Evaluating Hydroxytyrosol as a Healthier Alternative in No-Sulfites-Added Red Wine: Impacts on Chemical Stability and Sensory Profiles During Bottle Aging

• Medium HT doses increased the overall preference at 6,9,12 months • High HT doses (60–120 mg/750 mL) offered better antioxidant persistence • HT showed no interaction with SO₂ in model wine • Results support HT’s potential in cleaner-label, no-sulfites-added wine production Hydroxytyrosol (HT), a natural phenolic antioxidant, was evaluated as a potential alternative to sulfur dioxide (SO₂) in no-sulfites-added (NSA) organic Sangiovese red wine. The wine was enriched with HT at three concentrations (30, 60, and 120 mg/750 mL) and compared to a control over 12 months of storage at room temperature. Parallel model wine studies were conducted to investigate HT-SO₂ interactions and better understand their independent antioxidant behaviour. HT-enriched wine demonstrated dynamic chemical evolution, with HT levels increasing during early storage, declining between six and nine months, likely due to autoxidation and transformation, and stabilizing thereafter. Higher HT concentrations enhanced polyphenol content, reduced dissolved oxygen, and positively influenced sensory attributes such as “red fruit,” “dried fruit,” and “vegetative” notes, especially in early stages. Although sensory and chemical differences among samples diminished after nine months, HT-enriched wine retained improved colour stability (a*, C*) and preserved mineral content (Mg, K, Ca) throughout storage. In model wine, HT degradation was concentration-dependent, and its stability was unaffected by SO₂, confirming independent mechanisms of action. HT slightly enhanced SO₂ retention but did not interfere with its antioxidant role. Sensory analysis showed increased overall preference for wine with 60 and 120 mg/750 mL HT during specific periods. These findings highlight HT’s potential as a viable, natural additive to improve oxidative stability and sensory complexity in NSA red wine, though further studies are needed to refine its application and assess regulatory implications in wine.