• Food Science of Animal Resources
• /
• v.36 no.4
• /
• pp.508-515
• /
• 2016

This study aimed to investigate the functional and physicochemical properties of yogurt, supplemented with germinated brown rice (GBR) containing γ-aminobutyric acid (GABA), during storage. GBR was produced by soaking brown rice at 30℃, and saccharified germinated brown rice (SGBR) was produced by treating brown rice with α- and β-amylase for 1 h, at 80℃ and 60℃, respectively. Yogurt was manufactured using a commercial starter (YC-X11, CHR. Hansen, Denmark) at 37℃ for 12 h. The fatty acids and GABA contents were analyzed using GC and HPLC, respectively. The fatty acids in the cereal samples consisted of oleic, linoleic, and palmitic acid. The portion of oleic acid was the highest, at 35.65% in GBR, and 32.16% in SGBR. During germination, the oleic acid content increased, whereas linolenic and palmitic acid contents from GBR tended to decrease. Although the portion of saturated fatty acids, such as stearic and myristic acid, decreased significantly (p<0.05), that of unsaturated fatty acids, such as oleic and linoleic acid, increased with an increase in supplementation of BR, GBR, or SGBR in the yogurt. The yogurt, supplemented with cereal samples, showed a tendency of an increase in the concentration of GABA with an increase in the supplementation of the cereal samples. However, yogurt supplemented with GBR showed the highest concentration of GABA, regardless of the supplementation of the cereal samples. These results indicated that yogurt supplemented with BR, GBR, or SGBR could be a promising dairy product.

• Journal of Dairy Science and Biotechnology
• /
• v.14 no.1
• /
• pp.97-118
• /
• 1996

All over the world there is an increasing consumer awareness of the potential influence of various foodstuffs on our health. Today dairy products are expected to be more just food. They have to taste well, appeal and give pleasure, provide of well-being, provide specific health benefits and prevent disease. This paper reviews the different types of fermented milks and their microflora and includes recent work on yogurt, soft cheese and buttermilks, kefir and koumiss. There is considerable interest in the new health promoting products which are now available. Meanwhile during the last decade a new generation of fermented milk products containing selected intestinal bacteria has been introduced to the markets. These are discussed in the light of some recent findings on the ability to lower the blood cholesterol concentration and stimulate the immune response and also describes some fermented milk products available, selection criteria for commercial starter cultures.

• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.4
• /
• pp.602-609
• /
• 2002

Lao-chao is a traditional Chinese fermented rice product with a sweet and fruity flavor, containing high levels of glucose, a little alcohol and milk-clotting characteristics. In order to optimize commercial production of lao-chao, Rhizopus javanicus and Saccharomyces cerevisiae were selected as the mold and yeast starter, respectively. A commercial mixed starter (chiu-yao) was used as control. Fermentation of the experimental combination revealed a sharp drop in pH (to 4.5) on the fourth day, remaining constant thereafter. Content of reducing sugars gradually decreased throughout the entire fermentation period. Of the free amino acids, higher quantities of alanine, leucine, proline, glutamic acid, glutamine and $NH_3$ were noted. For sugars, glucose revealed the highest concentration, while organic acid levels, including those for oxalic, lactic, citric and pyroglutamic acid, increased throughout the fermentation period. Twenty-one compounds were identified by gas chromatography from aroma concentrates of the lao-chao culture filtrate, prepared using the headspace method. For the flavor components, higher quantities of ethanol, fusel oil and ester were determined in both culture filtrates. In regard to the evaluation of yogurt-like product, there were significant differences in alcoholic smell, texture and curd firmness.

• Journal of Animal Science and Technology
• /
• v.52 no.2
• /
• pp.141-148
• /
• 2010

The aim of this study was to develop a new starter for fermented milk. The approach started with 103 acid-producing isolates from Kimchi, a type of spiced, fermented cabbage and then PCR screening was used to identify 72 Lactobacillus strains. The ability to inhibit the growth of food-borne human pathogens (Escherichia coli, Salmonella enteritidis, Staphylococcus aureus) of these strains were measured, using the paper disk method. Among them, one bacterium (LHB55) that showed a strong antibacterial activity against food-borne human pathogens was identified and further characterized, using 16S rDNA sequencing and API 50CHL system. Because this isolate was identified as L. plantarum, it was named as L. plantarum LHB55. The yogurt produced using commercial LAB with L. plantarum LHB55 did not display properties that are microbially or physico-chemically different from the control group, which suggests that L. plantarum LHB55 can be used as a useful starter for yogurt containing high antibacterial activity. We think that identifying effective starter strains enabling further development of fermented milk that can deliver better health benefits such as antimicrobial properties is of high significance, and thus our effort in this type of approach will continue.

• Korean Journal of Food Science and Technology
• /
• v.48 no.3
• /
• pp.231-240
• /
• 2016

The purpose of this study was to investigate the effect of exopolysaccharide (EPS)-producing Leuconostoc and Weissella isolates from kimchi as a probiotic starter and replacement for thickening agents such as pectin and gums in yogurt. Potential probiotic isolates were first screened for their acid and bile tolerance, and then evaluated for antimicrobial activity against Escherichia coli and Salmonella Typhimurium. When the selected Leuconostoc or Weissella isolates were co-inoculated in yogurt without a thickening agent, the yogurt with 4% sucrose produced lower syneresis values than the control and had higher EPS yields. The isolates were able to survive at a level of $10^6CFU/mL$ when incubated at $4^{\circ}C$ for 12 days. This study shows that EPS-producing Leuconostoc and Weissella strains have the potential to produce a synbiotic yogurt.

• Journal of Microbiology and Biotechnology
• /
• v.33 no.6
• /
• pp.780-787
• /
• 2023

Two mannitol producing lactic acid bacteria were isolated from pa (green onion)- kimchi, identified and named as Leuconostoc mesenteroides SKP 88 and Leuconostoc citreum SKP 92, respectively. Both isolates grew well at 25-30℃, initial pH 6-8, and 3% and lower NaCl concentration. Both isolates converted fructose into mannitol efficiently when grown on MRS broth containing fructose and glucose. Glucose was used as a carbon source and fructose was used as a precursor for mannitol. Mannitol yields were the highest in MRS broth with 3% fructose and 2% glucose. Shine muscat juice fermentation was done using each isolate as a starter. As fermentation progressed, decrease in pH and increases in titratable acidity and viable counts were observed. L. mesenteroides SKP 88 showed better mannitol conversion ability than L. citreum SKP 92, and shine muscat juice fermented with L. mesenteroides SKP 88 showed the mannitol production of 41.6 g/l at 48 h, and juice fermented with L. citreum SKP 92 showed 23.4 g/l at the same time. Yogurt fermentations showed similar patterns, and yogurt fermented with L. mesenteroides SKP 88 showed the mannitol production of 15.13 g/l. These results showed that both strains are useful as starters for healthy fermented foods with reduced fructose contents.

• Food Science of Animal Resources
• /
• v.29 no.5
• /
• pp.619-626
• /
• 2009

As a trial for the development of a new starter culture for yogurt products, more than two hundred lactic acid bacteria strains were isolated from raw milk and healthy human feces. The strains that showed excellent growth and acid production ability in the 10% skim milk media were selected and identified as Lactobacillus casei through the API carbohydrate fermentation pattern and 16S rDNA sequence analysis. L. casei CU2604 was further investigated for its physiological characteristics as a starter culture compared with a commercial strain. The CU2604 strain showed good acid production and growth characteristics in milk, which were comparable to those of the L. casei Shirota strain. Despite the fact that both these strains displayed the same sugar fermenting pattern and PFGE band pattern, and had similar growth characteristic in milk, L. casei CU2604 exhibited different fatty acid composition in the cell wall, showed more tolerance to bile and to pH, and presented better growth inhibition activity against pathogenic bacteria. Based on these results, the L. casei CU2604 strain holds great promise for use as a novel and efficient starter culture in the production of yogurt. Additional studies on the probiotic characteristics of this strain are currently being conducted.

• Journal of Microbiology and Biotechnology
• /
• v.30 no.6
• /
• pp.903-911
• /
• 2020

Addition of probiotics to yogurt with desired health benefits is gaining increasing attention. To further understand the effect of probiotic Lactobacillus plantarum on the quality and function of fermented milk, probiotic fermented milk (PFM) made with probiotic L. plantarum K25 and yogurt starter (L. delbrueckii ssp. bulgaricus and Streptococcus thermophilus) was compared with the control fermented milk (FM) made with only the yogurt starter. The probiotic strain was shown to survive well with a viable count of 7.1 ± 0.1 log CFU/g in the PFM sample after 21 days of storage at 4℃. The strain was shown to promote formation of volatiles such as acetoin and 2,3-butanediol with milk fragrance, and it did not cause post-acidification during refrigerated storage. Metabolomics analysis by GC-MS datasets coupled with multivariate statistical analysis showed that addition of L. plantarum K25 increased formation of over 20 metabolites detected in fermented milk, among which γ-aminobutyric acid was the most prominent. Together with several other metabolites with relatively high levels in fermented milk such as glyceric acid, malic acid, succinic acid, glycine, alanine, ribose, and 1,3-dihydroxyacetone, they might play important roles in the probiotic function of L. plantarum K25. Further assay of the bioactivity of the PFM sample showed significant (p < 0.05) increase of ACE inhibitory activity from 22.3% at day 1 to 49.3% at day 21 of the refrigerated storage. Therefore, probiotic L. plantarum K25 could be explored for potential application in functional dairy products.

• Microbiology and Biotechnology Letters
• /
• v.12 no.4
• /
• pp.285-291
• /
• 1984

In making liquid yoghurt, the influences of proteolytic ability of lactic acid bacteria on acid production and on protein stability were investigated. L. bulgaricus CH-2, L. helviticus IAM 1042 and L. jugurti 3048 showed a comparatively high proteolytic activity in milk, while L. casei YIT 9018 did not show any marked proteolysis. Starter organisms having high proteolytic ability showed more rapid growth and acid production than those having low ability in milk. The most active proteolysis occurred during logarithmic growth phase of yogurt organisms, and most of the proteolysis took place in the first 24-48 hrs of incubation. Highly proteolysed yogurts made by L. bulgaricus CH-2, L. jugurti 3048, L. helviticus IAM 1042, L. acidophilus L-54 and L. casei 3012 had low protein solubility at pH 3.5 and had much protein precipitates during storage of product, but those having little protein hydrolysates made by L. casei YIT 9018 or artificial acidification showed no precipitation during keeping.

• Food Science of Animal Resources
• /
• v.29 no.4
• /
• pp.500-505
• /
• 2009

This study was carried out to fortify the antimicrobial activity of yogurt by adding garlic juice to it. A raw garlic bulb was grated and heated with Glycyrrhiza uralensis to improve its antimicrobial activity and palatability. Yogurt was made with 0, 4, 8, and 12% garlic juice, and was evaluated in terms of its lactic starter growth, physico-chemical characteristics, growth inhibitory activity against Staphylococcus aureus KCCM 40510, and sensory characteristics. The garlic juice significantly increased the growth of the yogurt starter (p<0.05), which was highest with the addition of 4% garlic juice. Significant (p<0.05) inhibition of S. aureus KCCM 40510 occurred with the addition of 12% garlic juice. The preference was lowered with the addition of garlic juice, but the addition of 4% garlic juice showed no significant difference (p>0.05). To increase the antimicrobial activity of yogurt with the addition of garlic juice, further studies on the increase in the palatability of garlic juice are necessary.