Abstract
•Fungal protease FPII hydrolysed sheep β-lactoglobulin.•Four β-lactoglobulin peptide sequence regions were studied.•Synthetic peptides were analysed containing sequence differences.•Synthetic peptides exhibited differences in antioxidant and ACE inhibitory bioactivity.
Fungal protease FPII was found to hydrolyse sheep β-lactoglobulin (β-Lg), and the hydrolysate exhibited substantial antioxidant and ACE inhibition bioactivities. From analysis of the peptide sequences in the hydrolysate in relation to bioactivity, synthetic peptides corresponding to four regions of sequence in β-Lg (LAFNPTQLEGQCHV, DTDYKKYLLF, LDAQSAPLRVY and VEELKPTPE) were analysed for bioactivity. Additional synthetic peptides were designed to examine the bioactivity of different parts of the above four sequences, and the effect of amino acid substitutions on bioactivity. The results show that parts of the peptide sequences contribute differently to bioactivity and substitution of amino acids has a substantial effect on antioxidant and ACE inhibition activities.