USE OF YEAST EXTRACT TO IMPROVE YIELD AND COLD STORAGE OF OYSTER MUSHROOM.

Abstract

Three experiments were conducted in the Dept.of Hort./College of Agric./Univ.of Baghdad from 20/11/2010 to15/6/2011.The spawn of white strain of oyster mushroom (Pleurotus ostreatus (Jacq. Fr.))was produced using tissue culture . Yeast extract (50 ml)before and after boiling for 15 min was added to the plastic bag after the incubation stage at the following concentrations,0%or2.5%or 5%or 10%. The results showed that the fresh and dry yield and the biological efficiency(BE)increased with the increase of the yeast extract concentration ( boiled or unboiled) but the effect of the boiled extract was better than the un boiled extract. Use of 10% boiled extract increased the fresh yield from 507.7g/kg of substrate to 918.41g/kg of substrate ,while the un boiled yeast extract increased the fresh yield to 813.8g/kg of substrate only. Use of 10% boiled extract increased the dry yield and the BE significantly compared with all other treatment. Use of 10% yeast extract (boiled or unboiled) increased the percentage of the protein and the dry matter significantly in the fruiting bodies of oyster mushroom. Treatments with yeast extract (boiled or unboiled )had no significant effects on the percentage of decay, weight loss, protein loss and dry matter loss after storage.