Influence of non-thermal processing and storage conditions on the release of health-related compounds after in vitro gastrointestinal digestion of fiber-enriched strawberry juices

Abstract

Strawberry juices enriched with inulin and oligofructose were treated using non-thermal processing techniques [ultrasound (7.5 min, 40 kHz, 180 W) combined or not with antimicrobials vanillin (1.25 mg/mL) or geraniol (0.225 µL/mL)] and stored for two weeks at 5 °C. The impact of the non-thermal processing and storage conditions on the release of health-related compounds (phenolic compounds, flavonoids and ascorbic acid), and on the total antioxidant capacity (determined by DDPH and TEAC assays) after in vitro gastrointestinal digestion was investigated. After gastric digestion, the release of most of bioactive compounds decreased in comparison with non-processed juices. Conversely, exposing the treated juices to simulated intestinal conditions enhanced the release of phenolic and flavonoid compounds and the total antioxidant capacity (determined by the TEAC assay). Storage conditions led to slight changes in bioactive compounds’ content. In conclusion, fiber-enriched strawberry juices preserved with non-thermal processing are an important source of nutritionally relevant compounds.