Bioactive compounds content and antioxidant capacity of strawberry fruit (Fragaria x Ananassa cv. Camarosa) treated by pulsed light

ESCOBAR-TOVAR, ALEJANDRA; GÓMEZ, PAULA; ALZAMORA, STELLA M.

Chicago

Congreso; Institute of Food Technologists Annual Meeting 2016; 2016

Institute of Food Technologists

Pulsed light (PL) treatment has emerged in recent years as an alternative method for surface decontamination of foods. In previous studies it was demonstrated that the application of specific PL fluencies could be able to extend the shelf life of strawberry fruit, reducing the incidence of postharvest molds and deleting the softening along cold storage.The objective of this work was to analyze the impact of pulsed light treatments on functional quality of strawberry fruits. To this end, the effect of PL fluence and refrigerated storage on total anthocyanin and phenolic contents and antioxidant capacity was investigated.PL treatments were performed with a Xenon RS-3000B Steripulse-XL system, which generated high intensity pulsed light (200 to 1100 nm). Strawberries (Fragaria x Ananassa cv. Camarosa) were exposed to irradiation for 10 and 20 s at 10 cm from the lamp, corresponding to fluencies of 11.9 and 23.9 J/cm2, respectively. PL treated fruits were compared to a control (non-irradiated fruit) throughout 8 days of storage at 6±1ºC. At selected intervals of the storage period, the total anthocyanin content, total phenolic content (TPC) and the hydrophilic antioxidant capacity (measured as Oxygen Radical Absorbance Capacity, ORACFL) were determined. In the analyses 10 strawberries for each treatment and storage time were evaluated. Non-treated strawberries showed a significant increase in anthocyanin content along storage. 10 s PL-treated strawberries did not show significant changes in anthocyanin accumulation compare to the control, while the content of this pigment in samples treated 20 s was significantly lower. The variations observed in anthocyanin content did not correlate with changes in total phenolic content, since TPC in all the samples slightly decrease throughout the storage. In addition, there were not significant differences in hydrophilic ORAC activity of samples neither due to treatments nor the storage time.Results showed that the hydrophilic antioxidant capacity and the total phenolic content of strawberries were not affected by PL treatments. However, a treatment of 23.9 J/cm2 reduced the anthocyanin accumulation during refrigerated storage, which would be associated with a delay in ripening induced by pulsed light.