Color, Mechanical, and Microstructural Properties of Vacuum Assisted Microwave Dried Saskatoon Berries

Saskatoon berries were dried using a vacuum assisted microwave technique. Central composite rotate design and response surface methodology were used to develop the regression models and to study the influence of drying processing variables (microwave power, drying time, and fruit load) on color, mechanical properties, and microstructure of dried berries. All the three variables had significant effects on the above mentioned properties (p < 0.05). Drying affected the color at variable levels and increased the lightness of dried berries compared to frozen berries. Hardness, gumminess, and chewiness of dried berries increased and springiness and cohesiveness of dried berries decreased with microwave power and drying time. The porosity and the destruction level in the microstructure of dried berries increased with the microwave power. The findings of this study will be useful to identify desirable microwave-vacuum drying operating conditions for targeted dried Saskatoon berry products.