Physicochemical properties and yields of sunflower protein enzymatic hydrolysates as affected by enzyme and defatted sunflower meal

The effect of sunflower meals [industrial defatted sunflower meal (IDSM) and laboratory defatted sunflower meals (LDSM)] and enzymes (fungal protease, trypsin, and papain) on the yield and physicochemical properties of sunflower protein hydrolysates was investigated. The hydrolysate was prepared from the soluble portion of a sunflower meal-enzyme slurry after hydrolysis. Enzymatic hydrolysis solubilized a substantial portion of total protein content in all defatted sunflower meals, leading to a great increase in protein content of the hydrolysate. The type of enzyme significantly (p <0.05) affected the product yield and protein recovery from IDSM. Papain gave the lowest product yield (47.4%) and protein recovery (83.8%) from IDSM substrate. More proteins were recovered from IDSM than LDSM with fungal protease. Higher protein recovery (96.4%) and protein content (80.4%) were obtained from 1% fat LDSM hydrolyzed with papain than from 18% fat LDSM or 1% fat IDSM. Fungal protease hydrolysates possessed significant antioxidant activity. All hydrolysates with papain had the highest emulsion capacity. Hydrolysate produced from a pilot-plant scale had similar characteristics to that from the laboratory scale. These results suggest that a proper enzyme and defatted sunflower meal should be considered for the commercial production of the protein hydrolysates because different enzymes and meals can result in different yields, functional properties, and compositions of the hydrolysates.