The effect of some agro- industrial wastes on yield, nutritional characteristics and antioxidant activities of Hericium erinaceus isolates

Four isolates of Hericium erinaceus cultivated in different growing media were investigated for their mycelial growth, yield, biological efficiency (BE), macro and micro element content, total phenolic content and antioxidant activity. In the study, oak sawdust (OS) was used as a base substrate, and cottonseed hulls (CSH) and olive press cake (OPC) were added at the ratios of 9:1, 8:2 and 7:3 to prepare the growing media. The control medium was prepared using OS and wheat bran (WB) at the rate of 8:2. The spawn run-period was shorter in all H. erinaceus isolates growing in the OS:WB (control) medium. The yield and BE (%) of H. erinaceus isolates ranged between 76.7 and 152.9 g/kg and 22.3-44.4%, respectively, depending on the growing medium used. The highest yield and BE% for all H. erinaceus isolates, except He-Trabzon, was obtained on 7OS:3CSH medium. The nutritional composition of H. erinaceus isolates varied with the growing medium, but there was no direct relationship between the macro- and micro-element content of the growing media and the nutrient content of the fruitbodies. The antioxidant activity and phenolic content of H. erinaceus isolates grown on different growing media ranged between 1.76 and 4.92 μmol TE/g fw and 0.318-0.663 mg GAE/g fw, respectively. The antioxidant activity and phenolic content of He- Ankara, He-Denizli and He-Trabzon were not affected by the growing media, whereas the addition of OPC to the oak sawdust substrate had a noticeable effect on the phenolic content and antioxidant activity of the fruitbodies of HE-İzmit. According to the results, cotton seed hulls and olive pess cake can be recommended as alternative additive materials to wheat bran to increase the yield of H. erinaceus. Finally, the use of olive press cake as substrate incrases the phenolic content of H. erinaceus mushrooms.