Pasting, Texture and Cooking Characteristics of Whole Grain Extruded Rice With Selenium and Zinc

Abstract

Selenium and zinc are essential trace elements in the human body and play an important role in maintaining body health, but there are still many people suffering from selenium and zinc deficiency in China. Compared with rice, brown rice (BR) is favored because it contains more nutrients such as protein, fat, dietary fiber, vitamins, and minerals. Therefore, BR, L-selenomethylselenocysteine, and L-zinc lactate were used as raw materials; selenium and zinc extruded rice (SZER) was prepared by a twin-screw extruder. Meanwhile, SZER and BR were evaluated, respectively. Research results showed that compared with BR, SZER texture was elastic, and it was aging slowly; the internal structure was uniform, and the surface was loose and porous, so it was easier to cook and produced a pleasant aroma. The crystal structure of starch changed from A-type to V-type, the relative crystallinity and the density of the starch crystal area decreased, and part of the double helix structure was destroyed. The selenium and zinc contents of SZER were 193.03 μg/kg and 21.53 mg/kg, respectively. The edible quality of SZER was close to that of natural rice, which could not only improve the edible quality of BR but also provide an effective way for people to supplement selenium and zinc elements.