Effect of accelerated ageing (RF drying) on cooking and textural characteristics of BPT 5204 and GGV 0502 rice varieties

Abstract

The effect of radio frequency (RF) heat treatment on cooking and textural characteristics of BPT 5204 and GGV 0502 rice varieties was investigated. The freshly harvested and milled rice samples were exposed to RF waves of 27.2 MHZ frequency for 5, 10 and 15 min. The results revealed that the water uptake ratio (3.53 and 4.24; 3.91 and 4.78), volume expansion (466.46 and 481.86; 526.27 and 552.34 mm3), solid loss (6.71 and 6.63; 4.60 and 5.51%) and elongation ratio (1.37 and 1.58; 1.63 and 1.91) were found for fresh and naturally aged rice samples of BPT 5204 and GGV 0502 respectively, whereas the values for hardness (124.94 and 136.17; 239.56 and 295.42 g) adhesiveness (-0.35 and -0.25; -0.514 and -0.45 g.s) cohesiveness ( 0.419 and 0.407; 0.572 and 0.608) and springiness (0.892 and 0.824; 0.996 and 1.03) were observed for these samples. The RF heat treatment to the fresh rice samples of both the varieties increased the water uptake, volume expansion and elongation ratio, hardness, adhesiveness, cohesiveness and springiness whereas the solid loss was found decreased. RF heating for 15 min resulted in better cooking quality and textural characteristics of treated BPT 5204 and GGV 0502 rice varieties and were found on par with the values of naturally aged rice samples (control).