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• pp.468-475
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• 2005

To determine the effect of different fermentation level on the quality of Nabak Kimchi during storage, this study was carried by analysing the result of physico-chemical properties, microbiological characteristics and sensory evaluation of Nabak Kimchi stored up to 24 days. For the physico-chemical properties, pH, total acidity, reducing sugar, carbon dioxide contents, color values were investigated while for the microbiological characteristics, total microbial counts and lactic acid bacteria were studied. Nabak Kimchi products were fermented at six different level of temperature and time and stored in Kimchi refrigerator at $4^{\circ}C$ for 24 days. As the storage period increased, the pH values of LF15, SF25 and LF25 decreased rapidly after initial fermentation and the pH values of SF4, LF4 and SF15 increased slightly in the beginning and then decreased. total acidity increased as storage period proceeded. the amount of reducing sugar was 4.92mg/ml before fermentation and increased significantly and reached its maximum values then decreased. lightness and redness of Nabak Kimchi decreased as storage period became longer, but yellow of Nabak Kimchi increased during storage. Total microbial counts of SF25 and LF25 reached to the highest at the 6th day and total microbial counts of LF15 reached to the highest at the 12th day and then significantly decreased. However, total microbial counts of SF4, LF4 and SF15 continuously increased up to the 24th day. The number of lactic acid bacteria was similar to the phase of the change of total microbial counts.