Artificial aging of rice using a sterilization box equipped with infrared heating and ultraviolet‐C radiation

Abstract

AbstractAging of rice starts from the time of its harvest and continues until it is consumed. It positively impacts the cooking and eating qualities of rice, but natural aging takes years. In this study, artificial aging of rice was carried out at 70°C using simultaneous infrared (IR) radiation heating (3.18 × 104 W/m2) for 1, 3, 5, and 7 h and ultraviolet‐C (UV‐C) irradiation (49.24 J/cm2‐h) in a designed box. IR heating at 70°C combined with UV‐C irradiation for 5 h was the optimized condition for artificial aging. At optimized conditions, the proportionate change of rice was the highest as 0.21, followed by that for naturally aged (0.15) and non‐aged (0.08). The values of elongation ratio and actual elongation after cooking were the highest in artificial aging, followed by those for naturally aged and non‐aged rice. Water uptake (%) value was also the highest for artificial aging (89.62%), followed by that for naturally aged (68.45%) and non‐aged (59.93%) rice. Furthermore, nutritional values, microstructure, and antibacterial studies were carried out at optimized conditions. No significant changes in nutritional values viz., starch, protein, and fat were observed in artificially aged rice in comparison to one‐year‐old naturally aged rice. Electron microscopy analysis showed no changes in the structure of starch granules, which further revealed no adverse effect of IR radiation heating on the microstructure of rice. Results from the spread plate assay showed no growth of bacterial colony indicating the antibacterial effectiveness of artificial aging. Thus, simultaneous artificial aging as well as surface disinfection of rice can be carried out by combining IR radiation heating and UV‐C irradiation. These observations endorsed the effectiveness of the designed box for the artificial aging of rice without compromising the cooking and nutritional qualities. A preliminary sensory test was conducted. Overall, an efficient, inexpensive, and easy‐to‐handle artificial aging combined with surface disinfection was accomplished.