The effects of high CO2 levels on anthocyanin composition, antioxidant activity and soluble sugar content of strawberries stored at low non-freezing temperature

Anthocyanins and sugars are involved in the responses of fruit to environmental stress. The effect of low temperature (0 °C) in ‘Camarosa’ strawberries and also the influence of high CO2 levels (20% CO2 for 3 days) on the water-soluble sugars and on the levels of individual anthocyanins were assessed, as well as their association with antioxidant activity, total phenolics and colour. Anthocyanins were assessed by HPLC-DAD-MS, myo-inositol by IC-PAD and the antioxidant capacity using the ABTS scavenging assay. When compared with untreated strawberries, exposure to high CO2 prevented the increases in total phenolics and each of the five major anthocyanins quantified, while it triggered the consumption of soluble sugars, mainly sucrose and myo-inositol. The decrease of these soluble solutes could represent an adaptive strategy of CO2-treated strawberries to cope with storage at low temperature.