Sensory profiling and changes in colour and phenolic composition produced by malolactic fermentation in red minority varieties

This research studies the sensory properties and chemical composition of varietal wines made with minority varieties from La Rioja (Spain) and it analyses the transformations in phenolic compounds and colour parameters occurring during the malolactic fermentation. In this sense, all the analysed parameters underwent changes of the same magnitude during this stage and both anthocyanin and hydroxycinnamic acid distribution was found to be dependent on the grape variety and not on the winemaking process. Wines made with these varieties showed high values of resveratrol that could lead to healthier wines, and the variety Maturana Tinta de Navarrete was found to share quite similarities in the chemical parameters with Tempranillo, studied as a reference variety. In the sensory analysis, and although all the wines obtained good punctuations, Monastel and Maturana Tinta de Navarrete were the best valued. Monastel had the highest colour intensity and both varieties showed high aromatic intensity and great complexity. In mouth, Monastel showed the greater persistence, mount length and structure and Maturana Tinta de Navarrete was described as fresh and pleasant. In conclusion, this research shows the first characterization of these wines and provides data to be used as a chemotaxonomic tool to fingerprint them. Moreover, it opens the door to the use of minority varieties providing a viable alternative to traditional grape varieties cultivated in La Rioja and favouring consumer offer and wine differentiation.

► Red minority wine varieties from La Rioja (Spain) are studied.
► Sensory properties and colour and phenolic changes during winemaking are analysed.
► All wine behaviours are the same during malolactic fermentation.
► Final wine composition is dependent on grape variety.
► All varieties are optimal to obtain high quality wines to be aged.