Modification of Corn Starch and Fine Flour by Acid and Gamma Irradiation. Part 1. Chemical Investigation of the Modified Products

Abstract

Fine flour from corn and the isolated starch were dextrinized in the presence of acid and irradiated with y‐rays. Starch irradiated with high doses of y‐rays was highly modified while fine flour was less affected. The irradiated starch was reduced with sodium borohydride and then hydrolysed. Erythritol and other compounds were identified in the hydrolysate. It was concluded that the C2‐C3 bonds in the intermediate glucose units are probably broken by irradiation. Such hypothesis was confirmed by periodate oxidation, hydrolysis with α‐amylase and ferricyanide number determination of the irradiated starch.

Modification of poovan banana (Musa AAB) starch by γ‐irradiation: effect on in vitro digestibility, molecular structure and physico‐chemical properties

“…Increased carboxyl content in starch occurred due to the degradation of starch by gamma irradiation, which causes the generation and transformation of free radicals and follows the low‐molecular products with the number of carboxylic acids and aldehydes (Sharpatyi, ). This variation in the carboxyl content in irradiated starches could be due to the formation of acids such as formic, acetic, pyruvic and glucuronic acids by the action of free radicals (Ghali et al ., ). These results were comparable with other studies (Chung & Liu, ; Ashwar et al ., ).…”

Modification of bean starch by γ-irradiation: Effect on functional and morphological properties

“…Abd Allah, Foda, and El Saadany (1974) observed substantial increase in the production of formic acid in irradiated wheat starch. Formic, pyruvic, acetic and glucuronic acids are formed during irradiation of starch (Ghali, Ibrahim, Gabr, & Aziz, 1979) which therefore could be responsible, not only for the elevation in carboxyl content levels with irradiation dose but also for reduction in pH values of all starch samples. Similar findings were reported by Chung, Hoover, and Liu (2009) and Chung and Liu (2010) with irradiated corn and bean starch respectively.…”

Molecular structure and physicochemical properties of potato and bean starches as affected by gamma-irradiation

“…The radiation degradation of starch is initiated by the generation and transformation of free radicals and follows the low-molecular products with the number of carboxylic acids and aldehydes [23]. Ghali et al [24] reported that formic, acetic, pyruvic and glucuronic acids were formed during irradiation of starch. Therefore, the main degradation products formed during irradiation of native starch were carboxylic acids, which resulted in an increase in carboxyl content and a decrease in pH value of all starch samples.…”