• Food Science of Animal Resources
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• v.29 no.4
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• pp.415-422
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• 2009

In this study, several factors were analyzed in an effort to determine the effects of transglutaminase (TGase) treatment on sodium caseinate (NaCN), ${\alpha}--lactalbumin$ (${\alpha}-La$), and ${\beta}-lactoglobulin$ (${\beta}-Lg$) polymerization reactions. The results of SDSPAGE showed that NaCN was slightly hydrolyzed to molecular weights of 50-400 kDa according to activation time. ${\alpha}-La$ formed high-molecular polymers of 30-300 kDa, whereas ${\beta}-Lg$ remained almost completely unhydrolyzed. Melting temperatures of NaCN, ${\alpha}-La$ with and without TGase were all in the range of $100{\pm}10^{\circ}C$ under the endothermic curve, and the melting temperature of ${\beta}-Lg$ with TGase was lower than that with TGase. When the proteins were incubated for 3 h with TGase, the micrographic structures showed a small quantity of sediment and broad layers. The final ${\alpha}-La$ residues remained at a level of 21.38%, and the TGase-treated ${\alpha}-La$ was confirmed to have undergone a profound loss of mass, to 18.25%. The DPPH-radical scavenging activity of NaCN and ${\beta}-Lg$ with TGase treatment was higher than that observed in the untreated sample, while those of ${\alpha}-La$ increased with concentration.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.3
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• pp.505-509
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• 2001

This study was carried out to evaluate the application of food irradiation technology as a method for reducing milk allergies. Bovine $\alpha$-casein, $\beta$-casein, $textsc{k}$-casein, $\alpha$-lactalbumin(ALA), $\beta$-lactoglobulin (BLG) and serum albumin (BSA) were used as model allergens of milk proteins and the proten solution (2.0 mg/mL) with 0.01 M phosphate buffered saline (pH 7.4) was irradiated at 3, 5 and 10 kGy. Using milk-hypersensitive patients IgE (MHP-IgE), the changes of binding ability to irradiated proteins were observed by competitive indirect enzyme-linked immunosorbent assay (Ci-ELISA). Affinity of MHP-IgE to milk proteins was higher in ALA and BLG than that of other proteins. Standard curve to each non-irradiated protein could be made with MHP-IgE for quantifying milk allergens. Binding abilities of MHP-IgE to the irradiated proteins, however, decreased with different slopes of the standard curves. Sensitivity of gamma irradiation was higher in ALA and BLG than of other proteins. These results indicated that irradiation technology can be used to reduce the milk hypersensitivity.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.3
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• pp.420-422
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• 2004

This study was to demonstrate a rapid novel method for detection of adulterated cow milk in goat milk using modified staining protocol after native polyacrylamide gel electrophoresis (PAGE). Samples of cow milk and goat milk containing 0, 0.5, 1.0 and 2.0% (v/v) of cow milk were analyzed. Low levels of cow milk mixed in goat milk were identified by the presence of higher mobility of $\beta$-lactoglobulin A ($\beta$-Lg A) in cow milk. By mini-gel electrophoresis, a distinguishable protein profile was visualized in 25 min using the modified Coomassie blue staining solution, in which methanol (50%) was replaced with ethanol (20%) and the concentrations of Coomassie blue and acetic acid were reduced from 2 to 0.13% and 10 to 5%, respectively. To visualize the milk proteins, gels in the staining solution were water-bathed in boiling water for 5 min and then cooled down immediately for 3-5 min. The sensitivity of this method is relatively high, allowing examination of 1% cow milk in goat milk. The procedure presented here is also very cost-effective due to less reagents needed. This simplified method would be useful and applicable to dairy industry for routine examination of goat milk.

• Food Science and Biotechnology
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• v.14 no.1
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• pp.131-136
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• 2005

The selective extraction behavior of lactoferrin (Lf) from whey protein mixture was examined using reverse micelles formed by the cationic surfactant, cetyldimethylammonium bromide (CDAB). The major whey proteins, including ${\beta}$-lactoglobulin, ${\alpha}$-lactalbumin and bovine serum albumin, were solubilized from aqueous phase to organic phase while Lf was recovered in the aqueous phase. The solubilization behaviors of the proteins were manipulated by the process parameters such as the pH and salt concentration of the aqueous phase and the surfactant concentration in the organic phase. Efficient forward extraction was achieved with sodium borate buffer (50 mM, pH 9) containing 50 mM KCl and organic phase containing 100 mM CDAB. Based on SDS-PAGE and densitometry, about 96% of the initial Lf remained in the aqueous phase after forward extraction. The dialyzed Lf fully maintained its bacteriostatic activity against E. coli O157:H7.

• Journal of Dairy Science and Biotechnology
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• v.35 no.2
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• pp.105-111
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• 2017

There have been numerous reports indicating that milk proteins influence immune functions. Colostrum refers to the breast milk of mammals, secreted starting from the fourth or fifth day after delivery. It has abundant nutrition for the survival of newborn infants. Most importantly, it contains bioactive substances with growth-stimulating and antibiotic, functions. Thus, the colostrum has various physiological roles. This study measured the differences in the composition of colostrum derived from dairy cattle, hanwoo, porcine, and goat sources. The results showed that immunoglobulin, lactoferrin, lactoperoxidase, serum albumin, IgG heavy chain, and IgG light chain were significantly higher in the colostrum of dairy cattle, hanwoo, and goats, but low in porcine colostrum. There was no significant difference in ${\alpha}_{S2}$-casein, ${\alpha}_{S1}$-casein, ${\beta}$-casein, ${\kappa}$-casein, ${\beta}$-lactoglobulin, and ${\alpha}$-lactalbumin contents until seven days after birth. However, porcine colostrum showed high contents of all proteins from the first day to the second day after delivery.

• Food Science of Animal Resources
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• v.30 no.6
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• pp.923-929
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• 2010

Colostral whey prepared from colostrum (pooled from first six post-partum milkings) was heated for 10 min at $100^{\circ}C$ Heated colostral whey was incubated with 1% enzymes (protein equivalent basis) for 15, 30, 60, 90, and 120 min at $50^{\circ}C$. Papain, pepsin, trypsin, and alcalase produced different degrees of hydrolysis (DH), 10.66%, 12.42%, 10.83%, and 25.31%, respectively, at an incubation time of 120 min. The SDS-PAGE reveals that significant amounts of bovine serum albumin (BSA), ${\beta}$-lactoglobulin (${\beta}$-LG), and ${\alpha}$-lactalbumin (${\alpha}$-LA) survived papain digestion. In contrast, pepsin completely removed BSA but not ${\beta}$-LG present in heated colostral whey. Alcalase completely eliminated BSA, ${\beta}$-LG, and ${\alpha}$-LA. This differential hydrolysis was confirmed by reversed-phase HPLC analysis. Using ion-exchange chromatography, fraction-1 (F-1) was obtained from alcalase hydrolysate at a NaCl gradient concentration of 0.25 M. Reversed-phase HPLC chromatograms of alcalase F-1 showed numerous small peaks, which probably indicate that a variety of new peptides were produced. Iron content of alcalase F-1 was 28.94 ppm, which was the highest among all enzyme fractions, whereas iron content of colostral whey was 36.56 ppm. Main amino acids contained in alcalase F-1 were Thr (15.45%), Glu (14.12%), and Ser (10.39%). Therefore, alcalase can be used to generate good iron-binding peptides in heated colostral whey, and the resulting iron-binding peptides could be suitable as a value-added food ingredient for food supplements.

• Food Science of Animal Resources
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• v.22 no.1
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• pp.72-76
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• 2002

Bovine serum albumin(BSA), $\alpha$-lactalbumin($\alpha$-LA), $\beta$-lactoglobulin($\beta$-LG) and bovine immunoglobulin G (IgG) were investigated the cytotoxicity on tumor cell lines. $\alpha$-LA was showned a tendency of dose dependaent on cytotoxicity using WiDr. The growth of WiDr was inhibited 82% by 1mg/ml of $\alpha$-LA. However, IgG, BSA and $\beta$-LG were not shown the cytotoxicity on WiDr. When $\alpha$-LA was purified by using high pressure liquid chromatography(HPLC), the main component($\alpha$-LA) was eluted at 33.057 min and extremely small quantities eluted at 32.310 min. The cytotoxicity of main component (eluted at 33.057 min peak) was lower than commercial $\alpha$-LA. And the cytotoxic activity of hydrolyzed $\alpha$-LA and $\alpha$-LA treated with EDTA were lower than commercial $\alpha$-LA on tumor cells.

• Clinical and Experimental Pediatrics
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• v.49 no.10
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• pp.1061-1066
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• 2006

Purpose : The purpose of this study was to research whether measurement of cow's milk specific IgE on the newborn would be helpful in the diagnosis of cow's milk allergy. We tried to find out the relation between cow's milk specific IgE and other allergy diseases by following up cases. Methods : We reviewed clinical features of 87 episodes in infants less than 4 weeks old who were positive in cow's milk specific IgE test. For the study group, history taking, physical examinations, elimination and cow's milk specific IgE tests were carried out. We investigated the connection among cow' milk specific IgE, allergic disease and family history in 40 of 87 patients we could follow up on. Results : The mean age of the study group was $17.2{\pm}5.4days$. The subjects were classified in four groups according into allergens : 87 milk allergy positive patients, 24 casein positive, 38 ${\alpha}$-lactoalbumin positive, and 75 ${\beta}$-lactoglobulin positive. The number of patients who had follow-ups for more than 6 months to was 40(45.9 percent). The patients whose parents had allergic disease numberred 10(25 percent). Fiften patients had allergic diseases, 4 had asthma and 11 atopic dermatitis. According to the follow-up study, there is a significant relation between casein positive patients and allergic disease. But there is no statistical and significant relation between cow's milk specific IgE and a family history of allergic disease. Conclusion : For the newborn babies, elimination tests and cow's milk specific IgE tests can be useful in the diagnosis of IgE-mediated or mixed milk allergies.

• Food Science of Animal Resources
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• v.37 no.1
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• pp.62-70
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• 2017

The aim of this study was identifying a suitable food grade enzymes to hydrolyze whey protein concentrates (WPCs), to give the highest bioactivity. WPCs from ultrafiltration retentate were adjusted to 35% protein (WPC-35) and hydrolyzed by enzymes, alcalase, ${\alpha}-chymotrypsin$, pepsin, protease M, protease S, and trypsin at different hydrolysis times (0, 0.5, 1, 2, 3, 4, and 5 h). These 36 types of hydrolysates were analyzed for their prominent peptides ${\beta}-lactoglobulin$ (${\beta}-Lg$) and ${\alpha}-lactalbumin$ (${\alpha}-La$), to identify the proteolytic activity of each enzyme. Protease S showed the highest proteolytic activity and angiotensin converting enzyme inhibitory activity of IC50, 0.099 mg/mL (91.55%) while trypsin showed the weakest effect. Antihypertensive and antioxidative peptides associated with ${\beta}-Lg$ hydrolysates were identified in WPC-35 hydrolysates (WPH-35) that hydrolyzed by the enzymes, trypsin and protease S. WPH-35 treated with protease S in 0.5 h, responded positively to usage as a bioactive component in different applications of pharmaceutical or related industries.

• Archives of Pharmacal Research
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• v.25 no.3
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• pp.381-386
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• 2002

The objective of this study was to link conformational changes of proteins at a water/methylene chloride interface to their destabilization upon emulsification. When 4 aqueous protein solutions (bovine serum albumin, $\beta$-lactoglobulin, ovalbumin, or ribonuclease) were emulsified in methylene chloride, considerable proportions of all the proteins became water insoluble aggregates. There were also noticeable changes in the compositions of their water-soluble species. A series of water/methylene chloride interfacial reactions upon the proteins was considered a major cause of the phenomena observed. Based on this supposition, the interfacial tension was determined by a Kruss DVT-10 drop volume tensiometer under various experimental conditions. It substantiated that the interfacial tension was high enough to cause the adsorption of all the proteins. Under our experimental conditions, their presence in the aqueous phase resulted in reductions of the interfacial tension by the degrees of 8.5 - 17.1 mN $m^{-1}$. In addition, dynamic changes in the interfacial tension were monitored to compare relative rates at which the adsorbed proteins underwent conformational, structural rearrangements at the interface. Such information helped make a prediction about how easily proteins would denature and aggregate during emulsification. Our study indicated that emulsifying aqueous protein solutions in organic solvents should be handled with care, due to adverse interfacial effects.