“…Protein hydrolysates are prepared by enzymatic, chemical or thermal hydrolysis of a variety of animal and plant residues, including animal epithelial or connective tissues (Cavani et al 2006;Ertani et al 2009Ertani et al , 2013aGrabowska et al 2012;Kauffman et al 2007;Kunicki et al 2010;Maini 2006;Morales-Payan and Stall 2003), animal collagen and elastine (Cavani et al 2006), carob germ protein (Parrado et al 2008), alfalfa residue (Schiavon et al 2008;Ertani et al 2009Ertani et al , 2013b, wheat-condensed distiller solubles (García-Martínez et al 2010 Protein/peptide and free amino acid contents of the hydrolysates vary in these preparations in the range of 1-85 % (w/w) and 2-18 % (w/w), respectively. The major amino acids include alanine, arginine, glycine, proline, glutamate, glutamine, valine and leucine (Parrado et al 2008;Ertani et al 2009;García-Martínez et al 2010). Siapton contains a high proportion of proline and glycine while in carob germ hydrolysate glutamine and arginine predominate (Parrado et al 2008).…”