Thermal versus high pressure processing of carrots: A comparative pilot-scale study on equivalent basis

This report describes the first study comparing different high pressure (HP) and thermal treatments at intensities ranging from mild pasteurization to sterilization conditions. To allow a fair comparison, the processing conditions were selected based on the principles of equivalence. Moreover, pilot- and industrial-scale equipment were opted for, supporting conditions close to industrial application. The overall impact on carrot quality was characterized by analyzing a wide range of quality attributes, including specific (micro)nutrients (carotenoids and sugars), process-induced contaminants (furfural and 5-hydroxymethylfurfural), enzyme activities (pectin methylesterase and peroxidase) and other relevant quality aspects (texture, dry matter content and color). This study demonstrated that the potential benefit of HP over thermal processing of carrots is largely dependent on the processing intensity applied. Thermal sterilization affected carrot quality the most, while mild and severe thermal pasteurization, mild and severe HP pasteurization and HP sterilization resulted in a comparable overall quality. The extensive nature of this investigation and the corresponding results can be considered of key importance for further implementation of HP technology in the food industry, since a correct and complete assessment of process-induced changes is of major importance in the context of legislative aspects of novel processing technologies. ► Fair comparison of thermal and HP processing of carrots. ► Per processing intensity, thermal and HP treatments with equivalent microbial safety. ► In-depth characterization of carrot quality after thermal and HP processing. ► Potential benefit of HP over thermal processing depends on processing intensity. ► Thermal sterilization largest impact on quality, all other treatments comparable.