High Hydrostatic Pressure vs. Thermal Pasteurization: The Effect on the Bioactive Compound Profile of a Citrus Maqui Beverage

Abstract

The effects of high hydrostatic pressure (HHP) compared to thermal pasteurization (TP) were studied in healthy citrus-maqui beverages. The impact of the processing technologies on the microbiological and phytochemical profile was assessed by applying two HHP treatments at 450 and 600 MPa for 180 s and TP at 85 °C for 15 s. The shelf life under refrigeration (4 °C) and room temperature (20 °C) was monitored for 90 days. All treatments ensured microbiological stability at both storage temperatures. Aside from that, the physicochemical parameters were not significantly different after processing or throughout the storage period. Regarding color parameters, an increase in the reddish coloration was observed during storage for those beverages treated by HHP. In general, phenolic compounds were little affected by the processing technique, even when treatment under HHP was more stable than by TP during storage. On the other hand, vitamin C showed great degradation after processing under any condition. It can be concluded that HHP is an effective alternative to thermal treatments, achieving effective microbial inactivation and extending the shelf life of the juices by contributing to a better preservation of color and bioactive compounds.

Keywords: anthocyanin; flavanones; high hydrostatic pressure; thermal pasteurization; vitamin C.

Figure 1

Changes in content of vitamin C (mg/100 mL) for juices subjected to high hydrostatic pressure (HHP—450 MPa and HHP—600 MPa) and thermal pasteurization (TP—85 °C), measured during storage for 90 days under refrigerated conditions at 4 °C (A) and 20 °C (B) under darkness conditions. Bars with different lowercase letters within each time point were different statistically at p < 0.05 according to the analysis of variance (ANOVA) and Tukey’s multiple range test.

Figure 2

Changes of content in the total flavanones (mg/100 mL) of juices subjected to high hydrostatic pressure (HHP— 450 and HHP —600 MPa) and thermal pasteurization (TP— 85 °C), measured during storage for 90 days in refrigerated conditions at 4 °C (A) and 20 °C (B) under darkness conditions. Bars with different lowercase letters within each time point were different statistically at p < 0.05 according with the analysis of variance (ANOVA) and Tukey’s multiple range test.

Figure 3

Changes in content of total anthocyanins (mg/100 mL) of juices subjected to high hydrostatic pressure (HHP—450 and HHP—600 MPa) and thermal pasteurization (TP—85 °C), measured during storage for 90 days in refrigerated conditions at 4 °C (A) and 20 °C (B) under darkness conditions. Bars with different lowercase letters within each time point were different statistically at p < 0.05 according to the analysis of variance (ANOVA) and Tukey’s multiple range test.

Figure 4

Visual appearance of citrus-maqui based beverages processed by HHP at different pressure levels (HHP—450 MPa and HHP—600MPa) and TP—85°C over 90 days of storage at 4°C (a) and 20°C (b).