Effect of degree of polishing on the biochemical and cooking quality of aromatic rice

The effect of extended polishing (0 to 105 seconds of polishing at an increment of 15s) and natural aging (0 to 180 days, at an interval of 30 days for paddy and polished rice) on quality aspects of three varieties of aromatic rice viz., Pusa Basmati, Tilak Chandan and Chini Kamini was investigated. The quality attributes included, kernel elongation ratio, volume expansion ratio, solid loss, amylose content, alkali digestion value, gel consistency and aroma. Regression analysis was performed to correlate the degree of polishing with quality parameters of experimented varieties of aromatic rice. The response pattern of all the experimented varieties could be divided into three zones based on degree of polishing. The cooking quality parameters increased at a higher rate in the under polished zone and reached the peak values in well polished zone (8 to 10%).The over polished zone (>10%) showed almost same level of quality attributes. Thus further polishing (higher than 10%) is undesirable and may be uneconomical due to reduced head yield. Therefore the degree of polishing must be specified while expressing the quality of polished rice.

Author : Kalpana Rayaguru, J.P. Pandey