Physicochemical properties of hydrolysates from enzymatic hydrolysis of pumpkin (Cucurbita moschata) protein meal

Pumpkin protein meal was hydrolysed by alcalase, flavourzyme, protamex and neutrase. Physicochemical characteristics were evaluated by previously published methods using pumpkin protein hydrolysates (PPHs) and pumpkin protein meal (PPM) as a control. Hydrolysis had significantly changed the physicochemical characteristics of protein meal and its functionality as well. Different enzymes had different specificity towards proteins which resulted into peptides of different molecular weight, size and sequence of amino acids that determined surface properties. Hydrolysates prepared by alcalase (HA) showed highest protein content (92.22%), best molecular weight distribution of peptides (98%) over the range of 180-5000Da, highest degree of hydrolysis (14.20%), yield (53.29%), solubility (93.40%) and emulsification capacity (61.1 m2/g) at pH11, foaming capacity (64.39%) , fat absorption capacity (3.28mg/ml) and best gelation properties (2.00%). However, Hydrolysates prepared by flavourzyme (HF) showed highest emulsification (73.20%) and foaming stability (47.94%) after 120 minutes. Hydrolysates prepared by protamex (HP) showed the best water holding capacity (2.24 mg/mL), while hydrolysates prepared by neutrase (HN) had highest content of total amino acid (76.01%). The results suggest that pumpkin oil processing by-product can be converted into hydrolysates which are a good source of protein fortification for a variety of food products as well as a potential food ingredient.