Effects of supplementing rice straw growth substrate with cotton seeds on the analytical characteristics of the mushroom, Pleurotus florida (Block & Tsao)

Incorporation of cotton seed powder (3%) with rice straw substrate, while culturing Pleurotus florida, enhanced mushroom yield and net protein yield. The free sugars and polymeric carbohydrates were 13.2% and 39.6% in mushrooms grown on rice straw (RS-M) and 8.3% and 19.8% in the mushrooms grown on cotton seed-supplemented rice straw (CS-M). There was a significant decrease in the total dietary fibre content due to cotton seed supplementation. There was a desired softening (∼45% reduction in firmness) observed in the CS-M as measured on a Zenken texturometer. The free amino acids showed about 125% increase in the CS-M compared to the RS-M. There was a significant increase in most of the essential amino acids, such as leucine, isoleucine, valine, cysteine, methionine and phenylalanine. The total protein content (Kjeldahl N × 4.38) showed ∼90% increase in the CS-M. The total lipids increased by 35% due to cotton seed supplementation of the rice straw substrate; there was a predominance of unsaturated fatty acids, and linoleic acid in particular.