Effect of Blanching Methods on Chlorophyll Content and Quality Changes During Frozen Storage of Cowpea

This study aims to explore ways to improve the postharvest green preservation of cowpea pods and subsequent quality changes during frozen storage. Chlorophyll content was the main evaluation indicator. In single-factor and orthogonal experiments, the best results were obtained by storing sliced pods at −20 °C after blanching them at 100 °C for 50 seconds in a mixture containing 0.09% baking soda and 1.5% soybean oil, with a solid-to-liquid ratio of 1 : 10. These conditions resulted in the highest chlorophyll and vitamin C content, reduced weight loss and decay rates, and superior sensory quality, significantly extending market quality from 15 to 25 days of storage.