Study on the stability of peptide-calcium complex from tilapia scale protein hydrolysates

The stability of peptide-calcium complex from tilapia scale protein hydrolysates was investigated by in vitro simulated gastrointestinal digestion, the resistance of small intestinal brush border membrane, coexistence of food composition, pH, heat treatment and other factors. Results showed that the tilapia fish peptide-calcium complex had high tolerance to the degradation of digestive enzymes and the small intestinal brush border membrane, but was sensitive to heat treatment, and the calcium-binding activity was decreased significantly when the temperature up to 50℃ (p<0.05) . With NaCl and lactose treatment, peptide-calcium complex maintained a good stability and had a combining rate of 89.65% under pH9.0. The results suggested tilapia scale peptide and calcium mainly existed in the form of the peptide-calcium complex in the small intestine to prevent calcium precipitation under alkaline conditions.