Encapsulated kinnow peel powder using freeze drying: Effect of maltodextrin and gum arabic concentrations on physiochemical, functional and thermal properties

Abstract

Microencapsulation is a promising technology to protect the sensitive compounds, and volatile substances present in plant extract. This study investigates the microencapsulation of kinnow peel powder (KPP) using freeze drying, focusing on gum arabic (GA) and maltodextrin (MD) as coating materials. Six formulations were prepared with varying ratios of kinnow peel slurry (KPS), MD, and GA: T1 (100/0/0), T2 (85/10/5), T3 (85/5/10), T4 (85/7.5/7.5), T5 (85/15/0), and T6 (85/0/15). T6 showed the highest emulsion stability and smallest droplet size, indicating superior stability. Increased GA concentration in the wall material enhanced encapsulation efficiency, reduced water activity, and improved flowability while decreasing hygroscopicity. T6 (85/0/15) had the best encapsulation efficiency, while T5 (85/15/0) was most effective in retaining phenolics (92.81 %), flavonoids (92.17 %), and antioxidants. Conclusively, this study highlights that the agro-industrial waste KPP can be utilized as bioactive compound-enriched microencapsulated powders, suitable for fortification in various products in the food industry.