Enzymatic production of maltodextrins derived from sago flour using heat-stable alpha-amylase and pullulanase

Abstract

Maltodextrins are produced by starch modification in a partial hydrolysis thus altered physical sago properties. Sago as one of starch resources has characteristic with high amylopectin that influences high viscosity during cooking. Partial hydrolysis or liquefaction will influences starch hydrolysis and the size of maltodextrin produced. The aim of this study was to analyze the degree of sago starch hydrolysis during the enzymatic process using single α-amylase and combination with pullulanase The starting solids content was 20% (w/v), with adjusted pH to 6.5, and calcium (Ca2+ ions) addition as high as 50 ppm. The majority of starches used in the study contain 0.2 % (w/v), to combination of 0.2 % (w/w) and 0, 3 gram per kg of sago. The sago suspension temperatures were started from 105 °C lowered to 60 °C for 30 minutes, respectively. Optimum liquefied starch yields, which accounted for virtually all of the starch present, were obtained at temperatures of 80°C and above, for 120 minutes, with each sampling every 20 minutes. Observed parameters were levels of reducing sugars, degree of hydrolysis, and refined sago starch. The result showed that there was a significant increase in reducing sugars, degree of hydrolysis during 120 minutes until liquefaction process for both enzymatic treatments. The amount of reducing sugars was 95.76 g/L at 120 min for the single α-amylase and 98.84 g/L combination with pullulanase. The degree of hydrolysis was 37.93 % at 120 minutes for the single α-amylase and 37.32 % combination with pullulanase, whereas 0.035 % and 0.038 % for refined sago starch value respectively.