• Title/Summary/Keyword: Whey

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Studies on the Changes in Chemical Composition and Microbiological Aspects of Raw Milk by Microwave Heating (Microwave 열처리에 의한 원유의 화학적 및 미생물학적 성상의 변화에 관한 연구)

  • Shin, Byeong Hong;Kim, Jong Woo
    • Korean Journal of Agricultural Science
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    • v.25 no.2
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    • pp.181-198
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    • 1998
  • In order to determine the optimum pasteurization conditions by microwave heating(MWH) at $50^{\circ}C{\sim}70^{\circ}C$ for 30 minute compared with water bath heating(WBH) at $65^{\circ}C$ for 30minute during storage at $5^{\circ}C$, the chemical composition, microbiological changes and keeping quality were examined and the results were as follows: 1. The fat protein lactose, total solid contents of raw milk, at $50{\sim}70^{\circ}C$ for 30 min. in MWH and at 65 for $30^{\circ}C$ min. in WBH did not changed significantly during the storage at $5^{\circ}C$. 2. The pH and acidity for the raw milk untreated were 6.75 and 0.16%, and those of MWH heated and WBH milk wee 6.75~6.50 and 0.16%~0.19%, phosphatase test were negative at $61^{\circ}C$ for 20 min. at $62^{\circ}C$ for 15 min. at $63^{\circ}C$ for 10 min. at $64^{\circ}C$ for 5 min. at $65^{\circ}C$ for 5 min. in MWH and at $65^{\circ}C$ for 30 min. in WBH. 3. Whey protein content was $18.53mg/m{\ell}$ in raw milk untreated, however, those were decreased as the heating temperature increased. The proteolytic activity of treated milk by WBH(44%) was lower than that by MWH(94%). 4. Total bacteria counts were $2.8{\times}10^5CFU/m{\ell}$ in raw milk untreated, $2.8{\times}10^3CFU/m{\ell}$ at $65^{\circ}C$ for 30 min. $2.4{\times}10^3CFU/m{\ell}$ at $70^{\circ}C$ for 30 min. in MWH and $3.0{\times}10^3CFU/m{\ell}$ at $65^{\circ}C$ for 30 min. in WBH. Because total bacteria count did not increased in MWH at $65^{\circ}C$, $70^{\circ}C$ for 30 min. and $65^{\circ}C$ for 30 min. in WBH during the 10 days storaging, Also, total bacteria counts for treated milk were a most drastic decrease after $61^{\circ}C$, $62^{\circ}C$, $63^{\circ}C$, $64^{\circ}C$, $65^{\circ}C$ for 5 min. in MWH. 5. Coliform bacteria counts were $2.6{\times}10^3CFU/m{\ell}$ in raw milk untreated. There were not detected at $55^{\circ}C{\sim}70^{\circ}C$ for 30 min. in MWH and at $65^{\circ}C$ for 30 min. in WBH. Coliform bacteria counts were not detected after $61^{\circ}C$, $62^{\circ}C$, $63^{\circ}C$, $64^{\circ}C$, $65^{\circ}C$ for 5 min. in MWH. 6. Thermoduric bacteria counts were $5.2{\times}10^4CFU/m{\ell}$ in raw milk untreated, $2.0{\times}10^3CFU/m{\ell}$ at $65^{\circ}C$ for 30 min. $1.9{\times}10^3CFU/m{\ell}$ at $70^{\circ}C$ for 30min. in MWH and $2.2{\times}10^3CFU/m{\ell}$ at $65^{\circ}C$ for 30 min. in WBH. Because thermoduric bacteria counts did not increased in MWH at $65^{\circ}C$, $70^{\circ}C$ for 30 min. and $65^{\circ}C$ for 30 min. in WBH during the 10days storaging. Also, thermoduric bacteria counts were a most drastic decrease after $61^{\circ}C$, $62^{\circ}C$, $63^{\circ}C$, $64^{\circ}C$, $65^{\circ}C$ for 5 min. in MWH. 7. Psychrotrophic bacteria counts were $2.8{\times}10^5CFU/m{\ell}$ in raw milk untreated, $2.0{\times}10^1CFU/m{\ell}$ at $65^{\circ}C$ for 30 min. $2.0{\times}10^1CFU/m{\ell}$ at $70^{\circ}C$ for 30 min. in MWH and $3.0{\times}10^1CFU/m{\ell}$ at $65^{\circ}C$for 30 min. in WBH. Because psychrotrophic bacteria counts did not increased in MWH at $65^{\circ}C$, $70^{\circ}C$ for 30min. and $65^{\circ}C$ for 30 min. in WBH during the 10 days storaging. Also, psychrotrophic bacteria counts were a most drastic decrease after $61^{\circ}C$, $62^{\circ}C$, $63^{\circ}C$, $64^{\circ}C$, $65^{\circ}C$ for 5 min. in MWH.

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Effects of Replacing Soy Protein Concentrate with Fermented Soy Protein in Starter Diet on Growth Performance and Ileal Amino Acid Digestibility in Weaned Pigs

  • Min, B.J.;Cho, J.H.;Chen, Y.J.;Kim, H.J.;Yoo, J.S.;Wang, Q.;Kim, I.H.;Cho, W.T.;Lee, S.S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.1
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    • pp.99-106
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    • 2009
  • For Exp. 1, 120 ((Yorkshire${\times}$Landrace)${\times}$Duroc) weaned pigs (7.96${\pm}$0.01 kg average initial BW, 21 days weaning) were used in a 28 d-growth assay to determine the effects of replacing soy protein concentrate (SPC) with fermented soy protein (FSP) in a starter diet (d 0 to 7) on the growth performance, apparent fecal amino acid digestibility and subsequent performance in weaned pigs. Dietary treatments included: i) FSP0 (basal diet; whey-skim milk powder-SPC based diet); ii) FSP5 (replacing SPC with 5% FSP); iii) FSP10 (replacing SPC with 10% FSP). Pigs were fed the phase I diet for 7 days, and then each group was fed a common commercial diet for 21 days to determine the effect of previous diet on subsequent performance. Average daily gain (ADG) from d 5 to 7 (linear effect, p = 0.01) and d 7 to 14 (linear effect, p<0.001) were increased as FSP level increased. The pigs fed with FSP was heavier than the pigs fed with SPC at d 5 to 7 and d 7 to 14 after weaning (p<0.05). In the entire period (d 0 to 28), there were no significant differences in weight gain and final weight between SPC and FSP diets (p>0.05). Average daily feed intake (ADFI) was higher in pigs fed with the 5% FSP diet than those fed with the other diets at d 0 to 2 post-weaning (quadratic effect, p = 0.05). Also, for the entire period of phase I (d 0 to 7), pigs consumed more 5% FSP diet compared to other treatments (quadratic effect, p = 0.03). Gain/feed (G/F) was not affected by dietary SPC or FSP in phase I and subsequent periods, but G/F from d 5 to 7 after weaning was improved linearly (p = 0.04) as dietary FSP level increased. Pigs fed with 10% FSP also improved G/F compared with those fed only SPC (p<0.05). At d 7, there were linear increments in fecal dry matter (DM) (p<0.1) and nitrogen (N) (p<0.01) digestibilities as the dietary FSP level increased. The digestibilities of fecal essential and total amino acids were increased as the FSP level increased (linear effect, p<0.1). For Exp. 2, three ((Yorkshire${\times}$Landrace)${\times}$Duroc) weaned barrows (average initial BW of 7.32 kg) were surgically fitted with a simple T-cannula approximately 15 cm prior to the ileo-cecal junction. The experimental designs were 3${\times}$3 latin squares with pigs and periods as blocking criteria. Dietary treatments and composition were the same as in Exp. 1. Apparent ileal N digestibility was increased as FSP level was increased (linear effect, p<0.05). The dietary treatments (SPC and FSP) did not affect apparent ileal DM digestibility (p>0.05). Among essential amino acids, apparent digestibility of ileal arginine (Arg), lysine (Lys), methionine (Met) and phenylalanine (Phe) were improved as the FSP level increased (linear effect, p<0.1). Also, apparent ileal total essential, non-essential and total amino acid digestibilities were increased linearly (p<0.1). In conclusion, replacing SPC with fermented soy protein appeared beneficial in growth performance, N and amino acid digestibility during the early 7 days after weaning, and an equivalent effect showed on growth performance in subsequent period of 7 to 28 days after weaning.

NIRS AS AN ESSENTIAL TOOL IN FOOD SAFETY PROGRAMS: FEED INGREDIENTS PREDICTION H COMMERCIAL COMPOUND FEEDING STUFFS

  • Varo, Ana-Garrido;MariaDoloresPerezMarin;Cabrera, Augusto-Gomez;JoseEmilioGuerrero Ginel;FelixdePaz;NatividadDelgado
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1153-1153
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    • 2001
  • Directive 79/373/EEC on the marketing of compound feeding stuffs, provided far a flexible declaration arrangement confined to the indication of the feed materials without stating their quantity and the possibility was retained to declare categories of feed materials instead of declaring the feed materials themselves. However, the BSE (Bovine Spongiform Encephalopathy) and the dioxin crisis have demonstrated the inadequacy of the current provisions and the need of detailed qualitative and quantitative information. On 10 January 2000 the Commission submitted to the Council a proposal for a Directive related to the marketing of compound feeding stuffs and the Council adopted a Common Position (EC N$^{\circ}$/2001) published at the Official Journal of the European Communities of 2. 2. 2001. According to the EC (EC N$^{\circ}$ 6/2001) the feeds material contained in compound feeding stufs intended for animals other than pets must be declared according to their percentage by weight, by descending order of weight and within the following brackets (I :< 30%; II :> 15 to 30%; III :> 5 to 15%; IV : 2% to 5%; V: < 2%). For practical reasons, it shall be allowed that the declarations of feed materials included in the compound feeding stuffs are provided on an ad hoc label or accompanying document. However, documents alone will not be sufficient to restore public confidence on the animal feed industry. The objective of the present work is to obtain calibration equations fur the instanteneous and simultaneous prediction of the chemical composition and the percentage of ingredients of unground compound feeding stuffs. A total of 287 samples of unground compound feeds marketed in Spain were scanned in a FOSS-NIR Systems 6500 monochromator using a rectangular cup with a quartz window (16 $\times$ 3.5 cm). Calibration equations were obtained for the prediction of moisture ($R^2$= 0.84, SECV = 0.54), crude protein ($R^2$= 0.96, SECV = 0.75), fat ($R^2$= 0.86, SECV = 0.54), crude fiber ($R^2$= 0.97, SECV = 0.63) and ashes ($R^2$= 0.86, SECV = 0.83). The sane set of spectroscopic data was used to predict the ingredient composition of the compound feeds. The preliminary results show that NIRS has an excellent ability ($r^2$$\geq$ 0, 9; RPD $\geq$ 3) for the prediction of the percentage of inclusion of alfalfa, sunflower meal, gluten meal, sugar beet pulp, palm meal, poultry meal, total meat meal (meat and bone meal and poultry meal) and whey. Other equations with a good predictive performance ($R^2$$\geq$0, 7; 2$\leq$RPD$\leq$3) were the obtained for the prediction of soya bean meal, corn, molasses, animal fat and lupin meal. The equations obtained for the prediction of other constituents (barley, bran, rice, manioc, meat and bone meal, fish meal, calcium carbonate, ammonium clorure and salt have an accuracy enough to fulfill the requirements layed down by the Common Position (EC Nº 6/2001). NIRS technology should be considered as an essential tool in food Safety Programs.

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Research Trends and Future Directions for R&D Vitalization of Domestic Dairy Industry (국내 유가공산업의 R&D활성화를 위한 연구 동향과 방향)

  • Yoon, Sung-Sik
    • Journal of Dairy Science and Biotechnology
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    • v.29 no.1
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    • pp.23-31
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    • 2011
  • Domestic dairy industry is now standing at the crossroad for planning next fifty years, mainly because economic and environmental situations surrounding Korean peninsula are fast changing. For the aspects of dairy consumption, fresh milk consumed less, while consumption of the other milk and dairy products is slightly increasing every year. In 2010, it is approximately estimated that 1,939,000 tons of raw milk was used and the supply would be short by about 35,000 tons, based on the amounts in the previous year. Currently, multilateral negotiations against US and EU are underway. When it will be in effect in the future, significant damage would be expected in the dairy and livestock sectors, leading to cut domestic milk supply. Quality of farm-gate milk is graded as 1A on average 90% or more, loaded with very low in microbial and somatic cell counts. Therefore, policy implications have to be placed toward switch currently the UHT processing method to Pasteurization or the LTLT technology, by which natural flavors and nutrients in milk mostly remain after heat treatment. Domestic cheese products comprise only 10% and the rest is occupied by the various kinds of imported natural products. The market size keeps increasing up to 65,423,000 tons last year. When it comes to vitalization of our natural cheese industry, cheese whey, which is a main by-product in cheese manufacture, is a critical issue to be solved and also "On-Farm Processing" would be combined with a growth of big dairy companies when few immediate issues among the relevant regulations will be eased and alleviated in the near future. Fermented milk market is recorded as a single area of gradual increase in the past 10 years, Korea. Fermented yogurts with health claims targeted stomach, liver, and intestine are popular and has grown fast in sales amounts. In this context, researches on beneficial probiotic lactic acid bacteria are one of the important projects for domestic milk and dairy industries. Labelling regulations on efficacy or health-promoting effects of functional dairy products, which is the most important issue facing domestic dairy processors, should be urgently examined toward commercial expression of the functionality by lawful means. Colostrum, a nutrition-rich yellowish fluid, is roaded with immune, growth and tissue repair factors. Bovine colostrum, a raw material for immune milk preparations and infant formula, can be used to treat or prevent infections of the gastrointestinal tract. Nanotechnology can be applied to develop new milk and dairy products such as micro-encapsulated lactase milk for consumers suffering lactose intolerance. Raw milk is suggested to be managed by its usage in the processing line because imbalance of supply and demand is structural problem in every country and thus the usage systems as in the advanced dairy countries is worth of bench-marking to stabilize milk supply and demand. Raw milk produced is desirable to divide into the three parts; domestic, import, and buffering purposes. It is strongly recommended that a domestic dairy control center as an institutional framework should be urgently established as is Dairy Board in New Zealand and Australia. Lastly, government policy should be directed to foster the highly-educated people who are majoring in Dairy Sciences or working in the dairy industry by means of financial support in studying and training abroad as well.

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Effects of Dietary Probiotics Supplementation on Growth Performance and Fecal Gas Emmission in Nursing and Finishing Pigs (자돈 및 비육돈에 있어 생균제의 첨가가 생산성 및 분내 가스 발생에 미치는 영향)

  • Hong, J.U.;Kim, I.H.;Kwon, O.S.;Kim, J.H.;Min, B.J.;Lee, W.B.
    • Journal of Animal Science and Technology
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    • v.44 no.3
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    • pp.305-314
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    • 2002
  • For the Exp. 1, a total of seventy two pigs (10.53${\pm}$0.02kg average initial body weight) were used in a 38-d growth assay to determine the effects of Saccharomyces cerevisiae (SC) supplementation on growth performance and fecal microbial populations. Dietary treatments included 1) CON (corn-dried whey-SBM based diet), 2) SC0.2 (CON diet+0.2% SC) and 3) SC0.4 (CON diet+0.4% SC). Through the entire experimental period, ADG, ADFI and gain/feed were not significantly different among the treatments. At d 7 and 14 after the onset of the experiment, fecal Lactobacilli sp. count increased as the concentration of SC in the diets was increased (linear effect, P$<$0.01). At d 7 after the onset of the experiment, fecal Escherichia coli count decreased as the concentration of SC in the diets was increased (linear effect, P$<$0.02, quadratic effect, P$<$0.03). For the Exp. 2, forty five pigs (49.71${\pm}$0.45kg average initial body weight) were used in a 28-d growth assay to determine the effects of complex probiotics (CPB, Phichia anomala ST, Galactomyces geotrichum SR59, Thiobacillus sp.) supplementation on growth performance, nutrient digestibility and fecal $NH_3$-N and volatile fatty acid concentrations. Dietary treatments included 1) CON (corn-SBM based diet), 2) CPB0.2 (CON diet+0.2% CPB) and 3) CPB0.3 (CON diet+0.3% CPB). Through the entire experimental period, pigs fed CPB0.3 diet significantly increased their ADG compared to pigs fed CON and CPB0.2 diets (P$<$0.05). Also, apparent digestibility of DM and N in pigs fed CPB0.3 diet was greater than for pigs fed CON diet (P$<$0.05). Fecal $NH_3$-N decreased (P$<$0.05) in the pigs fed CPB diet compared to pigs fed CON diets. Also, pigs fed CPB0.3 diet significantly decreased their fecal propionic acid compared to pigs fed CON diets (P$<$0.05). In conclusion, the results obtained from these feeding trials suggest that the dietary SC for nursery pigs affects fecal microbial population. In finishing pigs, supplemental CPB was effective to improve ADG and nutrient digestibility but to decrease fecal noxious gas emission.

Effect of Dietary α-1,6-Galactosidase and β-1,4-Mannanase on Growth Performance and Nutrient Digestibility in Nursery and Growing Pigs (자돈 및 육성돈에 있어 α-1,6-galactosidase와 β-1,4-mannanase의 사료내 첨가가 성장 및 영양소 소화율에 미치는 영향)

  • Kwon, O. S.;Kim, I. H.;Lee, S. H.;Hong, J. W.;Kim, J. H.;Moon, T. H.;Lee, J. H.
    • Journal of Animal Science and Technology
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    • v.45 no.2
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    • pp.211-218
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    • 2003
  • For the Exp. 1, a total of sixty pigs (10.57$\pm$0.30kg average initial body weight) were used in a 15-d growth assay to determine the effect of dietary $\alpha$-1,6-galactosidase and $\beta$-1,4-mannanase on growth performance and nutrient digestibility. Dietary treatments included 1) CON (corn-dried whey-SBM based diet), 2) EC0.1 (CON diet+0.1% enzyme complex of $\alpha$-1,6-galactosidase and $\beta$-1,4-mannanase). Through the entire experimental period, gain/feed of pigs fed EC0.1 diet was higher (0.43 vs 0.52) than that of pigs fed CON diet (P<0.05). Pigs fed EC0.1 diet showed significant (P<0.05) improvement in dry matter (74.82% vs 82.41%) and nitrogen (70.59% vs 77.88%) digestibilities compared to pigs fed CON diet. For the Exp. 2, a total of thirty six pigs (22.30$\pm$0.45kg average initial body weight) were used in a 30-d growth assay to determine the effects of dietary $\alpha$-1,6-galactosidase and $\beta$-1,4-mannanase in low energy diet on growth performance and nutrient digestibility. Dietary treatments included 1) AME (adequate ME diet), 2) AME+EC0.1 (AME diet+0.1% enzyme complex) and LME+EC0.1 (low ME diet + 0.1% enzyme complex). Through the entire experimental period, average daily feed intake of pigs fed enzyme complex supplemented diets was higher than that of pigs fed CON diet (P<0.05). Also, pigs fed AME+EC0.1 diet showed significant (P<0.05) increase in ADFI (1,401g vs 1,733g) compared to pigs fed CON diet. Pigs fed enzyme complex supplemented diet showed significant (P<0.05) improvement in dry matter and nitrogen digestibilities compared to pigs fed CON diet. In conclusion, the results obtained from these feeding trials suggest that the supplementation of $\alpha$-1,6-galactosidase and $\beta$-1,4-mannanase was an effective means for improving growth performance and dry matter and nitrogen digestibilities in nursery and growing pigs.

Development of New Functional Dairy Products Containing Probiotics for Improving Human Health: A Review (Probiotics를 이용한 새로운 건강 증진 기능성 유제품 개발에 관한 연구: 총설)

  • Kim, Dong-Hyeon;Chon, Jung-Whan;Kim, Hyun-Sook;Kim, Hong-Seok;Song, Kwang-Young;Kim, Soo-Ki;Jeong, Dong-Gwan;Seo, Kun-Ho
    • Journal of Dairy Science and Biotechnology
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    • v.33 no.1
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    • pp.35-46
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    • 2015
  • Recently, much attention has been paid to the development of a value-added food category containing probiotics so as to improve human health and prevent diseases. Among various foods, the health benefits of milk and dairy products are known to humanity, and could be attributed to the bioactive components present in milk. In fermented milk products, the health benefits could be due to suitable modulation activities produced by the action of probiotic bacteria. Besides the modification of various milk components, probiotics might also act directly as preventive and therapeutic agents against some severe diseases. Probiotics promote health via their positive effects on the immune response, stimulation of natural immunity, and modulation of the production of antimicrobial peptides, cytokines, and so on. Whey proteins, a byproduct of cheese production could also have anticarcinogenic, immunostimulatory, antimicrobial, and health-promoting activities such as improving insulin sensitivity and reducing fat deposition. Therefore, milk and dairy products containing probiotics could provide various opportunities in the field of functional foods. Additionally, these functional foods may be important in the human diet and may help improve human health and prevent diseases.

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General Composition of Mozzarella Cheese Made from Concentrated Milk Derived by Ultrafiltration (한외여과 농축유로 제조한 모짜렐라 치즈의 일반성분 조성에 관한 연구)

  • Chon, Jung-Whan;Park, Jun-Ho;Lee, Jong-Ik;Song, Kwang-Young;Kim, Dong-Hyeon;Kim, Hong-Seok;Hyeon, Ji-Yeon;Seo, Kun-Ho
    • Journal of Dairy Science and Biotechnology
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    • v.30 no.1
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    • pp.55-67
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    • 2012
  • We compared the general composition of Mozzarella cheese manufactured by the traditional method and by an ultrafiltration technique. The comparison of the general components between raw milk and the retentate of ultrafiltration (CF 2 and CF 3) demonstrated the following. The fat, protein, and non-fat solid contents of the retentate were higher than those of raw milk, but the lactose content was lower. The effect of 3 factors-fat content (0.5% and 3%), bacterial populations (30,000 CFU/mL and 100,000 CFU/mL), and ratio of added starter and rennet (50, 65, or 80)-on Mozzarella cheese made by the traditional method and made using the retentate of ultrafiltration (CF 2 and CF 3) were compared. Total solids (TS), fat, lactose, total nitrogen (TN), water soluble nitrogen (WSN), non-protein nitrogen (NPN), and salt (NaCl) were affected by fat content, bacterial population, and the ratio of starter and rennet added, but the ash content was not affected. During storage at $4^{\circ}C$ over a period of 3 months, the TS, WSN, NPN, and NaCl contents increased significantly (p<0.05), but fat, lactose, and TN contents decreased significantly (p<0.05), while ash contents remained constant. In whey, the protein, lactose, and solids not fat contents were higher in cheese made from ultrafiltration retentate than in traditional Mozzarella cheese. These results indicate that ultrafiltration can be applied to producing several Mozzarella-type cheeses in order to meet consumer needs.

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Identification and Characterization of Lactobacillus salivarius subsp. salivarius from Korean Feces

  • Bae, Hyoung-Churl
    • Proceedings of the Korean Society for Food Science of Animal Resources Conference
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    • 2004.05a
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    • pp.89-119
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    • 2004
  • This study was conducted to isolate lactobacilli having probiotic characteristics to be used as health adjuncts with fermented milk products. Acid tolerant strains were selected in Lactobacilli MRS broth adjusted to pH 4.0 from 80 healthy persons (infants, children and adults). And bile tolerant strains were examined in Lactobacilli MRS broth in which 1.0% bile salt was added. By estimation above characteristics, the strains No. 27, which was isolated from adult feces, was selected and identified as Lactobacillus salivarius subsp. salivarius based on carbohydrate fermentation and 16S rDNA sequencing. It was used as a probiotic strain in fermented milk products. The pH of fermented milk decreased from pH 6.7 to 5.0 and titratable acidity increased from 0.3% to 1.0% by L. salivarius subsp. salivarius (isolation strain 20, 35, and 37), when incubated for 36 h at $37^{\circ}C$. The number of viable cell counts of fermented milk was maximized at this incubation condition. The SDS-PAGE evidenced no significant change of casein but distinct changes of whey protein were observed by isolated L. salivarius subsp. salivarius for titratable acidity being incubated by $0.9{\sim}1.0%$ at $37^{\circ}C$. All of the strains produced 83.43 to 131.96 mM of lactic acid and 5.39 to 26.85 mM of isobutyric acid in fermented products. The in vitro culture experiment was performed to evaluate ability to reduce cholesterol levels and antimicrobial activity in the growth medium. The selected L. salivarius subsp. salivarius reduced $23{\sim}38%$ of cholesterol content in lactobacilli MRS broth during bacterial growth for 24 hours at $37^{\circ}C$. All of the isolated L. salivarius subsp. salivarius had an excellent antibacterial activity with $15{\sim}25$ mm of inhibition zone to E. coli KCTC1039, S. enteritidis KCCM3313, S. typhimurium M-15, and S. typhimurium KCCM40253 when its pH had not been adjusted. Also, all of the isolated L. salivarius subsp. salivarius had partial inhibition zone to E. coli KCTC1039, E. coli KCTC0115 and S. enteritidis KCCM3313 when it had been adjusted to pH 5.7. The selected strains were determined to have resistances of twelve antibiotic. Strains 27 and 35 among the L. salivarius subsp. salivarius showed the highest resistance to the antibiotics. Purified ${\alpha}$-galactosidase was obtained by DEAE-Sephadex A-50 ion exchange chromatography, Mono-Q ion exchange chromatography and HPLC column chromatography from L. salivarius subsp. salivarius 27. The specific activity of the purified enzyme was 8,994 units/mg protein, representing an 17.09 folds purification of the original cell crude extract. The molecular weight of enzyme was identified about 53,000 dalton by 12% SDS-PAGE. Optimal temperature and pH for activity of this enzyme were $40^{\circ}C$ and 7.0 respectively. The enzyme was found to be stable between 25 and $50^{\circ}C$. ${\alpha}$-galactosidase activity was lost rapidly below pH 5.0 and above pH 9.0. This enzyme was liberated galactose from melibiose, raffinose, and stachyose, and also the hydrolysis rate of substrate was compound by HPLC. These results indicated that some of the L. salivarius subsp. salivarius (strain 27 and 35) are considered as effective probiotic strains with a potential for industrial applications, but the further study is needed to establish their use as probiotics in vivo.

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Effects of calcium and vitamin D intake level on lipid metabolism in growing rats (칼슘과 비타민 D의 섭취 수준이 성장기 흰쥐의 지질대사에 미치는 영향)

  • Lee, Sun-Min;Lee, Yeon-Joo;Won, Eun-Sook;Lee, Sang-Sun
    • Journal of Nutrition and Health
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    • v.47 no.2
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    • pp.89-98
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    • 2014
  • Purpose: Association of low intake of calcium (Ca) and inadequate vitamin D (VD) status with higher prevalence rates of obesity has been reported. This study was conducted in order to investigate the effects of different levels of whey Ca and VD intake on lipid metabolism in growing rats. Methods: A total of 56 five-week-old male Sprague-Dawley rats were divided into seven groups and fed for five weeks. Ca groups were divided into three levels, low, normal, and high (0.25%, 0.5%, 1%). VD subgroups in the low and high Ca groups were divided into three levels, low, normal, and high (10 IU, 1,000 IU, and 5,000 IU). The effects of Ca and VD on each group were evaluated by two way ANOVA. Results: Significantly higher amounts of abdominal fat, visceral fat, and epididymal fat were observed in the Low-Ca groups than in the Normal-Ca and High-Ca groups. Serum leptin levels of Low-Ca groups were higher than those of Normal-Ca and High-Ca groups. The highest serum parathyroid hormone concentration was observed in the low Ca low VD group. The levels of serum 25(OH)D were significantly increased with increasing dietary VD levels. Significantly higher serum levels of triglycerides, total cholesterol, and HDL-cholesterol were observed in the low Ca groups than in the normal Ca and high Ca groups. Conclusion: These results indicate that low calcium intake increased serum lipid level and body fat amount.