• Journal of Dairy Science and Biotechnology
• /
• 제18권1호
• /
• pp.61-72
• /
• 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.

• 한국축산식품학회지
• /
• 제39권1호
• /
• pp.84-92
• /
• 2019

Listeria monocytogenes is a major cause of serious foodborne illness in the dairy foods. Although Caenorhabditis elegans model is well established as a virulence model of pathogenic bacteria, its application on L. monocytogenes is critically unclear. The objective of this study was to carry out an evaluation of L. monocytogenes toxicity using C. elegans nematode as a simple host model. We found that C. elegans nematodes have high susceptibility to L. monocytogenes infection, as a consequence of accumulation of bacteria in the worms' intestine. However, L. innocua, which is known to be non-toxic, is not accumulate in the intestine of worms and is not toxic similarly to Escherichia coli OP50 known as the normal feed source of C. elegans. Importantly, immune-associated genes of C. elegans were intensely upregulated more than 3.0-fold when they exposed to L. monocytogenes. In conclusion, we established that C. elegans is an effective model for studying the toxicity of L. monocytogenes and we anticipate that this system will result in the discovery of many potential anti-listeria agents for dairy foods.

• 한국축산식품학회지
• /
• 제33권1호
• /
• pp.75-82
• /
• 2013

This study aimed to isolate lactic acid bacteria (LAB) from Kimchi and to identify suitable probiotic strain for application in fermented dairy product as a commercial starter culture. A total of 106 (LAB) strains were isolated from Kimchi collected from different regions in Korea and their phenotypic characteristics were assayed. Four isolates from MRS agar plates were selected and designated as DKL109, DKL119, DKL121 and DKL128. They were identified first by API 50 CHL kit and then 16S rRNA gene sequencing. DKL121 and DKL128 were identified as Lactobacillus paracasei and Lactobacillus casei, respectively. Other two isolates (DKL109 and DKL119) were identified as Lactobacillus plantarum. To estimate their applicability in dairy products, the characteristics including acid and bile tolerance, cold shock induced cryotolerance and enzymatic activities were determined. There was wide variation in ability of strains to acid tolerance, but no significant differences in bile tolerance, cold shock induced cryotolerance within selected strains. DKL119 and DKL121 showed the highest resistance to acid and bile and the highest ${\beta}$-galactosidase activity, respectively. When these two strains were used for yogurt preparation as a single starter culture, their viable cell counts reached to $1.0{\times}10^9CFU/mL$. Lactobacillus plantarum DKL119 showed faster acid development than commercial starter culture. Also storage trials at $10^{\circ}C$ showed that the viability of these strains was retained over 15 d. With these results, it was indicated that probiotics isolated from Kimchi can be used in yogurt manufacturing as a starter culture.

• Journal of Microbiology and Biotechnology
• /
• 제31권6호
• /
• pp.840-846
• /
• 2021

To improve the bile salt and acid tolerance of probiotics against gastrointestinal stresses, we investigated the effects of soybean lecithin and whey protein concentrate (WPC) 80 on the bile salt tolerance of Lacticaseibacillus paracasei L9 using a single-factor methodology, which was optimized using response surface methodology (RSM). The survival rate of L. paracasei L9 treated with 0.3% (w/v) bile salt for 2.5 h, and combined with soybean lecithin or WPC 80, was lower than 1%. After optimization, the survival rate of L. paracasei L9 incubated in 0.3% bile salt for 2.5 h reached 52.5% at a ratio of 0.74% soybean lecithin and 2.54% WPC 80. Moreover, this optimized method improved the survival rate of L. paracasei L9 in low pH condition and can be applied to other lactic acid bacteria (LAB) strains. Conclusively, the combination of soybean lecithin and WPC 80 significantly improved the bile salt and acid tolerance of LAB. Our study provides a novel approach for enhancing the gastrointestinal tolerance of LAB by combining food-derived components that have different properties.

• Journal of Dairy Science and Biotechnology
• /
• 제39권1호
• /
• pp.27-35
• /
• 2021

본 연구에서는 CPP와 CSO를 사용하여 제조한 나노 복합체의 유식품 적용성 및 포집된 생리활성물질인 비타민 D의 in vitro release를 평가하였다. 그 결과, CPP/CSO 나노 복합체는 model milk 및 model yogurt 적용 후 12일간의 저장기간 동안 높은 물리적 안정성을 지녀 식품 적용성이 뛰어남을 규명하였다. 또한 제조 공정 요인인 CPP 농도와 pH 조절을 통해 비타민 D를 90% 이상 포집할 수 있었으며, in vitro release 평가를 통해 비타민 D를 위에서 보호하고, 장에서 release 하는 나노 복합체의 특성을 규명하였다. 결론적으로 본 연구에서 제조된 CPP/CSO 나노 복합체는 뛰어난 유식품 적용성을 지닐 뿐만 아니라, 칼슘흡수 증진을 위한 비타민 D를 효과적으로 포집할 수 있으며, 포집된 비타민 D를 소장까지 안전하게 전달할 수 있는 효과적인 나노 전달체로 활용될 수 있을 것으로 기대된다.

• Journal of Animal Science and Technology
• /
• 제65권6호
• /
• pp.1124-1150
• /
• 2023

This study aimed to analyze the leading research materials and research trends related to livestock food in Asia in recent years and propose future research agendas to ultimately contribute to the development of related livestock species. On analyzing more than 200 relevant articles, a high frequency of studies on livestock species and products with large breeding scales and vast markets was observed. Asia possesses the largest pig population and most extensive pork market, followed by that of beef, chicken, and milk; moreover, blood and egg markets have also been studied. Regarding research keywords, "meat quality" and "probiotics" were the most common, followed by "antioxidants", which have been extensively studied in the past, and "cultured meat", which has recently gained traction. The future research agenda for meat products is expected to be dominated by alternative livestock products, such as cultured and plant-derived meats; improved meat product functionality and safety; the environmental impacts of livestock farming; and animal welfare research. The future research agenda for dairy products is anticipated to include animal welfare, dairy production, probiotic-based development of high-quality functional dairy products, the development of alternative dairy products, and the advancement of lactose-free or personalized dairy products. However, determining the extent to which the various research articles' findings have been applied in real-world industry proved challenging, and research related to animal food laws and policies and consumer surveys was lacking. In addition, studies on alternatives for sustainable livestock development could not be identified. Therefore, future research may augment industrial application, and multidisciplinary research related to animal food laws and policies as well as eco-friendly livestock production should be strengthened.

• Journal of Dairy Science and Biotechnology
• /
• 제25권2호
• /
• pp.21-28
• /
• 2007

Recently, the field of microbiology has been transformed by huge increasing number of publicly available whole-genome sequences. This sequence information has significantly enhanced our understanding of the physiology, genetics, and evolutionary development of bacteria. Among the gastrointestinal microorganisms, bifidobacteria represent the most important human commensals because of their contribution to maintaining a balanced gastrointestinal tract microbiota. In recent years bifidobacteria have drawn much scientific attention due to their use as live bacteria in numerous food products with various health-related claims. For this reason, these bacteria constitute a growing area of interest with respect to genomics, molecular biology, and genetics. Recent genome sequencing of a number of bifidobacterial species has allowed access to the complete genetic make-up of these bacteria. This review will focus how genomic data has allowed us to understand bifidobacterial evolution, while also revealing genetic functions that explains their presence in the particular ecological environment of the gastrointestinal tract.

• Journal of Dairy Science and Biotechnology
• /
• 제39권1호
• /
• pp.36-50
• /
• 2021

This study aimed to evaluate the biological potential of functional food, i.e., specific peptides obtained from the hydrolysis of milk protein, by assessing their antioxidant and antibacterial properties. For the preparation of casein hydrolysates, commercial enzymes were added to 10% casein solution in a 1:200 (w/v) ratio, and samples were collected each hour. Based on the assessment of the degree of hydrolysis (DH) of casein hydrolysates, it was observed that the concentration of all enzymatic hydrolysates increased rapidly from 30 to 40 minutes. However, no change was observed in their concentrations after 150 minutes. Protamex® and Neutrase® exhibited the highest DH when compared to other enzymes. Furthermore, SDS-PAGE was performed for analyzing the proteolytic pattern of each enzyme, except for Flavourzyme®, and peptides in the size range of 20-25 kDa were identified. Subsequently, peptides produced by two enzymes were isolated using a preparative liquid chromatography system. Overall, NF3, NF4, PF5, and PF6 showed higher antioxidant potential than other peptide fractions. Moreover, NF7 and PF3 exhibited the highest antibacterial activity. In this study, we evaluated the biological potential of novel casein-derived peptides that may find application in the food and healthcare industry.

• Journal of Dairy Science and Biotechnology
• /
• 제41권1호
• /
• pp.1-8
• /
• 2023

Response surface methodology (RSM) is a statistical approach widely used in food processing to optimize the formulation, processing conditions, and quality of food products. The homogenization process is achieved by subjecting milk to high pressure, which breaks down fat globules and disperses fat more evenly throughout milk. This study focuses on an application of RSM including the logit transformation to predict the efficiency of milk homogenization, which can be maximized by minimizing the relative difference in fat percentage between the top part and the remainder of milk. To avoid a negative predicted value of the minimum of this proportion, the logit transformation is used to turn the proportion into the logit, whose possible values are real numbers. Then, the logit values are modeled and optimized. Subsequently, the logistic transformation is used to turn the predicted logit into the predicted proportion. From our model, the optimum condition for the maximized efficiency of milk homogenization was predicted as the combination of a homogenizer pressure of 30 MPa, a storage temperature of 10℃, and a storage period of 10 days. Additionally, with a combination of a homogenizer pressure of 30 MPa, a storage temperature of 10℃, and a storage period of 50 days, the level of milk homogenization was predicted to be acceptable, even with the problem of extrapolation taken into account.

• 축산식품과학과 산업
• /
• 제6권1호
• /
• pp.55-62
• /
• 2017