Investigation of Properties of Long-grain Brown Rice Treated by Low-pressure Plasma

Abstract

The impact of low-pressure plasma treatment on the properties of long-grain brown rice was investigated, and the process of quick cooking brown rice was developed. The microstructure of the brown rice surface and the cooking, textural, and pasting properties of plasma-treated brown rice were determined. Indica brown rice was treated for 30 min at voltage settings of 1, 2, and 3 kV. The plasma treatment resulted in the etching of the brown rice surface, which allowed water to be easily absorbed by the rice kernel during soaking. After plasma treatment, the cooking time, elongation ratio, width expansion ratio, water absorption, and cooking loss of brown rice were all reduced. Plasma treatment caused a significant decrease in peak viscosity and breakdown. In addition, the decreases in enthalpy and crystallinity, measured by differential scanning calorimeter and X-ray diffractometer, showed that the starch structure of brown rice was influenced by low-pressure plasma. Thus, low-pressure plasma is a novel processing technology to modify and reduce the cooking time of brown rice.