Development of Selected Value-Added Products from Sago Frond

Sago frond is produced in abundance upon harvesting of sago palms for starch extraction. Thousands of sago fronds being disposed each day, turned into slowly-degradable waste and prove to be detrimental to the environment. Despite being rich in cellulose, sago fronds in general, are still underutilised and to date, valorisation of sago fronds is still limited. Thus, this study aims to investigate the potential of sap and solid sago frond for production of value-added products. This work is divided in two parts. In the first part, the sago frond sap (SFSp) from two selected growth stages of sago palm (Angkat Punggung and Upong Muda) was characterised in terms of sugar, starch and mineral contents. Following that, the feasibility of the SFSp as a fermentation medium for bioethanol production by Saccharomyces cerevisiae was investigated. The effect of sterilisation of SFSp on fermentation performance was determined. In the second part, sago frond sugar (SFS) was produced via enzymatic hydrolysis of dried solid sago frond fibre. Then, the potential of the sugar as an antifungal agent was examined. The results from this work show that all SFSp has an acidic pH, with glucose as major sugar component and it also consists of minerals such as calcium, potassium, manganese and magnesium, which are useful as fermentation nutrients. The results clearly show that sap, obtained from inner circle frond (Upong Muda palm) is a good substrate for bioethanol production as it exhibited the highest amount of glucose and xylose, at 68 g/L and 29 g/L, respectively. Direct fermentation of SFSp for bioethanol production by S. cerevisiae, without the need for any pre-treatment or hydrolysis was found to be feasible. Similar yeast cell growth and ethanol production were observed when both sterilised and non-sterilised SFSp were used as a fermentation media. High ethanol yield of 0.35 g/g and fermentation efficiency of 69% were achieved in fermentations using non-sterilised SFSp. The addition of 5 g/L YE to non-sterilised SFSp was found to result in further enhancement of the bioethanol production with the ethanol yield increased to 0.41 g/g, and the fermentation efficiency increased to 81%. Moreover, it was found that cellobiose produced from 95% concentrated brown and purified SFS has been proven capable to inhibit the growth of Candida albicans and Candida tropicalis. Thus, it can be concluded that sago frond sap and sugar can be utilised for the production of value-added products. Development of sago fronds into value-added products will benefit local sago farmers industry and help to minimise the impact of the environmental pollution, which is otherwise caused by the disposal of sago waste