THE IMPACT OF EDIBLE MUSHROOM MYCELIUM FERMENTATION ON THE ORGANOLEPTIC PROPERTIES OF CEREAL GRAINS

Abstract

The article presents the results of the organoleptic evaluation of fermented сereal grains (whole-grain buckwheat, peas, wheat, pearl barley, rice, corn) fermented by basidiomycete fungi (Cyclocybe cylindracea, Flammulina velutipes, Hericium erinaceus, Hypsizygus marmoreus, Laetiporus sulphureus, Lentinula edodes, Pholiota nameko, Pleurotus citrinopileatus, P. djamor, P. eryngii, P. ostreatus, P. pulmonarius) with the aim of assessing the potential for creating vegan products similar to “Tempeh.” A descriptor dictionary was developed for the evaluation of organoleptic characteristics, which included terms describing product properties such as taste, odor, texture, and appearance. Differences in the organoleptic parameters of fermented сereal grains were found depending on the type of fungus, the substrate, and the fermentation duration. All fungi species effectively colonized the сereal grains with their mycelium. According to the screening results, the highest organoleptic scores for overall appearance, odor, taste, and texture were achieved in wheat and rice fermented with the mycelium of P. eryngii, P. ostreatus, P. pulmonarius, and F. velutipes. The overall appearance of the сereal grains fermented with fungal mycelium did not significantly differ, although there was a tendency for the formation of white mycelium, which was denser on the outside than inside. The odor of the сereal grains changed the most depending on the fermentation duration. The most intense odors, which received the highest scores, were established on the 14th day of fermentation in all samples except for wheat fermented with P. ostreatus. The most pronounced odors in the fermented сereal grains were grassy, fungal, earthy, and nutty, while the most frequently recorded tastes were sweet, fungal, and grassy. The least variable parameter was the consistency of the fermented сereal grains. Principal component analysis showed the presence of two factors influencing the organoleptic parameters of the fermented сereal grains: the dominant factor being the fermentation substrate, and the other being the fungal species and fermentation duration. Wheat was found to be a more universal substrate for obtaining a fermented product with high organoleptic properties. The highest organoleptic scores across all parameters were obtained for wheat fermented with P. ostreatus mycelium with an optimal fermentation period of 21 to 28 days. The relative stability of all four sensory descriptors was established for P. eryngii, which may indicate a more stable nature of the metabolic processes of this species in the studied rice and wheat samples. Both species of Pleurotus are promising subjects for further research aimed at studying the biosynthetic activity of metabolites, which may potentially determine the functional properties of fermented products