Sweet and sour cherries contain several polyphenols that possess antioxidant and anti-inflammatory properties. Aim of this study was to investigate the effect of the maturity stage on phenol content and biological properties of extract of a local Morello-type of sour cherry (Prunus cerasus L.), “visciola”. The study of total phenol content and total antioxidant potential was associated with the evaluation of the antioxidant property of extracts using a copper catalyzed human low density lipoproteins (LDL) oxidation as experimental model. Moreover, using albumin glycated by methylglyoxal, we evaluated the anti-glycation effect of fruit extract. The results demonstrated that fully ripened fruits exert higher antioxidant and anti-glycation properties when compared with partially ripened fruits. Information about the health-promoting components of “visciola” could lead to a better understanding and an increased consumption of these, including its use as functional food.