Effects of gamma irradiation to physico-chemical and microbial properties of mushrooms processed food

EFFECTS OF GAMMA IRRADIATION TO PHYSICO-CHEMICAL AND MICROBIAL PROPERTIES OF MUSHROOMS PROCESSED FOOD. It has researched the impact of gamma irradiation on Physico-chemical and microbiological properties steamed oyster mushrooms. Cooked oyster mushrooms (Pleurotus ostreatus) or pepes of mushrooms is one type of processed fast food from edible mushroom. The purpose of this study was to determine the effect of a moderate dose of gamma irradiation on the quality of steamed oyster mushrooms during storage. Materials Pepes of mushrooms that had been prepared in the packaging of banana leaves cooked, then cooled and packed vacuum (without oxygen) with polyethylene HDPE plastic lamination. Pepes of oyster mushrooms that have been wrapped in plastic was inserted into the Styrofoam box containing solid CO2 (-79 oC) subsequently irradiated at a dose of 5 and 7.5 kGy, and without irradiation as a control. After irradiated samples were stored in cold storage (refrigerator). Tests were conducted immediately after irradiation or weeks 0, 2, 4, 6, and 8 weeks, with testing parameters include testing of physico-chemical properties, microbiological and organoleptic features of subjective testing. Testing of physico-chemical properties include moisture content, pH, water activity (Aw), fat content, protein content, acid number, TBA, and antioxidant activity, while Microbial testing covering a total of aerobic bacteria and molds and yeasts. The results showed that moderate doses of irradiation does not affect the water content, pH, water activity (Aw), fat content and protein content Pepes of mushrooms, while the acid value, thiobarbituric acid (TBA), and the antioxidant activity changes mainly due to storage. Generally, the organoleptic quality of steamed mushrooms control (without irradiation) only last up to 2 weeks, while 5 7.5 kGy irradiated pepes of mushrooms can last up to 8 weeks of storage.