Gamma radiation in increasing productivity of Agaricus bisporus and Pleurotus sajor-caju and enhancing storage life of P. sajor-caju.

Abstract

Gamma radiation of spawn of Agaricus bisporus and Pleurotus sajor-caju at doses of 0.1 to 0.3 kGy and 0.1 to 0.25 kGy respectively, reduced the mycelial spawn run time and exerted a stimulatory effect on the growth of these two mushrooms. Irradiation also increased yield of these mushrooms. In all cases of the former, the highest yield of 2.57g was recorded from spawn irradiated at 0.3 kGy, while with the latter, best yield of 1119 g was recorded from spawn treated with 0.25 kGy. The control (non-irradiated) spawns of A. bisporus and P. sajor-caju gave yields of 2.03 g and 565 g espectively. Thus, a major boost in yields could be achieved using this technology. The shelf life of P. sajor-caju could be extended upto 9 days by 0.5 kGy of radiation, when the treated fruit bodies were held at 15°C as against the un-irradiated ones which had a shelf-life of 6 days. This dose neither adversely affected the browning of the fruit bodies at 45°C, nor lowered their protein (protein + free amino acids) and carbohydrate contents. Irradiation, however, at all the doses from 0.1 to 0.75 kGy enhanced the rehydration ratio and total free amino acid contents. The rehydration ratio of 0.62 was the maximum, reached with a dose of 0.25 kGy as against the control. which showed a value of 5.0. Dehydration along with gamma radiation treatment could play an important role for long term storage of mushrooms. Weight loss of un-dehydrated fruit bodies also decreased as a result of irradiation.