Impact of a new postharvest disinfection method based on peracetic acid fogging on the phenolic profile of strawberries

The retentions of fresh strawberry individual phenolic compounds after fogging using an environmentally friendly sanitizer based on peracetic acid (PAA) (mixture of 5% peracetic acid and 20% hydrogen peroxide) were studied and modeled as a function of the concentration (3.4, 20.0, 60.0, 100.0 and 116.6 μL PAA L−1 air chamber) and the treatment time (5.7, 15.0, 37.5, 60.0 and 69.3 min), using Response Surface Methodology. Information obtained from high performance liquid chromatography with photodiode array and fluorescence detection in combination with mass spectrometry was used for analyzing and quantifying the phenolics that naturally occur in strawberries (variety 'Camarosa') and to study the effects of PAA on them. Results showed that PAA fogging at certain concentrations and times caused degradation in the phenolic profile of strawberries. Anthocyanins were the most affected of the phenolic compounds, followed by proanthocyanidins with a low degree of polymerization, hydroxycinnamic acid derivatives, and the ellagitannin Sanguiin H-6. In general, pelargonidin-based anthocyanins were more susceptible to oxidation than cyanidin-based anthocyanin under the same PAA fogging conditions. In summary, the stability of strawberry individual phenolic compounds after fogging treatments was dependent on the concentration and the exposure time of PAA treatments as well as the chemical nature of them. The models developed herein allow to predict retentions of individual phenolic compounds at different fogging PAA conditions.