Increase of protein extraction yield from rapeseed meal through a pretreatment with phytase

BACKGROUND: Rapeseed meal is a good source of high-quality vegetal protein but contains antinutritional compounds that limit its use for human and animal feed. The aim of this study was to develop a methodology to enhance alkaline protein extraction of rapeseed meal and to produce protein-rich products with low levels of phytic acid. Different phytase dosages and operating conditionswere used for rapeseed meal pretreatment followed by alkaline extraction at different temperatures, time, pH and solid/liquid ratios (S/L). RESULTS: The highest protein extraction yield attained was 72.1%, for 2 h at 55 degrees C, with a phytase dosage of 0.8 U g(-1) when the alkaline extractionwas performed at 75 degrees C, pH12.5 and 60 min for an S/L ratio of 10 g 100mL(-1) water. The extraction yields were higher than those previously obtained without enzymatic pretreatment. CONCLUSION: Phytase pretreatment enhanced alkaline extraction yield of proteins fromrapeseed meal. This procedure allowed also the production of rapeseed protein concentrates with very low levels of phytic acid, similar to 1g kg(-1), improving their nutritional properties and commercial value. Moreover, after the pretreatment, the amount of phytic acid in the remaining rapeseed meal decreases about 25%. (C) 2016 Society of Chemical Industry