Impact of three different dehydration methods on nutritional values and sensory quality of dried broccoli, oranges, and carrots

Abstract

Radiant Energy Vacuum (REV)‐dried broccoli, oranges, and carrots prepared by the optimal drying protocols determined in this study were compared to the freeze‐dried and air‐dried samples based on the nutritional values before and after drying. An accelerated shelf‐life study for REV‐dried broccoli, oranges, and carrots was also conducted. For all the samples, REV drying significantly shortened the processing time. The REV‐dried samples had much higher retention of the nutritional values (vitamin C, β‐carotene) compared to the conventional air‐drying process, and the values were also competitive to those of the freeze‐dried samples. Although freeze‐drying resulted in the best rehydration property, the REV‐dried samples still earned the highest scores in the sensory test. In the accelerated shelf‐life study conducted on the REV‐dried samples, the moisture content and water activity stayed at the same level, but the nutritional values showed a downward trend. The sensory properties fluctuated in the shelf‐life but still gained positive feedback from the panelists. Moreover, the testing method for β‐carotene content was uniquely designed in this project and could be a semi‐quantitative method to refer to.