Novel drying pretreatment technologies and their applications in the food industry

Fresh foods especially fruits, vegetables, meat, poultry and aquatic products are highly perishable due to high moisture content and rich nutrient matrix, which leads to microbial growth, enzymatic and oxidative reactions. As a common food processing method, drying inhibits spoilage microorganisms and oxidation reactions as well as retaining nutrients by reducing the moisture content and water activity in food, thus extending product storage life. Pretreatment is a key step for the drying operation. Compared to traditional pretreated and untreated samples, the development and application of new non-thermal pretreatment technologies can not only improve moisture distribution and reduce energy consumption, but also further improve the functional and nutritional attributes of dried products. In the present study, some novel non-thermal pretreatment technologies including cold plasma, ultrasound and pulsed electric field were reviewed. Their detailed working principles and equipment, positive effects on agricultural products and meat products, as well as some possible pros and cons for application are also presented to provide some reference for the development and application of these pretreatment technologies.