Furan formation as a function of pressure, temperature and time conditions in spinach purée

•Furan concentration increased as a function of processing temperature and time.•Rate of furan formation was (apparently) independent of precursor concentration.•Pressure level of 600 MPa had no effect on the rate of furan formation.•Furan reduction by high-pressure high-temperature processing due to shorter process.

In recent studies, innovative high-pressure high-temperature processing (HPHT) has presented itself as an interesting alternative for furan reduction in sterilized, vegetable-based foods. In order to explain the observed furan reduction following HPHT treatment, furan formation was studied under a range of pressure, temperature and time conditions, using spinach purée as a case study. For all the treatments, no furan was detected during the dynamic heating-up phase, followed by a steady increase in furan concentrations at isothermal(-isobaric) conditions. The increase in furan concentrations at isothermal(-isobaric) treatment conditions could be adequately described by an empirical, zero-order model. A pressure level of 600 MPa did not affect the rate of furan formation in spinach purée, as opposed to the processing temperature and time. As a result, the reduced furan concentrations for HPHT processing could be explained by the faster heating and cooling rates, resulting in shorter processing times as compared with conventional retort processing.