ViewpointNonthermal processing technologies as elicitors to induce the biosynthesis and accumulation of nutraceuticals in plant foods

- Nonthermal permeabilizing methods elicit the biosynthesis of antioxidants in crops.
- A hypothetical model on how these technologies elicit stress responses is proposed.
- ROS are proposed as the signaling molecules that induce the stress response.
- Future perspectives on this research area are discussed.

BackgroundFruits and vegetables contain high levels of nutraceuticals, and thus their consumption is associated with the prevention of different chronic-diseases. The application of postharvest abiotic stresses (i.e. wounding stress) induces the accumulation of bioactive compounds in fresh produce. In this context, previous reports in literature suggest that nonthermal processing technologies [i.e. ultrasound (US), high pressure processing (HPP), and pulsed electric fields (PEF)] activate the biosynthesis of nutraceuticals in crops by a similar mechanism exerted by wounding stress. However, research on this area is scarce and it is still under debate if the higher levels of nutraceuticals detected in plant foods treated with emerging technologies are due to higher extractability or due to elicitation of metabolic pathways.Scope and approachIn the present view-point paper, the response of horticultural crops to abiotic stresses with special emphasis to wounding is reviewed as a basis to propose a hypothetical model explaining how US, HPP and PEF technologies could act as abiotic elicitors for the biosynthesis of nutraceuticals.Key findings and conclusionsReports on literature strongly suggest that US, HPP and PEF induce immediate and late stress responses similar to wounding stress. However, further studies including “omic” approaches and physiological measurements, as response variables must be performed to validate the model herein proposed. Furthermore, additional investigations should elucidate optimum nonthermal technologies processing conditions that induce the highest accumulation of nutraceuticals in horticultural crops. These crops could be commercialized in the nutraceutical market or used as raw materials for the production of functional foods.

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