Effect of high pressure processing (HPP) on microbial safety, physicochemical properties, and bioactive compounds of whey-based sweet lime (whey-lime) beverage

Abstract

The effects of high pressure processing (HPP) applying 500 MPa for 10 min at 25 °C on microbial inactivation and stability of quality parameters [bioactive compounds, phenolic content, antioxidant capacity, color, NEBI (non-enzymatic browning index), and sensory analysis] were studied. It was found that HPP treated whey-lime beverage achieved the maximum shelf-life of 120 days by keeping the microbial populations below the detection limit throughout the storage period (p < 0.01). The effect of HPP was also compared with the heat treatment (90 °C for 60 s). HPP processing preserved the antioxidant capacity (54.2%) and color of the whey-lime during the entire storage period (p < 0.01), whereas, heat processing degraded it to 76.7%. Furthermore, HPP treated whey-lime retained the maximum content of phenolics (60.2%) with sustained values of non-enzymatic browning index (0.181 ± 0.03) in comparison to heat (37.8%, 1.97 ± 0.2). However, both treatments did not induce any major changes in pH and °brix values of whey-lime. Sensory quality parameters of untreated whey-lime degraded with storage, whereas, overall quality of pressurized samples were negligibly altered. Electron microscopy was used as a tool to find the damage induced to microbial cells. Investigation of the morphology showed the leakage of cellular debris owing to the rupture of their cellular membranes under HPP. Thus, HPP processing may lead to an immensely potential technology for the production of high quality whey-lime beverage over heat treatment.