Abstract:
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/cm2 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.
