• Journal of Microbiology and Biotechnology
• /
• 제7권1호
• /
• pp.1-7
• /
• 1997

The efficient manufacture of fermented dairy products on an industrial scale requires a supply of reliable starter cultures with properties suited to desired product specifications. These cultures must be backed by relevant research and development activities. This article describes the issues involved in establishing a centre to provide starter culture R & D for a group of independent cheese manufacturing companies, and discusses a strategic approach to the management of starter cultures.

• Journal of Dairy Science and Biotechnology
• /
• 제24권1호
• /
• pp.65-73
• /
• 2006

This study was to review recent reports in effects of various starter cultures on the viscosity in stirred yogurt. The rheological properties of yogurt have received considerable attention in the literature. Most yogurts are typically made by mixed cultures of Lactobacillus bulgaricus and Streptococcus thermophilus. The viscosity of yogurt made by mixed cultures was much higher than that of yogurt by single cultures. Since texture of stirred yogurt is the result of both acid aggregation of casein micelles and production of exopoly-saccharides, it is suggested that yogurt be made by the exopolysaccharide-producing cultures in order to increase viscosity, Both types of exopolysaccharides are capsule and loose slime(ropy). But it is desirable to use encapsulated nonropy strains. And Bifidobacteria affects adversely to the viscosity of yogurt. Therefore, starter cultures which have an effect on yogurt viscosity have been widely demonstrated. This review is the search for the development of viscosity in stirred yogurt.

• 한국식품영양과학회지
• /
• 제33권8호
• /
• pp.1343-1347
• /
• 2004

국내에서 시판 중인 요구르트의 CLA 함량과 상업용 dairy starter 유산균의 CLA 생산능을 조사하였다. 시판 요구르트 중의 CLA 함량은 4.1∼14.8 mg/100 g이었으며, 원료 우유사용비율이 낮아질수록 제품에 함유된 CLA 함량도 낮아지는 경향을 보였다. CLA 함량과 stearic acid, oleic acid, linoleic acid 및 linolenic acid의 함량, CLA 함량과 지방함량간에는 정의 상관관계를 보였다. 상업용 dairy starter 유산균 67균주 중 L. acidophilus 1종, L. casei 1종 및 Streptococcus thermophilus 3종 등 모두 5 균주가 기질로 첨가한 linoleic acid로부터 CLA를 생성하였다 또한 생성된 CLA는 cis-9, trans-11 이성체가 70% 이상으로 대부분을 차지하였다. 이들을 이용한 발효유는 대조구에 비해서 1.7∼2.6 mg/100 g의 CLA 함량의 증가를 보였으며, CLA 전환율은 6.1∼8.6%였다.

• Journal of Dairy Science and Biotechnology
• /
• 제22권2호
• /
• pp.119-130
• /
• 2004

Application of lactic acid bacteria in the markets are divided into four categories: dairy industry, health food industry, animal feed industry and pharmaceutical industries. Recently, Lactobacillus acidophilus have been used in the food industry and have obtained great attention as key cultures for health benefit. Since commercial application of L. acidophilus has become a common practice, characterization of these cultures were made. Futhermore, the strains selected should produce a final dairy product possessing good taste and acceptable body and texture, a selection step that cannot be achieved unless the product is actually manufactured. Conjugated linoleic acid (CLA) have been recognized as antioxidants, cancer inhibitors, cholesterol depressing agents, and growth promoting factors. Food products from ruminants, particularly dairy products, are the major dietary source of CLA f3r humans. The CLA content in yogurt or cheese can be increased by action of the starter cultures. The finding of the production of CLA by food starter culture opens interesting perspectives far the future in producing fermented products enriched in CLA.

• Journal of Dairy Science and Biotechnology
• /
• 제39권1호
• /
• pp.20-26
• /
• 2021

Lactase (β-galactosidase) is abundant in the small intestine during early childhood and gradually decreases with age. Lactic acid bacteria (LAB) present in yogurt could survive in the stomach, and lactase produced by these LAB can aid in lactose breakdown in the small intestine, thereby reducing lactose intolerance. This study aims to provide preliminary data for development of lactose-free yogurts for the elderly, and investigate the effect of lactose-hydrolyzed milk on the growth of starter cultures. The pH during yogurt fermentation using lactose-free milk was slightly higher at 2 and 4 h of incubation, but reached 4.5 at the end of incubation, similar to that of the yogurt prepared from regular milk. The number of viable cells of Streptococcus thermophilus reached 108 CFU/mL after 2 h of incubation and increased to 109 CFU/mL after 4 h of incubation. During yogurt fermentation, the viable cells of Lactobacillus species and Bifidobacterium longum did not affect lactose hydrolysis. Although lactose-hydrolyzed milk did not promote the growth of starter cultures, manufacturing yogurt with lactose-free milk could be beneficial for the intestinal health of lactose-sensitive elderly.

• Journal of Dairy Science and Biotechnology
• /
• 제14권1호
• /
• 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.

• Journal of Dairy Science and Biotechnology
• /
• 제40권1호
• /
• pp.48-56
• /
• 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.

• Journal of Microbiology and Biotechnology
• /
• 제30권9호
• /
• pp.1404-1411
• /
• 2020

Lactic acid bacteria (LAB) play an important role in dairy fermentations, notably as cheese starter cultures. During the cheese production and ripening period, various enzymes from milk, rennet, starter cultures, and non-starter LABs are involved in flavor formation pathways, including glycolysis, proteolysis, and lipolysis. Among these three pathways, starter LABs are particularly related to amino acid degradation, presumably as the origins of major flavor compounds. Therefore, we used several enzymes as major criteria for the selection of starter bacteria with flavor-forming ability. Lactococcus lactis subsp. lactis LDTM6802 and Lactococcus lactis subsp. cremoris LDTM6803, isolated from Korean raw milk and cucumber kimchi, were confirmed by using multiplex PCR and characterized as starter bacteria. The combinations of starter bacteria were validated in a miniature Gouda-type cheese model. The flavor compounds of the tested miniature cheeses were analyzed and profiled by using an electronic nose. Compared to commercial industrial cheese starters, selected starter bacteria showed lower pH, and more variety in their flavor profile. These results demonstrated that LDTM6802 and LDTM6803 as starter bacteria have potent starter properties with a characteristic flavor-forming ability in cheese.

• 한국축산식품학회지
• /
• 제36권3호
• /
• pp.427-434
• /
• 2016

Benzoic acid is occasionally used as a raw material supplement in food products and is sometimes generated during the fermentation process. In this study, the production of naturally occurring yogurt preservatives was investigated for various starter cultures and incubation temperatures, and considered food regulations. Streptococcus thermophilus, Lactobacillus acidophilus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus rhamnosus, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus reuteri, Lactobacillus plantarum, Bifidobacterium longum, Bifidobacterium lactis, Bifidobacterium bifidum, Bifidobacterium infantis, and Bifidobacterium breve were used as yogurt starter cultures in commercial starters. Among these strains, L. rhamnosus and L. paracasei showed the highest production of benzoic acid. Therefore, the use of L. rhamnosus, L. paracasei, S. thermophilus, and different incubation temperatures were examined to optimize benzoic acid production. Response surface methodology (RSM) based on a central composite design was performed for various incubation temperatures (35-44℃) and starter culture inoculum ratios (0-0.04%) in a commercial range of dairy fermentation processes. The optimum conditions were 0.04% L. rhamnosus, 0.01% L. paracasei, 0.02% S. thermophilus, and 38.12℃, and the predicted and estimated concentrations of benzoic acid were 13.31 and 13.94 mg/kg, respectively. These conditions maximized naturally occurring benzoic acid production during the yogurt fermentation process, and the observed production levels satisfied regulatory guidelines for benzoic acid in dairy products.

• Journal of Dairy Science and Biotechnology
• /
• 제36권3호
• /
• pp.178-185
• /
• 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.