Atmospheric Composition and Respiration of Fresh shiitake Mushroom in Modified Atmosphere Packages

The respiration rates of fresh shiitake mushroom were measured in modified atmosphere packaging (MAP) with LDPE and PVC films at 0,5,15,20 and 30℃. The results indicated that respiration rates were suppressed by decreasing O2 and increasing CO2 concentration at 5, 15, 20 and 30℃, but it was not changed much at 0℃ inside both LDPE and PVC packages. The respiratory quotient(RQ) breakpoints were mainly controlled by O2 concentration and little affected by CO2 concentration. Moreover, there was temperature dependence of RQ breakpoint for fresh mushroom in MAP with high linear correlation confident (r=0.928). In the aerobic respiration period, the respiration rates of fresh mushroom were also significantly affected by O2 concentration. The effect of the storage time became grater factor next toO2 concentration at 15 and 20℃. These results suggest that better keeping quality for fresh shiitake mushroom could be obtained from low O2 atmosphere conditions above RQ breakpoint at low temperature