Effect of parboiling and puffing processes on the physicochemical, functional, optical, pasting, thermal, textural and structural properties of selected Indica rice

Abstract

The selected Gurjari rice variety was identified as intermediate amylose content (20.52 ± 0.30%) Indica, medium grain size, coarse rice based on physico-chemical characteristics. Changes in the properties of rice on parboiling and puffing process were investigated and reported the statistical differences at p ≤ 0.05. The studied attributes are physico-chemical, functional, textural, pasting, thermal, optical, micro-structural, XRD and FTIR characteristics. Process of puffing has significantly (p ≤ 0.05) increased the dimensional parameters almost twice of original dimension and thus reduced the hardness of puffed rice by eight times. The process of puffing significantly (p ≤ 0.05) reduced the moisture content of puffed rice with the enhancement of five times the surface area with the reduced the bulk density more than nine times. Water absorption index and water solubility index were significantly affected on process of puffing. Puffed rice being a precooked product the pasting time were observed as lowest. The differential scanning calorimetric assessment of Gurjari rice indicated as the selected rice is among the low gelatinization temperature rice. The lighter colored puffed rice with the enhanced level of resistant starch associated with puffed rice improves the functionality of the developed puffed rice to consume directly as ready-to-eat or to be used as ready to use item in the preparation of various functional foods thereof.