• Title/Summary/Keyword: Milk quality

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A Study on the Deterioration of Raw Milk Quality by the Growth of Psychrotrophic Bacteria (원유의 저온성 세균의 증식에 의한 유질변화에 관한연구)

  • 정충일;강국희;이재영
    • Journal of Food Hygiene and Safety
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    • v.1 no.2
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    • pp.151-156
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    • 1986
  • A trial was carried out to check the seasonal variation in total bacterial counts (T.B.C.) and psychrotrophic bacterial counts (P.B.C.) and to investigate the quality deterioration of raw milk collected from dairy farms in Kyunggi area, Korea. T.B.C. of raw milk exceeded $10^{7}/ml$ in summer and $10^{6}/ml$ in winter 1980, but they have gradually decreased from 1983. In 1985, the counts showed less than $2{\times}10^{6}/ml$ through the whole year. The same tendency of improvement in coliform counts was shown. The counts were higher than $10^{6}/ml$ in summer and $10^{5}/ml$ in winter 1982, but they were kept lower than $1{\times}10^{5}/ml$ in 1985 through the whole year. Free fatty acids and free amino acids were increased in raw milk stored at $5^{\circ}C\;and\;10^{\circ}C$, by the growth of psychrotrophic bacteria.

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Gene polymorphisms influencing yield, composition and technological properties of milk from Czech Simmental and Holstein cows

  • Citek, Jindrich;Brzakova, Michaela;Hanusova, Lenka;Hanus, Oto;Vecerek, Libor;Samkova, Eva;Krizova, Zuzana;Hostickova, Irena;Kavova, Tereza;Strakova, Karolina;Hasonova, Lucie
    • Animal Bioscience
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    • v.34 no.1
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    • pp.2-11
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    • 2021
  • Objective: The aim of the study was to evaluate the influence of polymorphic loci and other factors on milk performance and the technological properties of milk. Methods: The analysis was performed on Simmental and Holstein cows in field conditions (n = 748). Milk yield in kg, fat and protein percentage and yield were evaluated. Technological properties were evaluated by milk fermentation ability, renneting, and an alcohol test. Polymorphisms in the acyl-CoA diacylgycerol transferase 1 (DGAT1), leptin (LEP), fatty acid synthase (FASN), stearoyl CoA desaturase 1 (SCD1), casein beta (CSN2), casein kappa (CSN3), and lactoglobulin beta genes were genotyped, and association analysis was performed. Results: The DGAT1 AA genotype was associated with higher milk, protein and fat yields (p<0.05). The MM genotype in the LEP gene was associated with a lower protein percentage and the W allele with a higher protein percentage (p<0.05). In cows with the FASN GG genotype, the protein percentage was higher, but the A allele was associated with higher milk, protein and fat yields than the G allele. The TT genotype in SCD1 was associated with the lowest milk, protein and fat yields and with the highest milk protein percentage (p<0.01). The T allele had higher values than the C allele (p<0.05) except for fat percentage. The genotype CSN3 AA was associated with a significantly heightened milk yield; BB was associated with a high protein percentage. The effect of the alleles on the technological properties was not significant. The CSN2 BB genotype was associated with the best alcohol test (p<0.01), and the renneting order was inverse. Milk from cows with the CSN2 A1A1 genotype was best in the milk fermentation ability. CSN3 significantly affected the technological properties. Conclusion: The findings revealed the potential of some polymorphic loci for use in dairy cattle breeding and for the management of milk quality. In field research, the pivotal role of farms in milk yield, composition and technological properties was confirmed.

Study on the Quality of Whoie Crop Silage and Yield by Stage of Maturity of Rye Plant II. Quality of whole crop rye silage by stage of maturity (호맥의 생육시기별 수량과 Whole crop silage의 품질에 관한 연구 II. 호맥의 생육시기별 Silage의 품질)

  • 고영두;곽종형;문영식
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.7 no.3
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    • pp.153-156
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    • 1987
  • With a purpose of evaluation rye crop as winter green feed, a cultivar was sown in autumn and harvested at booting, heading, milk, dough and yellow-ripe stages, and processed into silage. The quality of the silage was assessed in terms of ammonia-N, recovery rate in dry matter, pH, and the composition of organic acids. The results obtained are: 1. The recovery rate in dry matter from the silage was the highest when harvested at yellow stage (P<0.01). The ratio of ammonia-N to total-N was low when the rye crop was harvested during milk (9.4%) and dough ( 12.7%) stages (P$NH_3-N$. 3. Silage quality based on the composition of organic acids was highly evaluated when the crop was harvested during milk, and dough stages. 4. Considering both the DM yield and quality of the silage, it was found that rye crop should be harvested at dough stage and ensiled.

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Effects of Cow에s Milk Addition on the Quality of Soybean Curd (우유 첨가가 두부 품질에 미치는 영향)

  • 김중만;김형태;최용배;황호선;김태영
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.22 no.4
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    • pp.437-442
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    • 1993
  • Soybean curds were made from the mixture of soybean milk and cow's milk (raw milk) at the ratio of 10, 20, 30, 40, 50% (v/v), and then the general composition and mineral content, pH, yield, firmness by sensory evaluation and amino acid composition were investigated. As cow's milk addition increased, total sugar crude fat, crude protein, ash content, firmness, weight and volume of the soybean curd were increased. Whereas moisture content decreased, $Ca^{++}$, $K^{+}$, and Na$^{+}$ were increased, but $Mg^{++}$ and Fe$^{++}$ decreased. In sensory evaluation, color (white), firmness, flavor, and taste were higher than those of control as cow's milk increased. By adding cow's milk at the ratio of 10, 20, 30, 40%, and 50%, sulfur containing amino acid content such as methionine and cystine were enriched 1.31, 1.58, 1.67, 1.85, and 1.95 times, respectively.

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Characterization and ACE Inhibitory Activity of Fermented Milk with Probiotic Lactobacillus plantarum K25 as Analyzed by GC-MS-Based Metabolomics Approach

  • Zhang, Min;Jiang, Yunyun;Cai, Miao;Yang, Zhennai
    • Journal of Microbiology and Biotechnology
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    • v.30 no.6
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    • pp.903-911
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    • 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.

Research of Functional Milk by Segmentation Strategy (세분화전략에 의한 기능성우유 패키지디자인 연구)

  • Lee, Jong-Woo
    • The Journal of the Korea Contents Association
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    • v.8 no.1
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    • pp.377-385
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    • 2008
  • Nowadays, the demand of functional white milk has been augmented because of the widespread well-being popularity. Especially, in case of white milk, there are brisk efforts In segmentation of the functional product, in an effort to break through the limitation of creating new demands out of fixed demands and school meal service. The companies are also looking for the solution in the development of functional white milk in that they have no other way to increase the customers' demand, but the differentiation of the product, since the companies consider that content of white milks are exactly the same that there is no need to compete. Following this, the package design availed of the development of functional milk and took important charge of conveying and emphasizing the product's functional special quality and information to customers. Consequently, in this research, we will going to look at more desirable design differentiation strategy of functional milk by examining the basics of functional milk and by analysing the functional characteristic of current products and the expression strategy of package design.

Ensiled Banana Wastes with Molasses or Whey for Lactating Buffaloes during Early Lactation

  • Khattab, H.M.;Kholif, A.M.;EI-Alamy, H.A.;Salem, F.A.;EI-Shewy, A.A.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.5
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    • pp.619-624
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    • 2000
  • Low-quality roughages [banana wastes (B), wheat straw (WS) and dried broiler litter (BL)] were ensiled using either sweet whey (W) or diluted molasses (M) as rehydration media to study their effects on milk yield, milk composition and some parameters of blood plasma. The feeding trial involved 25 lactating buffaloes in five groups (five animals each). Buffaloes as control animals received diets of concentrate feed mixture, rice straw and wastelages (70:30:00). In the other 4 treatments, the wastelages replaced 50% of rice straw in the control diets. The wastelages were BL:B:M(3:2:10) (T1), BL:WS:M (3:2:10) (T2), BL:B:W (3:2:10) (T3) and BL:WS:W (3:2:10) (T4) on a fresh matter basis, during the 1st 17 weeks of lactation period. Results indicated that feeding lactating buffaloes on wastelages resulted in slightly higher (p>0.05) milk yield, 4% fat-corrected-milk yield and feed efficiency, and slightly lowered (p>0.05) contents of milk total solids, fat and protein. Wastelages, especially BL-B-M, increased (p<0.05) milk non-protein-nitrogen and ash contents and plasma urea, GOT and GPT. The results demonstrate that banana plant wastes with some additives in silage form may be good untraditional roughage for lactating buffaloes without any adverse effect on milk production.

Current Status and Prospects of Korean Dairy Industry (낙농 산업의 현황과 발전 방향)

  • Lee, Sang-Soo
    • Journal of Dairy Science and Biotechnology
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    • v.25 no.2
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    • pp.33-40
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    • 2007
  • The Korean dairy industry has been developed continuously for the past seventy years both in quality and quantity; now the total amount of dairy products accounts for 13 percent of that of livestock production - a remarkable turnover. Korea now stands at the 13th economic power around the world and it is inevitable that we must pursue an open-door policy at a global level; the dairy industry should also strengthen its potentialities in the long term in order to compete with advanced dairy countries. It is predicted that the impact of DDA agreement and FTA negotiations on the domestic dairy industry will be great; so it is urgently needed that we should reconsider the current status of the dairy industry and comprehensive mesures for dairy industry development to improve its international competitiveness. Such measures comprise the three aspects: first, reforming the policy of dairy industry-related systems, second, improving the productivity and third, expanding the consumption of dairy products. In terms of the system reforming, the most important things are, above all, the planned production relevant to market needs, the milk supply and demand management, and the raw milk transaction method. Secondly, the appropriate scale of management is important for the enhancement of productivity together with the modernization of dairy facilities. Thirdly, step-up effort is needed to expand the milk consumption; especially, more milk should be provided to the students by improving the standing milk ration system in middle and senior high schools. The government should make more effort to support and develop new dairy products tuned to consumers' taste, accelerating the publicity of diverse and steady milk consumption together with related organizations.

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Changes in milk production and blood metabolism of lactating dairy cows fed Saccharomyces cerevisiae culture fluid under heat stress

  • Lim, Dong-Hyun;Han, Man-Hye;Ki, Kwang-Seok;Kim, Tae-Il;Park, Sung-Min;Kim, Dong-Hyeon;Kim, Younghoon
    • Journal of Animal Science and Technology
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    • v.63 no.6
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    • pp.1433-1442
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    • 2021
  • In this study, Saccharomyces cerevisiae culture fluid (SCCF) has been added to a diet of lactating dairy cows to attempt to improve the ruminal fermentation and potentially increase the dry matter intake (DMI) and milk yield. This study was conducted to investigate the effects of SCCF on the milk yield and blood biochemistry in lactating cows during the summer. Twenty-four Holstein dairy cows were randomly assigned to one of four treatments: (1) total mixed ration (TMR-1) (Control); (2) TMR-1 supplemented with SCCF (T1); (3) TMR-2 (containing alfalfa hay) (T2); and (4) TMR-2 supplemented with SCCF (T3). SCCF (5 ml/head, 2.0×107 CFU/mL) was mixed with TMRs daily before feeding to dairy cows. The mean daily temperature-humidity index (THI) during this trial was 76.92 ± 0.51 on average and ranged from 73.04 to 81.19. For particle size distribution, TMR-2 had a lower >19 mm fraction and a higher 8-9 mm fraction than TMR-1 (p < 0.05). The type of TMR did not influence the DMI, body weight (BW), milk yield and composition, or blood metabolites. The milk yield and composition were not affected by the SCCF supplementation, but somatic cell counts were reduced by feeding SCCF (p < 0.05). Feeding SCCF significantly increased the DMI but did not affect the milk yield of dairy cows. The NEFA concentration was slightly decreased compared to that in the control and T2 groups without SCCF. Feeding a yeast culture of S. cerevisiae may improve the feed intake, milk quality and energy balance of dairy cows under heat stress.

Rheological, Physical and Sensory Evaluation of Low-Fat Cupuassu Goat Milk Yogurts Supplemented with Fat Replacer

  • Costa, Marion P.;Rosario, Anisio Iuri L.S.;Silva, Vitor L.M.;Vieira, Carla P.;Conte-Junior, Carlos A.
    • Food Science of Animal Resources
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    • v.42 no.2
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    • pp.210-224
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    • 2022
  • The use of skim milk is a strategy to increase goat milk yogurt acceptability. However, it can negatively affect yogurt rheology because fat plays a vital role in dairy structural integrity. Thus, this study aimed to investigate the effects of fat replacers on the rheological, physical, and sensory parameters of low-fat cupuassu goat milk yogurts during refrigerated storage (28 days). Five goat milk yogurts formulations were carried out: whole yogurt (WY), skim yogurt (SY), skim yogurt with inulin (SIY), skim yogurt with maltodextrin (SMY), and skim yogurt with whey protein (SWY). Treatments were subjected to bacterial counts, chemical composition, pH, water holding capacity, instrumental color and texture, rheological and sensory analyses. All samples showed reducing pH values, water holding capacity, and L* and b* value during storage. Regarding texture, the firmness and consistency decreased during storage. On the other hand, the viscosity index significantly increased during refrigerated storage time. Moreover, all treatments exhibited viscoelastic behaviour. In addition, SIY and SMY showed the highest apparent viscosity. Furthermore, SIY, SMY, and SWY formulations exhibited positive sensory scores for appearance, color, aroma, texture, and viscosity. However, the overall acceptability and purchase intention did not differ statistically between WY and the fat-replacement treatments (SIY, SMY, and SWY). These results indicate that fat substitutes improved the quality of skimmed formulations. Thus, inulin and maltodextrin have the potential as functional fat replaces to produce low-fat goat milk yogurts.