UV-B and blue light supplementation improves tomato quality and antioxidant dynamics: A novel approach for sustainable greenhouse production

Light plays a crucial role in influencing crop yield and the accumulation of bioactive compounds, which potentially enhance human health benefits through their antioxidant properties. However, the effect of supplementing blue (B) and ultraviolet-B (UV-B) light on ascorbic acid (AsA), hydroxycinnamic acids (HCAs), total phenolic content (TPC), and antioxidant activity (AA), along with fruit firmness and yield attributes in tomatoes, has not yet been fully explored. This study assessed how exposure to supplemental blue (B), UV-B, or combined (B+UV-B) light affects greenhouse tomato yield, firmness, and antioxidant compounds in two varieties. Additionally, this study is the first to employ a mathematical modeling approach to understand the AA kinetics in tomatoes under different supplemental lights. We found that blue light alone significantly enhanced the yield and firmness in both varieties. Similarly, UV-B light alone also showed an increase in yield, AsA, and most of the HCAs. The combined B+UV-B light treatment resulted in firmer fruits with high HCAs without compromising the yield. AA kinetics best fitted to an exponential rise to the maxima model, with the B+UV-B treatment exhibiting the highest slope value, suggesting a substantially higher accumulation of fast-acting antioxidants. Therefore, the use of blue and UV-B light, alone or in combination, in greenhouse tomato production offers significant potential for application in the fresh tomato market (yielding firmer, nutrient-dense fruits) as well as for the processed tomato industry (ensuring the stability of antioxidant compounds for an extended duration).