Effect of Four Drying Methods on the Quality of Intermediate Moisture Lowbush Blueberries

Abstract

Lowbush blueberries have been processed by freeze dry, forced air, vacuum oven, and micro-convection methods to a moisture content of 16-25%. The drying effect on the product quality was evaluated. There were no significant differences in vitamin A and niacin retention except freeze dried berries had higher vitamin C retention. No significant differences occurred in retention of mineral content except higher sodium and lower magnesium were found in the micro-convection and freeze dry methods, respectively. Freeze dried and vacuum dried blueberries had higher soluble solids retention and were darker and redder than forced air or micro-convection dried berries. Freeze dried berries were found to have highest rehydration ratio and lowest bulk density.

Effect of drying method on the moisture sorption isotherms for Inonotus obliquus mushroom

“…2). This is due to the fact that freeze-drying method provides a dry product with porous structure as supported by scanning electron micrographs (Lee, Seog, & Lee, 2007) and little or no shrinkage and with higher adsorptive capacity than the other methods (Tsami et al, 1999;Yang & Atallah, 1985). This is in accordance with the results of Ko, Lee, Lee, and Ha (1999) on Shiitake mushroom powder, those of Shin, Hwang, and Yoon (2003) on ginger powder, and those of Park, Ha, and Lee (2002) on Agaricus mushroom powder.…”

Effects of drying on the phenolics content and antioxidant activity of muscadine pomace

“…HAD is generally favoured due to its low operating cost, and because comparatively less drying time is required than that for FD. In conventional HAD, high temperatures are employed that adversely affect the texture, colour, flavour, and nutritional value of the products in question (Schadle, Burns, & Talley, 1983;Yang & Atallah, 1985). FD is a more "gentle technique" that does not expose the product to high temperatures and helps preserve quality parameters (e.g., colour, flavour, nutrients, phenolics, and antioxidant activity) associated with the product (Flink, 1975).…”

Drying Related Properties of Apple

“…texture (Krokida et al, 1998a). density and porosity (Krokida & Maroulis, 1997) and sorption characteristics of materials (Yang & Atallah. 1985).…”