The gelatinization and retrogradation properties of wheat starch with the addition of stearic acid and sodium alginate

Abstract

The gelatinization and retrogradation properties of wheat starch (WS) with the addition of the combination of stearic acid and sodium alginate (C-SA-AG) were investigated in this study. The results of differential scanning calorimetry (DSC) showed that C-SA-AG significantly increased the gelatinization onset temperature of WS by 2.6–3.4 °C, whereas decreased the gelatinization enthalpy of WS by 5.7–6.7 J/g. This suggested that C-SA-AG could obviously delay the gelatinization process of WS. The gel firmness, retrogradation enthalpy, the ratio of intensity at the band of 1047 cm−1 to 1022 cm−1 (R1047/1022), and the relative crystallinity (RC) of WS were significantly decreased with the addition of C-SA-AG by 322–346 g, 0.51–1.78 J/g, 0.06–0.12, and 7.12–9.05% after stored for 7 days at 4 °C, respectively. However, the loss factor (tanδt/tanδ0) was increased by 0.49–0.54 after sweeping for 120 min. This suggested that C-SA-AG could effectively retard the retrogradation of WS. During storage, the retrograded WS containing SA showed V-type crystal structure, which lost the A-type crystal structure of native WS.