Evaluation of the viscoelastic properties of pork liver pâté during sterilisation observed in situ

Abstract

The first aim of the study was to observe in situ changes in the viscoelastic properties of pork liver pâté during an increase in temperature (the target temperature of 122 °C), holding it (10 min), and the subsequent cooling thereof using a dynamic oscillatory rheometry equipped with a pressure cell. At the same time, the samples were treated according to the same sterilisation mode in an autoclave. The second objective was to characterise the physical, chemical and microscopic properties of the sterilised pork liver pâté samples after 7 days of storage at 5 °C. A sharp decrease in the values of the storage (G'; Pa) and loss (G''; Pa) moduli up to ≈58 °C was followed by a stagnation of these parameters up to ≈70 °C and a further increase in G' and G'' up to ≈85 °C. After cooling the sterilised samples, the G' and G'' values were significantly higher than those of the original untreated sample. Knowledge about the course of the viscoelastic moduli development during sterilisation and subsequent cooling and the quality characteristics of final food products is crucial for the control of these processes during manufacturing and for information important for pipeline transport. In the future, selected hydrocolloids could be evaluated as possible substances for confirmation of their effect on the viscoelastic properties during sterilisation.