• Korean journal of food and cookery science
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• v.31 no.1
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• pp.98-102
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• 2015

Allium hookeri, a member of the onion family, has long been mainly cultivated for food and medicinal use in Southeast Asian countries, owing to its various biological properties. However, no studies of the anti-oxidative effects of fermented A. hookeri root extracts have been conducted to date. Therefore, this study investigated the effect of different starter cultures on the antioxidant activities of hot water extract of A. hookeri root by using the following five strains: Lactobacillus acidophilus, Bifidobacterum longum, Enterococcus faecium, Streptococcus thermophilus, and Saccharomyces cerevisiae. DPPH and ABTS radical scavenging activity, total phenolic acid contents, and total antioxidant capacity were higher in the hot water extract of A. hookeri root fermented with starter cultures than those of A. hookeri root. Among hot water extract of A. hookeri root fermented with starter cultures, fementing with S. cerevisiae showed the highest antioxidant activities. The results of this study provide new evidence of the anti-oxidative properties of A. hookeri root with starter cultures, indicating that it may be highly valuable as a natural product owing to its high-quality functional components.

• Korean Journal of Food Science and Technology
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• v.27 no.6
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• pp.939-943
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• 1995

This study was carried out to investigate neutral volatile compounds and sensory quality of yogurt during the storage of 15 days at $10^{\circ}C$. The yogurt was manufactured with mixed culture containing Lactobacillus acidophilus, Bifidobacterium bifidum and Streptococcus salvarius subsp. thermophilus. Among the volatile compounds, acetaldehyde, acetone and ethanol increased significantly, and 2-butanone and 2-heptanone increased slightly but diacetyl did not increase during the storage periods. In sensory test, the flavor scores of yogurt were not different during the period, but those of off-flavor were significantly different (p<0.05). In correlation between the volatile compounds and sensory test, there was negative correlation between acetone and yogurt flavor, but positive correlations between ethanol and off-flavor (p<0.05). The results suggested that the volatile flavor compound may not affect the quality of yogurt during 15d storage period at $10^{\circ}C$.

• Journal of Microbiology and Biotechnology
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• v.18 no.7
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• pp.1266-1273
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• 2008

Lactic acid bacteria (LAB) with antimicrobial activity and high exopolysaccharide (EPS) production ability isolated from sourdough were studied for their fermentation characteristics as potential new starter cultures. The values of pH, titratable acidity, and viable cell counts were $4.06{\pm}0.009-4.50{\pm}0.015,\;0.787{\pm}0.020%-1.172{\pm}0.018%,\;and\;8.78{\pm}0.08-8.98{\pm}0.06$ log CFU/ml, respectively. In order to select probiotics with a high survival rate in the gut, isolates were tested to assess resistance against the artificial gastric acid and bile juice. Viable LAB counts were significantly (p<0.05) affected by the acidity. At pH 2.0, the total declines in the initial bacterial counts were 4.52$\pm$0.07 log for S. thermophilus St-Body-1, >7.98$\pm$0.03 log for E. flavescens DU-10, >7.95$\pm$0.05 log for E. faecium DU-12, and 3.15$\pm$0.06 log for L. amylovorus DU-21. Among the strains, L. amylovorus DU-21 was the only strain that had bile tolerance under simulated gastrointestinal conditions. In order to improve EPS production by L. amylovorus DU-21, the influence of carbon source was studied. When glucose was used as a carbon source, EPS production dramatically increased to 17.19$\pm$0.28 g/l (p<0.05). The maximum cell growth (10.012$\pm$>0.012 log CFU/ml) and EPS production (18.71$\pm$0.19 g/l) were achieved when 15 g/l of glucose was employed as the carbon source.

• Applied Biological Chemistry
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• v.50 no.1
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• pp.48-52
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• 2007

Yogurt base was prepared from skim milk supplemented with 0.2-1.0% (w/v) garlic powder and fermented with lactic acid bacteria (the mixed strain of Lactobacillus acidophilus, Bifidobacterium longum and Streptococcus thermophilus) at 40$^{\circ}C$ for 18 h. Quality characteristics of the prepared yogurt were evaluated for acid production (pH and titratable acidity), number of viable cells, viscosity and sensory properties. The addition of garlic powder inhibited the growth of lactic acid bacteria and decreased the acid production. After 18 h incubation, titratable acidity of garlic yogurt was 1.28-1.08% and was lower than that (1.35%) of yogurt made with only skim milk. However, the viscosity of yogurt was remarkably increased by the addition of garlic powder. The sensory score of yogurt added with 0.2% garlic powder was similar to ordinary yogurt in flavor and overall acceptability. According to sensory score and fermentation characteristics, the optimum concentration of garlic powder was around 0.2%.

• Journal of Life Science
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• v.17 no.12
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• pp.1754-1759
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• 2007

This study is performed to assess the preparation and characterization of lactic acid bacteria (Sterpoccoccus thermophilus) loaded with alginate microsphere using alginate and chitosan for the efficient delivery of lactic acid bacteria to large intestine. Size and morphology of alginate microsphere were confirmed $6{\sim}10{\mu}m$ with spherical shape by scanning electronic microscope (SEM). Biodegradation study of alginate was investigated at different buffer solutions (pH 1.2 and 7.4). This result showed that alginate microsphere did not degrade at pH 1.2 buffer solution but it's degradation occurred from first day at pH 7.4 buffer solution. Survivability test of lactic acid bacteria in alginate microsphere showed that it was keeping activity of lactic acid bacteria by chroma meter. Therefore, the introduction of alginate microsphere might be a potential system to efficiently delivery lactic acid to large intestine.

• Korean Journal of Food Science and Technology
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• v.24 no.6
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• pp.528-534
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• 1992

Growth stimulatory material for lactic acid bacteria was extracted from radish and radish green juice and its growth stimulatory effect was tested. Dried methanol-precipitated growth stimulatory material was lightly grayish white powder, Its ash content is 44% and approximately 50% of the ash is sulfur. It has reddish brown color upon solubilization in water. The material had unchanged stimulatory effect when it was treated with proteinase or pectinase, or ashed. The growth stimulatory activity was dialyzable. The material was able to counteract the growth inhibitory effect of EDTA. When selected lactic acid bacteria were grown at $30^{\circ}C$ for 24 hours in peptone(0.5%)-yeast extract(0.5%)-glucose(2%) broth with and without 0.5% growth stimulatory material, the material stimulated the growth of Lactobacillus plantarum, L. fermentum, L. leichmanii, L. sake, L. brevis, L. acidophilus, L. casei, Pediococcus pentosaceus, Leuconostoc mesenteroides, Streptococcus faecalis, S. lactis, S. cremoris and S. thermophilus by 19, 1833, 133, 444, 840, 32, 14, 18, 6, 17, 4, 5 and 4 times, respectively.

• Journal of Life Science
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• v.26 no.12
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• pp.1438-1445
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• 2016

Yeast can be post-contaminated by the equipment, producer, or air, and this can degrade yogurt quality. This study aimed to demonstrate the yeast inhibiting effect in fermented milk by adding Lactobacillus paracasei and Lactobacillus rhamnosus along with current fermenting lactic acid bacteria such as Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. A certain amount of yeast was added to fermented milk samples that were soon after stored at variable temperatures, and the number of yeast cells was counted periodically. The swelling phenomenon caused by the gas produced by the yeast in fermented products was also observed. In the two experiments, compared to the control, the L. paracasei- and L. rhamnosus-added-groups showed much slower rate of yeast appearance and lower frequency of swelling phenomena. This suggests that using a mixture of L. paracasei and L. rhamnosus in fermented milk inhibits the growth of yeast. Furthermore, if the products are stored at $10^{\circ}C$, post-acidification is rarely seen in the experimental group compared to the control group. This means that the organoleptic flavor can be kept consistent from the production day till the expiration day, resulting in improved organoleptic quality for customers. In other words, the use of L. paracasei and L. rhamnosus in fermented milk will result in the following positive effects: improvement in storage stability by delaying yeast appearance, increase in quality consistency by inhibiting post-acidification, and improved organoleptic quality by enhancing texture and flavor.

• Food Science and Preservation
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• v.24 no.8
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• pp.1180-1187
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• 2017

Zingiber officinale Roscoe, commonly known as ginger, has long been used as a powerful health-promoting antioxidant that supports cellular health of the human body. The objective of this study was to compare the antioxidant and antimicrobial activities of the samples with aging and fermentation. Antioxidant activities of the samples were compared using total phenol, flavonoid contents, ABTS cation radical scavenging activity and DPPH radical scavenging activity. Antimicrobial activities were also examined using the paper disc method and minimum inhibitory concentration (MIC). Acidity of the fermented ginger (FG) with lactic acid bacteria showed a significantly higher value than that of the ginger (GG). The content of 6-gingerol, a bioactive component in ginger, decreased in all fermented gingers but 6-shogaol which is also one of the main valuable ingredients showed the increased content at ginger fermented with Streptococcus thermophilus and Lactobacillus acidphilus. Flavonoid contents of the FG and GG did not show significant differences. However, ABTS cation radical scavenging activity and DPPH radical scavenging activity were 10-30% increased in the samples with fermentation (p<0.05), respectively. The samples of the disc showed an inhibitory effect on growth of gram positive Staphylococcus aureus and Listeria monocytogenes. Zinger with fermentation showed higher antioxidant and antimicrobial activities. Thus, we conclude that aging and fermentation can be a helpful process to increase the functional effects of ginger.

• Food Science and Preservation
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• v.18 no.6
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• pp.973-979
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• 2011

The grape cultivar Campbell Early has high levels of malic acid as well as tartaric acid. The high concentration of total acid in the Campbell Early wine is a critical aspect of the wine's sensory characteristics. To prevent the deterioration of the wine's quality, which is caused by the strong sour taste derived from the raw material in wine making, the deacidification factor was investigated via carbonic maceration under different temperature conditions, especially in the presence or absence of malolactic bacteria. Based on the results of the presence test of the malolactic bacteria during carbonic-maceration treatment, Lactobacillus brevis, Lactobacillus plantarum, and Streptococcus thermophilus were characterized morphologically and were identified via biochemical tests and 16S-rRNA-gene-sequencing analysis. The isolated strains were found not to consume malic acid and to produce lactic acid. Moreover, these strains were consumed as soluble solids. The isolated strains are popularly known as lactic-acid bacteria and should have produced lactic acid from glucose. The Oenococcus oeni of the malolactic bacteria was not isolated. These results showed that the isolated strains are not deacidified during carbonic-maceration treatment.

• Korean Journal of Food Science and Technology
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• v.51 no.3
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• pp.200-206
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• 2019

A potentially functional yogurt co-fermented with Monascus-fermented soybean powder (MFSP) was prepared, and its quality and antioxidant properties were investigated. Skim milk powder with (SMP+MFSP, 1:1, w/w) or without MFSP (SMP; control) was fermented by probiotic cultures consisting of L. delbrueckii subsp. bulgaricus KCTC 3635 and S. thermophilus KCTC 5092. The functional yogurt fermented with MFSP contained significantly (p<0.05) higher levels of ${\gamma}-aminobutryric$ acid (GABA; $107.22{\pm}3.06{\mu}g/g$), isoflavone aglycone (daidzein+genistein; $201.21{\pm}6.29{\mu}g/g$), and ubiquinone ($39.05{\pm}0.08{\mu}g/g$) than the control yogurt. During fermentation at $36^{\circ}C$ for 48 h, the functional yogurt displayed higher titratable acidity, viable cell numbers, and radical scavenging activity and a lower pH than the control yogurt (p<0.05). These results indicate that MFSP has great potential for enriching the free isoflavones, GABA, and ubiquinone contents in yogurt.