Physico-chemical and rheological properties of fruit and vegetable juices as affected by high pressure homogenization: A review

In recent years, the consumers' demands for fruit and vegetable juices (F&VJ), such as higher nutritive values, minimal processing and high quality have been growing rapidly. High pressure homogenization (HPH) is a non-thermal technology that has been widely studied as a partial or total substitute for thermal fluid food processing. The present work summarized the effect of HPH on the particle size distribution (PSD), microstructure, pulp sedimentation (PS), serum cloudiness (SC) or turbidity, color change (CC), bioactive compounds (BC) and antioxidant activity (AA), rheological properties (RP) and sensorial properties. The juices considered were apple, banana, blueberry, carrot, cashew apple, grape, kiwifruit, mango, orange, clementine, pineapple, salustiana, strawberry, taro and tomato juices. HPH changed the F&VJ PSD, physical properties, RP, SC, PS behavior, color and microstructure by disrupting the suspended pulp particles. Recent progress in high-pressure homogenization technology and the design of new homogenization valves were able to stand pressures up to 400-600 MPa. This have opened new opportunities to homogenization processing in the food industry to reduce particle sizes well below the micron and, consequently, permitted the development of new products with differentiated from traditional ones by physico-chemical characteristics and RP. It caused the size reduction of juices' particle below the visual detection limit. The successful application of HPH treatments may provide with a new generation of minimally processed products, hopefully closer to the fresh ones in relation to the organoleptic and nutritive properties as well, as safe and lasting as the pasteurized ones. In addition, it can improve viscosity, color, cloudiness and stability of suspended solids (SS) in F&VJ.