Simulated digestion of glycosylated caseinate-polyphenol complexes: Effect on bifidobacteria and tumor cell lines

Resumen del trabajo presentado a la 4th International Conference on Food Digestion, celebrada en Napoles (Italia) del 17 al 19 de marzo de 2015.Due to its various health benefits, the formulation of polyphenols-fortified food is desirable. Since polyphenols are known to show an affinity towards proteins, complexation with casein may provide a way to deliver polyphenols in food. This is of particularly interest since dairy foods are considered a good vehicle for the delivery of bioactive components as they are an integral part of many populations diet. The aim of this study was to examine the interaction of polyphenols with glycosylated caseinates and to evaluate the biological activities of the complexes before and after an in-vitro digestion. Interaction between polyphenols and glycosylated caseinate was analyzed by dynamic light scattering. Results showed that glycosylated caseinate presented a bimodal size distribution with a main peak at 500 nm and a minor peak at 30 nm. In the presence of polyphenols a similar size distribution was observed but the main particle population is now around 30 nm and a minor population was detected at 300 nm, indicating that polyphenols induced some kind of disaggregation of the protein. Effect on gut microbiota was evaluated by assessing Bifidobacterium Spp. growth on digested samples. Satisfactorily, no adverse effects were found in their growth since polyphenols are effective antimicrobials towards harmful bacteria. The antiproliferative activity against nine different tumor cell lines was also analyzed and it was observed that digested polyphenols have an IC50 between 28 and 58 µg/mL, while digested polyphenols complexed with glycosylated caseinate have an IC50 between 3 and 30 µg/mL, depending on the cell line. We concluded that polyphenols complexation to glycosylated caseinate improve their stability during in-vitro gastrointestinal digestion without affecting beneficial gut microflora.Peer Reviewe