Effect of annealing and α-amylase extract on the rheological properties, syneresis, and water holding capacity of different starches
Hisham ALQAH, Mohammed Alamri, Abdellatif A. Mohamed, Shahzad Hussain, Akram A. Abdo Qasem, Mohamed A. Ibraheem, Hany M. Yehia
Abstract
The objective of this study was to determine the impact of annealing and enzyme extract on the gel properties of chickpea (C.P), corn (C.S), Turkish bean (T.B), sweet potato (S.P.S), and wheat starches (W.S). Starches were annealed at different temperatures and times in excess water with or without germinated sorghum extract (GSE). The concentration of α-amylase in the GSE was 5 mg/10 mL. Dynamic rheological properties, freeze-thaw stability and water holding capacity (WHC) were investigated. The dynamic rheological parameters of the native or GSE-treated starches varied significantly (p < 0.05), while the G` of some starches were frequency-independent others exhibited sharp increase in G` at low frequencies. Unlike T.B and S.P.S, the G` of the native C.P and C.S starches was significantly (p < 0.05) reduced by annealing, whereas GSE-treatment reduced G` of all gels regardless of annealing temperature or time. Starch gels demonstrated significant (p<0.05) reduction in freeze thaw stability and increase in water holding capacity after annealing and GSE treatment.