the effect of pre-treatments in combination with hot air, vacuum and hot-a microwave drying methods the progress of the drying process, and textural, and colour and rehydration rate on button mushroom (agaricus bisporus)

the effect of pre-treatments in combination with hot air, vacuum and hot-a microwave drying methods the progress of the drying process, and textural, and colour and rehydration rate on button mushroom (agaricus bisporus) slices were investigated. in this work, one of the following methods: hot air, vacuum drying or microwave-assisted convective drying and also different pre-drying treatments, viz. blanching (with hot water or vapour) and sulphitation, were applied. textural properties of button mushroom were measured during drying and rehydration using a texture analyser. the colour changes of samples during drying and rehydration were analysed applying a hunterlab colorimeter. during drying, hardness of mushrooms was increased. sulphitation pre-treatment improved the structural and rehydration rate of the dried samples, but had varying effects on the colour. microwave energy reduced drying time and can modify the structure, colour and texture strength of the final product. the effect of microwave treatment on colour varied with the type of pre-treatment applied before drying. microwave samples showed also the highest rate of rehydration among all samples.