3. Results and discussion
3.1. The mass balance of MHP preparation
According to the procedure described in Section 2.3, the head part of the P. eryngii fruiting body in the waste bag-log was collected and processed. A composition list and its mass balance result for this process are summarized in Table 1. The identified items can be categorized as water (82.55%), polysaccharide (0.31%), gel-like materials (1.85%), undissolved materials (0.857%), and MHP (14.43%). This means that more than 90% of the dried fruiting body’s head can be processed to MHP. The prepared MHP was employed as the nitrogen source for the subsequent mycelial biomass and EPS production in P. eryngii submerged culture.