Effects of chemical modification on functional and physical properties of African star apple kernel (Chrysophyllum albidnum) starch

Abstract

Starch isolated from Chrysophyllum albidnum (African star apple) was subjected to modification by acetylation, carboxymethylation and succinylation process. Chemical modifications effect on functional properties as well as physiochemical parameters of starch was analysed. The percentage yield of native starch was 73.22±0.93%; however the value increased after modifications. The proximate determination of the non-starch components of the native starch on a dry weight basis was 19.32±2.40 moisture, 0.0045±0.00020 ash, 0.085±0.030 fat and 0.25±0.12% crude protein, respectively. Chemical modification reduced the values for all the non-starch components. The swelling power and solubility increased as the temperature increased between the ranges of 50–90°C. Native and modified starches absorbed more oil than water and it is pH dependent. Pasting characteristics decreased after acetylation but increased after carboxymethylation and succinylation. The results of bulk densities showed that native and modified starches are very light (<0.8 g/ml). All these characteristics showed that C. albidnum starch can be utilized in both food and non-food applications. Key words: Functional and physical properties, African star apple kernel, chemical modifications, native, starch.