Suwanna PichaiyongvongdeeBoonyakrit RattanapunWachira SingkongTeeranuch ChysirichoteNujira RasamipaiboonJiraporn Phongsopa2025-07-072025-07-072025Current Research in Nutrition and Food Science2347467X10.12944/CRNFSJ.13.1.182-s2.0-105001726810https://repository.dusit.ac.th/handle/123456789/7302In general, most traditional cream soups are high in carbohydrates and low in calcium, fiber, and phytochemicals, which reduces their nutritional value. Therefore, the development of purple sweet potato soup fortified with Chinese kale was important to enhance its nutritional value and address malnutrition. This innovative product combines the health benefits of purple sweet potato due to its antioxidant properties, while Chinese kale was a rich source of calcium and dietary fiber, making it a more nutritious and health-promoting food. This research investigated the effects of different pre-processing and drying methods on the physicochemical and cooking properties of freeze-dried soup products made from purple sweet potato (PP) and Chinese kale (CK). CK was blanched in 1% NaCl and 1% NaHCO3 solutions and then tray-drying and freeze-drying techniques were used. It was found that CK branched in 1% NaCl solution and freeze-dried retained significant levels of chlorophyll, calcium, fiber, and antioxidants. © 2025 The Author(s). Published by Enviro Research Publishers.All Open Access; Gold Open AccessCalciumChinese KaleDrying MethodsPurple Sweet PotatoesSoup PowderArticleScopus