Suitability of oak wood chips and ultrasound for the production of prickly pear vinegar: Colour, antioxidant activity, polyphenols, and volatile compounds

Abstract

The traditional production method for high-quality vinegars involves their ageing in oak casks, a rather costly, and time consuming process. Two different accelerated-ageing techniques, traditional stirring (TS) and ultrasound (US), in the presence of Spanish oak chips, was applied to the production of prickly pear vinegar (PPV). Compared to TS, the US vinegar samples macerated for 14 days exhibited lower L∗ values and a higher red tone (a∗). The increment in the total polyphenol index of the vinegars was associated to a higher antioxidant activity, with the highest values corresponding to US vinegars treated for only 30 min. The polyphenols, p-hydroxybenzaldehyde, catechin, vanillin, and syringaldehyde were only detected in aged vinegars. Regarding the aged vinegars' volatile content, a greater amount of esters and aldehydes was observed. The use of US together with oak chips appears to be a reliable alternative for the production of PPV vinegars with improved properties in a shorter time.