In vitro antioxidant capacity of tomato products: Relationships with their lycopene, phytoene, phytofluene and alpha-tocopherol contents, evaluation of interactions and correlation with reflectance measurements

- Phytofluene (PF) shows a high antioxidant capacity towards ABTS˙+.
- Lycopene (LYC) and PF seem to have a higher weight in the TEAC than α-tocopherol.
- Potential synergistic and antagonistic effects between lycopene and α-tocopherol were observed.
- The LYC levels can be rapidly and accurately assessed from some reflectance readings.
- The TEAC values can also be assessed likewise. This is important for quality control.

Tomato products were analysed for their carotenoids and α-tocopherol contents to study the contribution of individual compounds to the antioxidant capacity and assess the existence of interactions. Besides, the applicability of reflectance measurements for the estimation of the Trolox Equivalent Antioxidant Capacity (TEAC) was explored. Statistically significant regression coefficients were found between TEAC values and carotenoids and α-tocopherol levels. Lycopene seemed to have the highest contribution, followed by phytofluene. The results showed that the antioxidant capacity of phytofluene warrants further investigation. It was observed that there can be interactions between lycopene and α-tocopherol, although just the lycopene/α-tocopherol ratio cannot be used to predict the kind of interaction. More knowledge of these interactions would supply new tools for the industry to develop more optimized ingredients. Finally, the lycopene levels and TEAC values can be estimated by considering reflectance readings at certain wavelengths, which is important for field and quality control applications.