Application of pulsed electric field in reducing internal browning and maintaining the functional potential of ‘Pérola’ pineapple¹

ABSTRACT

The pineapple, the most important fruit in the state of Paraíba, is characterized as an important generator of employment, income and regional development. With the increase in production, challenges arise in reaching distant competitive markets, including exports, making refrigerated storage necessary. However, pineapple, a tropical fruit, is subject to Chilling Injury (CI) when stored under sub-optimal temperatures, below 12 °C, which provide internal browning (IB) and quality loss. The use of pulsed electric field (PEF), a non-thermal technology, can be an alternative in ensuring the control of IB in pineapple. Therefore, the objective of this work was to evaluate the influence of PEF application on IB, enzyme expression and activity, bioactive compounds and antioxidant activity of ‘Pérola’ pineapple. Initially, to define the best strategy, 8 kV/cm of PEF was applied to pineapples directly and indirectly (drinking water), in 4 levels of electrical pulses: 0 (control), 5, 20 and 35, proving to be the most efficient the indirect pulses. From these results, a completely randomized design was used, with indirect application of PEF at the four levels in pineapples, with 5 periods of evaluations at refrigeration at 5 °C, followed by transferring at each period for two more days to the room condition, in 4 replicants (3 fruit / rep). The indirect application of 35 pulses provided a reduction in expression and enzyme activity, IB and maintained the functional potential, being a promising alternative for the storage of pineapple under sub-optimal temperatures.

Keywords:
Non-thermal Technology; Browning Index; Chilling Injury; Enzyme Expression and Activity; Antioxidant Activity