• Journal of Dairy Science and Biotechnology
• /
• v.31 no.1
• /
• pp.67-73
• /
• 2013

Food allergy is defined as adverse reactions toward food mediated by aberrant immune mechanisms. Cow's milk allergy is one of the most common food allergies in childhood. This allergy is normally outgrown in the first year of life, however 15% of allergic children remain allergic. Cow's milk allergy seem to be associated with casein (${\alpha}_{s1}$-CN), ${\beta}$-lactoglobulin and whey protein. In addition to this, many other milk proteins are antigenic and capable of inducing immune responses. Various food processing affects the stability, structure and intermolecular interactions of cow milk proteins, as a result reduction the allergenic capacity. Heating, hydrolysis, chemical, proteolytic and other processes such as gamma-ray irradiation, high pressure, using probiotics treatments of milk to obtain hypoallergenic milk have been developed to reduce allergic reactions.

• BMB Reports
• /
• v.34 no.5
• /
• pp.457-462
• /
• 2001

Using the monomolecular film technique, we compared the interfacial properties of Staphylococcus simulans lipase (SSL) and Staphylococcus aureus lipase (SAL). These two enzymes act specifically on glycerides without any detectable phospholipase activity when using various phospholipids. Our results show that the maximum rate of racemic dicaprin (rac-dicaprin) hydrolysis was displayed at pH 8.5, or 6.5 with Staphylococcus simulans lipase or Staphylococcus aureus lipase, respectively The two enzymes interact strongly with egg-phosphatidyl choline (egg-PC) monomolecular films, evidenced by a critical surface pressure value of around $23\;mN{\cdot}m^{-1}$. In contrast to pancreatic lipases, $\beta$-lactoglobulin, a tensioactive protein, failed to inhibit Staphylococcus simulans lipase and Staphylococcus aureus lipase. A kinetic study on the surface pressure dependency, stereoselectivity, and regioselectivity of Staphylococcus simulans lipase and Staphylococcus aureus lipase was performed using optically pure stereoisomers of diglycerides (1,2-sn-dicaprin and 2,3-sn-dicaprin) and a prochiral isomer (1,3-sn-dicaprin) that were spread as monomolecular films at the air-water interface. Both staphylococcal lipases acted preferentially on distal carboxylic ester groups of the diglyceride isomer (1,3-sn-dicaprin). Furthermore, Staphylococcus simulans lipase was found to be markedly stereoselective for the sn-3 position of the 2,3-sn-dicaprin isomer.

• Korean Journal of Agricultural Science
• /
• v.39 no.4
• /
• pp.577-581
• /
• 2012

The polymorphisms of several genes including Leptin (LEP), beta-lactoglobulin (LGB) and Prolactin receptor (PRLR) have been shown to affect milk composition traits in dairy cattle. But, the effects of these polymorphisms on the milk traits of Philippine water buffalo are still unclear. In the Philippines, buffalo are the major milk producers most of which are the Philippine carabao (PC), the American Murrah Buffalo (AMB) and Bulgarian Murrah Buffalo (BMB). The LEP, LGB and PRLR genes are considered to be associated with milk production traits. The objective of the present study was to identify the single nucleotide polymorphisms (SNPs) in the LEP, LGB and PRLR genes of PC, AMB and BMB and to investigate the effect of the SNPs on milk production traits in these buffalo. Genetic polymorphisms were screened by DNA sequencing and 12 SNPs were detected in BMB; 5 SNPs were in LEP exon3 region (G14227A, G14343A, T14502C, C14526T, G14603A); 5 SNPs were in LGB exon 2 region (G1861C, A1900G, G1901T, T1948C, G1949A); 2 SNPs were in PRLR exon 6 (T59047C, T59109C). Also, 12 polymorphism sites between cattle and buffalo were identified. Our analysis of the association between SNPs and milk production traits should be useful in future studies of buffalo breeding to improve lactation performance.

• Korean Journal of Food Science and Technology
• /
• v.38 no.2
• /
• pp.304-308
• /
• 2006

This study was performed to understand the behavior of protein mobility and intensity of enzymatic hydrolysis according to crosslinking of sodium caseinate, whey protein isolate, skim milk and whole milk powders with or without transglutaminase (TGase, w/w = 200 : 1) at $38^{\circ}C$. Whey protein was limited to crosslinking and skim milk was relatively more increased in high molecular polymer than whole milk. The degree of crosslinking decreased in the order of sodium caseinate>skim milk>whole milk>whey protein isolate. The SDS-PAGE results indicated that main bands of TGase treated samples had a high mobility and formed bands of molecular weights below 15 kDa by hydrolysis with pepsin after 10 min of reaction time. However, ${\beta}-lactoglobulin$ showed remarkable stability against pepsin hydrolysis treated with and without TGase. The high molecular polymers were easily hydrolyzed with digestive enzymes in vitro experiment. These results suggested that novel dairy products using TGase would have no special digestive problem in human body.

• Mass Spectrometry Letters
• /
• v.5 no.3
• /
• pp.63-69
• /
• 2014

In this study, we present a new isotope-coded carbamidomethylation (iCCM)-based quantitative proteomics, as a complementary strategy for conventional isotope labeling strategies, with providing the simplicity, ease of use, and robustness. In iCCM-based quantification, two proteome samples can be separately isotope-labeled by means of covalently reaction of all cysteinyl residues in proteins with iodoacetamide (IAA) and its isotope (IAA-$^{13}C_2$, $D_2$), denoted as CM and iCCM, respectively, leading to a mass shift of all cysteinyl residues to be + 4 Da. To evaluate iCCM-based isotope labeling in proteomic quantification, 6 protein standards (i.e., bovine serum albumin, serotransferrin, lysozyme, beta-lactoglobulin, beta-galactosidase, and alpha-lactalbumin) isotopically labeled with IAA and its isotope, mixed equally, and followed by proteolytic digestion. The resulting CM-/iCCM-labeled peptide mixtures were analyzed using a nLC-ESI-FT orbitrap-MS/MS. From our experimental results, we found that the efficiency of iCCM-based quantification is more superior to that of mTRAQ, as a conventional nonisobaric labeling method, in which both of a number of identified peptides from 6 protein standards and the less quantitative variations in the relative abundance ratios of heavy-/light-labeled corresponding peptide pairs. Finally, we applied the developed iCCM-based quantitative method to lung cancer serum proteome in order to evaluate the potential in biomarker discovery study.

• Asian-Australasian Journal of Animal Sciences
• /
• v.30 no.12
• /
• pp.1684-1688
• /
• 2017

Objective: From a review of published information on genetic association studies, a meta-analysis was conducted to determine the influence of the genes ${\kappa}-casein$ (CSN3) and ${\beta}-lactoglobulin$ (LGB) on milk yield traits in Holstein, Jersey, Brown Swiss, and Fleckvieh. Methods: The GLIMMIX procedure was used to analyze milk production and percentage of protein and fat in milk. Models included the main effects and all their possible two-way interactions; not estimable effects and non-significant (p>0.05) two-way interactions were dropped from the models. The three traits analyzed used Poisson distribution and a log link function and were determined with the Interactive Data Analysis of SAS software. Least square means and multiple mean comparisons were obtained and performed for significant main effects and their interactions (p<0.0255). Results: Interaction of breed by gene showed that Holstein and Fleckvieh were the breeds on which CSN3 ($6.01%{\pm}0.19%$ and $5.98%{\pm}0.22%$), and LGB ($6.02%{\pm}0.19%$ and $5.70%{\pm}0.22%$) have the greatest influence. Interaction of breed by genotype nested in the analyzed gene indicated that Holstein and Jersey showed greater influence of the CSN3 AA genotype, $6.04%{\pm}0.22%$ and $5.59%{\pm}0.31%$ than the other genotypes, while LGB AA genotype had the largest influence on the traits analyzed, $6.05%{\pm}0.20%$ and $5.60%{\pm}0.19%$, respectively. Furthermore, interaction of type of statistical model by genotype nested in the analyzed gene indicated that CSN3 and LGB genes had similar behavior, maintaining a difference of more than 7% across analyzed genotypes. These results could indicate that both Holstein and Jersey have had lower substitution allele effect in selection programs that include CSN3 and LGB genes than Brown Swiss and Fleckvieh. Conclusion: Breed determined which genotypes had the greatest association with analyzed traits. The mixed model based in Bayesian or Ridge Regression was the best alternative to analyze CSN3 and LGB gene effects on milk yield and protein and fat percentages.

• Journal of Nutrition and Health
• /
• v.29 no.6
• /
• pp.569-577
• /
• 1996

This study was performed to determine the effect of maternal protein intake on 1) the concentration of immune substances in milk 2) degree of passive immunity to pups via lactation, and 3) specific antibody production to a specific antigen, $\beta$-lactoglobulin(BLG). 4) the effect of passive immunity that pups received from mother during lactation on the production of antibodies when the pups were challenged to the same antigen. Part of the female rats were immunized with BLG before and during pregnancy. The pregnant rats were placed into either 25% or 10% isolated soy protein diet throughout gestation and lactation. After weaning, pups from each group continued to be fed the same diet. At 18 weeks of age, all the pups were challenged with BLG. Total IgA and IgG, lysozyme, BLG-specific IgA and IgG were measured in dam's serum, dam's milk, and pup's serum. Total IgG, and lysozyme in dam's serum and milk were higher in high protein group. Total IgA and IgG in pup's serum remained higher in high protein group from 5 to 18 weeks of age. BLG-specific antibodies were found in the milk and serum of immunized dams, and in serum of pups born to immunized dams but not in the non-immunized group. BLG-specific IgA and IgG were again higher in high protein group and declined with time. The concentration decreased faster in the low proetein group than in the high protein groups. After immunization the pups with LBG, serum BLG-specific antibodies were not differ between rats born to immunized dams and those born to non-immunized dams. Therefore passive immunity rats received via milk as a pup had no effect on the BLG-specific antibody production later in life. This study shows the importance of protein status of mother and strongly support to the endorsement of breast feeding.

• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.7
• /
• pp.1120-1126
• /
• 2007

An iron-fortified whey protein concentrate (Fe-WPC) was prepared by addition of ferric chloride to concentrated whey. A large part of the iron in the Fe-WPC existed as complexes with proteins such as ${\beta}$-lactoglobulin. The bioavailability of iron from Fe-WPC was evaluated using iron-deficient rats, in comparison with heme iron. Rats were separated into a control group and an iron-deficiency group. Rats in the control group were given the standard diet containing ferrous sulfate as the source of iron throughout the experimental feeding period. Rats in the iron-deficiency group were made anemic by feeding on an Fe-deficient diet without any added iron for 3 wk. After the iron-deficiency period, the iron-deficiency group was separated into an Fe-WPC group and a heme iron group fed Fe-WPC and hemin as the sole source of iron, respectively. The hemoglobin content, iron content in liver, hemoglobin regeneration efficiency (HRE) and apparent iron absorption rate were examined when iron-deficient rats were fed either Fe-WPC or hemin as the sole source of iron for 20 d. Hemoglobin content was significantly higher in the rats fed the Fe-WPC diet than in rats fed the hemin diet. HRE in rats fed the Fe-WPC diet was significantly higher than in rats fed the hemin diet. The apparent iron absorption rate in rats fed the Fe-WPC diet tended to be higher than in rats fed the hemin diet (p = 0.054). The solubility of iron in the small intestine of rats at 2.5 h after ingestion of the Fe-WPC diet was approximately twice that of rats fed the hemin diet. These results indicated that the iron bioavailability of Fe-WPC was higher than that of hemin, which seemed due, in part, to the different iron solubility in the intestine.

• Journal of Dairy Science and Biotechnology
• /
• v.30 no.1
• /
• pp.17-22
• /
• 2012

Since the prevalence of allergies is increasing, food allergy is a major concern for consumers, as well as for the food industry. The foods that account for over 90% of all moderate to severe allergic reactions to food are milk, eggs, peanuts, soybeans, fish, shellfish, wheat, and tree nuts. Of these food allergens, milk is one of the major animal food allergens in infants and young children. Milk is the first food that an infant is exposed to; therefore, the sensitization rate of milk in sensitive individuals is understandably higher. The mechanisms involved in allergic reactions caused by this hypersensitivity are similar to those of other immune-mediated allergic reactions. The reactions occur in the gastrointestinal tract, skin, and respiratory tract, with headaches and psychological disorders occurring in some instances. The major allergenic proteins in milk are casein, ${\beta}$-lactoglobulin, and ${\alpha}$-lactalbumin, while some of the minor allergenic proteins are lactoferrin, bovine serum albumin, and immunoglobulin. Reliable allergen detection and quantification are essential for compliance with food allergen-labeling regulations, which protect the consumer and facilitate international trade.

• Journal of Dairy Science and Biotechnology
• /
• v.35 no.4
• /
• pp.270-285
• /
• 2017

Among milk proteins, caseins are not subjected to chemical changes during heat treatment of milk; however, whey proteins are partially denatured following heat treatment. The degree of whey protein denaturation by heat treatment is decreased in the order of high temperature short time (HTST) > low temperature long time (LTLT) > direct-ultra-high temperature (UHT) > indirect-UHT. As a result of heat treatment, several changes, including variations in milk nitrogen, interactions between beta-lactoglobulin and k-casein, variations in calcium sulfate and casein micelle size, and delay of milk coagulation by chymosin action, were observed. Lysine, an important essential amino acid found in milk, was partially inactivated during heat treatment. Therefore, the available amount of lysine decreased slightly (1~4% decrease) after heat treatment, However, the influence of heat treatment on the nutritional value of milk was negligible. Nutritional value and nitrogen balance did not differ significantly between UHT and LTLT in milk. In conclusion, our results showed that heat treatment of milk did not alter protein quality. Whey proteins denatured to a limited extent during the heat treatment process, and the nutritional value and protein quality were unaffected by heat treatment.