Combined effects of ultra-high pressure homogenization and short-wave ultraviolet radiation on the properties of cloudy apple juice

Abstract

This work addresses the physicochemical, enzymatic and sensory changes in cloudy apple juice treated by ultra- high pressure homogenization (UHPH) and short-wave ultraviolet radiation (UV–C) applied at 20 ¿C. Those technologies were applied in single and combined treatments at different UHPH pressures (200–300 MPa) and UV-C doses (14.3–27.8 J/mL). UV-C treatments could not effectively inactivate enzymes, but treatments at 300- MPa UHPH reduced pectin methylesterase activity to a 24.6%, and polyphenol oxidase activity was not detected. Those samples presented a higher antioxidant capacity (283% measured by FRAP, and 286.4% by DPPH) than in non-treated juice, and after a combination with 28.7 J/mL of UV-C the polyphenols content augmented to 277.6%. Sensory evaluation revealed that UHPH at 300 MPa and UV-C at 21.5 J/mL significantly changed perceptible odour and overall flavour of cloudy apple juice, while treatments at 200 MPa didn’t produce any significant changes in the different parameters.