Development of food products with addition of rapeseed presscake fermented by Rhizopus

Abstract

Purpose The purpose of this paper is to explore the prospects and limitations of consumer acceptance towards food products that have been enriched with rapeseed protein in the form of fermented rapeseed presscake. Design/methodology/approach In total, 16 different food products with up to 18 per cent fermented rapeseed presscake were developed. Three types of vegetarian spreads and one type of bread were formulated, and consumer acceptance was assessed by sensory evaluation, questionnaires and in a focus group. Findings The fermentation of the rapeseed presscake by using the tempeh mould, Rhizopus oligosporus, had little if any effect on the bitterness of the presscake, and the bitter taste and aftertaste of the fermented presscake limited its use in food products. However, promising results were obtained when the breads and vegetarian spreads that were prepared with 5–6 per cent dried fermented rapeseed presscake were presented to sensory panels and to consumers, provided that the bitterness was masked, to some degree, by appropriate formulations and processes. Research limitations/implications Responders consisted mainly of younger people open to sustainable, plant-based nutrition, and may not represent the general population. Nevertheless, the results have implications for further research on utilization of rapeseed proteins. Practical implications It is possible to use the fermented rapeseed presscake to enrich various foods with protein or to replace other proteins, e.g. from animals or soybeans, provided that the degree of degradation of undesired compounds can be better standardized. Originality/value This study provides useful information for how to increase the use of underutilized plant proteins for human nutrition.