Effect of modified atmosphere packaging on the quality of germinated parboiled brown rice

Germinated parboiled brown rice (GPBR) is a healthy Thai food. To extend the quality of GPBR cv. KDML 105 with 8.06% moisture content, the effects of three packaging conditions on the characteristics of GPBR were investigated. GPBR in laminated (nylon/LLDPE) bags was sealed as follows: vacuum-sealed, 40% N₂-sealed with 60% CO₂ (60% CO₂+40% N₂), or 100% N₂-sealed before storage under ambient conditions (30±2°C, 70±5% RH) for 15 months. GPBR in all the packages exhibited delayed fungal proliferation and very low aflatoxin B₁ contamination (<0.82 μg/kg). The 100% N₂-sealed package was the best treatment to preserve GPBR quality, as indicated by the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity and free fatty acid content as well as the least rancidity and brownness. As observed through a scanning electron microscope, compared with vacuum-sealed packages and those sealed with 60% CO2+40% N₂, the lowest hardness texture and the least elongation of cooked rice in 100% N₂-sealed package were linked to a lesser compact GPBR endosperm ultrastructure.