In situ gelatinization of starch using hot stage microscopy

Starch gelatinization is important in food processing and industrial use. Granule swelling and gelatinization temperature of 11 starches from different plants were investigated in situ using hot stage microscopy during heating. The amylose content, swelling power, pasting temperature and thermal property of these starches were also measured. The results showed that hot stage microscopy was suitable for measuring granule swelling and the gelatinization temperature of starch during heating. The sectional area swelling percentage of starch granules measured using hot stage microscopy was significantly positively correlated with the swelling power. The gelatinization temperature measured using hot stage microscopy was significantly positively correlated with the pasting temperature and with the thermal property for all 11 starches. For rice starches with the same crystallinity and similar size, the gelatinization temperature was negatively correlated with the amylose content and positively correlated with the swelling power and the sectional area swelling percentage at 95°C.