Melania Casertano

Background: The use of baobab seed beverages as coffee alternatives represents a novel approach to upcycling by-products. Baobab seed aqueous extract is caffeine-free and contains numerous compounds of nutritional interest. The composition and sensory characteristics of baobab seed beverage can be modulated by roasting and brewing conditions. Objective: This study aimed to assess the effect of using different fluidised bed roasting temperatures and microwave infusion on the nutritional and functional properties of the beverage. Results: Higher roasting temperatures increased solubility, melanoidin content, pH, titratable acidity, colour, phenolic content, and antioxidant activity, while the concentration of chlorogenic acid and caffeic acid decreased. Upon microwave infusion, antioxidant activity, phenolic content (gallic acid, coumaric acid, caffeic acid, and vanillic acid), protein content, and soluble fibre content increased. Chlorogenic acid was not present in microwave-infused samples, and the amount of caffeic acid decreased. The fat content remained similar across all samples. The major volatile components identified in the roasted seeds were furans and pyrazines. Conclusions: These findings highlight the potential of baobab seed beverages as coffee alternatives and the impact of roasting and brewing conditions on their nutritional and functional properties.

The objective of this study was to evaluate the influence of a probiotic formula on the production of neuroactive compounds in different parts of the colon in batch culture and in vitro gut simulator experiments. Thirteen lactic acid bacterial strains, belonging to the species Levilactobacillus brevis, Lactiplantibacillus plantarum, Lacticaseibacillus paracasei, Ligilactobacillus salivarius, Streptococcus thermophilus, were characterised for their in vitro ability to produce neurotransmitters. L. brevis P30021 and L. plantarum P30025 were selected based on their capability to produce γ-aminobutyric acid (GABA) and acetylcholine in vitro. A probiotic formulation with potential psychobiotic activity was prepared and tested in a batch culture of human microbiota monitoring the formation of GABA and acetylcholine. Samples of the three colonic tracts were taken from the Simulator of the Human Intestinal Microbiota (SHIME®) evaluating the production of GABA and other neurotransmitters by LC-MS. Short chain fatty acids (SCFA) by GC and microbiota composition by 16S rRNA gene sequencing were also determined. Probiotic supplementation led to the formation of GABA and acetylcholine with a decrease in glutamate concentrations in the in vitro batch fermentation. Production of GABA after the treatment with probiotics was confirmed in the SHIME® short-term experiment. No differences in short-chain fatty acids were observed up to 72 h of fermentation. Different microbiota composition was found in the three different parts of the colon, with a higher abundance of Veillonellaceae in the ascending colon vessels. The probiotic-exposed microbiota showed higher levels of Bacteroides, a gut microbe associated with anti-inflammatory activities and a potential GABA producer. Results demonstrate the impact of the tested probiotic formula on gut microbiota structure and GABA production. In conclusion, the probiotic treatment changed the microbiota composition and increased neuroactive metabolites production, indicating promising potential as psychobiotics, even if further clinical evidence is needed to confirm the effectiveness of these probiotics in improving mental health.