• Food Science of Animal Resources
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• v.37 no.6
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• pp.940-947
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• 2017

Goat milk has a protein composition similar to that of breast milk and contains abundant nutrients, but its use in functional foods is rather limited in comparison to milk from other sources. The aim of this study was to prepare a goat A2 ${\beta}$-casein fraction with improved digestibility and hypoallergenic properties. We investigated the optimal conditions for the separation of A2 ${\beta}$-casein fraction from goat milk by pH adjustment to pH 4.4 and treating the casein suspension with calcium chloride (0.05 M for 1 h at $25^{\circ}C$). Selective reduction of ${\beta}$- lactoglobulin and ${\alpha}_s$-casein was confirmed using sodium dodecyl sulphate-polyacrylamide gel electrophoresis and reverse-phase high-performance liquid chromatography. The hypoallergenic property of A2 ${\beta}$-casein fraction was examined by measuring the release of histamine and tumor necrosis factor alpha from HMC-1 human mast cells exposed to different proteins, including A2 ${\beta}$-casein fraction. There was no significant difference in levels of both indicators between A2 ${\beta}$-casein treatment and the control (no protein treatment). The A2 ${\beta}$-casein fraction is abundant in essential amino acids, especially, branched-chain amino acids (leucine, valine, and isoleucine). The physicochemical properties of A2 ${\beta}$-casein fraction, including protein solubility and viscosity, are similar to those of bovine whole casein which is widely used as a protein source in various foods. Therefore, the goat A2 ${\beta}$-casein fraction may be useful as a food material with good digestibility and hypoallergenic properties for infants, the elderly, and people with metabolic disorders.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.488-493
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• 2009

A protein isolate was prepared from black soybean (Glycine max L. Merrill) that possessed higher antioxidant activity than ordinary white soy protein isolates. The isolate was partially hydrolyzed by alcalase to reduce the allergenicity of black soybean. Alcalase remarkably reduced the molecular mass of the major soybean allergens that have molecular weights of 53, 38, and 24 kDa. Hydrolytic breakdown occurred more effectively in Gly m Bd 30K than in Gly m Bd 60K or Gly m Bd 28K. Alcalase hydrolysis increased the solubility and hydrophobicity of the black soybean protein isolate. The foaming activity and stability of black soybean proteins were highly increased by the partial hydrolysis.