Analytical strategies for characterization and validation of functional dairy foods

Functional foods (FFs) are food products to be consumed as part of a balanced diet. They provide physiological benefits or reduce the risk of chronic disease beyond basic nutritional functions. Functional foods containing probiotics and/or prebiotics have gained much interest in recent years due to their health-promoting capacity. The main objective of this review is to discuss the analytical strategies that have been used to validate FFs associated with dairy products containing probiotics and/or prebiotics. In these products, the biochemical events, carried out by enzymes of different sources (milk, bacteria, rennet) leading to the transformation of milk to diverse products (e.g., yoghurt and cheese), are glycolysis, proteolysis and lipolysis. We present the analytical methodologies used to study the microbial probiotic flora and to evaluate the biochemical transformations, the associated functionality in terms of intestinal microbiome and the safety of such FFs. We address the analytical figures of merit. We cover the advantages and the disadvantages of such analytical methodologies and comment on future applications and potential research interest within this field.