Sunday, August 1, 2010
Pacific Concourse (Hyatt Regency San Francisco)
Oil palm trees have an economic life span of approximately 25 years, after which old trees are felled and replanted. Although some portion of the felled trunks is utilized for plywood manufacturing, almost all of them have no practical way of utilization and become troublesome wastes. In an attempt to develop a method to utilize old oil palm trunks for usable materials production, we found that the felled oil palm trunk contains large quantity of sap, which accounts for 70 to 80% of the whole trunk weight, and that abundant glucose and other fermentable sugars exist in the sap. Furthermore, we found that sugar concentrations in the sap increased remarkably by proper aging. We collected oil palm trunks of different cultivars in Malaysia and analyzed sugar concentrations in the sap from the trunks during storage. Total sugar concentration in the sap commonly increased from 8 ～9% to 14%～15% , which is the comparable concentration of sugar cane juice, after 30 days of storage . In addition, oil palm sap was found to be rich in various kinds of amino acids, organic acids, minerals and vitamins. Ethanol and lactic acid were easily produced from the sap by fermentations of yeast and lactic acid bacteria, respectively, at comparable rates and yields to the reference fermentations, where glucose was used as the substrate. These results indicate that oil palm trunks felled for replanting are significant resources for producing fuel ethanol and lactic acid in palm oil-producing countries such as Malaysia and Indonesia.