Abstract

The product could not be effectively expanded and the puffing temperature was too high, which usually occurred during the explosion puffing drying process of fruits and vegetables. CO₂ high-pressure and low-temperature explosion puffing drying technology was investigated as potential means for the production of apple snack food. The samples were pre-dried with hot air to a moisture content of 15% to 20% (w.b.). The process factors including puffing pressure difference (0.86–1.54 MPa), puffing temperature (53–87 °C), and vacuum drying time (28–62 min) were investigated using response surface methodology with central composite design. The optimum CO₂ high-pressure and low-temperature explosion puffing drying conditions were puffing pressure difference, puffing temperature, and vacuum drying time of 1.25 MPa, 74 °C, and 33 min, respectively. At this optimal condition, expansion ratio, rehydration ratio, and crispness were found to be 1.7, 2.23 g/g, and 29.3, respectively. Apple crisps obtained under optimal processing conditions have a highly porous structure from SEM micrographs.

摘要

产品不能有效膨化，膨化温度过高，多发生在果蔬爆炸膨化干燥过程中。研究了CO ₂高压低温爆炸膨化干燥技术作为生产苹果休闲食品的潜在手段。样品用热空气预干燥至水分含量为 15% 至 20% (wb)。使用响应面方法和中心复合设计研究了包括膨化压差 (0.86–1.54 MPa)、膨化温度 (53–87 °C) 和真空干燥时间 (28–62 分钟) 在内的工艺因素。最佳 CO ₂高压和低温爆炸膨化干燥条件分别为膨化压差、膨化温度和真空干燥时间分别为1.25 MPa、74 ℃和33 min。在此最佳条件下，膨胀率、再水化率和脆度分别为 1.7、2.23 g/g 和 29.3。从 SEM 显微照片来看，在最佳加工条件下获得的苹果脆片具有高度多孔的结构。