OPTIMIZATION OF PROCESS VARIABLES FOR ACCELERATED AGING OF BASMATI RICE

Abstract

ABSTRACTExperiments were conducted to develop a process for accelerated aging of aromatic rice. Freshly harvested clean paddy of “Pusa Basmati” variety was conditioned as per the experimental design. Response surface methodology for three variables at five levels was used. Central composite rotatable design was used to optimize the temperature (30–50C), relative humidity (50–90%) and aging period (3–14 days) to accelerate the aging process for paddy. The optimum levels of process variables were based on the desired milling and cooking quality indices. The quality attributes included milling yield, kernel elongation ratio, volume expansion ratio, solid loss, amylose content, gel consistency and aroma. A complete second‐order polynomial model was fitted to the data and the adequacy of the model was tested. The models were then used to interpret the effect of various input parameters on the response. The total effect of individual input variables and combined effect of all these variables at linear and quadratic level on head yield was significant at 1% level. Similar interpretation of the effect of various input parameters on the responses have been done in details. The common optimum condition for accelerated aging of paddy was found to be 43.4C, 71.0% relative humidity (RH) and 11.4 days.PRACTICAL APPLICATIONFreshly harvested rice is less preferred by consumers because of poor cooking properties like less kernel elongation and volume expansion ratio with more solids loss and softer gel consistency. Aging brings about progressive desirable changes in the grain. The natural aging process is time‐consuming and also requires proper storage. Therefore, the aging process may be accelerated by subjecting the grains to appropriate environmental conditions to bring about the acceptable properties so that the full potential of domestic as well as export market may be explored at the right time with a relatively high price. The information obtained from this study may be used in designing thermal processing to obtain aged rice within a short period.