Comparison of Freeze-Drying with Three Different Combinations of Drying Methods and Their Influence on Colour, Texture, Microstructure and Nutrient Retention of Button Mushroom (Agaricus bisporus) Slices

Mariga, A. M

2013

ABSTRACT

Freeze-drying (FD) and three different combinations of drying methods: freeze-drying combined with hot air drying (FD+AD), freeze-drying combined with vacuum drying (FD+VD) and freeze-drying combined with microwave vacuum drying (FD+MVD) were used to dry button mushroom slices. A comprehensive analysis of dried products was performed on their colour, texture, nutrient retention, microstructure and energy consumption. The results showed that, under conditions of 38 % moisture content changing point, most of the parameters including L* values, a* values, average density and hardness of FD+VD and FD+MVD samples had no remarkable changes (p>0.05) compared with FD samples. However, only FD+MVD method can reduce drying time by 35.63 % in comparison of FD method, although all the combination drying methods can reduce the energy consumption. Moreover, FD+VD and FD+MVD products were better than FD+AD products in nutrient retention except that content of vitamin C was comparatively lower during FD+MVD process. In conclusion, the FD+MVD method has advantages in terms of efficiency and energy saving and could be preferred to produce high-quality products.

Copyright © 2019  Chuka University. All Rights Reserved.