Effect of Drying Method and Coating With Gum Arabic on Physicochemical Properties, Betalain Content, LDL Oxidation, and Storage Stability of Dried Red Beetroot Slices

Red beetroot is a unique vegetable crop with high nutritional value and various health benefits, but due to the short shelf life, it requires a suitable preservation method. The purpose of the current investigation is to study the impacts of pretreatment coating with gum Arabic and drying method (oven, microwave, and freeze-drying) on the quality parameters and storage stability of beetroot slices. Freeze-dried beetroot samples showed the lowest moisture content (MC) (7.59%) and the highest rehydration ratio (RR) (5.47), betalain content (48.57 mg/100 g), antioxidant activity (70.92%), and overall acceptability scores (4.48). Generally, the pretreatment coating with gum Arabic reduced the degradation of betalain and antioxidants and maintained higher sensory scores of dried beetroot samples compared to uncoated ones. The beetroot extract prepared from freeze-dried and coated with gum Arabic samples decreased the oxidation of low-density lipoprotein (LDL) compared to control. Freeze-dried samples coated with gum Arabic revealed higher storage stability (after 4 weeks of storage at room temperature) in terms of betalain content and antioxidant activity with values of 43.84 mg/100 g and 67.02%, respectively, compared to uncoated ones which recorded 35.15 mg/100 g and 64.22% for betalain content and antioxidant activity, respectively. Generally, freeze-drying and coating with gum Arabic is considered a promising treatment to maintain the quality and storage stability of dried beetroot slices. Further investigations including nutritional, technological, and economic aspects are required for the optimum application in the future.