In this study, the effects of static and multi-pulsed mild-intensity high hydrostatic pressure (HHP) treatments (60 or 100 MPa, ~23 °C) on the extractability and accumulation of phenolics and carotenoids in whole carrots were evaluated. HHP treatments were applied for the time needed to reach the desired pressure (come-up-time, CUT) either as a single pulse or multi-pulse (2P, 3P, and 4P). Likewise, a single sustained treatment (5 min) applied at 60 or 100 MPa was evaluated. Individual carotenoids, free and bound phenolics were quantified after HHP treatment and subsequent storage (48 h, 15 °C). As an immediate HHP response, phenolic extractability increased by 66.65% and 80.77% in carrots treated with 3P 100 MPa and 4P 60 MPa, respectively. After storage, CUT 60 MPa treatment accumulated free (163.05%) and bound (36.95%) phenolics. Regarding carotenoids, total xanthophylls increased by 27.16% after CUT 60 MPa treatment, whereas no changes were observed after storage. Results indicate that HHP processing of whole carrots at mild conditions is a feasible innovative tool to enhance the nutraceutical properties of whole carrots by increasing their free and bound phenolic content while maintaining carotenoid levels. HHP treated carrots can be used as a new functional food or as raw material for the production of food and beverages with enhanced levels of nutraceuticals.

Wounding stress induces the accumulation of phenolics in carrots. However, its effect on cell-wall constituents has not been studied. Extrusion generates modifications in high-fiber food matrices. In this study, the combined effect of wounding stress and extrusion on cell-wall constituents and functional properties of carrots was evaluated. Wounding stress was applied by shredding carrots and storing the tissue (48 h/15°C). The stressed tissue (wounding stress carrot, WSC) was dehydrated and then extruded at temperature, 60 or 100°C, and screw configuration, continuous or expansion. Extrudates were milled and analyzed for cell-wall constituents and other physicochemical parameters. Cellulose content increased (112%) as a response to wounding. Furthermore, extrudates obtained from WSC showed higher content of cell-wall components. For instance, insoluble and total lignin content increased (54–84%) with extrusion conditions. Furthermore, WSC showed higher oil absorption index and lower water solubility index (WSI); whereas extrudates showed the highest WSI.