Maximizing Glucose Production From Palm Kernel Cake (Pkc) From Which Residual Oil Was Removed Supercritically Via Solid State Fermentation (Ssf) Method Using Trichoderma Reesi Isolate Pro-A1

摘要

The present trial was carried out to evaluate the effects of incubation temperature, pH and time during solid state fermentation (SSF) of PKC substrates using Trichoderma Isolate Pro-A, on glucose production from the substrates before and after the residual oil is extracted via Supercritical Fluid Extraction (SFE) technique. Residual oil was removed from one portion of 250μM-sized Palm Palm Kernel Cake (PKC) substrate, using SC-CO2 as the solvent in supercritical fluid extraction (SFE) technique (Oil-less treatment), whereas no residual oil was removed from the other portion of the substrate (Oily treatment). Both treatments (Oil-less and Oily) were subjected to SSF, using Trichoderma Isolate Pro-A incubated at three temperatures (20, 30 and 40°C), three pHs (3, 5 and 7) and at four time intervals (4, 8, 12 and 16 hours) accordingly, and the glucose concentration produced during SSF was quantified. Results showed that glucose production by the fungus from both treatments was significantly higher at 30°C, at pH 5 and at incubation time of 16 hours accordingly. However, the glucose production by Trichoderma reesi was significantly (p<0.01) higher in the Oil-less PKC treatment, from which the residual oil had been removed through the SFE technique. The results of this trial suggest that the removal of residual oil from PKC enhances its use as substrate for glucose production via SSF, using Trichoderma reesi. The results also indicate that temperature, pH and incubation time are important factors to consider during SSF with the green fungus (Trichoderma reesi). It is concluded here, based on the results of this study, that SSF at temperature of 30°C, at pH 5 and incubation time of 16 hr are ideal for higher glucose production by Trichoderma reesi on PKC substrates. Introduction The agricultural industry in Malaysia generates large quantities of wastes, which has been estimated at approximately 5 million tons per annum and this is expected to increase by two-fold or more by the year 2010 (Pang et al. 2006). One notable feature of these generated wastes however, is that majority originate from the palm industry including; oil palm trunks and fronds, palm kernel and palm kernel cake (PKC), among many other materials.PKC is a waste product generated after crushing the palm kernel, to extract the oil from the fruit using the screw-press extraction (expeller) technique (Alimon 2004; Akpan, et al., 2005; Soltan, 2009). The global production of this by-product has consistently increased in volume with the expansion of the oil palm industry in many countries in Asia (particularly Malaysia and Indonesia) and Africa in recent years. The global production of PKC in the year 2002 was estimated at over 4 million metric tons (Atasie and Akinhanmi, 2009). The proximate composition of PKC suggests that it could be classified as an energy feed, as it is richly composed of nutrients containing (on the average); 59.9% carbohydrate, 10.2% fat, 2% sugar and 391 kcal of energy. It is also an important source of protein (18.6% crude protein, consisting of high quality amino acids), contains crude dietary fiber of 37% and average residual oil content of 10% (Alimon 2004). The analysis of PKC showed that over 60% is cell wall components, with the fiber content composed of mainly insoluble, mannose-based polysaccharides (Alimon 2004). Jaafar and Javis (1994) also noted that PKC cell wall consists of 58% mannan, 12% cellulose and 4% xylan.The use of large quantities of cell wall components like cellulose, mannan and ligno-cellulose in agricultural wastes available in the environment as raw materials for solid state fermentation (SSF) processes for use in animal feedstock continue to receive global attention (Alimon 2004; Soltan, 2009; Wallace et al., 2010). The potential of PKC as a feed ingredient for ruminant animals in the livestock feeds industry after fungi fermentation is well documented (Akpan et al., 2005). However, the major existing problem in the