Targeted and non-targeted approaches to ImprUV the nutritional profile of greenhouse crops

Sammanfattning: This work was made to discover if greenhouse crops, particularly broccoli and Chinese cabbage, can change their metabolism and therefore their nutritional profile depending on what ultraviolet radiation (UV) they were exposed during growth. This is important since the world’s population increases and therefore, we need to be able to produce foods with increased nutritional quality. To explore whether we can use UV for that, we first analyzed the plant extracts searching for changes in plant metabolism after exposure to UV light and then subjected the plants exposed or not to UV to an in vitro fermentation system that mimics the digestion by the human gut microbiota. The latter was done to understand how our gut microbiota can metabolize plants with distinct metabolite profile and whether this will impact in the levels of metabolites with beneficial health effects. We started by applying different UV treatments during growth of broccoli and Chinese cabbage (i.e., plants were grown using standard growth conditions or they were exposed to supplementary UVA or to supplementary UVB) and for the analysis of plants, we applied a non-targeted approach to explore overall changes in metabolism induced by UV light. The plants were further subjected to an in vitro fermentation approach to simulate human digestion. The obtained fermentation extracts were further analyzed for levels of short-chain fatty acids (SCFA) at different time points during the in vitro fermentation. Major insights from this experiment were that the different light contributes to significant changes in the plant’s metabolic profile depending on what light they were cultured in. However, such changes in plant metabolism does not change how our gut microbiota produce SCFA during fermentation. Another conclusion when exploring broccoli and Chinese cabbage is that UV effects cannot be generalized to different plants. This depends on their different genotypes, even in the same species, which gives different response of light on the plant’s receptors. No differences in the SCFA profile were found after fermentation of control and UV-exposed plants; however, results from plant extracts indicate that a more comprehensive analysis of fermentation extracts might reveal changes in how our gut microbiota metabolizes plant components. Although further analysis is needed to confirm such hypothesis, the pipeline showed that UV light influences metabolism of broccoli and cabbage and therefore modulate plant metabolism and their potential impact on human health by increasing the levels of compounds with antioxidant properties.