Processing effects on the protein quality and functional properties of cold-pressed pumpkin seed meal

Abstract

Environmental and food security challenges due to a growing world population may be overcome by using alternative protein sources for the human diet. By-products from edible oil processing industries are potential sources due to their high protein content. Pumpkin seed meals were evaluated regarding proximate composition, in vitro protein digestibility (IVPD), amino acid profile and score, and antinutritional factors. Conventional thermal processing, microwave, and ultrasound treatments impact on samples’ nutritional quality were assessed using a central composite experimental design. Raw pumpkin seed meal presented up to 45% protein content and 86% IVPD. Processing increased IVPD up to 96%, with optimized conditions of 87.8 °C, pH8.0, and 37 min, for all processes. Lysine was the only limiting amino acid for raw and processed samples. Phytic acid decreased by 31%, while trypsin inhibitory activity was reduced by 84%. Pumpkin seed by-product is a promising high-quality plant protein source for food formulations.