• Food Science and Preservation
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• v.31 no.1
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• pp.149-160
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• 2024

Dextran is a glucose homo-polysaccharide with a predominantly α-1,6 glycosidic linkage of microbial source and is known to be produced primarily by lactic acid bacteria. However, it can also be obtained through the dextran dextrinase of acetic acid bacteria (Gluconobacter oxydans). The dextrin-based dextran was obtained from rice starch using G. oxydans fermentation of rice hydrolysate, and its properties were studied. Both dextrin- and rice hydrolysate-added media maintained the OD value of 6 after 20 h of incubation with acetic acid bacteria, and the gel permeation chromatography (GPC) analysis of the supernatant after 72 h of incubation confirmed that a polymeric material with DP of 480 and 405, which was different from the composition of the substrate in the medium, was produced. The glucose linkage pattern of the polysaccharide was confirmed using the proton nuclear magnetic resonance (¹H-NMR) and the increased α-1,4:α-1,6 bond ratio from 0.23 and 0.13 to 1:2.37 and 1:4.4, respectively, indicating that the main bonds were converted to α-1,6 bonds. The treatment of dextrin with a rat-derived alpha-glucosidase digestive enzyme resulted in a slow release of glucose, suggesting that rice hydrolysate can be converted to dextran using acetic acid bacteria with glycosyltransferase activity to produce high-value bio-materials with slowly digestible properties.

• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.1
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• pp.43-50
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• 2005

The purpose of this study is to discuss the ways to consistently feed high quality corn silage(CS). This study evaluated the effect of the corn silage, after a certain time has elapsed, on the chemical composition and fermentation characteristics after feedout during the winter feeding period of the CS. Six samples of CS from four dairy farms(E1, E2, E3, and L1 ) were taken in order to feed the milking cows over a winter feeding Period from November of 2002 until February of the following year, 2003(six samples were taken at the fellowing dates in the following order: sample one was taken on the 23rd Nov. 2002, sample two on the 5th of Dec. 2002, 3rd sample on the 23rd of Dec. 2002, 4th sample on the 7th of Jan. 2003, 5th sample on the 22nd of Jan. 2003, and the 6th sampling was carried out on the 6th of Feb. 2003) at the three sampling sites after the opening of the trench silos at intervals of 15 days. In the dry matter contents of CS, there wasn't any specific tendency according to the elapsed time in the range of 21.3~$27.3\%$ at all low dairy farm(E1, E2, E3, and L1). And the average dry matter contents were 24.1, 25.9, 23.6, and $20.4\%$. Considering the Proper amount of the dry matter of CS during the ripen yellow stage, the appropriate moisture content was $33\%$ (NRC, 1989), and these dry matter contents were all low. A consistent tendency was not found in the contents of CS. The average of CP contents were 10.2, 8.0, 8.5, and $9.8\%$ at the E1, E2, E3, and L1 farms, and there were significant differences. The TDN contents of CS were not different among forms according to the time elapsed. The pH, according to the time elapsed after opening of the CS, there were no differences at each of E1, E2, E3, md L1 farms. Average pH were 3.5, 3.9, 3.6, and 4.1, md all of them were in normal range. In the lactic acid contents of CS, a consistent tendency was not found among four farms. But according to the time elapsed. there was a goat difference from 1.13~$7.8\%$ The acetate, propionate, and butyrate contents of CS were very low. In this study, there was no significant difference in the CS's chemical composition and fermentation characteristics according to the elapsed time at all four dairy farms. Considering the proper dry matter contents of CS during the ripen yellow stage, the appropriate dry matter content was $33\%$, and dry matter contents of few farms were all low. To enhance the quality of corn silage should be ensiled com at proper dry matter content range from 28 to $35\%$ Therefore, content of the corn plant should be always be closely monitored prior to beginning harvest.

• Food Science and Preservation
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• v.23 no.5
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• pp.718-726
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• 2016

Sweet pumpkin paste (SPP) was fermented by Leuconostoc mesenteroides SM at $25^{\circ}C$ for 3 days for enhancing its physicochemical properties. SPPs with 5%, 10%, and 15% solid contents (SC) were fortified with 20% sucrose and 0.5% yeast extract. The unfermented SPP with 15% SC indicated L, a, and b color values of 25.02, 4.66, and 13.35, respectively, and a consistency index of $48.6Pa{\cdot}s^n$. During the 3 days of fermentation, both the a and b color values decreased slightly, whereas the consistency index increased to $188.8Pa{\cdot}s^n$, giving the fermented product a pudding-like consistency. This fermented SPP (15% SC) showed the highest acid production and viable cell counts among samples, indicating pH 3.85, 1.30% acidity and $9.2{\times}10^8CFU/mL$ respectively. The added sucrose was completely utilized after 1 day of fermentation. After 3 days, the insoluble and soluble dextran contents were 8.9% and 4.5%, respectively. Furthermore, the contents of mannitol and fructose were 3.11% and 1.76%, respectively. Regarding the sensory evaluation, this fermented sample also indicated the highest color, taste and texture scores, and was the overall preferred sample. In conclusion, the fermented SPP with 15% SC was carotinoid-rich a wholesome pumpkin-based product that is rich in probiotics and lactic bacteria-produced mannitol and dextran, which gave the product an acceptable viscous pudding-like consistency and good organoleptic properties.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.7
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• pp.1006-1016
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• 2011

Saltwort (Salicornia herbacea L.), as a natural additive for regulating Mul-kimchi fermentation, was assessed for physicochemical and sensory characteristics of Yulmoo Mul-kimchi during storage. Saltwort in the form powder was directly added to the Yulmoo Mul-kimchi preparation at 0 (control), 1, 3, 5, and 7% (w/v) per weight of salt to evaluate their physicochemical, sensory, and microbiological characteristics in storage at $10^{\circ}C$ for 30 days. The pH values of all treatments were high, indicating a less acidic environment in all treatments compared to those of the control sample throughout the preservation period. Total acidity increased with storage time as is usually seen with normal kimchi fermentations, whereas the increases were more gradual in the 3 and 5% treatments. The increases in total vitamin C continued until days 6 (control) to 13 (7%), and were different according to the amount of added saltwort and then they decreased after each peak. The fluctuation in reducing sugars fol owed a similar trends of total vitamin C content by showing an initial increase, followed by a decrease based on the saltwort concentration and storage day. The 5% treatment was most effective for suppressing the increase in turbidity among all treatments. The 3 and 5% treatments showed the highest lactic acid bacteria counts during the entire preservation period. In the sensory evaluation results, adding saltwort at more than 3% concentration attained an overall higher scores of acceptability with respect to color, smell, taste, fresh taste, sour taste, crisp, and overall acceptability characteristics. In conclusion, adding saltwort, particularly at concentrations of 3 and 5% extended the preservation period of Yulmoo Mul-kimchi by retarding fermentation effectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.12
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• pp.1843-1851
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• 2014

This study evaluated the quality characteristics and antioxidant activities of barley Doenjang (soybean paste) containing various contents (4, 12, and 20%) of kelp extracts. After 60 days of fermentation, pH, acidity, and viscosity of Doenjang were 5.80~6.86, 0.57~1.87%, and 4,913.3~9,333.3 cps, respectively, showing significant differences according to content of kelp extracts. Amino-type nitrogen contents was 902.60~921.90 mg%. For color values, L and b values increased significantly (P<0.001), whereas a value decreased slightly according to kelp extracts. DPPH radical scavenging effect ($IC_{50}$) for butylated hydroxyanisole ranged from 10.28 mg/mL to 23.23 mg/mL. DPPH radical scavenging effects of control was highest among the samples. The total polyphenol and flavonoid contents were 12.72~6.37 mg tannic acid equivalence/g, and $0.98{\sim}1.56{\mu}g$ rutin equivalence/g, respectively. Initial counts of total bacteria and lactic acid bacteria were 7.20~7.57 log CFU/g, and 4.20~4.71 log CFU/g respectively, showing significant difference according treatment and fermentation (P<0.05). In the sensory evaluation, 20% kelp extract Doenjang (5.6) showed higher overall acceptability than other samples (6.5) (P<0.01). Especially, umami taste (6.1) and texture (6.4) of 20% kelp extract Doenjang were higher than those of control (P<0.05). These results suggest that Doenjang containing kelp extracts, will be good for industrial fields.

• The Korean Journal of Food And Nutrition
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• v.24 no.3
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• pp.367-375
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• 2011

For this study, Korean-type Koumiss was made by the fermentation of mixed cultures, in which yeast, Kuyveromyces, and microflora, Streptococcus thermophiles and Lactobacillus bulgaricus, were inoculated into 10% skimmed milk with added whey powder(control: A, 2%: B, 4%: C, 6%: D, and 8%: E). Fat, protein, lactose, titratable acidity, pH, the number of lactic acid bacteria, the number of yeast, alcohol content, volatile fatty acids, volatile free amino acids and minerals were measured in the products. The results were as follows: As the dosage of whey powder increased, fat increased from 0.74% in the control to 2.30% in sample E, protein increased from 2.95% in the control to 4.39% in sample E and lactose increased from 3.10% in the control to 7.43% in sample E. Titratable acidity and pH increased gradually. The number of lactic acid bacteria increased from $10^9\;cfu/m{\ell}$ in the control to $3.8{\times}10^9\;cfu/m{\ell}$ in sample E, and the number of yeast increased from $6.1{\times}10^7\;cfu/m{\ell}$ in the control to $1.65{\times}10^8\;cfu/m{\ell}$ in sample E, according to the increase of whey powder content. For alcohol content, the average values were 0.863%, 0.967%, 0.890%, 1.290%, and 1.313% for the control and samples B, C, D, and E, respectively. As the dosage of whey powder increased, alcohol content showed a tendency to gradually increase. The average alcohol content of E was 1.313 and this was higher than the alcohol content of Kazahstana-type Koumiss with 1.08%. Sixteen types of free amino acids were detected. Glycine was the lowest in the control at $0.38mg/m{\ell}$ and sample E contained $0.64mg/m{\ell}$. Histidine was also low in the control at $0.42mg/m{\ell}$ and sample E contained $0.65mg/m{\ell}$. On the other hand, glutamic acid was highest at $4.13mg/m{\ell}$ in the control whereas sample E had $6.96mg/m{\ell}$. Proline was also high in the control at $1.71mg/m{\ell}$ in control, but E contained $2.80mg/m{\ell}$. Aspartic acid and leucine were greater in sample E than in the control. For volatile free fatty acids, content generally had a tendency to increase in the control, and samples B, C, D, and E. Content of acetic acid gradually increased from $12,661{\mu}g/100m{\ell}$ in the control to $37,140{\mu}g/m{\ell}$ in sample E. Butyric acid was not detected in the control and was measured as $1,950{\mu}g/100m{\ell}$ in sample E. Caproic acid content was $177{\mu}g/100m{\ell}$ in the control and $812{\mu}g/100m{\ell}$ in sample E, and it increased according to the increase of whey powder content. Valeric acid was measured in a small amount in the control as $22{\mu}g/100m{\ell}$, but it was not detected in any other case. Mineral contents of Ca, P, and Mg increased from 1,042.38 ppm, 863.61 ppm, and 101.28 ppm in the control to 1,535.12 ppm, 1,336.71 ppm, and 162.44 ppm in sample E, respectively. Na content was increased from 447.19 ppm in the control to 1,001.57 ppm in sample E. The content of K was increased from 1,266.39 ppm in the control to 2,613.93 ppm in E. Mineral content also increased with whey powder content. In sensory evaluations, the scores increased as whey powder content increased. Flavor was lowest in the control with 6.3 points and highest in E with 8.2 points. Body and texture were highest at 4.2 points in the control, which did not have added whey powder. In the case of appearance, there were no great differences among the samples.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.389-396
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• 2016

This study examined the improving effect of DFA IV obtained from bacterial fermentation on the gut health. The effects of the dietary DFA IV on the intestinal mass, short chain fatty acids production and pH were evaluated in vivo. Sprague-Dawley rats were fed the 0% (control) or 1% DFA IV supplemented diets for 3 weeks. Supplementation of DFA IV resulted in a significant increase in cecal tissue and wall weights. Together with the lowering of the cecal and colonic pH, the amount of acetate and butyrate increased by 1.6 and 3.2 fold of the control group in the cecum, respectively, in the rats fed DFA IV diets. The DFA IV diet also significantly increased the cecal lactate 1.5 fold compared to the control diet, indicating that dietary DFA IV stimulated the growth of lactic acid bacteria and bifidobacteria in the intestine. Based on the above results, it is concluded that the dietary DFA IV may be used as a putative prebiotic supplement.

• Journal of Animal Science and Technology
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• v.52 no.4
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• pp.281-286
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• 2010

In this study, feeding fermented colostrum to Holstein calves was investigated to find out the effects on their growth and inhibition of diarrhea. The results of this study showed that the mixture of L. rhamnosus and E. faecium would be proper bacteria for fermentation of colostrum because of favorable odor, inhibition of coliform bacteria and high number of lactic acid bacterial count. Among the groups of calves fed 0, 5, 10 and 20% of fermented colostrums, average body weight gain for 28 days on feeding fermented colostrum were 16.6, 16.6, 17.4 and 18 kg, respectively showing that calves fed 20% fermented colostrum achieved the highest body weight gain. Occurrence of diarrhea due to feeding various levels of fermented colostrum was also recorded. Three calves out of 5 suffered diarrhea in 0%, 5%, and 20% group, on the other hand, all 5 calves suffered diarrhea in 10% group. Diarrhea persisted for durations were 2.7, 2.4, 4.0, and 2.4 days in 0, 5, 10, and 20% group, respectively. Fermented colostrum did not prevent the occurrence of diarrhea. In overall, addition of fermented colostrum above 10% level showed favorable effects in gaining body weight under the conditions of adding more portions of the fermented colostrum either for 14 days or longer feeding period of the fermented colostrum. On the other hand, fermented colostrum showed no beneficial effect in prevention of diarrhea in this study.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.5
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• pp.721-726
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• 2012

Lactic acid bacteria (LAB) are able to secrete antimicrobial peptides called bacteriocins, which inhibit other bacteria such as pathogenic microorganisms. Therefore, bacteriocin-producing starters can be used as natural biopreservatives for various foods. The objective of this study was to screen and characterize bacteriocin-producing LAB from Kimchi and to investigate their applicability as a starter in Kimchi fermentation. To screen bacteriocin-producing LAB, gram-positive and gram-negative bacteria were used as indicators. To measure the antimicrobial activities of isolates, agar well diffusion assay method was used. According to the results, bacteriocin produced by $Lb.$ $sakei$ B16 showed antimicrobial activity against $Listeria$ $monocytogenes$ ATCC 19115, $Escherichia$ $coli$ KCTC 1467, and$Lactobacillus$ $plantarum$ KTCT 3104. Furthermore, bacteriocin was very stable after treatment with high temperature and high and low pH, but its effects were inhibited by treatment with proteolytic enzymes such as trypsin, proteinase K, and ${\alpha}$-chymotrypsin, revealing their bacteriocin-like protein- based structure. These results suggest that $Lb.$ $sakei$ B16 and its bacteriocin are good candidates as a functional probiotic and natural biopreservative, respectively, in fermented foods.

• Journal of Dairy Science and Biotechnology
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• v.31 no.2
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• pp.99-108
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• 2013

Kefir is a unique fermented dairy product resulting from combined lactic acid and alcoholic fermentation of lactose in milk. Kefir is produced by the microbial activity of kefir grains. Kefir has numerous health benefits such as the reduction of cholesterol levels, stimulation of the immune system, antimutagenic and anticarcinogenic properties, and improvements of lactose intolerance. Furthermore, kefir is excellent as both a dietetic beverage and for protection against various diseases in small babies. Therefore, kefir has recently been regarded as an important functional dairy food. To date, the majority of research on kefir has focused on the applications of functional kefir using advanced biotechnology methods. The purpose of this review article is to facilitate the recognition of kefir as a novel functional food.