Characterisation of bioactive compounds in berries from plants grown under innovative photovoltaic greenhouses

BACKGROUND: Bioactive compounds, mainly polyphenols, present in berries, are thought to be responsible for the health benefits of these fruit. Therefore, it is worthwhile to define the optimal environmental conditions to maximise their polyphenol content. OBJECTIVE: With the aim to define the optimal conditions for berry cultivation in an innovative environment, red raspberry, wild strawberry and blackberry plants were grown in a traditional greenhouse in comparison with two photovoltaic greenhouses with different shading area. METHODS: Hydroalcoholic extracts of ripe berries were evaluated by HPLC analysis, for their anthocyanins, organic acids and sugar contents. Moreover, phenolic content (by the Folin-Ciocalteu assay) and antioxidant activity (by the Trolox equivalent antioxidant capacity-TEAC assay) were assayed on the same berry extracts. RESULTS: Total anthocyanins, phenols content and antioxidant capacity tended to increase in berries grown under shading. The sugars content was, mostly, not negatively influenced by the shading. Conversely, the organic acids content, in some instances, increased along with the shading percentage. CONCLUSIONS: It can be concluded that it is possible to combine the greenhouse production of high-quality berries (with a particular focus on polyphenols, bioactive compounds valuable for human health) with the production of renewable energy, in the context of sustainable agriculture.