• Asian-Australasian Journal of Animal Sciences
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• v.17 no.10
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• pp.1459-1464
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• 2004

The purpose of this research was to investigate the potential use of cheese whey protein (CWP), a cheese by-product. The physiological activity of calcium-binding peptides in CWP may be used as a food additive that prevents bone disorders. This research also examined the characteristics of calcium-binding peptides. After the CWP was heat treated, it was hydrolyzed by trypsin. Then calcium-binding peptides were separated and purified by ion-exchange chromatography and reverse phase HPLC, respectively. To examine the characteristics of the purified calcium-binding peptides, amino acid composition and amino acid sequence were analyzed. Calcium-binding peptides with a small molecular weight of about 1.4 to 3.4 kDa were identified in the fraction that was flowed out from 0.25 M NaCl step gradient by ion-exchange chromatography of tryptic hydrolysates. The results of the amino acid analysis revealed that glutamic acid in a calcium-binding site took up most part of the amino acids including a quantity of proline, leucine and lysine. The amino acid sequence of calcium-binding peptides showed Phe-Leu-Asp-Asp-Asp-Leu-Thr-Asp and Ile-Leu-Asp-Lys from $\alpha$-LA and Ile-Pro-Ala-Val-Phe-Lys and Val-Tyr-Val-Glu-Glu-Leu-Lys from ${\beta}$-LG.

• Journal of Dairy Science and Biotechnology
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• v.28 no.1
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• pp.17-28
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• 2010

A substantial body of evidence has emerged over the last decade in support of the novel concept that dietary calcium and dairy foods play an important role in regulating energy metabolism and thereby promote healthy weight management and reduce obesity risk. This concept has been demonstrated in experimental animals studies, cross-sectional and prospective population studies and a number of randomized clinical trials. Notably, the effects of dairy foods in weight management are more consistent than the effects of supplemental calcium across clinical trials, and calcium per se is responsible for approximately 40-50% of the effects of dairy. The calcium component is only effective in individuals with chronically low calcium intake, as it serves to prevent the endocrine response to low calcium diets which otherwise favors adipocyte energy storage; calcium also serves to promote energy loss via formation of calcium soaps in the gastrointestinal tract and thereby reduce fat absorption. The calcium-independent anti-obesity bioactivity of dairy resides primarily in whey. The key components identified to date are leucine and bioactive peptides resulting from whey protein digestion. The high concentration of leucine in whey stimulates a repartitioning of dietary energy from adipose tissue to skeletal muscle where it provides the energy required for leucine-stimulated protein synthesis, resulting in increased loss of adipose tissue and preservation of skeletal muscle mass during weight loss. Finally, dairy rich diets suppress the oxidative and inflammatory responses to obesity and thereby attenuate the diabetes and cardiovascular disease risk associated with obesity.

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2004.05a
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• pp.223-223
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• 2004

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.5
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• pp.712-718
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• 2004

This study was carried out to separate the calcium-binding protein derived from enzymatic hydrolysates of cheese whey protein. CWPs (cheese whey protein) heated for 10 min at $100^{\circ}C$ were hydrolyzed by trypsin, papain W-40, protease S, neutrase 1.5 and pepsin, and then properties of hydrolysates, separation of calcium-binding protein and analysis of calcium-binding ability were investigated. The DH (degree of hydrolysis) and NPN (non protein nitrogen) of heated-CWP hydrolysates by commercial enzymes were higher in trypsin than those of other commercial enzymes. In the result of SDS-PAGE (sodium dodecyl sulphate polyacrylamide gel electrophoresis), $\beta$-LG and $\alpha$-LA in trypsin hydrolysates were almost eliminated and the molecular weight of peptides derived from trypsin hydrolysates were smaller than 7 kDa. In the RP-HPLC (reverse phase HPLC) analysis, $\alpha$-LA was mostly eliminated, but $\beta$-LG was not affected by heat treatment and the RP-HPLC patterns of trypsin hydrolysates were similar to those of SDS-PAGE. In ion exchange chromatography, trypsin hydrolysates were shown to peak from 0.25 M NaCl and 0.5 M NaCl, and calcium-binding ability is associated with the large peak, which was eluted at a 0.25 M NaCl gradient concentration. Based on the results of this experiment, heated-CWP hydrolysates by trypsin were shown to have calcium-binding ability.

• Preventive Nutrition and Food Science
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• v.2 no.4
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• pp.281-284
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• 1997

Heat-induced gelation is an important functional property of whey proteins. Preheating of calcium reduced whey was reported to increase gel strength. 5% whey-protein solutions were preheated at pH7 and at various temperatures(60~8$0^{\circ}C$) for 15 minutes. The amount of soluble aggregates and denaturation enthalpy of preheated whey proteins were measured. Preheating temperature was negatively correlated with denaturation enthalpy($R^2$=0.857, P=0.08) and positive with the amount of soluble aggregates($R^2$=0.921, P=0.002). Denaturation enthalpy was negatively correlated with gel strength($R^2$=0.93, P=0.002). Soluble aggregates and gel strength were positively correlated($R^2$=0.972, P=0.0003). The formation of three dimensional gel network requires controlled protein denaturation and aggregation. Since preheating leads to the partial denaturation of proteins and the formation of soluble aggregates, preheated whey proteins have a higher gel strength than non-preheated one.

• Applied Biological Chemistry
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• v.37 no.5
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• pp.370-378
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• 1994

Soybean curd added with 40% of cow’s milk was prepared with eight coagulants such as calcium acetate, calcium lactate, calcium chloride, calcium sulfate, magnesium chloride, glucono-delta lactone (GDL), acetic acid and lactic acid. The curd products were evaluated by the chemical composition, coprecipitation porperties, mineral content, yield, color and textural characteristics. The lowest concentrations for protein coprepitation were 0.3% (v/v) for calcium salts, 0.4% (v/v) for magnesium chloride, 0.2% (v/v) for organic acids. Turbidity and crude protein of whey were markedly decreased at these concentrations. The optimal concentrations of coagualnts used for soybean curd preperation were 1.2% (v/v) for calcium acetate, calcium sulfate and calcium lactate, 1.0% (v/v) for calcium chloride and GDL, 0.8% (v/v) for magnesium chloride and lactic acid, 0.6% (v/v) for acetic acid. It was observed that of the eight coagulants tested, calcium chloride provided a satisfactory curd in quality. Calcium content of soybean curds by the calcium salt coagulants was higher than that by organic acid coagulants. Through the examination on the textural properties by a texturemeter was found out that acetic acid treated soybean curd among the organic acids, calcium salts and magnesium chloride treated curds had very high hardness value. All the curd products prepared in this experiment had a pale yellow color as affected by the value of L (lightness), a (redness) and b (yellowness). Although the colorimetric readings showed that the soybean curds prepared with the organic acids had higher L value but lower a and b value in comparison to calcium salts and magnesium chloride treated curds.

• Food Science of Animal Resources
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• v.38 no.6
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• pp.1179-1188
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• 2018

This study aimed to investigate the combined effect of using natural calcium mixtures and various binding ingredients as replacers for synthetic phosphate in ground pork products. We performed seven treatments: control (0.3% phosphate blend), treatment 1 (0.5% natural calcium mixtures [NCM, which comprised 0.2% oyster shell calcium and 0.3% egg shell calcium powder] and 0.25% egg white powder), treatment 2 (0.5% NCM and 0.25% whey protein concentrate), treatment 3 (0.5% NCM and 0.25% concentrated soybean protein), treatment 4 (0.5% NCM and 0.25% isolated soybean protein), treatment 5 (0.5% NCM and 0.25% carrageenan), and treatment 6 (0.5% NCM and 0.25% collagen powder). All the treatment mixtures had higher pH and lower cooking loss than the control, which was treated with phosphate. We found that NCM and binding ingredients had no negative effects on the moisture content, lightness, and yellowness of the cooked ground pork products. Treatments 3 and 4 showed significantly lower CIE $a^*$ values than the control. Treatments 2 and 6 improved the textural properties of the products. In conclusion, the combination of NCM with whey protein concentrate or collagen powder could be suitable for producing phosphate-free meat products.

• Food Science of Animal Resources
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• v.34 no.3
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• pp.372-377
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• 2014

This study was conducted to evaluate the effects of oyster shell calcium powder (OSCP) as a substitute for phosphates in curing agent, on the quality of restructured pork ham. Restructured pork ham was processed under six treatment conditions: T1 (no additives), T2 (0.3% sodium tripolyphosphate), T3 (1.5% NaCl+0.5% whey protein), T4 (1.5% NaCl+0.5% whey protein+0.15% OSCP), T5 (1.5% NaCl+0.5% whey protein+0.3% OSCP), and T6 (1.5% NaCl+0.5% whey protein+0.5% OSCP). Addition of OSCP significantly increased the ash content and pH of restructured pork ham (p<0.05), but did not affect the cooking loss and water holding capacity values of restructured pork ham. Addition of OSCP had no effect on Hunter a and b surface color values of restructured pork ham, but did decrease the Hunter L surface color value (p<0.05). The addition of 0.5% OSCP showed significantly higher chewiness and springiness values of restructured pork ham, compared with the addition of phosphates (p<0.05). In conclusion, the addition of OSCP combined with low NaCl and 0.5% whey protein can be considered a viable substitute for phosphates in the curing agent, when processing restructured pork ham.

• Food Science of Animal Resources
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• v.38 no.6
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• pp.1246-1252
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• 2018

This study was conducted to investigate the effects of the addition levels of a phosphate replacer blend in ground pork sausages. The phosphate replacer consisted of 0.2% oyster shell calcium powder, 0.3% egg shell calcium powder, and 0.25% whey protein concentrate. Depending on the presence or absence of synthetic phosphate and the addition level of phosphate replacer, the following products were processed: control (+) (0.3% phosphate), control (-) (non-phosphate), 20AL (20% replacer), 40AL (40% replacer), 60AL (60% replacer), 80AL (80% replacer), and 100AL (100% replacer). The pH values of pork sausages increased (p<0.05) with increasing addition level of the phosphate replacer. When more than 40% of the phosphate replacer was added to pork samples (40AL, 60AL, 80AL, and 100AL), cooking loss was significantly reduced compared to both the control (+) and control (-). However, no significant differences were observed in the moisture content and CIE $L^*$ values between the controls and the treatments with a phosphate replacer. The control (+) and 100AL treatment had the highest (p<0.05) hardness, but the samples with the phosphate replacer were not significantly different in cohesiveness and springiness from the control (+). As addition level increased, the gumminess and chewiness of the products with the phosphate replacer increased, which were lower than those of the control (+). Therefore, more than 40% of a phosphate replacer may possibly substitute synthetic phosphate to improve product yields in ground pork sausages, although further studies may be needed for improving the textural properties of the final products.

• Food Science and Preservation
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• v.11 no.1
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• pp.34-37
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• 2004

Calcium powder from whey (WCF) was added to enrich the calcium content of kimchi, and the mixing ratios of it to salted Chinese cabbage were 0.5, 1.0 and 1.5％. Quality characteristics of kimchi such as pH, titratable acidity, reducing sugar content and microbial loads were measured during fermentation at 10$^{\circ}C$. Kimchi samples with WCF showed a higher level in pH and titratable acidity than that of control during fermentation. Kimchi having higher WCF maintained a higher in pH and titratable acidity, and titratable acidity was above 1.0％ about 12 days in kimchi sample with 0.5％ WCF. Reducing sugar content was steadily decrease after 5 days, and control maintained a higher than others. Microbial load was similar until 10 days, but control was lower than kimchi samples with WCF. Based on the titratable acidity, kimchi with WCF had a limitation in shelf life.