Anthocyanins (ACNs) are plant secondary metabolites from the flavonoid family. Red to blue fruits are major dietary sources of ACNs (up to 1 g/100 g FW), being cyanidin-3-O-glucoside (Cy3G) one of the most widely distributed. Cy3G confers a red hue to fruits, but its content in raspberries and strawberries is low. It has a good radical scavenging capacity (RSC) against superoxide but not hydroxyl radicals, and its oxidative potential is pH-dependent (58 mV/pH unit). After intake, Cy3G can be metabolized (phases I, II) by oral epithelial cells, absorbed by the gastric epithelium (1%–10%) and it is gut-transformed (phase II & microbial metabolism), reaching the bloodstream (<1%) and urine (about 0.02%) in low amounts. In humans and Caco-2 cells, Cy3G’s major metabolites are protocatechuic acid and phloroglucinaldehyde which are also subjected to entero-hepatic recycling, although caffeic acid and peonidin-3-glucoside seem to be strictly produced in the large bowel and renal tissues. Solid evidence supports Cy3G’s bioactivity as DNA-RSC, gastro protective, anti-inflammatory, anti-thrombotic chemo-preventive and as an epigenetic factor, exerting protection against Helicobacter pylori infection, age-related diseases, type 2 diabetes, cardiovascular disease, metabolic syndrome and oral cancer. Most relevant mechanisms include RSC, epigenetic action, competitive protein-binding and enzyme inhibition. These and other novel aspects on Cy3G’s physical-chemistry, foodomics, and health effects are discussed.

This work evaluated the feasibility of using electrochemical methods to quantify antioxidants in food oil samples (mainly olive oil). The methods used for analysis were CUPRAC (cupric ion antioxidant capacity), DPPH (2,2-diphenyl-1-picrylhydrazyl), and direct quantification by voltammetry using CPEs (carbon paste electrodes); in the last one, an oil was employed as a binder. Through this study, it was possible to prove that these methodologies are easy to perform and generate reproducible results. The quantification limits were 1.05 × 10⁻⁷ M for EI (Electrochemical Index), 3.24 × 10⁻⁶ M for DPPH, and 1.09 × 10⁻⁴ M in the case of CUPRAC; all the methods had almost the same magnitude of linear range. Also, some differences were found between the obtained results by the studied methods; such differences were attributed to the nature of each chemical probe (proton or electron transfer) for DPPH and CUPRAC and the nature of the electroactive antioxidant molecules present in the sample in the case of CPEs.