Quality of juices from different grape cultivars obtained by distinct extraction systems

The objective of the present work was to evaluate the physicochemical and sensory quality of juices from different grape cultivars resulting from two extraction methods. Juices from eight grape cultivars (‘Bordô’, ‘SCS 421 Paulina’, ‘BRS Carmem’, ‘Concord’, ‘BRS Cora’, ‘Isabel’, ‘Isabel Precoce’ and ‘BRS Violeta’) were prepared using two extraction systems: an integral suquifier; an adapted heat exchanger. Physicochemical determinations, such as soluble solids, pH, titratable acidity, ratio (relation between soluble solids and titratable acidity), reducing sugars, density, turbidity, color, total polyphenols, anthocyanins and antioxidant activity, were evaluated in the obtained juices. Sensory assessment of the juices was also carried out based on the attributes “pleasant aroma”, “unpleasant aroma”, “acidity”, “sweetness”, “balance”, “body”, “astringency” and “overall impression”. The soluble solids content was higher when the integral suquifier was used, while total acidity was lower when the adapted heat exchanger was used for ‘BRS Carmem’ and ‘BRS Violeta’ grape cultivars. The “overall impression” of the juices showed no difference between the treatments for most grape cultivars. According to the physicochemical and antioxidant activity evaluations, the integral suquifier had superior results than the adapted heat exchanger for ‘SCS 421 Paulina’, ‘BRS Carmem’, ‘Concord’ and ‘Isabel Precoce’ grape cultivars. Sensorially, the extraction methods used did not influenced the acceptance of the juices, except for ‘BRS Carmem’, which showed greater appreciation when extracted by the integral suquifier, and for ‘Bordô’, which was more appreciated when extracted by the adapted heat exchanger method.