Infuence of gamma radiation on some textural properties of fresh and dried oyster mushrooms (Pleurotus ostreatus)

Abstract

Food processing involves the input of thermal, mechanical, photonic or ionising radiation energy.Gamma irradiation is usually perceived to energize and make foods radioactive which ultimately modify their chemical composition mainly the texture. Texture profile analysis (TPA) was used to evaluate the texture parameters of hardness, fracturability, cohesiveness, springiness, gumminess, chewiness, adhesiveness and resilience of the mushrooms. Fresh, dried and rehydrated mushrooms (Pleurotus ostreatus) were exposed to gamma radiation doses of 0, 0.5, 1, 1.5 and 2 kGy at a dose rate of 1.7 kGy hr-1.The fresh products had an average moisture content of 80.3- 85.0% while dried mushrooms had average moisture content of 11- 14%. Rehydrated mushrooms had moisture content range of 42.3- 49.7%.Dose of 1.5 kGy was most apparent on hardness, resilience, springiness and adhesiveness. Cohesiveness increased as dried mushrooms were rehydrated. Hardness, fracturability, gumminess and chewiness decreased as radiation increased with dried mushrooms. Although the results obtained showed that irradiation had significant (P<0.05) effects on fresh, dried and rehydrated mushrooms, irradiation process is encouraged because of persistent high food losses from infestation,contamination, and spoilage; food-borne diseases; and growing international trade in food products that must meet strict import standards of quality and quarantine