Research on Processing Characteristics of Sedum aizoon L. and Development of Low-GI Meal Replacement Powder

Low Glycemic Index (low-GI) meal replacement powders are increasingly sought for weight management. Sedum aizoon L. is a promising vegetable raw material, yet its processing characteristics remain poorly characterized. This study systematically evaluated the effects of four pretreatments (untreated, freeze–thaw, blanching, blanching plus green protection) and two drying methods (hot-air drying, freeze drying) on S. aizoon L. from the Diqing Plateau, Sedum aizoon L., and optimized a low-GI meal replacement formula. The results revealed that blanching and blanching plus green protection shortened hot-air-drying time by approximately 50% and improved the flowability and compactness of powder (Hausner ratio 1.26, Carr index 20.46%). Qualitative and quantitative analyses revealed that Sedum aizoon L. contained various bioactive substances such as flavonoids and phenolic acids. Freeze drying better retained polyphenols, flavonoids, and vitamin C; the freeze–thaw plus freeze drying exhibited the optimal color protection effect with a chlorophyll content of 1.4843 mg/g. Dried Sedum aizoon L. was evaluated by a trained panel plus electronic nose analysis, while the meal replacement powder was assessed by electronic nose and electronic tongue. A single-factor test, a Plackett–Burman test and a response surface methodology were adopted to optimize the optimal formula of meal replacement powder: Sedum aizoon L. powder 2.3 g, skim milk powder 2.8 g, sugar powder 1.6 g, grain powder 4 g, nut powder 2.6 g, and konjac powder 0.55 g. The meal replacement powder has low estimated GI (eGI) value (eGI < 55) and high dietary fiber content (43.4 g/100 g), with superior aroma and taste versus a commercial reference. These findings support the industrial production of Sedum aizoon L.-based low-GI meal replacement food.