Overview of Nonthermal Processing Techniques of Citrus Fruits

Consumers perceive citrus juices, especially orange juice, often regarded as a plentiful reservoir of vitamin C, minerals, and carotenoids. Improving citrus fruit juices’ shelf life and quality without altering physiochemical and organoleptic characteristics is a big challenge for the food processing industries. The bioactive compounds (being volatile) present in citrus fruits are susceptible to heat treatment and result in undesirable nutritional and organoleptic changes. It laid the concept for developing several nonthermal process techniques for the minimal and natural processing of citrus fruit juices and its products as an option for heat processing. The nonthermal method can suit all needs while retaining the freshness of citrus fruit juice. Among the various nonthermal methods, pulsed electric field, sonication, high-pressure processing, high-pressure homogenization, irradiation, and membrane processing result in less undesirable influence on sensory, flavor, and nutritional characteristics. Integrated nonthermal techniques have the advantage of reduced process and residence time, efficient heat and mass transfer, reasonable control over browning reactions, enhanced juice quality, prolonged shelf life, and greater control over enzymatic activity and microbial growth in citrus fruit juices.