A Functional Smoothie from Carrots with Induced Enhanced Phenolic Content

Abstract

Carrots are worldwide highly consumed due to their sensory characteristics and health-promoting properties. However, their low phenolic/antioxidant levels may be highly increased with abiotic stresses. Accordingly, phenolic/antioxidant enhancements and related phenylalanine ammonia-lyase (PAL) activity of carrot shreds under different treatments (UV-C radiation and hyperoxia conditions) were studied after a pre-enrichment incubation of 72 h at 15 °C. Subsequently, a carrot smoothie prepared from enriched carrot shreds was heat-treated (90 °C for 30 s) and stored at 5 °C up to 14 days. Heat-treated smoothies showed a good physicochemical and microbiological quality (<6 log CFU g−1) after 14 days at 5 °C, although those non-irradiated samples registered lower psychrophilic and yeast and mold levels. Heat-treated smoothie from non-irradiated shreds stored under hyperoxia conditions showed the highest total phenolic content of 13.82 mg chlorogenic acid equivalent (ChAE) kg−1 fw (87 % chlorogenic acid) after 14 days at 5 °C. Total phenolic content was in accordance with PAL and total antioxidant capacity. Conclusively, a pre-enrichment incubation of carrot shreds under hyperoxia conditions allowed to obtain a functional smoothie with high phenolic levels and good microbiological and physicochemical quality up to 14 days at 5 °C.