Optimized production of plant-derived juices and purees with minimal impact on quality aspects (HIGHQJUICE)

Although several initiatives were started in recent years to bring targeted knowledge development and dissemination on the use and application possibilities of innovative grinding, pressing and preserving technologies to food companies, their industrial implementation remains limited in Flanders. In the meantime, the results of HighQJuice project are available. For the apple juice, the combination of spiral filter press and classic thermal pasteurization resulted in a nice bright yellow color that was preserved during storage. Just like the PEF treatment, the classical thermal pasteurization resulted in a good inactivation of the PPO and POD enzymes. That was less the case with the HPP treatments. PEF treatment in turn resulted in the highest Vit C content in the juice. The juice stability in the HPP treated juices was also less good due to residual PME activity during storage. In summary, it can be said that the combination of spiral filter press and classical thermal pasteurization is the best combination for the production of long-lasting juices.

For the kale, different process intensities of a traditional thermal treatment were compared with an RF treatment. Through analyses of color, texture, taste and enzyme activity, the impact of the processing was mapped. The most intensive classical heat treatment at 128 °C resulted in the least attractive puree. There was little difference between treatment at 90 °C with the traditional approach or via RF, only some differences were measurable in the aroma profile.

The Flemish fruit and vegetable processing companies now have more concrete process information at their disposal to tackle the targeted production of juices and purees, with maximum quality retention (taste, color, etc.). Product differentiation through the use of new technology is within reach.