• Food Science and Preservation
• /
• v.23 no.1
• /
• pp.117-126
• /
• 2016

This study was performed to provide information for improving the quality characteristics of tangerine peel Soksungjang. Tangerine peel Soksungjangs were prepared with 10% tangerine peel powder by addition of different koji such as Rhizopus oligosporus (RS, RTS) and Aspergillus oryzae (AS, ATS). As a result, the moisture content was not changed and crude protein content decreased during fermentation in all samples. The pH of RS (Soksungjang manufactured with Rhizopus oligosporus koji) and RTS (Soksungjang manufactured with Rhizopus oligosporus koji and 10% tangerine peel powder) was not changed, whereas pH of AS (Soksungjang manufactured with Aspergillus oryzae) and ATS (Soksungjang manufactured with Aspergillus oryzae koji and 10% tangerine peel powder) decreased rapidly after 10 days of fermentation. The acidity values of all the samples increased during fermentation. The major free sugars were glucose, fructose, and maltose; while, the major organic acids were citric acid, succinic acid, acetic acid, and lactic acid in all the samples. The amino nitrogen content and protease activity were highest in the AS and ATS. Conversely, the reducing sugar content and ${\alpha}$-amylase activity were highest in the RS and RTS. The major free amino acids in all samples were glutamic acid, lysine, leucine, and arginine. Sixty kinds of volatile flavor compounds were identified from all samples; the majority of which were 21 alcohols, 14 hydrocarbons, 5 esters, and others identifies as acids, ketones, and aldehydes.

• Food Science and Preservation
• /
• v.20 no.6
• /
• pp.886-893
• /
• 2013

Several indigenous sulfite-resistant yeasts were isolated at the microbial succession stage of yeast flora during spontaneous fermentation of Campbell Early grapes using a YPD plate that contained 200 mg/L or 500 mg/L potassium metabisulfite. When they were applied to the wine fermentation using the Campbell Early grape and apple juices, strains S13 and D8 showed strong alcohol fermentation and good flavor production. They were identified as Saccharomyces cerevisiae in the phylogenetic analysis based on their ITS 1-5.8S-ITS II DNA sequences. The two yeast strains grew to a high cell density in the YPD media supplemented with 40%(w/v) glucose. They also grew rapidly in the YPD media at $40^{\circ}C$. While strain S13 showed some differences in cell density at the two temperatures, no marked difference was observed during the culture of strain D8. The strains grew relatively well at pH 5.0 and 9.0 compared with pH 7.0, which was the optimum pH for their growth. Especially, strain S13 cultivated in the YPD media at pH 9.0 grew to 93% of the growth of strain D8, which was obtained at pH 7.0.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.42 no.8
• /
• pp.1175-1182
• /
• 2013

The purpose of this study was to evaluate the functional characteristics of fermented mixed grain beverages obtained using different microbial species and to evaluate their suitability for consumption. Various fermented mixed grain beverages were prepared through fermentation with Aspergillus (A.) oryzae CF1003 (A), A. acidus KACC46420 (B), Rhizopus (R.) delemar KACC46149 (C), R. oryzae KACC45714 (D), R. oryzae KACC46148 (E), A-E mixed strains (F), A. oryzae CF1001 (G), A. acidus CF1005 (H) and A+H mixed strains (I). The visual appearance, flavor, taste, and the antioxidant capacity of each fermented beverage were then assessed. The chromaticity and aesthetic quality of the fermented beverage was measured and all fermented beverages appeared yellow. The C-, G-, H- and I-fermented beverages received scores of 3.319, 3.206, 3.170 and 3.025 points, respectively, following a sensory evaluation, while the others received less than 3 points. The polyphenol content of the different beverages were similar, while the flavonoid content significantly differed. In particular, the flavonoid content of the C- and E-fermented beverages was significantly higher than other beverages. Although the electron donating ability and reducing power of the fermented beverages was very low, the superoxide dismutase (SOD)-like activity of all beverages (except the E-fermented beverage) increased in a concentration-dependent manner. Specifically, the SOD-like activity from the F-fermented beverage at 10,000 ppm was more than 50%. Interestingly, the antioxidant activities of the beverages were unrelated to their polyphenol or flavonoid levels. This study also found that the aesthetic qualities of G- and H-fermented beverages were the highest and that this was completely independent of their antioxidant capacity. Therefore, our results suggest that further studies are required to develop mixed grain-derived fermented beverages that can also fulfill a useful functional purpose.

• Korean journal of food and cookery science
• /
• v.31 no.6
• /
• pp.725-732
• /
• 2015

This study was conducted to evaluate the effects of ethanol on the prolongation of the shelf-life of kimchi paste. Kimchi paste was prepared by adding 0.5~3.0% ethanol, and then stored at $4^{\circ}C$ for 35 days. The retardation of kimchi paste fermentation was evaluated by measuring chemical, microbial, and sensory characteristics. Titratable acidity and pH showed a slight difference, depending on the ethanol concentration. The titratable acidity showed the low content in kimchi paste with 3.0% ethanol during fermentation, whereas the pH showed a reverse tendency, indicating that fermentation was inhibited under a high ethanol concentration. The changes in the sugar-reduced contents were similar to that of the pH. The growth of microorganisms such as total aerobic bacteria, lactic acid bacteria, yeasts and molds in kimchi paste during fermentation were inhibited by ethanol, and the addition of 3.0% ethanol was most effective to inhibit the microbial growth. The number of coliform bacteria was decreased during fermentation of kimchi paste and not detected in any sample at 35 days, except for kimchi paste with 3.0% ethanol. In sensory evaluation, the addition of 0.5~1.5% ethanol in kimchi paste was showed no significant difference on sensory properties compared to the kimchi paste without ethanol (p<0.05). As a result, it is considered that the addition of 1.5% ethanol is the most appropriate to maintain the quality of kimchi paste, without the changing the flavor.

• Korean Journal of Food Science and Technology
• /
• v.35 no.2
• /
• pp.166-172
• /
• 2003

Changes in the number of microorganisms, chemical composition, and sensory quality of chungkukjang by gamma-irradiation up to 120 kGy were investigated. The total viable cell counts in chungkukjang irradiated with 10 kGy decreased from $10^9\;CFU/g$ of the control to $10^5\;CFU/g$. Proximate chemical composition and pH of chungkukjang were not much affected by irradiation. Acidity of chungkukjang decreased by irradiation with over 20 kGy. Fatty acid contents of chungkukjang irradiated under 20 kGy were the same as those of the nonirradiated ones. Polyunsaturated fatty acids content, decreased at over 40 kGy. The color and odor of chungkukjang were not significantly affected by irradiation up to 20 kGy. Unpalatable odor (p<0.01), off-flavor (p<0.001), and fish-odor (p<0.001) increased, and brown intensity (p<0.05) and acceptability (p<0.001) decreased at over 20 kGy. Results indicate 20 kGy is sufficient to decrease the microbial count of chungkukjang and prevent decrease in the content of polyunsaturated fatty acids.

• Korean journal of food and cookery science
• /
• v.24 no.5
• /
• pp.573-579
• /
• 2008

In this study, kimchi containing Styela clava (Korean name: miduduk) was prepared, and the quality of the prepared kimchi was evaluated during 4 weeks of fermentation at $4^{\circ}C$. S. clava was added to salted cabbage at concentrations of 0, 1, 2, and 3%(w/w). The quality characteristics of the kimchi were determined by measuring pH, titratable acidity, salinity, color, and microbial amounts. All kimchi evidenced a rapid decrease in pH until 2 weeks, and then a gradual decline thereafter. Titratable acidity increased gradually until 2 weeks, then sharply increased thereafter. Salinity increased until 3 weeks. We noted only slight overall color differences between the kimchi samples. Total microbial and lactic acid bacterial counts achieved maximum levels at 3 weeks, and the kimchi to which 1 and 2% S. clava was added evidenced values higher than that of the controls. In our sensory evaluations, the kimchi to which 2% S. clava was added was scored highest in terms of color, flavor, and overall acceptance.

• Journal of Life Science
• /
• v.31 no.5
• /
• pp.520-526
• /
• 2021

Microbial protein is one of the sources of protein in the rumen and can also be the source of glutamate production. Glutamic acid is used as fuel in the metabolic reaction in the body and the synthesis of all proteins for muscle and other cell components, and it is essential for proper immune function. Moreover, it is used as a surfactant, buffer, chelating agent, flavor enhancer, and culture medium, as well as in agriculture for such things as growth supplements. Glutamic acid is a substrate in the bioproduction of gamma-aminobutyric acid (GABA). This review provides insights into the role of glutamic acid and glutamic acid-producing microorganisms that contain the glutamate decarboxylase gene. These glutamic acid-producing microorganisms could be used in producing GABA, which has been known to regulate body temperature, increase DM intake and milk production, and improve milk composition. Most of these glutamic acid and GABA-producing microorganisms are lactic acid-producing bacteria (LAB), such as the Lactococcus, Lactobacillus, Enterococcus, and Streptococcus species. Through GABA synthesis, succinate can be produced. With the help of succinate dehydrogenase, propionate, and other metabolites can be produced from succinate. Furthermore, clostridia, such as Clostridium tetanomorphum and anaerobic micrococci, ferment glutamate and form acetate and butyrate during fermentation. Propionate and other metabolites can provide energy through conversion to blood glucose in the liver that is needed for the mammary system to produce lactose and live weight gain. Hence, health status and growth rates in ruminants can be improved through the use of these glutamic acid and/or GABA-producing microorganisms.

• Journal of Animal Science and Technology
• /
• v.62 no.5
• /
• pp.702-712
• /
• 2020

Synthetic nitrite imparts a reddish-pink color to meat and a distinct flavor to meat products, delays lipid oxidation, and inhibits microbial growth and pathogens. However, excessive intake of nitrite might result in the production of carcinogenic nitrosamine, which might increase the risk of cancer in humans. Therefore, we aimed to find an alternative natural colorant for pork sausages. Pork sausages were mixed with 0.014% sodium nitrite (NaNO₂) alone (CON), without either NaNO₂ or purple-fleshed sweet potato powder (PP; CON1), 0.5% PP alone (PP1), 1% PP (PP2) alone, 0.011% NaNO₂ and 0.5% PP (SP1), and 0.011% NaNO₂ and 1% PP (SP2). The sausages were then cooked and stored for physicochemical analysis on days 0, 5, 10, 15, and 20. The a* and W* values were the greatest and lowest in the SP2 and CON1 treatments, respectively (p < 0.05). The concentrations of residual nitrite in the sausages at 20 days decreased in the order of CON > SP1, SP2 > PP2 > PP1, CON1. The fatty acid content was higher, and flavorous amino acids were more in PP2 (p < 0.05). The fatty acid composition was comparable between the SP2 and CON groups, but the contents of glutamic acid and alanine were greater in the SP2 group. In conclusion, SP2 (0.011% NaNO₂ with 1% PP) could be added as a natural colorant for pork sausage production, and NaNO₂ could be substituted with up to 20% PP without detrimental effects on sausage appearance and/or quality.

• Journal of Microbiology and Biotechnology
• /
• v.28 no.1
• /
• pp.105-108
• /
• 2018

Beef was dry aged for 40-60 days under controlled environmental conditions in a refrigerated room with a relative humidity of 75%-80% and air-flow. To date, there is little information on the microbial diversity and characteristics of dry aged beef. In this study, we explored the effect of change in meat microorganisms on dry aged beef. Initially, the total bacteria and LAB were significantly increased for 50 days during all dry aging periods. There was an absence of representative foodborne pathogens as well as coliforms. Interestingly, fungi including yeast and mold that possess specific features were observed during the dry aging period. The 5.8S rRNA sequencing results showed that potentially harmful yeasts/molds (Candida sp., Cladosporium sp., Rhodotorula sp.) were present at the initial point of dry aging and they disappeared with increasing dry aging time. Interestingly, Penicillium camemberti and Debaryomyces hansenii used for cheese manufacturing were observed with an increase in the dry aging period. Taken together, our results showed that the change in microorganisms exerts an influence on the quality and safety of dry aged beef, and our study identified that fungi may play an important role in the palatability and flavor development of dry aged beef.

• The Korean Journal of Physiology and Pharmacology
• /
• v.19 no.2
• /
• pp.183-189
• /
• 2015

Foeniculum vulgare Mill. (fennel) is used to flavor food, in cosmetics, as an antioxidant, and to treat microbial, diabetic and common inflammation. No study to date, however, has assessed the anti-inflammatory effects of fennel in experimental models of inflammation. The aims of this study were to investigate the anti-inflammatory effects of fennel in model of lipopolysaccharide (LPS)-induced acute lung injury. Mice were randomly assigned to seven groups (n=7~10). In five groups, the mice were intraperitoneally injected with 1% Tween 80-saline (vehicle), fennel (125, 250, $500{\mu}l/kg$), or dexamethasone (1 mg/kg), followed 1 h later by intratracheal instillation of LPS (1.5 mg/kg). In two groups, the mice were intraperitoneally injected with vehicle or fennel ($250{\mu}l/kg$), followed 1 h later by intratracheal instillation of sterile saline. Mice were sacrificed 4 h later, and bronchoalveolar lavage fluid (BALF) and lung tissues were obtained. Fennel significantly and dose-dependently reduced LDH activity and immune cell numbers in LPS treated mice. In addition fennel effectively suppressed the LPS-induced increases in the production of the inflammatory cytokines interleukin-6 and tumor necrosis factor-alpha, with $500{\mu}l/kg$ fennel showing maximal reduction. Fennel also significantly and dose-dependently reduced the activity of the proinflammatory mediator matrix metalloproteinase 9 and the immune modulator nitric oxide (NO). Assessments of the involvement of the MAPK signaling pathway showed that fennel significantly decreased the LPS-induced phosphorylation of ERK. Fennel effectively blocked the inflammatory processes induced by LPS, by regulating pro-inflammatory cytokine production, transcription factors, and NO.