Evaluation of the effect of two biostimulant treatments on qualitative parameters of different varieties of Brassica oleracea

The demand for fresh, functional, and nutraceutical foods has increased in recent decades, due to the growing interest in healthy food. Many studies proved the effectiveness of biostimulants on improving vegetables yield, quality, and their phytochemical composition. This work aims to understand the biostimulant effects on some quality parameters in three different cabbage (Brassica oleracea) varieties (classified as, early, medium-late, late, based on the length of the growing cycle). Plants were grown under field conditions and two commercial biostimulants were tested: Megafol and Actiwave. At harvest, the qualitative evaluation products included the determination of several compounds, such as: total and reducing sugars, sucrose, total glucosinolates, chlorophyll, carotenoids, phenolic, and anthocyanins. Results showed differences among the varieties and, in some cases, showed the effect of biostimulants treatment: the levels of sucrose increased in the late cabbage variety treated with Megafol, while the total glucosinolates content in the medium-late variety decreased. Actiwave treatment increased the amount of glucosinolates in the late variety. Both biostimulants increased the chlorophyll and carotenoids in the medium-late cabbage variety, improving the colour and antioxidants compounds. Actiwave increased the phenolic concentration. Moreover, an increment in total anthocyanin was found in the late cabbage variety treated with Actiwave. Further research will help to clarify which biostimulant is the best for each specific variety, in order to maximize the final product quality.