Effect of Different Moisture Contents on Crystallized State of Microwave Modified Tapioca Starch

Effect of microwave modification on tapioca starch at different moisture contents was studied with polarized light microscope. It was observed that loss of birefringence was initiated at hilum of granule. The polarization cross of most granules had become somewhat unclear, and reduction in clarity of the polarization cross was proportioned with the moisture contents of native starch as modification by microwave. When the moisture contents reached to 35.0%, the polariza- tion cross of most granules was lost, and the critical point of native starch was 30% in microwave modification.