3.7. Mineral content
Table 5 lists the mineral content of Pleurotus fruit bodies, harvested from different substrate combinations. Nitrogen (N) contents varied from 62.6–79.4 mg g−1 dw and were highest among the detected six mineral elements in fruit bodies. It was observed that N content of fruit bodies increased significantly with increasing concentrations of the cake (except at higher concentrations). This might have been due to enhanced nutrient supply from these nitrogen rich raw and detoxified mahua cakes. Also, fruit bodies harvested from WS supplemented with DMC were richer in N compared to those from harvested WS supplemented with CW DMC or raw MC. Potassium (K) ranked second (5.5–14.2 mg g−1 dw) followed by phosphorous (P) in the fruit bodies (5.2–9.4 mg g−1 dw). Iron (Fe), zinc (Zn) and manganese (Mn) were obtained in the ranges of 105.5–290.7 ppm, 75.4–191.0 ppm and 22.6–29.4 ppm, respectively. The values obtained here are greater than the reported values of 5.87–8.40 mg g−1 and 4.99–7.57 mg g−1 P for different Pleurotus spp. studied by Chang, Lau, and Cho (1981) and Guo et al. (2005), respectively. However they are less than that reported of 6.1–12.7 mg g−1 Fe, 10.3–33.2 mg g−1 K and 113–218 mg g−1 P in Pleurotus fruit bodies studied by Ragunathan and Swaminathan (2003).