Studies on genetic variants of alpha-lactalbumin and beta-lactoglobulin from milk of native Portuguese ovine and caprine breeds

• Tipo: Artigo em Revista Científica Internacional
• Data: 1999

Autores

Pintado, ME (Autor) Outra; F. Xavier Malcata (Autor) Outra

Revista

Título: International Journal of Food Science and Technology

Vol. 34 Nº 4

Páginas: 245-252

ISSN: 0950-5423

Editora: Wiley-Blackwell

Indexação

ISI Web of Knowledge - 7 Citações

Scopus - 7 Citações

Outras Informações

ID Authenticus: P-001-46V

DOI: 10.1046/j.1365-2621.1999.00258.x

Abstract (EN): alpha-Lactalbumin (alpha-La) and beta-lactoglobulin (beta-Lg) fractions were obtained from Portuguese native breeds of ewes and goats by preparative gel filtration and further purified by ion exchange; their genetic variants were characterized by isolectric focusing, and beta-Lg isolated was further characterized by differential scanning calorimetry. Separation of beta-Lg and alpha-La by molecular exclusion from native whey was relatively easy, whereas beta-Lg from both breeds accounted for a single peak via ion exchange under various gradients of NaCl. Isoelectric focusing has indicated that alpha-La from ovine and caprine wheys appears as a single variant in each case, as well as beta-Lg from caprine whey; however, beta-Lg from ovine whey appears as two peaks, tentatively denoted as beta-Lg A and B. Further comparison with bovine whey made it possible to rank whey proteins by increasing value of pi as follows: bovine beta-Lg A, bovine alpha-La, bovine beta-Lg B, ovine and caprine alpha-La, ovine beta-Lg A, and finally ovine beta-Lg B and caprine beta-Lg. beta-Lg from goat's whey showed the highest onset temperature of denaturation in the presence (78-97 degrees C) or absence (90-100 degrees C) of NaCl for every pH tested; when NaCl was present, a good correlation between pi and onset temperature of denaturation was obtained for pH values in the range 3.5-7.0.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 8