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Gelatinization properties of white maize starch from three varieties of corn subject to oxidized and acetylated-oxidized modification

Author: Nur Aini;Purwiyatno, H.

Abstract

Maize-starch in conventional form is limited in use because of it’s physically properties, e.g. highly retrogradation properties, syneresis pasta, and low stability of pasta at high temperature and low pH. This research aims to modify three variety of white cornstarch (Local Canggal, Srikandi, Pulut) through oxidation and acetylation-oxidation, in order to improve its gelatinization properties. Modification of oxidation process is carried out using sodium hipoclorite. Acetylation-oxidation is a process of oxidation followed by acetylation using acetic anhydride at slightly alkaline conditions. Furthermore, conventional-maize-starch is used to compare the results of these treatments. The results show that Pulut white cornstarch has lower gelatinization temperature than Srikandi and local Cangal varieties. Oxidized and acetylated-oxidized starches have: (1) gelatinization temperature, (2) peak viscosity and (3) retrogradation lower than conventional-maize-starch. Low retrogradation is caused by stabilizer effect that retard syneresis (freeze thaw stability). Oxidized and acetylated-oxidized of maize-starches produce gel that more hardness than conventional-maize-starch, even in waxy and non-waxy starches.

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