High pressure and foods—fruit/vegetable juices Original Research Article

The high pressure pasteurisation is capable to preserve the nutritional substances in juices such as sulforaphane in broccoli juice. This paper deals with the procedures how to maintain the highest content of this compound and other nutritional substances and how to prepare the consumer acceptable form of this juice. The final product—the apple–broccoli juice functional food (food supplement) was experimentally produced and tested. The high pressure pasteurisation process (500 MPa for 10 min) is capable to inactivate more than 5 log decades of the viable microorganisms present originally in the raw juice and product is free of coli-form bacteria, yeast, moulds and salmonella during 30 days of storage at the chilled room temperature conditions (temperature up to 5 °C). The high-pressure treated broccoli juices are comparable in sulforaphane content and anti-mutagenic activity with frozen version. Freezing of the broccoli before juicing decreased sulforaphane formation. The content of vitamin C depends on the holding time of the pressurisation, but it is independent of pressure level. The sensory quality of the high pressure treated apple–broccoli juice is comparable with frozen juice up to the 70 days of the storage.