Review on Non-thermal Technologies for the Preservation of Fruit Juices

Liquid food industries use different preservation methods to extend the shelf life of products by reducing both enzymatic and microorganism activities. Emerging non-thermal pasteurization techniques are applied in order to avoid thermal processes maintaining the microbial safety and quality of liquid foods. Non-thermal preservation technologies used in the liquid food industry include high-pressure processing (HPP), pulsed electric field (PEF), ultraviolet light (UV-C) and ultra-sonication (US). HPP is a method to target specific organisms by applying a pressure range of 100-1,000 MPa. PEF uses short pulses of a strong electric field applied to a flowing liquid food which affects the whole cell membrane of the organism. UV-C treatment at 253.7 nm has been proven to be appropriate for maintaining liquid quality and minimal deterioration of nutrients. US is applied to liquid foods in a lower frequency range of 20-100 kHz and a higher sound intensity of 10-1,000 W/cm to the breakdown of cells. According to scientific literature, those methods have been applied to fruit juices like orange, apple, pear, coconut water, etc. Most of the non-thermal methods achieved the Food and Drug Administration (FDA) requirement of a 5-log reduction of microorganisms without deteriorating the sensory and nutritional attributes of fruit juices. Some of these methods have already been commercialized and others are still in a pilot scale. This study gives a comprehensive overview of published literature regarding the potential for using non-thermal pasteurization methods to extend the shelf life of different fruit juices with minimal deterioration of nutritional and sensory quality.