• Journal of Dairy Science and Biotechnology
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• v.36 no.3
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• pp.178-185
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• 2018

Kefir, which originates in the Caucasian mountains, is a cultured milk beverage produced by a combination of acidic and alcoholic fermentation. Kefir products are commonly used as food vehicles to deliver health-promoting materials including kefran and lactic acid bacteria to consumers. The aim of this study was to develop a freeze-dried starter culture without yeast and assess the suitability of kefir-like dairy products for the growth of lactic acid bacteria and the acidification of milk. Pasteurized whole milk (SNF 8.5%) stored at $25^{\circ}C$ was aseptically inoculated with starter cultures (0.002% w/v); it was kept at $25^{\circ}C$ until the pH attained a value of 4.6. Ten grams of the kefir-like product sample was diluted with 90 mL of 0.15% peptone water diluent in a milk dilution bottle, followed by uniform mixing for 1 min. Viable cells of Lactobacillus species were enumerated on modified-MRS agar (pH 5.2), with incubation at $37^{\circ}C$ for 48 h. Viable cells of Lactococcus species were enumerated on M17-lactose agar, with incubation at $32^{\circ}C$ for 48 h. The pH attained a value of 4.6 after fermentation for 9 h 30 min (Starter 1), 9 h 45 min (Starter 2), and 12 h (Starter 3). The viable cell count of Lactobacillus sp. and Lactococcus sp. was initially $10^5{\sim}10^6CFU/g$; it increased significantly to $10^9CFU/g$ after 12 h of incubation. During the storage of the kefir-like products at $4^{\circ}C$ for 1 4 days, the total viable cell numbers were unchanged, but the pH decreased slightly. The consistency of the kefir products increased gradually during the storage. The organoleptic properties of the kefir products fermented using the new starter culture are more desirable than those of commercial kefir. These results suggest that the newly developed starter culture without yeast could be suitable for kefir fermentation.

• Food Science of Animal Resources
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• v.39 no.5
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• pp.804-819
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• 2019

Ezine cheese is a non-starter and long-ripened cheese produced in the Mount of Ida region of Canakkale, Turkey, with a protected designation of origin status. Non-starter lactic acid bacteria (NSLAB) have a substantial effect on the quality and final sensorial characteristics of long-ripened cheeses. The dominance of NSLAB can be attributed to their high tolerance to the hostile environment in cheese during ripening relative to many other microbial groups and to its ability to inhibit undesired microorganisms. These qualities promote the microbiological stability of long-ripened cheeses. In this study, 144 samples were collected from three dairies during the ripening period of Ezine cheese. Physicochemical composition and NSLAB identification analyses were performed using both conventional and molecular methods. According to the results of a 16S rRNA gene sequence analysis, 13 different species belonging to seven genera were identified. Enterococcus faecium (38.42%) and E. faecalis (18.94%) were dominant species during the cheese manufacturing process, surviving 12 months of ripening together with Lactobacillus paracasei (13.68%) and Lb. plantarum (11.05%). The results indicate that NSLAB contributes to the microbiological stability of Ezine cheese over 12 months of ripening. The isolation of NSLAB with antimicrobial activity, potential bacteriocin producers, yielded defined collections of natural NSLAB isolates from Ezine cheese that can be used to generate specific starter cultures for the production of Ezine cheese (PDO).

• Microbiology and Biotechnology Letters
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• v.10 no.3
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• pp.217-222
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• 1982

A lactic starter organism, Lactobaciilus casei YIT 9018 was treated with N-methyl-N'-nitro-N-nitrosoguanidine (NTG) to obtain phage-resistant mutants. Freshly grown cells suspended in citrate buffer were exposed to NTG of 50 g/$m\ell$ for 40 min. Among 88 colonies isolated eight colonies showed distinct resistance to phages isolated previously from milk plants. The eight new colonies showed character similar to the original L. casei except that they responded differently to phage of different sources and thus were designated as eight different mutants of L casei. From the phage resisting toaether with the fermentative ability equivalent to the mother organism the mutants may be considered to be used as starter cultures for fermented milk.

• Food Science of Animal Resources
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• v.30 no.2
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• pp.223-231
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• 2010

In order to develop a new starter for fermented milk, Lactobacillus paracasei subsp. paracasei BFI46 (BFI46) obtained from new-born infant feces was investigated for physiological characteristics. Good immunomodulating activity was evident compared with commercial lactic acid bacteria starter cultures. The optimum growth temperature of BFI46 was $40^{\circ}C$ with 12 h required to reach pH 4.3. Testing with 13 different antibiotics revealed greatest sensitivity of BFI46 to penicillin- G and chloramphenicol, and heightened resistance to neomycin, kanamycin and polymyxin. BFI46 displayed higher esterase activities compared to 18 other enzymes, was comparatively tolerant to bile juice and able to survive at pH 2 for 3 h, and displayed high resistance against Escherichia coli and Salmonella Typhimurium with a survival rate of 57.14% and 96.36%, respectively. The results indicate that BFI46 could be an excellent starter culture for fermented milk with high level of immunomodulating activity.

• Journal of the Korean Professional Engineers Association
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• v.18 no.4
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• pp.5-11
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• 1985

These preliminary studies have indicated that this approach in the manufacture and rippening of cheese slurry will be of practical application. The slurry thus prepared seems to have great potentiality in being suitable for incorporation into bakery products and the products thus prepared will have better nutritional qualities and flavour Indications have also been observed that a definite improvement in the quality of flavour may be obtained by employing suitable starter cultures as well as slight modification in the process.

• Journal of Dairy Science and Biotechnology
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• v.36 no.2
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• pp.125-131
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• 2018

The present study aimed to investigate the microbial diversity in Gouda cheese within the four months of ripening, via next-generation sequencing (NGS). Lactococcus (96.03%), and Leuconostoc (3.83%), used as starter cultures, constituted the majority of bacteria upon 454 pyrosequencing based on 16S rDNA sequences. However, no drastic differences were observed among other populations between the center and the surface portions of Gouda cheese during ripening. Although the proportion of subdominant species was <1%, slight differences in bacterial populations were observed in both the center and the surface portions. Taken together, our results suggest that environmental and processing variables of cheese manufacturing including pasteurization, starter, ripening conditions are important factors influencing the bacterial diversity in cheese and they can be used to alter nutrient profiles and metabolism and the flavor during ripening.

• Journal of Dairy Science and Biotechnology
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• v.18 no.1
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• pp.61-72
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• 2000

Consumers primarily consider flavor when they take yogurt. Recent researches on yogurt flavor productron its analytical technique have been extensively developed. These studies have provided a better understanding on the role of starter culture microorganisms on flavor formation and degradation. Yogurt volatile flavor compounds produced by the lactic cultures include acetaldehyde, diacetyl, ethanol and organic acid. Among them, acetaldehyde is recognized as a principal flavor component. since yogurt contains a delicate and low intense flavor, mild sample isolation techniques and sensitive identification means might be used. This paper attempts to discuss recent findings in yogurt flavor and to describe the application of yogurt flavor separation techniques. The section on practical aspects of culture selection based on flavor compound production and flavor analysis is also included.

• Journal of Dairy Science and Biotechnology
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• v.40 no.1
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• pp.48-56
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• 2022

Enterococcus species have been reported to produce unique flavoring ingredients in fermented dairy products. Generally, they were found in cheese and fermented dairy products. Enterococcus spp. produce extracellular polysaccharides and reduce blood cholesterol levels in humans. This study used heat-killed E. faecalis and E. faecium in yogurt production to increase safety during consumption. The addition of heat-killed E. faecalis and E. faecium to milk did not affect the fermentation time of yogurt production, the growth of starter cultures, and the viscosity of yogurt. These results concluded that heat-killed Enterococcus, rather than live Enterococcus, is sufficiently possible and even safer to be added to milk products. Enterococcus species could be used as a safe and functional food additive to fermented milk products and supplements in health foods.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.3
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• pp.198-204
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• 2005

Seeds of neem were collected from different parts of India and analyzed for their azadirachtin content by High Performance Liquid Chromatography (HPLC). In order to assess the effects of genotypic and geographical variation on azadirachtin content in cell cultures, callus development was attempted in the seeds containing high and low concentration of azadirachtin. The concentration of azadirachtin in callus cultures was significantly affected by the explant source. Seed kernels with higher azadirachtin content produced higher azadirachtin content in callus cultures and lower azadirachtin content was seen in callus cultures produced from seed kernels with low azadirachtin content. The protocol for development of elite stock culture of Azadirachta indica was established with the objective of selecting a high azadirachtin-producing cell line. The highest azadirachtin-producing cell line was selected and the effects of different media and illumination conditions on growth and azadirachtin production were studied in shake flask suspension culture. Detailed batch growth kinetics was also established. These studies provided elite starter culture and associated protocols for cultivation of A. indica plant cell culture in the bioreactor.

• The Korean Journal of Food And Nutrition
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• v.17 no.1
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• pp.8-17
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• 2004

The effect of chlorella extract on the growth and acid production of yoghurt starter was investigated in order to prepare the yoghurt added with chlorella extract. The various levels of chlorella extract powder were added to skim milk medium and the medium was fermented by single or mixed culture of 4 types of lactic acid bacteria such as Streptococcus thermophilus, Lactobacillus acidophilus, Lactobacillus casei, and Lactobacillus bulgaricus. The changes in acid production(pH, titratable acidity) and number of viable cells of the medium during fermentation in skim milk added with chlorella extract powder have determined. When chlorella extract powder was added to skim milk medium at the levels of 0.5%, 1.0%, 2.0%, and 3.0%, the addition of 0.5% chlorella extract powder with the single culture of Str. thermophilus, Lac. casei, and Lac. bulgaricus showed the highest number of viable cell counts after 9 hours incubation. And also all single cultures of the yoghurt starter produced the higher amounts of acid with the addition of 0.5% chlorella extract powder. When chlorella extract powder was added to the medium at the levels of 0.25%, 0.5%, 1.0%, and 2.0%, the addition of lower lever(0.25∼0.5%) of chlorella extract powder with the mixed culture of the lactic acid bacteria showed more the acidity of pH and the number of viable cell counts. Among the treatments tested, the addition of 0.25% chlorella extract powder with the mixed culture of Str. thermophilus and Lac. casei produced the highest number of viable cell counts after 12 hours incubation. Therefore it was suggested to manufacture the yoghurt with the addition of 0.25% chlorella extract powder and the inoculation of mixed culture of Str. thermophilus and Lac. casei for on the stimulation of growth of the yoghurt starter.