Development and optimization of a drying process for mushrooms in regard to product quality

Edible mushrooms are appreciated for their delicacy, flavour, nutritional and medicinal value. The well-established market acceptance of cultivated fruit bodies such as Agaricus bisporus and Pleurotus ostreatus has been followed by a spectacular increase in the popularity of wild-growing mushrooms. Boletus edulis and Morchella esculenta are products of considerable commercial and gastronomic importance in international markets. Owing to their extremely perishable nature along with the seasonal availability of fresh commodities, drying appears to be a useful approach to extend shelf life and ensure worldwide distribution. The primary goal of this research project is to design, characterize and evaluate a drying process for various mushrooms using alternative drying applications such as microwave dying or freeze drying in combination with conventional hot-air drying optimizing quality of dried products and drying time.

The objectives of the project are to:

• examine the effect of drying air conditions (temperature, humidity, air velocity) on drying behaviour of various mushrooms and to evaluate appropriate single-layer models for simulation of drying kinetics.
• assess the impact of the selected parameters on the end product quality in terms of colour, texture and rehydration ratio.
• provide experimental sorption isotherm data and apply a suitable numerical model to fit the sorption kinetics.
• determine colour and shrinkage changes during hot-air drying and correlate these properties with moisture content.