This study investigated the effects of five wall materials (soybean protein isolate, gum arabic, maltodextrin, resistant starch, and a soybean lecithin calcium caseinate mixture) on the physicochemical properties of spray-dried bitter gourd powders. All wall materials reduced moisture content, water activity, browning, agglomeration, and bitterness. Soybean lecithin calcium caseinate mixture was best at reducing hygroscopicity and masking bitterness, while soybean protein isolate best protected color. All wall materials improved flavonoid, saponin, and vitamin C preservation. Spray-dried powder with soybean protein isolate had the highest antioxidant and α-glucosidase inhibitory activity. These findings offer valuable guidance for producing high-quality bitter gourd products and processing similar fruits.
