• 한국축산식품학회지
• /
• 제34권4호
• /
• pp.543-551
• /
• 2014

The aim of this study was to evaluate the effect of proteolytic (Serratia liquefaciens, match %: 99.39) or lipolytic (Acinetobacter genomospecies 10, match %: 99.90) psychrotrophic bacteria (bacterial counts, analysis of free fatty acids (FFA) and analysis of free amino acids) on the microbial and chemical properties (yogurt composition), and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of yogurt during storage. Yogurts were prepared with raw milk preinoculated with each psychrotrophic bacteria. The total solid, fat, and protein content were not affected by preinoculation, but the pH of yogurt preinoculated with psychrotrophic bacteria was higher than in control. There was a dramatic increase in short chain free fatty acids among FFA in yogurt with Acinetobacter genomospecies 10. For 14 d of cold storage condition, SCFFA was 25.3 mg/kg to 34.4 mg/kg (1.36 times increased), MCFFA was 20.4 mg/kg to 25.7 mg/kg (1.26 times increased), and LCFFA was 240.2 mg/kg to 322.8 mg/kg (1.34 times increased). Serratia liquefaciens (match %: 99.39) in yogurt caused a greater accumulation of free amino acids (FAA), especially bitter peptides such as leucine, valine, arginine, and tyrosine, but SDS-PAGE showed that the inoculation of Serratia liquefaciens did not affect the degree of casein degradation during storage. Taken together, the excessive peptides and FFA in yogurt generated from psychrotrophic bacteria could develop off-flavors that degrade the quality of commercial yogurt products.

• 한국축산식품학회지
• /
• 제32권6호
• /
• pp.783-788
• /
• 2012

The aim of this study was to optimize the manufacturing condition of spreadable modified butter by RSM. Based on the central composite design, the degree of optimization was expressed as a SFC as a dependent variable (Y, %) determined by NMR with 23 experimental groups. Three independent variables were the contents of butter ($X_1$, 35-75%), the contents of grape seed oil ($X_2$, 15-35%), and the contents of hydrogenated soybean oil ($X_3$, 0-4%). As the result, SFC at $10^{\circ}C$ was ranged from 32.37 to 42.76%. In addition, the regression coefficients were calculated for SFC at $10^{\circ}C$ by RSREG. The regression model equation for the SFC was $Y=39.18-0.04X_1X_3$. Consequently, the optimal contents for manufacturing spreadable modified butter were determined as 55.18% for butter, 40.78% for grape seed oil, and 4.08% for hydrogenated soybean oil, respectively. The predicted response value for SFC at $10^{\circ}C$ was 30.20%, comparable to the actual experimental SFC value as 29.85%. Finally hardness and spreadability in reference butter and spreadable modified butter produced under the optimal conditions was measured. The hardness in spreadable modified butter was 31.80 N as compared to 69.92 N in reference butter. The spreadability in spreadable modified butter was 5.6 point as compared to reference butter. This difference may be due to the contents of solid fat by butter and hydrogenated soybean oil. This study showed that the SFC value at $10^{\circ}C$ could be a suitable indicator for the manufacturing spreadable modified butter to predict important attributes such as mouth feel, hardness and spreadability.

• 한국초지조사료학회지
• /
• 제33권3호
• /
• pp.193-196
• /
• 2013

This study was carried out to evaluate the physical characteristics of total mixed rations (TMR) prepared in Korea for improving productive effectiveness of dairy and beef cattle. The 40 samples of commercial TMR for dairy and beef cattle in 6 municipals were collected and analyzed for chemical composition and physical properties. There were significant regional differences (p<0.05) in dry matter and crude protein contents of TMR for dairy and beef cattle. In roughage value index (RVI), neutral detergent fiber (NDF) content, and physically effective NDF (peNDF)$_{1.18}$ content, there were no regional differences in TMR for dairy cattle, but there were significant regional differences (p<0.05) in TMR for beef cattle. Thus the results from this study support that because RVI, NDF content, and peNDF content in TMR for dairy and beef cattle exceeded recommended ranges, a little adjustment in TMR for dairy cattle will be necessary to obtain optimal productivity.

• 한국축산식품학회지
• /
• 제37권6호
• /
• pp.884-888
• /
• 2017

In this study, we report the morphogenetic analysis and genome sequence of a new WCP30 phage of Weissella cibaria, isolated from a fermented food. Based on its morphology, as observed by transmission electron microscopy, WCP30 phage belongs to the family Siphoviridae. Genomic analysis of WCP30 phage showed that it had a 33,697-bp double-stranded DNA genome with 41.2% G+C content. Bioinformatics analysis of the genome revealed 35 open reading frames. A BLASTN search showed that WCP30 phage had low sequence similarity compared to other phages infecting lactic acid bacteria. This is the first report of the morphological features and complete genome sequence of WCP30 phage, which may be useful for controlling the fermentation of dairy foods.

• 한국축산식품학회지
• /
• 제43권2호
• /
• pp.305-318
• /
• 2023

This study investigated the protein digestibility of chicken breast and thigh in an in vitro digestion model to determine the better protein sources for the elderly in terms of bioavailability. For this purpose, the biochemical traits of raw muscles and the structural properties of myofibrillar proteins were monitored. The thigh had higher pH, 10% trichloroacetic acid-soluble α-amino groups, and protein carbonyl content than the breast (p<0.05). In the proximate composition, the thigh had higher crude fat and lower crude protein content than the breast (p<0.05). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of myofibrillar proteins showed noticeable differences in the band intensities of tropomyosin α-chain and myosin light chain-3 between the thigh and breast. The intrinsic tryptophan fluorescence intensity of myosin was lower in the thigh than in the breast (p<0.05). Moreover, circular dichroism spectroscopy of myosin revealed that the thigh had higher α-helical and lower β-sheet structures than the breast (p<0.05). The cooked muscles were then chopped and digested in the elderly digestion model. The thigh had more α-amino groups than the breast after both gastric and gastrointestinal digestion (p<0.05). SDS-PAGE analysis of the gastric digesta showed that more bands remained in the digesta of the breast than that of the thigh. The content of proteins less than 3 kDa in the gastrointestinal digesta was also higher in the thigh than in the breast (p<0.05). These results reveal that chicken thigh with higher in vitro protein digestibility is a more appropriate protein source for the elderly than chicken breast.

• 한국식생활문화학회지
• /
• 제22권3호
• /
• pp.373-381
• /
• 2007

The elderly population in Korea is growing rapidly and their nutritional status is not acceptable. Data were collected from the self-administered questionnaire of 495 free living elderly, over 65years old, in Korea to asses the intake and consumption pattern of milk and dairy products. The questionnaire contains demographics, health related characteristics, and perception on milk, and consumption behaviors of milk and dairy products. Most of the elderly subjects understood that milk is good foods in terms of nutritive value and health. And 67% of the subjects satisfied with the sanitation status of milk on the markets. The kind of milk that majority of the subjects consumed was whole milk, and only 5.1% of them consumed low fat milk. Less than 20% of the subjects consumed milk everyday, living alone group consumed milk less frequently than living with others. It was found that the majority of the elderly subjects did not meet current recommendation for milk. Liquid and curd type yogurt were the major dairy products used among elderly, and the reasons were good taste and digestion. They believed that these kinds of dairy products help constipation and digestion problems. The price of milk was ranked for the first factor needed to be considered for milk and dairy products consumption in elderly korean.

• 한국축산식품학회지
• /
• 제26권4호
• /
• pp.540-547
• /
• 2006

This review highlights areas of interest in the cholesterol removal of milk and dairy products. The demand for cholesterol removal has increased due to consumer demand for cholesterol-reduced products. At present the best method for producing without changing flavor, taste and texture of the products is entrapping cholesterol by ${\beta}-cyclodextrin({\beta}-CD)$. Especially, crosslinking of ${\beta}-CD$ is important due to recycling that could be separated the ${\beta}-CD$ from treated cream or milk. The recycling can be up to 10 times with keeping the rate of cholesterol removal. Various functional milk and dairy products can be produced in this manner. This report reviews general information including methods of cholesterol removal, crosslinking of ${\beta}-CD$, and recycling of the ${\beta}-CD$ in milk and dairy products.

• Journal of Dairy Science and Biotechnology
• /
• 제41권4호
• /
• pp.163-178
• /
• 2023

The market size of functional health foods has experienced substantial growth driven by increasing consumer interest. In particular, the application of functional probiotics in various food products has resulted in consistent and progressive growth. One promising category is the application of probiotics in the manufacturing of cheese, which aligns with the rising demand for functional foods among consumers. The inherent advantages of cheese and probiotics provide consumers with a broad selection of functional foods. Therefore, it is crucial to identify functional probiotics that can withstand the cheese manufacturing process and exert significant effects on the flavor and taste of cheese. In this review, we discuss several strategies aimed at developing probiotic-supplemented cheeses for future dairy food markets.

• Journal of Dairy Science and Biotechnology
• /
• 제26권2호
• /
• pp.51-56
• /
• 2008

Using central composite design, we have designed optimization of the manufacturing of processed butter. And response surface analysis by least-square regression was used Statistical Analysis System(SAS). Central composite design can be achieved by response surface techniques that allow flexibility in modeling and analysis. Response surface methodology(RSM) was used to optimize hardness(%) using as independent variables; the content of butter($X_1$), ranging from 50 to 90(%), the content of soybean oil($X_2$), from 0 to 20(%), and the hydrogenated soybean oil($X_3$) from 0 to 4(%). The results on the regression coefficients calculated for overrun by response surface by least-square regression(RSREG) were followed. It was considered that the linear regression was significant(p<0.01). As for the processed butter, the regression model equation for the hardness(Y, %) to the change of an independent variable could be predicted as follow: $Y=60.88-8.92X_2-{29.3X_2}^2$. The optimal for the manufacturing of processed butter were determined at the content of butter of 88.22%, soybean oil of 6.71% and hydrogenated soybean oil of 2.36%, respectively. Optimum compositions were resulted in hardness of 65.78 N. Finally the reference sample(Butter in the morning, Seoul Dairy Co-op.) and processed butter manufacturing under the optimal conditions were compared with spreadability test. The spreadability scores result from reference sample and butter under optimal conditions was not found a significant difference.

• Journal of Dairy Science and Biotechnology
• /
• 제24권1호
• /
• pp.43-51
• /
• 2006

Producer prices of raw milk include following elements: a basic price, payment according to fat content, payment according to bacteriological quality and somatic cell count. The quality of raw milk has increased since last change of payment system according somatic cell count. But last change of payment system according to fat content is not effective. It is necessary to widen the range of equal price by fat content. Also it is necessary to include payment according to protein content.