Effect of high temperature-vacuum treatment at different periods on drying and quality characteristics of mushroom

In this thesis, the effect of conventional drying process on mushroom drying characteristics was evaluated by applying high temperature and vacuum pressure to sliced mushroom samples in different periods. High temperature (95°C-5 min)-vacuum pressure (-90 kPa) was applied as pre-treatment, mid-treatment and post-treatment. Effect of these treatments was evaluated on drying rate and diffusion coefficient. Water activity, rehydration capacity, shrinkage analysis, texture, color, total phenolic content and antioxidant activity analysis were performed on dried mushroom samples. Microscopic properties of mushroom slices were evaluated by SEM analysis. Efficient diffusion coefficient of mushroom slices was calculated between 3.09×10-9 – 5.83×10-9 m2/s. High temperature and vacuum pressure pre-treatment increased the drying rate and diffusion coefficient compared to the control; however, its physical and chemical properties were adversely affected. Post and mid-treatments were shortened drying time but only the effect of post-drying treatment on quality characteristics was similar to the control. As a result of this thesis, it has been seen that the high temperature - vacuum application applied at different stages affects the drying characteristics, physical and chemical properties differently. It has been observed that high temperature – vacuum application in industrial systems can be applied as hybrid with conventional drying.