Yield, Nutritional Content, and Antioxidant Activity ofPleurotus ostreatuson Corncobs Supplemented with Herb Residues

Abstract

Improper disposal of herb residues in China has caused severe problems to the surrounding environment and human safety. Three herb residues, i.e., compound Kushen injection residues (CKI) and part one and part two of Qizhitongluo Capsule residues (QC1 and QC2, respectively), were used for the cultivation of Pleurotus ostreatus. The effect of the supplementation of corncobs (CC) with different herb residues on yield, nutritional composition, and antioxidant activity of P. ostreatus was investigated. Compared to the control, the higher mycelial growth rate was observed on substrates CC +30% CKI and CC +30% QC1, while the higher yield was obtained from substrates CC +30% QC2 and CC +30% CKI. Moreover, chemical analysis of fruit bodies revealed that the addition of herb residues to CC significantly increased proteins, amino acids, ashes, minerals (Na and Ca), and total phenolic contents but significantly reduced carbohydrates and IC50 values of DPPH radicals. In addition, no heavy metals (Pb, Cd, and As) were detected in the fruiting bodies harvested from different substrate combinations. These results demonstrated that mixtures of CC with herb residues might be utilized as a novel, practical, and easily available substrate for the cultivation of P. ostreatus, which is beneficial for the effective management of herb residues.

Valorization of Olive Pruning Residues through Bioconversion into Edible Mushroom Pleurotus ostreatus (Jacq. Ex Fr.) P. Kumm. (1871) of Improved Nutritional Value

“…The use of WS : OLPR 1 : 3 has caused an increase in protein, carbohydrates, crude fiber, and iron contents in mushrooms, while that of WS : OLPR 3 : 1 (v/v) and WS : OLPR 1 : 3 (v/v) substrates has caused a decrease in fat and sodium contents. The latter had lower moisture, carbohydrates, and crude fiber contents than those in other early studies on various substrate types [ 2 , 58 ]. The reduction in carbohydrate contents of mushrooms was similarly reported by Koutrotsios et al [ 47 ] on mixtures of wheat straw and olive pruning substrates.…”

Effect of cultivating Pleurotus ostreatus on substrates supplemented with herb residues on yield characteristics, substrates degradation, and fruiting bodies’ properties

“…Pure cultures of P. ostreatus were routinely maintained on potato dextrose agar. The spawn preparation was conducted according to the method described by Jin et al 2 Substrate preparation CKI residues, QTC residues, and SSC residues were obtained from a local pharmaceutical company.…”

“…When flattening of the in-rolled margins of the mushroom caps was observed, the fruiting bodies were harvested in three flushes. 2…”

“…1 Thus, various approaches for utilizing these discarded materials, including composting and vermicomposting, pyrolysis, use of feed additives and biosorbents, and propagation of edible fungi, have been evaluated. 2,3 Mushroom cultivation can biodegrade industrial waste and transform it into proteinaceous food. 4 Pleurotus spp.…”

“…in northern China; however, the status of cheap and readily available herb residues implies that it is possible to develop novel biotransformation approaches that are low cost and highly efficient. Jin et al 2 recently showed that a substrate combination of CCs and herb residues at a ratio 5:3 may be used in the cultivation of Pleurotus ostreatus. However, the optimal conditions of this particular substrate formulation for mushroom cultivation have not been established.…”