Pistachio byproucts [s.i.c.] as substrate for shiitake mushrooms

The United States is expected to lead the global pistachio industry during the 2009-2010 harvest season, bringing in about 175,000 metric tons of nuts. Approximately 63% of this pistachio harvest will be composed of shells and hulls, the byproducts of the pistachio industry. The disposal of these byproducts is proving costly to producers, and many current disposal methods are damaging to the environment. It was the objective of this study to develop a potential market for pistachio shells and hulls by utilizing them as a mushroom substrate component. The production of shiitake mushrooms on a substrate composed of pistachio shells and hulls was evaluated to determine their suitability for this use. Five experimental substrates were developed using different ratios of shells and hulls. The mushroom production on some experimental blocks was shown to be more prolific than that of the control blocks, demonstrating that pistachio shells and hulls are a suitable substrate for the growth of shiitake mushrooms. Various quality parameters were measured on the harvested mushrooms such as color, texture, moisture content, and size, and it was found that the mushrooms grown on experimental substrates showed similar characteristics to those grown on the control. This study demonstrates potential to minimize or even eliminate the pistachio harvest waste stream, thus eliminating the environmental hazards associated with their current disposal, while at the same time developing a more cost effective substrate for the production of shiitake mushrooms.