Evaluation of volatile compounds and antioxidant capacity of some commercial rums from Dominican Repubblic

Some Dominican ‘heavy’ rums, of a single brand, available commercially and labelled as 8, 15, 18, 21 and 25 year-old have been evaluated and compared. Headspace solid-phase microextraction (HS-SPME) coupled to gas chromatography–mass spectrometry (GC–MS) was used to analyse volatile compounds and crocin kinetic competition test to evaluate their antioxidant capacity. The alcohols and esters profiles of rums labelled as 21- and 25 year-old were similar. The alcohols and fatty acids profiles of rums labelled as 15 and 18 year-old were similar. The esters profile of rums labelled as 8 and 15 year-old was similar. Significant differences were found for aldehydes and volatile phenols between all the rum samples. The antioxidant capacity resulted significantly higher in the older rums (21 and 25 year-old) than in the younger ones (8, 15 and 18 year-old). The effects of different operating conditions applied to a continuous dense-phase carbon dioxide (DPCD) system on antioxidant capacity and volatile compounds of apple juice were compared with current heat pasteurisation method. Only the microbial tests required by Italian Regulation to assure microbiological safety to ‘fruit juices and vegetables’ were performed, and DPCD-treated (15 MPa, 35 C, 15 min; 25 MPa, 35 C, 15 min), heat-pasteurised (75 C, 15 s) and untreated apple juice samples were considered. The DPCD processing carried out at 15 MPa resulted as effective as 25 MPa in reducing microbial cells. Trolox equivalent of DPCD treated at 25 MPa (0.41 mm) resulted significantly (P < 0.05) lower than DPCD treated at 15 MPa (0.48 mm). Head space analysis of volatile compounds indicated the lowest decrease in apple aroma compounds (59% esters and 59% aldehydes) in DPCD treated at 15 MPa.