Polyphenolic content and sensory profile assessed by e-nose and e-tongue of an orange juice fortified with polyphenol-enriched extracts using Natural Deep Eutectic Solvents

Natural deep eutectic solvents (NADES) are new green and environmentally friendly solvents used as an alternative to conventional organic solvents1. NADES are non-toxic and biodegradable2, which makes them suitable to be used in the food industry. The present study aimed to evaluate the sensory profile and the polyphenol content of orange juices fortified with orange peel NADES extracts at different concentrations. Four choline chloride-based NADES were mixed with fructose (ChChl:Fruc), glycerol (ChChl:Gly), and glycerol:citric acid (ChChl:Gly:CA) and used for the extraction of polyphenols from orange by-products. Fresh orange juice (OJ) was obtained by pressing and polyphenol-enriched extracts were added to the OJ at different percentages (10 – 50 %). The sensory profile was evaluated by e-tongue and e-nose analysis while total phenol content (TPC) by spectrophotometric techniques. Results from e-nose and e-tongue showed that 15% and 30% of supplementation represented the highest concentration without significantly deviating from pure OJ, respectively. For this reason, the 15% concentration of extracts was selected for subsequent determinations of total phenolic content, which was evidenced as ChChl:Fruc, ChChl:Xyl and ChChl:Gly:CA, but ChChl:Gly, provided 160% more TPC than the pure OJ. Although further studies are needed to define the microbiological stability and bioaccessibility of phenolic compounds, NADES may represent a green alternative to organic solvents for the extraction of phenolic compounds from orange by-products as well as for the formulation of new polyphenol-enriched food products.