Goat whey was hydrolysed by pepsin in an ultrafiltration membrane
enzymic reactor coupled with a 30 kDa mineral membrane. Peptides collected in the
permeate were resolved using reversed-phase HPLC. Their sequences were
determined by amino acid analysis, second order derivative spectra analysis and
mass spectrometry. Owing to the resistance of β-lactoglobulin (β-lg) towards pepsin,
the majority of peptides identified were derived from α-lactalbumin (α-la). Pepsin
showed a broad specificity of hydrolysis sites and generated a wide range of products
from dipeptides to very large peptides containing disulphide bridges. The molecular
masses of peptides resulting from α-la degradation were between 150 and 6900 Da:
36% were < 600 Da, 24% were 600–2000 Da and 40% were > 2000 Da.