Supercritical CO₂ food drying technique was investigated on red bell pepper with a lab-scale reactor equipped with CO₂ recirculation. Box–Behnken design was used as experimental design to analyze the impact of temperature (313–333 K), pressure (10–14 MPa), CO₂ flow rate (80–220 kg/h), and treatment time (6 and 16 h) on the final water activity. The results demonstrated that temperature was the most influential variable, reaching the lowest value of water activity (a_w = 0.262) at 333 K, 12 MPa, and 100 kg/h. Efficient drying with a similar final water activity could be achieved at the lowest temperature considered (313 K) and longer drying time (16 h) with an appropriate combination of pressure (14 MPa) and flow rate (160 kg/h). Sc-CO₂ samples showed similar values of color changes compared with freeze-dried samples with main differences corresponding to the “a” and “b” axes, i.e., in red and yellow. Textural properties of Sc-CO₂ dried samples were not statistically different compared with freeze-drying. Sensory evaluation showed promising evidence for the use of supercritical CO₂ as an alternative drying method to produce dried bell pepper products.

使用配备有CO ₂再循环的实验室规模的反应器，在红灯笼椒上研究了超临界CO ₂食品干燥技术。Box–Behnken设计用作实验设计，以分析温度（313–333 K），压力（10–14 MPa），CO ₂流量（80–220 kg / h）和处理时间（6和16）的影响h）关于最终的水活度。结果表明，温度是影响最大的变量，水活度最低（a _w = 0.262）在333 K，12 MPa和100 kg / h的条件下。在考虑的最低温度（313 K）和更长的干燥时间（16 h）的情况下，通过适当地组合压力（14 MPa）和流速（160 kg / h），可以实现具有类似最终水分活度的有效干燥。与冻干样品相比，Sc-CO ₂样品显示出相似的颜色变化值，主要差异对应于“ a”和“ b”轴，即红色和黄色。与冷冻干燥相比，Sc-CO ₂干燥样品的质地特性在统计学上没有差异。感官评估表明，使用超临界CO ₂作为生产干燥甜椒产品的替代干燥方法的有力证据。