INVESTIGATION OF THE EFFECT OF CHEMICAL MODIFICATION ON SOME QUALITY CHARACTERISTICS OF STARCH EXTRACTED FROM ACHA (Digitaria exilis) AND ITS NOODLES MAKING POTENTIAL

Abstract

Acha is rich in pentosan; a carbohydrate compound with good water absorption capacity properties that could be utilized in production of pasta products like noodles. This study investigated the effect of chemical modification (oxidation, acetylation, pre-gelatinization and dual) on proximate composition, functional, pasting, mineral, color and antioxidant properties of acha (Digitaria exilis) starch and its resultant noodles making potential. Starch was extracted from acha grains and then dried, milled and sieved through a 75-micron screen and the native and modified acha starch were substituted into wheat flour at 15% to produce noodles. Results showed that modified acha starches have significant influenced (p<0.05) in all the quality attributes evaluated. The modified acha starches showed least moisture content with an increase in protein and ash contents, while carbohydrates decreases when compared to the native starch. Modification increases and improved the functional characteristics of the acha starches. Pasting properties of native starch was significantly higher than modified starches. Some minerals element of native starch was most predominant than the modified starches. There was a slight reduction in phenolic and flavonoid compounds while colour of the acha sample was relatively higher due to modification. Conclusively, this study showed that starch modification improved the quality of acha and sensory scores revealed that the most preferred acha noodles are from pre-gelatinized acha starch. Thus, chemical modification could serve as alternative food grade starch additive for the possibility of new food applications.