In vitro evaluation of the prebiotic effect of red and white grape polyphenolic extracts.

Nowadays, the strong relationship between diet and health is well known. Although the primary role of diet is to provide nutrients to fulfill metabolic requirements, the use of foods to improve health and the state of well-being is an idea increasingly accepted by society in the last three decades. During the last years, an important number of scientific advances have been achieved in this field and, although in some situations, it is difficult to establish a distinction between "harmful" and "good" bacteria, experts agree in classifying the genera Bifidobacterium and Lactobacillus as beneficial bacteria. Thus, several strategies can be used to stimulate the proliferation of these beneficial intestinal bacteria, being one of them the consumption of prebiotics. The development of new prebiotics, with added functionality, is one of the most serious challenges shared not only by the scientific community but also by the food industry. The objective of this work was to evaluate the potential prebiotic effect of red and white grape residues, both obtained during the winemaking process. For such purpose, an in vitro study with pure cultures of Lactobacillus and Bifidobacterium was first conducted. Secondly, a study with mixed cultures using human fecal inocula was carried out in a simulator of the distal part of the colon. The obtained results showed an increase in the Lactobacillus and Bifidobacterium population, indicating that these ingredients are serious candidates to be considered as prebiotics.

Phytanic acid consumption and human health, risks, benefits and future trends: A review.

Phytanic acid is a methyl-branched fatty acid present in the human diet, derived from the enzymatic degradation of phytol and subsequently oxidized by the rumenal microbiota and certain marine organisms. Consequently, phytanic acid is carried into the human body by means of food ingestion, mostly via red meat, dairy products and fatty marine foods. This fatty acid accumulates in people with some peroxisomal disorders and is traditionally related to neurological damage. However, some benefits derived from phytanic acid intake have also been described, such as the prevention of metabolic syndrome or type 2 diabetes. The aim of this work was to conduct an overview of the literature on the phytanic acid content of foods, management of the phytanic content during food production and biochemical mechanisms of phytanic acid metabolism, as well as to assess the evidence for the health benefits and risks of phytanic acid consumption in human health.