Influence of microwave heating as accelerated aging on physicochemical, texture, pasting properties, and microstructure in brown rice of selected Indian rice varieties

• Published in: Journal of texture studies 2020-08, Vol.51 (4), p.663-679
• Main Authors: Devraj, Lavanya, Natarajan, Venkatachalapathy, Vadakkeppulpara Ramachandran, Sinija, Manicakam, Loganathan, Sarvanan, Shanmugasundaram
• Format: Article
• Language: English
• Subjects: accelerated aging; cooking characteristics; microstructure; microwave heating; pasting properties; sensory attributes; texture
• ISSN: 0022-4901; 1745-4603
• DOI: 10.1111/jtxs.12522

Most of the population does not prefer to consume brown rice because of its strong nutty and chewy texture imparted by bran and germ. The present study has been undertaken to investigate the influence of accelerated aging through microwave (MW) heating at a lower and higher MW power levels of 950 and 1,400 W for 72 and 91 s to observe the changes in physicochemical, texture, pasting properties, sensory attributes, and microstructure of selected rice varieties (Sona masuri and RNR‐15048) stored as brown rice for 6 months. The results revealed a significant decrease in moisture, amylose, free fatty acids (FFAs) with changes in color (L*, a*, and b* values) in both the varieties treated at 1,400 W for 91 s. An increase in kernel elongation ratio, water uptake, and a decrease in cooking time and solid loss was noted in both the varieties. After cooking, the texture of both the varieties showed an increase in hardness with reduced stickiness at both lower and higher MW power levels of 950 W for 72 s and 1,400 W for 91 s compared to untreated brown rice with an improved porous structure when observed under SEM analyzer followed by better water absorption and organoleptic properties after cooking. The reduction in final viscosity has been noted in both the varieties at 1,400 W for 91 s due to the binding of FFA with starch. Thus, the MW power level of 950 W for 72 s and 1,400 W for 91 s showed the better results for short‐grain varieties like Sona masuri and RNR‐15048 stored as brown rice.