Assessment of potential biological activities by grana padano and trentin grana in vitro digestates at different aging periods

INTRODUCTION: Nutrients and associated molecules besides their absorption can interact with intestinal cells and affect their functionality. The identification of this ability allow to obtain a health-centered nutrition. Food corresponding to these requirements are known as functional foods. OBJECTIVE: To identify the biological potential of peptide mixtures derived from Grana Padano (GP) and Trentin Grana (TG) in vitro digestates, at different maturation degree (from 13 up to 27 months). These cheeses are among the most consumed in Italian population. They are characterized by a huge content of calcium and peptides derived milk proteins. METHOD/DESIGN: Six cheese samples of Grana Padano (GP) and Trentin Grana (TN) at different aging were kindly provided by the Grana Padano Production Consortium. Before being tested on cell cultures, the samples were submitted to in vitro digestion. The supernatant obtained was collected and analyzed for protein and calcium determination. All experiments were performed in a 70% Caco2/ 30% HT-29 co-culture. MTT assay was used to measure cell viability. Measurement of the transepithelial electrical resistance (TEER) in co-colture was used to monitor the integrity of the cell layer after direct contact with cheese digestates. Video imaging experiments were performed to monitor cell calcium uptakes mediated by cheese digestates. Bone mineral matrix formation was assayed by Alizarin Red Staining in Saos2 osteoblast-like cells. RESULTS: GP and TN digestates can affect cell viability only at the major tested doses and after 24h incubation. The permeability of cells was not negatively modified by GP and TN digestates. Calcium uptake by cells was activated by GP and TN digestates also in absence of extracellular calcium ions. Bone mineral matrix formation was observed after treatment with GP and TN digestates in Saos2 cells. CONCLUSION: GP and TN can be considered as potential functional food even if future studies are necessary to confirm it.