PEF treatments of high specific energy permit the reduction of maceration time during vinification of Caladoc and Grenache grapes

Abstract

Phenolic compounds extracted from the solid parts of the grapes during the maceration-fermentation stage define many of the sensory attributes of red wine such as color, bitterness or astringency. The effect of moderate a PEF treatment (M-PEF) (5 kV·cm−1, 8.8 kJ·kg−1) and an intense PEF treatment (I-PEF) (5 kV·cm−1, 52.9 kJ·kg−1) on the reduction of maceration time during vinification of Caladoc and Grenache grapes was investigated. In both grape varieties, M-PEF treatment combined with 4 days of maceration was the most effective treatment in achieving high anthocyanin content, color intensity and total phenol index at the end of fermentation. The I-PEF treatment promoted a rapid release of anthocyanins and phenolic compounds, along with a fast increment in the color intensity of the must after 24 h of maceration. Although the color intensity and anthocyanin content decreased significantly throughout fermentation when grape pomace was removed after 24 h, these parameters were similar, after 3 months of bottling, in the case of Caladoc and slightly lower in Grenache than the control wine, for which maceration was extended for 10 days. Therefore, results obtained in this investigation are the first to demonstrate the potential of I-PEF for the reduction of maceration time to 24 h in red winemaking.