Plants as biofactories: Stress-induced production of chlorogenic acid isomers in potato tubers as affected by wounding intensity and storage time

In the present study, the feasibility of using wounded-potato tubers as biofactories of antioxidant phenolic compounds (PC) was evaluated. Potato tubers were wounded to obtain different wounding intensities (slices, pie-cuts, and shreds) and stored for 144 h at 10 °C. The accumulation of total and individual PC was determined during storage of the wounded-tissue. Results indicated that the highest accumulation of total PC was obtained at 96 h of storage for slices and pie-cuts. At this storage time, slices and pie-cuts showed 100% and 65% higher total PC content, respectively, whereas shredded-potatoes showed 40% lower PC content as compared with wholes before storage. The main PCs identified in wounded-potatoes were chlorogenic acid (CGA), neo-chlorogenic acid (neo-CGA), and crypto-chlorogenic acid (crypto-CGA). Results also indicated that selecting the wounding intensity to apply and storage time could manipulate the accumulation of specific PC in potato tubers. For instance, if the production of CGA or crypto-CGA were desirable, potato tubers should be wounded to obtain slices and pie-cuts. Likewise, to produce neo-CGA the appropriate wounding intensity should be pie-cuts. Furthermore, the highest accumulation of CGA and neo-CGA in wounded-potatoes was obtained at 96 h of storage, whereas for the crypto-CGA its highest accumulation was observed in wounded-potatoes stored for 144 h at 10 °C. The stressed-potato tubers with increased concentrations of chlorogenic acids could be used as a starting material for the extraction of high value antioxidant PC with potential applications in the pharmaceutical and dietary supplements industries.