Using Phenol-Rich Agro-Wastes as Substrates for the Cultivation of Hypsizygus ulmarius Mushroom with Enhanced Functional and Nutritional Potential

Abstract

This study aimed to transform phenolic-rich agricultural wastes into valuable foods by using them as new alternative substrates in mushroom cultivation and thus, to dispose of them without harming the environment. Thirteen growing media were tested for cultivation of Hypsizygus ulmarius in the study. The wheat straw (WS) and poplar sawdust (PS) were used as the main substrate and the green walnut husk (GWH) and grape pomace (GP) were added at the ratios of 10, 20, and 30%. One commercial growing medium was used as control. The relationships was assessed between the cultivation parameters and composition of the growing media. Moreover, the comparison of nutritional composition of mushroom carpophores among the treatments was performed. Straw-based media supplemented with GP and GWH promoted H. ulmarius yields (161.1 g kg -1 -235.4 g kg -1 ), biological efficiency (BE)% (44.8%-73.5%) compared to control media (225.7 g kg -1 , 64.5%, and 1.25, respectively). Moreover, the fruitbodies cultivated on growing media supplemented with different ratios of GP and GWH displayed high contents of protein (12.85%-17.0%), ash (8.54-11.90%), and carbohydrate (69.11%-75.15%), a total phenolic content of 2.68-4.26 mg gallic acid equivalents (GAE) per g, and a low content of fat (1.70%-3.50%). Considering the results of the study, it was concluded that by using growing media containing phenolic-rich wastes in H. ulmarius cultivation, especially GP, the environmental impact of these wastes can be reduced without compromising the current yield performance and nutritional quality of the mushroom.