Effect of high hydrostatic pressures on microorganisms, totalphenolic content and enzyme activity of mamey (Pouteria sapota) nectar.

Abstract

Mamey (Pouteria sapota) is a Mexican native fruit ofsweet flavor and high content of antioxidants.Some of these antioxidants are sensitive to high temperatures. Nonthermal technologies such as high hydrostatic pressures (HHP) could be an adequate alternative to traditional thermal pasteurization. Mamey nectars were treated under different HHP conditions and the effects on native microorganisms (mesophilic bacteria, molds and yeast), pectinmethylesterase (PME) and polyphenoloxidase (PPO) activities as well as on total phenolic content (TPC), were evaluated. Most HHP treatments conditions were equally effective to inactive native microorganisms. The application of HHP improved the extraction of TPC showing increments of 24% (400MPa/2min) to 64% (500MPa/2min) compared with the control samples. At 500MPa/5 and 10min maximum inactivation levels of PPO of about 40% were obtained, while PME activity showed decrements up to 70% at 400MPa/5min. HHP showed to be a potential technology to preserve mamey nectar, but more conditions should be tested to reach higher enzyme inactivation.