Influence of high-pressure processing at different temperatures on free amino acid and volatile compound profiles of dry-cured ham

The effect of high pressure processing (HPP) (600 MPa during 6 min) at different temperatures (0, 20 and 35 °C) in dry-cured ham has been studied in order to optimize the technique and reduce its impact on chemical characteristics, which are widely related with sensorial parameters. Vacuum-packed slices from 120 dry-cured hams were used. These slices were submitted to four different treatments: without application of pressure or temperature (CO), high pressure treatment at 0 °C (HPP-0), high pressure treatment at 20 °C (HPP-20), and high-pressure treatment at 35 °C (HPP-35). The effect of the treatments on free amino acids and volatile compounds profile was evaluated. The HPP-35 treatment significantly (P < 0.001) increased the total free amino acid content (6415.63 mg/100g dry matter) when compared to the contents of the CO, HPP-0 and HPP-20 treatments (5313.16, 4787.30 and 5072.48 mg/100g dry matter, respectively). Significant differences were also found among treatments in the content of 13 individual free amino acids, and HPP-35 samples presented the highest values in 12 of them. Similarly, the total volatile compound content was influenced by temperature-assisted HPP treatments. The HPP-35 treated samples showed the highest content (78,415.27 AU × 103/g dry-cured ham) and the HPP-0 treated samples the lowest content (28,584.14 AU × 103/g dry-cured ham). No significant differences were observed between CO and HPP-20 treatments. The fractions of volatile compounds derived from lipolysis, proteolysis and microbial activity were significantly modified by the different treatments. HPP-0 samples presented lower values of alcohol and hydrocarbon contents, whereas HPP-35 samples showed higher ketone and ester contents.