Improved starch extraction from different root crops using cellulose from Trichoderma sp. and pectinase from Aspergillus sp.

Extraction of starches from cassava tubers and sweet potato was done by enzymatic treatment using cellulase from Trichoderma sp. and pectinase from Aspegillus sp. The optimized conditions for starch extraction from cassava tubers by 18.12%. Yield of starch from untreated control and sweet potato were as follows: enzyme concentration= 0.5% (1:1) mixture of cellulase and pectinase; incubation time=4 hrs; sample: buffer dilution ratio=1:2 (w/v); incubation temperature=37 deg C. Enzyme treatment and optimization of extraction procedure was able to increase the yield of starch from cassava and enzyme treated cassava samples were 24.88% and 29.39%, respectively, representing percent recoveries of 77.75% and 91.84%. The same trend was obtained from sweet potato extraction wherein a 38.25% increase was obtained from enzyme treatment. Yields and recoveries of starch from untreated control and enzyme treated sweet potato slurries were 9.15% representing 65.36% and 12.65% representing 90.65%, respectively. The dried and powdered starches from untreated cassava and sweet potato slurries were off-white in color, whereas whiter starches were obtained from cassava and sweet potato treated with enzyme. Physico-chemical analyses of the cassava starch from enzyme treatment gave the following results: moisture content=7.32% (w/v), amylose content=17% (w/w), lipid content-0.80% and gelatinization temperature=69 deg C. For the analysis of sweet potato starch from enzyme treated slurry the following values were obtained: moisture content=6.97% (w/v), amylose content=18% (w/w), lipid content=1.45% and gelatinization temperature=65 deg C. The solubility patterns of the starches extracted from untreated and mixed enzyme treated cassava and sweet potato slurries were also determined. Comparison of the physico-chemical properties of the produced starches showed that there were no significant differences between the properties of untreated (control) and mixed enzyme treated starches. The use of cellulase and pectinase in the extraction of starch from cassava and sweet potato increased the percent yield and subsequent recoveries without compromising the quality of the starch produced.