Tomato marc’s impact upon probiotic organism’s survival: an alternative functional ingredient for fermented products

The consumption of dietary fiber (non-digestible carbohydrates that may be used as a carbon source by microorganisms has been shown to play an important role in the modulation of gut microbiota, inducing not only changes in it’s microbial composition but also changing the profile of metabolites produced by it. Tomato is one of the most widely consumed fruits. Besides being consumed fresh, there are several industries that focuses on the transformation of tomato into several other products (e.g. canned tomato, tomato pulp or ketchup) yielding the tomato peel and seeds (here referred to as tomato marc), as a by-product. The castaway tomato marc presents itself as an interesting source of bioactive materials such as carotenes and fibers, which in turn may allow for the valorisation of this product. Moreover, as this residue is comprised, in ca. 56%, of fibres, it is interesting to contemplate it’s usage as a food additive to matrixes with a low fiber content. Therefore, the present work aimed to evaluate the impact of dry tomato marc upon 4 commercially available probiotic microorganisms (Lactobacillus rhamnosus R11, Lactobacillus plantarum 299v, Bifidobacterium animalis Bo and Bifidobacterium longum BG3) while also contextualizing with the digestive process and evaluating if the impact of the removal of some bioactive constituents (phenolic compounds and carotenoids).