Exploring the Potential of Aspergillus oryzae for Sustainable Mycoprotein Production Using Okara and Soy Whey as Cost-Effective Substrates

Abstract

Mycoprotein is an alternative protein produced through fungal fermentation. However, it typically relies on refined glucose syrup derived from starch, which can be costly and unsustainable. This study investigates the potential of soybean processing by-products (okara and soy whey) as alternative substrates for producing mycoprotein using Aspergillus oryzae. A. oryzae was cultured for 7 days at 30 °C in diluted okara (1:50) and soy whey (1:1) with or without agitation (100 rpm). Soy whey produced higher biomass yields (369.2–408.8 mg dry biomass/g dry substrate), but had a lower biomass concentration (0.783–0.867 g dry weight/L). Conversely, okara produced a higher biomass concentration (2.02 g dry weight/L) with a yield of 114.7 mg dry biomass/g dry substrate. However, biomass formation in okara was only observed in static conditions, as agitation caused biomass to entangle with soy pulp, hampering its production. Additionally, okara tended to release protein into the media, while soy whey accumulated protein within the biomass, reaching up to 53% w/w protein content. The results of this study provide a promising approach to addressing both soybean processing waste reduction and food security concerns.