Abstract: In the ordinary air fryer on the addition of water spray DC pump and oil spray electromagnetic pump, developed a dual-jet function of the air fryer. The content of vitamin C in cowpeas were determined by fluorescence method after cooking through different cooking medium, the effects of air-frying with water or oil or only air on the cooking effect of cowpeas and their vitamin C were analyzed objectively, to verify the feasibility and effectiveness of the dual-jet functional design. Cowpeas had better cooking effect under air-frying condition with water/oil as medium, and the content and retention rate of vitamin C were higher, the content were (5.19±0.122) mg/100 g and (5.04±0.097) mg/100 g respectively, the retention rates were 29.34%±1.513% and 28.38%±0.985% respectively. The effect of cowpeas cooked under air-frying with only air as medium was poor, the content of vitamin C was only (3.33±0.118) mg/100 g, and the retention rate was only 17.75%±0.992%. This is closely related to the physical and chemical effects of water and oil on food during cooking.

Key words: Air fryer, Cowpea, Medium, Vitamin C