Study of Aromatic Components in the Course of Initiating Enzymatic Reactions in the Edible Mushroom Pleurotus Ostreatus

Abstract

Various branches of the food and medical industries widely use mushrooms, that is why their aromatic characteristics are quite important. This paper presents a comparative analysis of the aromatic and fatty acid composition of the mycelium of the edible oyster mushroom (Pleurotus ostreatus (Jacq.) P. Kumm., strain K-17) cultured on a glucose-peptone-yeast growth medium with wheat bran added. The quantitative and qualitative composition of the aromas has shown that wheat bran components affect the aroma-forming reactions during the growth of the mycelium of P. ostreatus. It has been established that the introduction of wheat bran increases the content of 1-octen-3-ol, the main fungal aromatic component. In the culture liquid, 1-octen-3-ol increases by 1.4 times, as compared with classic samples cultured on a growth medium without wheat bran. Also, in the mycelium cultured on a wheat bran-containing growth medium, the total quantity of identified aromatic components increases by 1.7 times. In this mycelium, the two main components of the mushroom’s aroma are formed: 1-octen-3-ol and hexanal. In other samples, these important components are absent. The results of this study confirm that the formation of the two main fungal aromatic components, 1‑octen-3-ol and hexanal, involves polyunsaturated fatty acids, namely linoleic acid. Its content decreased in parallel with the accumulation of aromatic components throughout culturing in the wheat bran-containing medium. The data obtained allow establishing how initiation of enzymatic oxidative reactions changes the aroma of P. ostreatus during surface culturing on a liquid medium. The research results reveal the regular patterns in the formation of aromatic components of macromycetes from lipid precursors. Addition of wheat bran to a growth medium unbalances the total content of aromatic components towards their accumulation in the mycelium. Since fruiting bodies and vegetative mycelium are similar in their biochemical composition, the results of studying the mycelium cultured on a liquid medium allow predicting how aromatic components will be formed in the fruiting bodies of oyster mushrooms.