• Asian-Australasian Journal of Animal Sciences
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• v.25 no.9
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• pp.1248-1254
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• 2012

The effect of silage additives on ensiling characteristics and nutritive value of Napier grass (Pennisetum purpureum) silages was studied. Napier grass silages were made with no additive, fermented juice of epiphytic lactic acid bacteria (FJLB), molasses or cassava meal. The ensiling characteristics were determined by ensiling Napier grass silages in airtight plastic pouches for 2, 4, 7, 14, 21 and 45 d. The effect of Napier grass silages treated with these additives on voluntary feed intake, digestibility, rumen fermentation and microbial rumen fermentation was determined in 4 fistulated cows using $4{\times}4$ Latin square design. The pH value of the treated silages rapidly decreased, and reached to the lowest value within 7 d of the start of fermentation, as compared to the control. Lactic acid content of silages treated with FJLB was stable at 14 d of fermentation and constant until 45 d of ensiling. At 45 d of ensiling, neutral detergent fiber (NDF) and acid detergent fiber (ADF) of silage treated with cassava meal were significantly lower (p<0.05) than the others. In the feeding trial, the intake of silage increased (p<0.05) in the cow fed with the treated silage. Among the treatments, dry matter intake was the lowest in the silage treated with cassava meal. The organic matter, crude protein and NDF digestibility of the silage treated with molasses was higher than the silage without additive and the silage treated with FJLB. The rumen parameters: ruminal pH, ammonia-nitrogen ($NH_3$-N), volatile fatty acid (VFA), blood urea nitrogen (BUN) and bacterial populations were not significantly different among the treatments. In conclusion, these studies confirmed that the applying of molasses improved fermentative quality, feed intake and digestibility of Napier grass.

• Journal of Microbiology and Biotechnology
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• v.30 no.8
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• pp.1227-1234
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• 2020

In this study, yeast cell immobilization was carried out in a packed bed reactor (PBR) to investigate the effects of the volumetric capacity of carriers as well as the different fermentation modes on fuel ethanol production. An optimal volumetric capacity of 10 g/l was found to obtain a high cell concentration. The productivity of immobilized cell fermentation was 16% higher than that of suspended-cell fermentation in batch and it reached a higher value of 4.28 g/l/h in repeated batches. Additionally, using this method, the ethanol yield (95.88%) was found to be higher than that of other tested methods due to low concentrations of residual sugars and free cells. Continuous ethanol production using four bioreactors showed a higher productivity (9.57 g/l/h) and yield (96.96%) with an ethanol concentration of 104.65 g/l obtained from 219.42 g/l of initial total sugar at a dilution rate of 0.092 h^-1. Furthermore, we reversed the substrate-feed flow directions in the in-series bioreactors to keep the cells at their highest activity and to extend the length of continuous fermentation. Our study demonstrates an effective method of ethanol production with a new immobilized approach, and that by switching the flow directions, traditional continuous fermentation can be greatly improved, which could have practical and broad implications in industrial applications.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.12
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• pp.1693-1700
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• 2012

In this study we examined the antioxidant activity and fermentation characteristics of black rice wine. The antioxidant activity of black rice wine was higher than the control, and DPPH radical scavenging activity showed a correlation with the anthocyanin content of rice wine. The pH remarkably decreased until 3 days of fermentation, and the gradually decreased. The reducing sugar and free sugar content reached a maximum at 1 day of fermentation due to enzyme activity. The amount of organic acids, especially lactic acid, increased during the fermentation period. Lactic acid bacteria and yeast count increased with time and amount of black rice. The L color value increased during fermentation regardless of treatments, and the a color value increased with ratio of black rice due to anthocyanin. For this reason, color was given a high score in black rice wine. But overall preference was high in rice wine made with less than 20% of black rice.

• Korean Journal of Food Science and Technology
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• v.43 no.4
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• pp.438-445
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• 2011

This study was performed to examine the physicochemical characteristics of Korean traditional fermented liquor added with citron juice and the levels (3, 6 and 9%) of citron (Citrus junos) juice during two-step-brewing. The pH of traditional Korean fermented liquor added with citron juice increased after 3 days of fermentation and then the pH values decreased from the sixth day. pH increased again at the end of fermentation. Total acidity increased after 5 days of fermentation until the sixth day, then decreased rapidly but increased slightly up to 12 days. Alcohol content increased to 12.76-14.32% after 12 days of fermentation. As the amount of added citron juice increased, alcohol content decreased. Amino acids increased after 12 days of fermentation. A sensory evaluation appearance, flavor, sourness, sweetness, bitterness and overall acceptance of Korean traditional fermented liquor added with 6% citron showed higher values than those of the control.

• The Korean Journal of Food And Nutrition
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• v.31 no.1
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• pp.24-32
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• 2018

In this study, the quality characteristics of cheonggukjang with addition of different quinoa were investigated. We evaluated the quality and sensory characteristics of cheonggukjang, including the pH, amino nitrogen, slime contents, color value, and total aerobic bacteria. Moreover, The anti-oxidant activities were measured as total polyphenol content, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, and superoxide dismutase (SOD) activity. The pH and amino nitrogen content were noted to significantly increase during the fermentation period in all the samples. The slime content of cheonggukjang added with quinoa increased with increased fermentation time, but cheonggukjang with addition of 20% of quinoa was decreased. The L value and b value decreased significantly with increased fermentation time, but the a value increased significantly. The microbial tests of cheonggukjang with addition of quinoa showed that the aerobic micro-organisms count was 7.45~9.10 Log cfu/g. Total polyphenol contents increased in all groups during the fermentation period, and activity increased with an increased percentage of added quinoa. The DPPH radical scavenging activity and SOD-like activity of cheonggukjang (with addition of quinoa) were also significantly higher than those of the control. The sensory quality of quinoa 10% cheonggukjang was stronger in flavor, and taste, and demonstrated a higher level of overall acceptability, when compared to the other groups.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.12
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• pp.1864-1872
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• 2019

Objective: This study was conducted to evaluate the effects of Ecklonia stolonifera (E. stolonifera) extract addition on in vitro ruminal fermentation characteristics, methanogenesis and microbial populations. Methods: One cannulated Holstein cow ($450{\pm}30kg$) consuming timothy hay and a commercial concentrate (60:40, w/w) twice daily (09:00 and 17:00) at 2% of body weight with free access to water and mineral block were used as rumen fluid donors. In vitro fermentation experiment, with timothy hay as substrate, was conducted for up to 72 h, with E. stolonifera extract added to achieve final concentration 1%, 3%, and 5% on timothy hay basis. Results: Administration of E. stolonifera extract to a ruminant fluid-artificial saliva mixture in vitro increased the total gas production. Unexpectedly, E. stolonifera extracts appeared to increase both methane emissions and hydrogen production, which is contrasts with previous observations with brown algae extracts used under in vitro fermentation conditions. Interestingly, real-time polymerase chain reaction indicated that as compared with the untreated control the ciliate-associated methanogen and Fibrobacter succinogenes populations decreased, whereas the Ruminococcus flavefaciens population increased as a result of E. stolonifera extract supplementation. Conclusion: E. stolonifera showed no detrimental effect on rumen fermentation characteristics and microbial population. Through these results E. stolonifera has potential as a viable feed supplement to ruminants.

• Korean Journal of Food Science and Technology
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• v.53 no.5
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• pp.514-520
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• 2021

This study identified and quantified the sugar-related metabolites and analyzed the structural features of starch in kimchi added with various concentrations of glutinous rice paste during fermentation. The pH values and total bacterial counts indicated that the fermentation of kimchi with 10% glutinous rice paste progressed more quickly than that of kimchi with other rice paste concentrations. The addition of glutinous rice pastes to kimchi resulted in increased glucose and decreased fructose contents during fermentation compared to the control kimchi. Maltose content increased significantly with increasing glutinous rice paste concentrations. The average chain length distribution of starch in kimchi decreased with increasing proportions of short chains as fermentation progressed. However, the average chain length distribution of starch increased with increasing glutinous rice paste concentration in kimchi. Our results confirmed that the sugar-related metabolites and starch structural changes were highly influenced by the added starch paste concentration.

• Journal of Microbiology and Biotechnology
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• v.31 no.11
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• pp.1552-1558
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• 2021

The diverse microbial communities in kimchi are dependent on fermentation period and temperature. Here, we investigated the effect of enterotoxigenic Escherichia coli (ETEC) during the fermentation of kimchi at two temperatures using high-throughput sequencing. There were no differences in pH between the control group, samples not inoculated with ETEC, and the ETEC group, samples inoculated with ETEC MFDS 1009477. The pH of the two groups, which were fermented at 10 and 25℃, decreased rapidly at the beginning of fermentation and then reached pH 3.96 and pH 3.62. In both groups, the genera Lactobacillus, Leuconostoc, and Weissella were predominant. Our result suggests that microbial communities during kimchi fermentation may be affected by the fermentation parameters, such as temperature and period, and not enterotoxigenic E. coli (ETEC).

• Korean Journal of Agricultural Science
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• v.49 no.3
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• pp.571-582
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• 2022

Cacao, a major ingredient for making chocolate, has been shown to have potent antioxidant effects. The consumption of raw cacao has beneficial effects on health. This study determined the fermentation properties of yoghurt that was manufactured with cacao nibs (Theobroma cacao L.). The pH of the yogurt containing the cacao nibs was lower than that of the control, and this reduction was both concentration and fermentation time-dependent. Furthermore, the number of lactic acid bacteria in the yogurt made with cacao and its viscosity increased in a cacao nibs dependent manner. In particular, the yoghurt with 5% cacao nibs added had the highest number of lactic acid bacteria at 48 hours at the end point of the fermentation. Whey protein degradation in yogurt containing cacao nibs increased with the fermentation time, and the organic acid production, especially lactic acid, in the yogurt containing cacao nibs increased significantly after 16 hours of fermentation. In addition, the total polyphenol content of the yogurt containing cacao nibs increased, which was proportional to the amount added. Sensory evaluations of the yogurts indicated that overall taste was less desirable as cacao nib loadings increased from 1 to 5% compared with controls. This result is due to the excessive acidity, which was strongly perceived in the absence of added sugar. The development of yogurts with cacao nibs is expected to contribute much to the appeal of fermented milk.

• Food Science and Preservation
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• v.30 no.6
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• pp.991-998
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• 2023

This study investigated the antioxidant activity of Aronia vinegar during acetic acid fermentation. As a result of acetic acid fermentation at 30℃ for 30 days with different initial ethanol contents, it was found that adjusting the initial ethanol content to 6% was optimal, at which 4.1% of acetic acid was produced. During fermentation under optimal conditions, the total polyphenol content decreased, but the content was higher than that of the control brown rice vinegar but lower than that of grape vinegar. The contents of flavonoids and tannins showed a decreasing pattern as acetic acid fermentation progressed, but they were higher than those of brown rice vinegar and grape vinegar. The DPPH scavenging activity was higher than 95.7% in all test groups, indicating that it would be possible to produce high-quality Aronia vinegar using the acetic acid fermentation method.