Effect of packaging methods and storage conditions on quality characteristics of flour product naan

The quality characteristics of naan from flour products under various packaging methods stored at different temperatures (25, 4 and - 20 °C) for different time (0-49 days) were investigated. Packaging methods included ordinary plastic packaging (OPP), vacuum packaging (VP) and deoxygenation packaging (DP). Sensory value, acid value, moisture content and microbial count of naan during storage were evaluated. The results showed that the total demerit points of sensory of DP naan stored at 25 °C had considerably lower levels. The moisture content of naan in DP and VP at 25 °C during storage had not been affected, while in OPP increased; the acid values of naan increased, but in DP was the lowest; the total microbiological count (MC) of naan in OPP, VP and DP at 5th day reached 2.25, 3.04 and 1.99 log CFU g^-1, respectively. At 4 and - 20 °C, the moisture content of naan in OPP, VP and DP during storage reduced, the acid values at storage the 38th day dramatically increased (p < 0.05), the MC slowly increased, but these in DP samples was lower. The Ultraviolet (UV) and microwave (MW) radiation time was varied to study its effect on the shelf life of naan at 25 °C. The moisture content of UV and MW treated naan were not significantly different from those of control naan (p > 0.05), but the demerit points, acid values and MC reduced, the shelf life of naan was extended. The combination of DP and MW methods was a better efficient way to reduced negative quality changes of naan during storage.