Effect of cooking and preservation on nutritional and phytochemical composition of the mushroom Amanita zambiana .

The effect of different cooking and preservation methods on the nutritional and phytochemical composition of the mushroom, Amanita zambiana , was investigated. Fresh mushrooms were boiled in water, fried, or microwaved. In addition, fresh mushrooms were either air-dried for 7 days or frozen at -20°C for 14 days. The protein, lipid, carbohydrate, and phenolic content of the treated mushrooms were measured and compared to the fresh mushroom contents. Frying increased the protein (2.01% ± 0.2% [fresh mushroom] to 2.23% ± 0.09%), lipid (14.68% ± 0.9% to 15.56% ± 0.34%), and carbohydrate (0.89% ± 0.01% to 2.69% ± 0.03%) content, while microwaving increased the protein (2.01% ± 0.2% to 3.64% ± 0.08%) and carbohydrate content (0.89% ± 0.01% to 2.26% ± 0.09%). Boiling only increased the carbohydrate content (0.89% ± 0.01% to 1.71% ± 0.05%) of the mushroom and significantly decreased ( p  < .05) the phenolic content (8.77 ± 0.1 to 1.46 ± 0.2 mg gallic acid equivalent (GAE)/g mushroom). Drying resulted in significant increase ( p  < .05) in protein (2.01 ± 0.2% to 24.36 ± 0.09%), carbohydrate (0.89% ± 0.01% to 58.67% ± 3.29%), and phenolic contents (8.77 ± 0.1 to 119.8 ± 0.7 mg GAE/g mushroom), while freezing only increased the carbohydrate content (0.89% ± 0.01% to 1.77% ± 0.03%). From the three cooking methods studied, frying is recommended as the most effective cooking procedure in retaining or enhancing the mushroom nutrients, while drying is a better preservation method than freezing.