Effect of modified atmosphere packaging on low molecular weight carbohydrates of oyster mushrooms

Experiments were conducted to study the effect of modified atmosphere packa ging on low molecular weight carbohydrates of oyster mushrooms (Pleurotus o streatus), during post-harvest storage at 5 and 15 degreesC, using highly p ermeable micro-perforated oriented polypropylene (OPP) film and ordinary OP P film packages. Changes in sugar and sugar alcohol contents among differen t treatments were measured, using high performance liquid chromatography (H PLC) technique. Among free sugars, trehalose content was observed to be var ying between pileus and stipe portion of the mushroom, in response to in-pa ck gaseous environment. Increases in pileus and stipe portions trehalose an d total sugar content were observed for mushrooms packaged in micro-perfora ted film packages at both the storage temperatures of 50 and 15 degreesC, w hile they reduced in ordinary OPP film packages and the reduction was obser ved to be more in stipes than pileus, indicating that low O-2 (0.446) and h igh CO2 (12 to 13%) observed in these packages had more adverse effect on s tipe portion trehalose and total sugar content. Among sugar alcohols. only mannitol was found to be affected under low O-2 and high CO2 conditions, pr evailing in ordinary OPP film packages at both the storage temperatures.