Effects of glutathione on structural and digestibility properties of high-hydrostatic-pressure-gelatinized maize starch with different amylose/amylopectin ratios

The effect of glutathione (GSH) on the digestibility, physicochemical, and structural properties of maize starch under 600 MPa for 20 min of high hydrostatic pressure (HHP) treatment was determined by in vitro digestion, differential scanning calorimetry (DSC), scanning electronic microscopy (SEM), particle size distribution analysis, Fourier transforms infrared spectroscopy (FT-IR), and Laser Confocal Raman (LC-Raman) microscopy. The findings indicate that the waxy maize starch (WMS) underwent complete gelatinization, whereas the high amylose starches had partial gelatinization. GSH induced a significant increase (p ≤ 0.05) in the slowly digestible starch (SDS) content and a decrease in the rapidly digestible starch (RDS) after HHP treatment. Thermal analysis revealed that GSH increased starch gelatinization temperature. The gelatinization characteristics showed that GSH inhibited starch retrogradation but did not contribute much to starch crystallinity. FT-IR and LC-Raman analyses confirmed the interaction of GSH with starch molecules. The present result emphasizes the impact of GSH on the modelling of starch digestibility and structure properties and inspires the development of new functional foods prepared with HHP.