Production of Maltose Syrup by Enzymatic Conversion of Rice Starch

Rice starch sample was converted into maltose syrup with comparison to corn starch sample. The conversion was carried out by both liquefaction using alpha-amylase (EC3.2.1.1) and saccharification using beta-amylase (EC 3.2.1.2) and pullulanase (EC 3.2.1.41). The morphologies of the rice starch and corn starch samples were characterized by scanning electron micrographs. The results demonstrated that granules size of the rice starch was significantly smaller than that of the corn starch, and the optimum liquefaction time of rice starch was markedly shorter than that of corn starch. The starch conversion to main impurities, such as isomaltose and higher oligosaccharides (maltotriose, maltotetraose, maltoheptaose, and maltohexaose) for rice starch sample were significantly lower than those for corn starch sample (P < 0.05), and starch conversion to maltose for rice starch sample was equivalent to that observed for the corn starch sample. It was concluded that the rice starch could be a good alternative to corn starch as raw material for maltose syrup production.