The aims of the current study were to follow: (1) the capability of the edible mushroom Pleurotus ostreatus to degrade cell wall components and soluble phenols of the olive mill solid waste (OMSW), and improve it for ruminant nutrition (2) the fate of oil and the lipid-soluble compounds tocopherols, squalene and β-sitosterol in the fermented OMSW. A significant decrease in oil and lipid-soluble compounds with a concomitant shift in the fatty acid profile and degradation of soluble phenols took place already after 14 d. The utilization of lipids by the fungus shifted the degradation of the structural carbohydrates to a later stage, and significantly reduced the metabolizable energy of the OMSW. We propose that edible fungi with reduced lipase activity would preserve the energy and health promoting ingredients of the oil, and force the fungus to degrade structural carbohydrates, thus improving its digestibility.
Bibliographical noteFunding Information:
We wish to thank Professor Oded Beja, Dr. Efraim Lewinsohn and Professor Zeev Arad for critically reviewing this manuscript. We thank Dr. Yoav Aharoni for his useful comments. The technical assistance of Ms. Alexandra Agranovsky and Ayala Meir is deeply acknowledged. This research was supported by funds of the Chief Scientist, Ministry of Agriculture and Rural Development, Israel, Grant Number 362-0190-08. Contribution No. 541/09 from the ARO, the Volcani Center, Bet Dagan, Israel.
- Cattle nutrition
- Olive mill solid waste
- Pleurotus ostreatus