• Korean Journal of Food Science and Technology
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• v.35 no.3
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• pp.461-469
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• 2003

Effects of fruit of Lycium chinense (Chinese matrimony vine) on enzyme activities, and microbial and physicochemical properties of kochjuang were investigated during 12 weeks of fermentation. Enzyme activities were higher during middle of fermentation, and protease activities increased as the ratio of L. chinense increased. Facultative anaerobic bacteria counts decreased in L. chinense-added kochujang, whereas viable cell count of yeasts was higher in 1% L. chinense-added kochujang. Consistency of kochujang decreased by addition of L. chinense. Hunter L- and a-values of L. chinense added kochujang were high, causing slight change in total color difference (E) as the ratio of L chinense increased. Moisture contents of kochujang increased during fermentation, whereas water activities decreased. As the ratio of L. chinense increased, water activities increased. Titrable acidities and oxidation-reduction potential increased by addition of L. chinense. Total sugar contents of kochujang decreased rapidly during fermentation, whereas reducing sugar contents increased up to $2{\sim}4$ weeks of fermentation. As the ratio of L. chinense increased, reducing sugar contents decreased. Ethanol contents of kochujang increased during fermentation, with higher values in 3% L. chinense-added kochujang. Amino and ammonia nitrogen contents of kochujang increased L. chinense content increased. After 12 weeks of fermentation, sensory results showed 3% L. chinense-added kochujang showed highest taste and overall acceptability, and color acceptability increased as L. chinense content increased.

• Food Science and Preservation
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• v.22 no.6
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• pp.796-803
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• 2015

The physicochemical properties and storage stability of blueberries fermented by lactic acid bacteria were investigated. The viable cell count of lactic acid bacteria slowly increased to 5.96 log CFU/mL after 72 hr of fermentation. The pH decreased whereas titratable acidity increased after fermentation. The contents of total anthocyanin (31.52 mg/100 g) and cyanidin-3-glucoside (C3G) (5.41 mg/100 g) after 72 hr of fermentation were higher than those of non-fermented blueberries (16.10 mg/100 g and 2.21 mg/100 g, respectively). The L and a value decreased, and the b and ${\Delta}$E value increased. The total polyphenol and flavonoid contents of fermented blueberries (2.21 g/100 g and 0.91 g/100 g, respectively) were higher than those of non-fermented blueberries (1.13 g/100 g and 0.49 g/100g, respectively). The DPPH radical scavenging activity and superoxide radical scavenging activity of the fermented blueberries were 30.74%, and 52.76%, respectively. The ferric reducing antioxidant power of the fermented blueberries ($256.42{\mu}M/g$) was higher than that of non-fermented blueberries ($191.52{\mu}M/g$). Anthocyanin and C3G content was stable in fermented blueberries after 42 days of storage. The results suggest that blueberries fermented by lactic acid bacteria have the potential to be functional materials in the food industry.

• Journal of Life Science
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• v.16 no.1
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• pp.141-147
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• 2006

The effect of traditional Doenjang supplemented with the extracts of herb medicines (refer as DHM) on the taste component and microbial properties was investigated. The DHMs were divided to four group. Fatty acid compositions were similar between DHMs and control as ratio of each fatty acid to total fatty acids. Concentration of total free amino acid from groups II , III and IV was higher than that of control. Major organic acids were phytic acid, lactic acid, and butyric acid. In isoflavone of DHMs, free daidzein and genistein contents were mostly similar among the groups, and groups m and W were slightly higher as compared with control. Viable cell count of DHMs was shown to be $2.5\times10^7\;CFU/ml$, a similar trend of control. Protease activity of DHMs was higher than that of control(67.65 units), but amylase activity between DHMs and control was almost identical Sensory scores of group II and IV were shown to be brighter than those of group I and II, and decreasing off-odor was more effective. In over all eating-quality, group III and IV were evaluated to be favorable as compared with control and the other DHMs because of supplementing the sweet taste of extracts to Korean indigenous Doenjang.

• Journal of agriculture & life science
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• v.46 no.1
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• pp.177-187
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• 2012

This study aimed to improve the quality with acomparison of quality characteristics by collecting Chungkukjang in the market, and to establish the foundation data for starter, which support to manufacture standardized Chungkukjang products. Firstly, Chungkukjang was collected from the industrial company and home-made production which located in the several regions of Korea. Moisture contents of collected Chungkukjang were ranged from 56.3 to 62.1% and salinity was 0.23 to 11.51%. Total nitrogen and amino nitrogen contents of Chungkukjang ranged from 5.82 to 8.76% and 173.71 to 2,700.66 mg%, respectively. Nitrogen degradation ratio, which means the proportion of amino nitrogen to total nitrogen, was 2.88~26.93%. Collected Chungkukjang AG and Z have predominant value in histamine and tyramine contents as 755.40 and 1913.51 mg/kg, respectively, and viable cells count in collected Chungkukjang, maximum was $9.6{\times}10^9CFU/g$. As a result, most products showed various properties in flavor and nutrition, and it is supposed to be caused on use of different soybean species and unstandardized fermentation process.

• Food Science and Preservation
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• v.12 no.4
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• pp.395-401
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• 2005

This study was carried out to investigate the changes in the fermentation characteristics of Kimchi prepared with various salts (Korean solar salt, Chinese solar salt, washed and dehydrated salt, purified salt and a processed salt). Acidity appeared to increase most rapidly in Kimchi prepared with Korean solar salt and reached higher level. Total microbial count slowly increased at the beginning of fermentation and reached maximum on 6 days, then decreased slowly. The number of lactic acid bacteria was rapidly increased up to $4{\sim}6$ days, and thereafter decreased slowly. In conclusion, any significant differences in fermentation characteristics analyzed was not observed in Kimchi prepared with various salts except acidity.

• Food Science of Animal Resources
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• v.44 no.5
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• pp.1142-1155
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• 2024

This study investigated the impact of packaging methods coupled with high barrier packaging loaded with titanium dioxide (TiO₂) on the quality of chilled pork. The experiment consisted of three treatment groups: air packaging (AP), vacuum packaging (VP), and vacuum antibacterial packaging (VAP). Changes in total viable count (TVC), pH value, total volatile basic nitrogen (TVB-N) value, sensory attributes, and water holding capacity of pork were analyzed at 0, 3, 6, 9, and 12 d. TVC of the VAP group was 5.85 Log CFU/g at 12 d, which was lower than that of AP (6.95 Log CFU/g) and VP (5.93 Log CFU/g). The antibacterial film incorporating TiO2 effectively inhibited microorganism growth. The VAP group exhibited the lowest pH value and TVB-N value among all the treatment groups at this time. The findings demonstrated that the application of VAP effectively preserved the sensory attributes of pork, the hardness, cohesiveness and adhesiveness of pork in VAP group were significantly superior than those in AP group (p<0.05), but not significantly compared with VP group. On the 12 d, the CIE a^* value of pork in VAP group was significantly higher (p<0.05). This exhibited that VAP could effectively maintain the freshness of chilled pork and extend the shelf life for 3 d compared to the AP group. These findings provide empirical evidence to support the practical implementation of TiO₂-loaded packaging film in the food industry.

• Food Science and Preservation
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• v.18 no.5
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• pp.786-794
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• 2011

To investigate the sanitary-quality level of commercial kimchi in South Korea, the pH, acidity, and microbial-flora changes in the kimchi were determined. Samples of kimchi produced by three different manufacturers (a small grocery store, a small/medium-sized enterprise, and a large food company) were collected. Freshly made kimchi was purchased and fermented at $10^{\circ}C$ for 10 days. The pH of the commercial kimchi on the purchased day was approximately pH 5.8, and that on the $10^{th}$ day of fermentation was ${\simeq}pH$ 4.1. The kimchi purchased from a large company showed a more rapid decline in pH level during fermentation. The saltiness of the kimchi purchased from a medium-sized company was slightly higher than those of the other commercial kimchi samples. The saccharinity index of the kimchi produced by a small grocery store was higher than those of the other samples, and its value deviation was also higher than those of the other commercial kimchi samples. A higher total viable-cell count and a higher lactic-acid bacteria (LAB) count were detected in the kimchi from the large food company at the beginning of fermentation compared to the samples of the two other kimchi manufacturers. The highest cell numbers of gram-positive bacteria (except LAB) and coliform bacteria were detected from the small-grocery-store kimchi, but the coliform bacteria count gradually decreased during fermentation although such bacteria were still detected until the $10^{th}$ day of fermentation. In contrast, coliform bacteria were not detected in the samples from the medium-sized and large food companies. Yeast, which is detected in over-ripened kimchi, was detected in the unfermented kimchi from the small grocery store, which had a below-0.36% acidity level. The gram-positive bacteria (except LAB) that were detected in all the tested commercial kimchi samples were determined to be Bacillus spp., and the gram-negative bacteria were determined to be Escherichia coli, Enterobacter spp., Sphingomonase spp., and Strenophomonas spp. The proportions of all the aforementioned bacteria in the kimchi samples, however, were different depending on the samples that were taken. These results indicate that a more sanitary kimchi production process and a more systematic kimchi production manual should be developed to industrialize and globalize kimchi.

• Journal of Dairy Science and Biotechnology
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• v.16 no.2
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• pp.90-97
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• 1998

This study was carried out to investigate changes of microbiological and sensory properties in various heat-treated market milks (LTLT, HTST, and UHT milks) stored at 10$^{\circ}C$ during 15d. Titratable acidity (TA) increased with storage, while pH tended to decrease. During the initial 9d, no difference was found in TA, however, after 9d, it was slightly higher in HTST and UHT milks than that in LTLT milk. In LTLT and HTST milks, total viable cells and psychrotrophs were dramatically increased during storage, In addition coliform and pathogenic bacteria were found at 12 and 15d. In UHT milk, total viable cells were found only at 15d. In sensory evaluation, LTLT and HTST milks developed a negligible off-flavor until 9d. At 12d, it became stronger in HTST milk than that in LTLT milk. In UHT milk, off-flavor was detected at 9d and increased rapidly there-after. The degree of off-flavor was little higher in HTST and UHT milks, compared with that of LTLT milk after 9d storage. These observations indicated that LTLT and HTST milks may not be microbiologically acceptable after 5d, while off-flavor was not detectable until 9d, In comparison, UHT milk keeps a good quality in microorganism until 15d, however, it may not be accepted in sensory aspect after 9d storage.

• Food Science and Preservation
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• v.17 no.4
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• pp.471-477
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• 2010

We explored the effects of curing and smoking conditions on the shelf life of Dombaeki (shark meat). Dombaeki cured for 12 h in an aqueous solution containing (per 100 ml) salt 5.6 g, sugar 14 g, and garlic powder 0.6 g, showed the best sensory quality among various samples cured for 0, 3, 6, 9, 12 or 24 hours. The optimum conditions for preparation of smoked Dombaeki (SD) were drying at $60^{\circ}C$ for 30 min, followed by cooking at $80^{\circ}C$ for 30 min and smoking at $65^{\circ}C$ for 40 min, as judged by sensory evaluation of taste, color, flavor, texture, and overall acceptability. The volatile basic nitrogen content of air- or vacuum-packed unsmoked Dombaeki (NSD) was above 20 mg% after storage for either 12 days or 5 weeks. However, the nitrogen contents of air- and vacuum-packed SD were less than 20 mg% after either 21 days or 10 weeks of storage at $10^{\circ}C$. The DPPH free radical-scavenging ability of SD (73.9%) was significantly higher than that of unsmoked meat (4.54%). The total polyphenol content of SD (745.6 g/g) was about 4-fold greater than that of unsmoked meat (179.5 g/g).The viable bacterial count of air- or vacuum-packed unsmoked meat was over $10^6\;CFU/g$ after storage for either 12 days or 5 weeks. However, air- or vacuum-packed SD had counts under $10^4\;CFU/g$ at all storage times tested. Changes in coliform bacterial levels paralleled those of total viable cells. The sensory quality (taste, color, flavor, appearance, texture, and overall acceptability) of SD was significantly better than that of NSD.

• Journal of Food Hygiene and Safety
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• v.25 no.4
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• pp.360-366
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• 2010

Doenjang (fermented soybean paste) is one of the korean traditional fermented soybean product which is consumed with cooked rice as a soup or paste. During the fermentation, soybean protein hydrolyzed into amino acids and various peptide, and various organic acids by mirobes related and enzymes produced by meju fermentation. Some commercial products locationally samples give more sour taste than normal due to abnormal fermentation which the reasons are not clear. Three samples that gave sour taste organoleptically were collected and analyzed their characteristics such as pH, moisture content, acidity and microbial counts. The pH of the sour sample were lower than the normal with higher acidity as pH 5.39 (normal) to pH 4.36 (S2) and 15.80 ml of(0.lN NaOH consumed) to 21.80 ml (S1) respectively. Salt and moisture contents were different with sour and normal Doenjang as 16.38% (normal) to 8.92% (S3) in salt and 55.94% (normal) to 49.34% (S1) in moisture content. Total viable counts were $4.1{\times}10^8$ (normal) to $8.0{\times}10^5$ (S2), and $3.4{\times}10^8$ (normal) to $8.0{\times}10^5$ (S2) in acid producing microbes at BCP plate. Yeast and mold were not detected. The composition of acids as mainly lactic acid and acetic acid of sour Doenjang. Total free amino acids content were lower the sour Doenjang than the normal.