• Animal Bioscience
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• v.36 no.5
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• pp.797-809
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• 2023

Objective: Many scientists have investigated solutions to reduce microbiological risks in dry-aged meat after the dry-aging technology was revived for high quality and value-added premium meat product in the market. This study aimed to investigate the effect of scoria powder in onggi (Korean earthenware) on the meat quality of pork loins during 21 days of dry aging and to elucidate its mechanism of action. Methods: The pork loins were randomly divided into three groups: aged in vacuum-packaging, onggi containing red clay only (OR), and onggi containing 30% red clay and 70% scoria powder (OS). Microbial analyses (total plate count and Lactobacillus spp.) and physicochemical analyses (pH, shear force, volatile basic nitrogen [VBN], water activity, 2-thiobarbituric acid reactive substances, water content, water holding capacity, cooking loss, and color analysis) of aged meat were conducted. Far-infrared ray emission, quantification of immobilized L. sakei and microstructure of onggi were investigated to understand the mechanism. Results: On day 21, the meat aged in OS exhibited lower pH, shear force, VBN, and water activity than those aged in OR, along with an increase in the number of Lactobacillus spp. OS had a smaller pore diameter than OR, implying lower gas permeability, which could promote the growth of L. sakei. Conclusion: OS improved the microbiological safety and storage stability of pork loin during dry aging by increasing number of Lactobacillus spp. possibly due to low permeability of OS.

• Journal of the Korean Society of Food Culture
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• v.39 no.2
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• pp.119-126
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• 2024

This study was conducted to examine the microbiological quality indicators (total bacterial count and coliform count) and physicochemical quality indicators (pH, redness, volatile basic nitrogen [VBN] content) of meat according to various storage temperatures (-20~15℃) and packaging methods (wrap, vacuum). Based on these results, we proposed a safe consumption period. Redness, pH, and VBN content were not considered appropriate for setting the expiration date, as the redness and pH of the meat after spoilage were better than the standard values for both vacuum and wrap packaging (p<0.05). Additionally, the VBN content at 2 and 4℃ increased slightly (fresh level) until the initial time of spoilage (1.0×10⁶ colony-forming unit [CFU]/cm²) and then increased rapidly thereafter. Therefore, the results were not consistent with microbial spoilage. When the decay point was evaluated based on the presence of microorganisms, vacuum packaging extended the storage period approximately 2.5-fold when compared with wrap packaging, and the meat could be stored at 2 or 4℃ for 40 or 23 days, respectively. Therefore, to evaluate meat quality, microbial indicators should be considered first. The microbiological standards proposed in this study can be used for safety management during the distribution of meat. However, to ensure meat safety, additional investigations of appropriate indicators of freshness must be conducted.

• The Korean Journal of Food And Nutrition
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• v.27 no.1
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• pp.31-42
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• 2014

This study was conducted to evaluate the effect of gamma irradiation (0.4, 0.6, 0.8, 1 and 1.5 kGy) on the microbiological, physicochemical and sensory qualities of imported orange during storage at $3^{\circ}C$ for 60 days. Total aerobic bacteria and yeast/mold counts in non-irradiated oranges were 3.59 and 3.75 log CFU/g, and those counts in irradiated oranges at 1.5 kGy were decreased by 1.75 and 2.26 log CFU/g, respectively. Moreover, those counts were decreased significantly according to a dose-dependent manner after gamma irradiation. The pH revealed no significant difference between the control and irradiated samples; however, titratable acidity was decreased significantly according to a dose-dependent manner and storage time. The vitamin C contents were decreased significantly according to a dose-dependent manner and storage time after gamma irradiation. Further, sensory evaluation testing revealed no significant difference between the control and irradiated samples, except 1.5 kGy. Samples irradiated at 1.5 kGy had the lowest values in color, sweetness, sourness, flavor, texture and overall acceptance. The results suggest that gamma irradiation was effective for ensuring microbiological safety; however, irradiated oranges at 1 and 1.5 kGy did not have good physicochemical and sensory qualities. Therefore, we can use the sample irradiated at 0.4~0.6 kGy as optimum-dose to be minimize on quality changes.

• Food Science of Animal Resources
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• v.41 no.4
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• pp.636-649
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• 2021

The aim of this study was to evaluate the effect of three different strains of lactic acid bacteria (LAB) starter cultures: Pediococcus pentosaceus (KC-13100) (PP), Lactobacillus plantarum (KCTC-21004) (LP1), and L. plantarum (KCTC-13093) (LP2) on the physicochemical and microbiological characteristics, and sensory quality of dry fermented sausages after 21 days of drying and ripening period. Treatments added with PP and LP2 strains showed a significant higher (p<0.05) LAB and total plat counts, and water activity (a_w) of all three treatments was below 0.85 after the completion of the ripening process. A significant variation (p<0.05) in pH values of treatments was exhibited due to the difference in acidification capacity of the LAB strains: LP2PP>LP2. Substantial variations (p<0.05) in shear force values were detected amongst three batches (LP2>LP1>PP). In sensory attributes, PP treated samples had significantly higher (p<0.05) color and overall acceptability scores. The current findings proved how important the optimal assortment of starter culture. Inoculation with PP produced importantly beneficial effects on sensory quality improvement of dry fermented sausage.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.4
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• pp.655-662
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• 2000

Electron beam (EB) irradiation was applied to study microbial decontamination effects for kochujang powder by determining their microbiological and physicochemical qualities over gamma ray (GR) irradiation. The samples showed a high microbial population, such as 105~106 CFU/g of total aerobic bacteria, negative of yeasts & molds and coliforms. Total bacterial counts were decreased by 1~2 log cycles with EB irradiation at 5~7.5 kGy, and 10 kGy irradiation was enough to improve the microbiological quality by reducing populations to below 104CFU/g, which was similar to gamma energy. Such doses were effective for controlling the microbial growth in stored samples during storage for 4 months at room temperature. Decimal reduction doses (D10 value) on initial bacterial populations were 2.88~3.02 kGy in EB and 3.57~3.59 kGy in GR, which were influenced by initial populations and energy types applied. Based upon the above results, 7.5~10 kGy irradiation caused negligible changes in Hunter's color, capsaicin, fatty acid composition and organoleptic qualities. Considering the quality changes resulting from subsequent storage, such as a decrease in capsanthin content and an increase in TBA value in the samples, it is recommendable to irradiate kochujang powder at 7.5~10 kGy when used for food processing.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.6
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• pp.1094-1099
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• 1998

Newly introduced aseptic process for cooked rice was optimized by evaluating the process parameters. The optimal conditions were as follows: ratio of washing water to rice, 3:1 by weight; steeping at 20oC for 20min; heat shock at 140oC for 7sec with 8 repetitions; addition of 0.2% glucono lactone solution; cooking at 103oC for 30min. The final products were incubated at 37oC and 50oC for 8 weeks and no spoilage was occurred at both temperatures. Furthermore, any significant losses of sensory and physicochemical qualities were not observed.

• Food Science and Biotechnology
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• v.18 no.1
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• pp.150-156
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• 2009

In this study, Staphylococcus carnosus isolated from traditional sucuk (Turkish dry-fermented sausage) was used in combination with Lactobacillus plantarum as a lactic culture in sucuk production. Sucuk produced with only L. plantarum was evaluated as a control group. Microbiological, physicochemical, and volatile profile characteristics of sucuk samples were investigated during ripening. In both sausages with S. carnosus and control group, pH value decreased to below 5.0 at the $3^{rd}$ day. In all samples, Aw value decreased as the ripening time progressed. Sausages with S. carnosus showed the higher nonprotein nitrogen (NPN) value than control group. However, the highest mean value for thiobarbituric acid reactive substances (TBARS) was observed in control group. Enterobacteriaceae dropped to undetectable levels at the $3^{rd}$ day in both groups. S. carnosus increased approximately 1 log unit within the first 3 days of the fermentation. In the presence of S. carnosus, significant changes were observed in only a few volatile compounds.

• The Korean Journal of Mycology
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• v.46 no.3
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• pp.307-314
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• 2018

The goal of this study was to investigate the microbiological characteristics of the ethanol-producing wild yeast, Aureobasidium pullulans P-1, isolated from flowers growing near the Yedang reservoir, Chungnam province, Korea, and in addition, to optimize its fermentation ability for the production of Makgeolli. A. pullulans P-1 was oval-shaped, and formed ascospores and pseudomycelium. The P-1 strain was a halophilic and sugar tolerant yeast which grew in 15% NaCl and 50% glucose-containing yeast extract-peptone-dextrose media. The P-1 strain was also resistant to 20% ethanol. Changes of the physicochemical properties during Makgeolli fermentation by A. pullulans P-1 were investigated. A maximum of 8.45% ethanol was obtained when a mixture of cooked rice, 150% water, and 35% ipguk per cooked rice was fermented by 5% A. pullulans P-1 culture broth at $25^{\circ}C$ for 10 days. Antihypertensive angiotensin I-converting enzyme inhibitory activity in the Makgeolli ferment produced by A. pullulans P-1 reached a high of 71.1% after 10 days.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.6
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• pp.845-852
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• 2014

The quality of commercial sauce products was evaluated through pH, soluble solid content, salinity, water activity and microbial analyses. The pH of sauces was 2.38~5.30, soluble solids were between 6.03 and 71.67, and distributions of salt were 0.23~5.00% in 32 commercial sauce products. In addition, water activity of vinegar red pepper sauce and spicy soft tofu stew stock were determined 0.773 and 0.988, respectively. Yeast, mold, Staphylococcus aureus, E. coli and coliform were not detected in any sauces. Higher level of total viable cells (TVC) resulted in pH over 4.2. TVC of shelf-stable sauces was 1.0~3.6 log CFU/g. TVC of seven sauce products was classified as non-potentially hazardous foods by temperature controlled for safety standard (TCS), even though levels were over acceptable guidelines of the USDA (3 log CFU/g). These results indicate that the standard and classification of commercial sauce products should be modified and controlled strictly.

• Food Science of Animal Resources
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• v.35 no.6
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• pp.731-737
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• 2015

This study was conducted to compare the meat qualities of loin (m. longissimus dorsi) and top round (m. semimembranosus) from Hanwoo and Holstein veal. Ten Hanwoo and Holstein calves were randomly selected from a local cattle farm and raised. They were slaughtered when they were 8 mon old and weighed. Weight and percentage in primal cuts and slaughter performance of Hanwoo and Holstein veal calves are obtained. Immediately after weighting, slices of loin and top round muscles were sampled. After vacuum packaging, the samples were subjected to proximate composition, physicochemical and microbiological analyses. Dressing weight and percentage were heavier and greater (p<0.05) in the Holstein than in the Hanwoo. Water contents of the top round muscle was higher in the Holstein than in the Hanwoo (p<0.05). Water-holding capacity, protein content and CIE L* (lightness) of both muscles were higher in the Holstein than in the Hanwoo veal, whereas fat content, pH, cooking loss, a* (redness), and b* (yellowness) were higher in the Hanwoo than in the Holstein veal (p<0.05). Thiobarbituric acid and volatile basic nitrogen values of both the muscles were lower in the Hanwoo than in the Holstein veal during the first 10 d of storage (p<0.05).