Recent advances in bio-based extraction processes for the recovery of bound phenolics from agro-industrial by-products and their biological activity.

Usually found bound to other complex molecules (e.g., lignin, hemicellulose), phenolic compounds (PC) are widely present in agro-industrial by-products, and their extraction is challenging. In recent times, research is starting to highlight the bioactive roles played by bound phenolics (BPC) in human health. This review aims at providing a critical update on recent advances in green techniques for the recovery of BPC, focusing on enzymatic-assisted (EAE) and fermentation-assisted extraction (FAE) as well as in the combination of technologies, showing variable yield and features. The present review also summarizes the most recent biological activities attributed to BPC extracts until now. The higher antioxidant activity of BPC-compared to FPC-coupled with their affordable by-product source make them medicinally potent and economically viable, promoting their integral upcycling and generating new revenue streams, business, and employment opportunities. In addition, EAE and FAE can have a biotransformative effect on the PC itself or its moiety, leading to improved extraction outcomes. Moreover, recent research on BPC extracts has reported promising anti-cancer and anti-diabetic activity. Yet further research is needed to elucidate their biological mechanisms and exploit the true potential of their applications in terms of new food products or ingredient development for human consumption.

Psychobiotics, gut microbiota and fermented foods can help preserving mental health.

Psychobiotics include a novel class of probiotic microorganisms that convey benefit upon the host's mental health via the dynamic microbiota-gut-brain crosstalk. Research is bolstering the concept that gut bacteria are involved in the transmission of information between the gut and the brain, engaging neural, immune, and endocrine pathways. Factors such as diet, stress and aging can shape the microbiota composition in a process that may also influence the onset and development of mental diseases. This review aims to provide an outline of the link between the microbiota and brain function focusing on preclinical and clinical evidence of the potential application of psychobiotics in the context of the cognitive process and performance. The occurrence of metabolic precursors of neurotransmitters in foods that can be converted by the gut microbiota and play a role in the gut-brain axis is discussed. The understanding of the molecular mechanisms by which communication occurs is still at its infancy; however clinical studies have shown that dietary interventions based on psychobiotics might be a novel nutritional approach targeting gut microbiota for managing cognitive performance and preventing memory decline across the lifespan.