Adding value to natural underutilized products for the synthesis of prebiotic oligosaccharides. Fundamentals behind their technological structure-function relationship

ANDREA GOMEZ ZAVAGLIA

Simposio; 6th International Symposium on Phytochemicals in Medicine and Food; 2022

CONFERENCIA PLENARIAFructo-oligosaccharides (FOS) are composed of a small number of fructose units linked by (2→ 1)-β-glycosidic bonds and having a single D-glucosyl unit at the non-reducing end. They can be obtained by enzymatic synthesis from sucrose using fructosyltransferases as biocatalysts. The reactions involve the cleavage of the β-2,1-glycosidic bond and the transfer of fructosyl moieties from carbohydrates acting as donors onto any acceptor other than water [1]. As most fructosyltransferases also have a hydrolytic activity, the production of FOS is a complex process involving reactions of synthesis and hydrolysis that occur simultaneously and lead, as a whole, to a mixture of FOS with different degrees of polymerization (DP), glucose and fructose. Within the concept of Circular Economy, using sucrose arising from different underutilized materials can acquire great importance to add them value. For example, carob flour (Prosopis nigra, containing ca. 50% sucrose), grape must (mainly composed of glucose and fructose) can be appropriate substrates for the synthesis of FOS [2,3]. Besides that, using them also provides naturally occurring phytochemicals to the final product.Considering that the conditions of synthesis (e.g., concentration of substrate, enzyme, pH, time of reaction) determine the composition of the obtained FOS, modulating the process enables the production of FOS with very diverse compositions, also having different technological applications [4-8].In this presentation, the fundamentals of the synthesis of FOS from sucrose, Prosopis nigra flour, grape must will be exposed together with their physico-chemical properties (e.g., vitrification). Examples of applications (e.g., dehydration matrices for the dehydration of probiotic bacteria) will be provided, also indicating the molecular mechanisms involved (e.g., interaction with DNA, lipid membranes).