Orange juice (OJ) contains a wide range of micronutrients and phytochemicals that have been found to exhibit preventive effects against the onset of several diseases. Moreover, alcoholic fermentation improves its content of bioactive antioxidant compounds. Thus, fermented orange juice (FOJ) with organic honey was finally investigated to obtain a demi-sec wine (dSW) and sec wine (SW). Sauro Giannini carried out this process at Cantina CITRO. Oxidative stress is responsible for the onset and progression of many chronic pathologies, including neurodegenerative diseases, cardiovascular diseases, cancer, diabetes, and obesity.

Thus, this study aimed to assess the antioxidant capacity of these new organic products to provide scientific evidence of their possible health benefits.

Using colorimetric assays, ferric reducing antioxidant power (FRAP) and ABTS radical scavenging activity (ARSA) were tested to provide information about the global antioxidant capacity. Moreover, the content of total polyphenols was evaluated. In addition, two principal polyphenols (tyrosol and hydroxytyrosol) were quantified by means of mass spectroscopy. Also, melatonin and its precursor tryptophan were quantified.

Although FOJ showed the best antioxidant capacity (FRAP: +24.30%; ARSA: +18.40%), SW increased the antioxidant activity (FRAP: +17.30%; ARSA: +6.20%), followed by dSW (FRAP: +16.60%; ARSA: +0.5%). This increase correlated positively with the polyphenol content (vs. FRAP: r = +0.872; vs. ABTS radical: r = −0.945). When polyphenols were quantified, both wines showed an increase in tyrosol (SW: 10.33 ng/mL; dSW: 12.57 ng/mL) and hydroxytyrosol (SW and dSW: 0.02 ng/mL) compared to the OJ. Finally, the fermentation consumed the tryptophan to synthesize the melatonin, whose values were maintained in both wines (≈ 20ng/mL). Melatonin is a ubiquitous molecule that is involved in numerous biological functions and is a well-known potent scavenger of reactive oxygen species.

In conclusion, these new wines from organic honey-fermented orange juice possess antioxidant capacity.