Extraction and Characterization of Non-Starch Polysaccharides from Different Growth Stages of Sago Starch

Abstract

Extraction of non-starch polysaccharides from the pith of sago (Metroxylon spp.) at four growth stages named as Plawei (palm at maximum vegetative growth), Bubul (flowering structure), Angau Muda (well develop flowering) and lastly Angau Tua (fruiting palm) was conducted using enzyme extraction method. The extracted NSP was classified into water-soluble polysaccharides (WIP) and water-insoluble polysaccharides (WIP). The percentage yield of WSP is 0.34-0.80%, significantly lower than WIP (8.32 to 10.19%) and only WIP were used throughout the study. Fourier Transform Infrared Analysis (FTIR) were conducted to verify the WIP and absorption bands was found at 3200-3600/cm (O-H), 2850-3000/cm (C-H), 2358/cm (N-H), 1600-1550/cm (C = C in aromatic rings), 1200-1100/cm (C-O-C) and lastly 1050-1150/cm (C-O). Therefore, the predominant components of extracted NSP are cellulose, hemicellulose, pectens and lignin. The particle size distribution of NSP showed decreasing trend as the age of the plant increase from Plawei (91.16 µm), Bubul (83.66 µm), Angau Muda (63.93 µm) and Angau Tua (46.54 µm). SEM showed the structure of WIP have been ruptured due to extensive extraction, looks like 'thin folded structure'. Then, 5% of NSP were added into the flour and analysis on physico-chemical properties were conducted. In terms of proximate analysis, only moisture and crude fiber content of NSP flour showed a significant increased compared to normal flour.