Production of some Sweet Desserts Products from Chemically Modified Corn Starch

摘要

Corn starch was modified through succinylation (SCS), acetylation (ACS), acid-thinning (αTCS) and oxidation (OCS). Ash, protein, fat, amylose and pH values were reduced following modifications. The highest yield value was obtained from all succinylated starch samples. Both swelling power and solubility increased with increase in temperature. Succinylation and acetylation improved swelling power while, oxidation and acid-thinning reduced it. All succinylation, oxidation and acid-thinning markedly improved solubility, whereas acetylaction reduced it. Swelling power and solubility of native and derivatized starch samples increased with increase in pH. Maximum Swelling powers and solubility were observed at pH 10. Solubility values of oxidized starch samples were higher than the other modified samples of starch. Water absorption capacity increased after succinylation and acetylation. In contrast, oil absorption capacity was reduced following succinylation but increased after acetylation. Studies conducted on paste clarity revealed that percentage transmittance at 650 nm increased after chemical modifications. The results indicated a reduction in gelation properties of the native starch after succinylation, acetylation and oxidation but acid-thinned samples had better gelating property than native sample. All modifications methods reduced Pv (peak viscosity during heating, Hv (hot paste viscosity at 95℃), HV30 (viscosity after 30 min holding at 95℃) and Cv (cold paste viscosity at 50℃) of modified starches compared with native starch while, Tp (℃) (initial pasting temperature) value increased in acid-thinned corn starch samples and reached to higher values than occurred in native starch. Hunter results showed that, succinylation and oxidation improved values of lightness (L) and reduced redness (a) values. Acid-thinning increased yellowness (b) values where, succinylated and acid-thinned samples had the least color difference (AE) among the samples investigated. From sensory evaluation results, pudding and jelly samples contained oxidized and acid-thinned corn starch had the highest values of all sensory characteristics compared to the other samples contained modified corn starch with acetylation and succinylation.