Stabilization of Prickly Pear Puree by High-Pressure Processing (HPP)

The food industry is experiencing an increasing demand for clean-labeled and minimally processed foods with high nutritional and health value. In this scenario, high- pressure processing (HPP) stands out among non-thermal treatments as a stabilization method that induces limited changes to the nutritional value, color, and flavor of the food, ensuring food safety and extending shelf life. This study assessed the potential of HPP as an alternative to thermal pasteurization for stabilizing prickly pear puree. To this aim, one batch of prickly pear puree was submitted to a HPP cycle (600 MPa for 180 s at 5°C), while another batch was pasteurized (80 °C for 30 s). After treatment, the samples were stored at 4°C for 42 days. The untreated (NT), pressurized (HP), and pasteurized (PAST) prickly pear purees were first compared on day 0 to evaluate the impact of treatments. Additionally, the stabilized purees (HP and PAST) were monitored weekly for 42 days to evaluate microbiological growth, pH and color change, bioactive compounds content (ascorbic acid, phenolic compounds), antioxidant activity, enzymatic activity (pectin methyl esterase, lipoxygenase, and polyphenol oxidase), and volatile organic compounds. Both treatments ensured microbial stabilization for 42 days under refrigeration. HPP ensured better color preservation, enhanced retention of ascorbic acid and did not significantly impact the total phenolic content. Our study highlighted similar inactivation levels for pectin methyl esterase and lipoxygenase following both treatments, while HPP was less effective at inactivating polyphenol oxidase: despite this, no negative impacts of HPP on color, sensory perception, or aromatic profile were observed. On the contrary, the volatile profile was better preserved with HPP, resembling the characteristics of fresh puree more closely than pasteurization.