Formation of Lysino-Alanine in Alkaline Extracts of Chicken Protein

Abstract

Bone residues from mechanical deboning of chicken backs, necks and spent layers were extracted at pH 9.2, 10.0, 10.7 and 11.5. The centrifuged liquid protein extracts were kept at 22, 35 and 50°C for 1, 4 and 16 h. Determinations of lysino-alanine (LAL) were made after freeze-drying and fat extraction of the treated samples. No LAL was detected in any samples treated for 1 h. Samples treated for 4 h showed measurable amounts of LAL only at pH 11.5 at all three temperatures used, and at pH 10.7 at 50°C. After 16 h, LAL was produced at all pH treatments at 50°C; small amounts were also formed at 22 and 35°C at pH 10.7 and 11.5. It is concluded that the proposed alkali extraction procedure would not produce LAL in the protein extract under technologically optimal conditions.