Effect of puffing on physical and antioxidant properties of brown rice

Abstract

The objective of this study was to investigate the effect of puffing process on the physical, antioxidant properties and mineral composition of brown rice. Bulk density significantly varied (P<0.05) among the puffing stages and was lowest in expanded rice. From Hunter colour analysis, the lowest L(∗) value and highest a(∗) and b(∗) values were observed for parboiled rice (P<0.05). A-type of diffraction pattern, observed in raw rice was altered by puffing process and led to the formation of B- and V-type patterns. Raman spectrum showed the intense peaks in raw rice and the intensity of those peaks was decreased during the puffing process. Scanning electron microscopy revealed a highly porous structure of expanded rice kernel. Significant decrease in the antioxidant properties was observed upon puffing process as compared to raw rice samples. Hence the present study demonstrates that the puffing process leads to the significant changes in the properties of brown rice.

Keywords: Antioxidants; Expanded rice; Minerals; Parboiling; Puffing.