Gelatinization properties of waxy and non-waxy rice powder as a raw material for instant rice gruel were investigated. Waxy and non-waxy rice powders were prepared by washing, steaming, freeze-drying and grinding. The XRD (X-ray diffraction) patternsof non-waxy and waxy rice powder were very similar and characterized by the typical cereal "A" type. They showed four strong intensity lines. After the second steaming, the high peaks of XRD almost completely disappeared, indicating both waxy and non-waxy rice powder became completely gelatinized after the second steaming. The RVA (rapid viscosity analyzer) viscosities of waxy and non-waxy rice powder were different. The non-waxy rice powder displayed low peak viscosity at high temperatures, while the waxy rice powder had high peak viscosity at low temperatures. The SEM (scanning electron microscope) of rice powders showed damaged granular structure having some granular disruptions. In conclusion, for rice powder as a raw material of instant rice gruel, rice should be heated by the second steaming. This is because waxy and non-waxy rice were not completely gelatinized until after the second steaming.
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