Washing with sodium hypochlorite or peracetic acid its impact on microbiological quality, phytochemical composition and antioxidant activity of mango peels

Until now, the effects of washing with sodium hypochlorite (SH) or peracetic acid (PAA) on fruit by-products were unknown. This study aims evaluate the impact of disinfection conditions on mango peels’ microbiological quality, phytochemical composition and antioxidant activity. Two Box-Behnken Designs were performed, one for each disinfectant. Three independent factors (food product to disinfectant solution ratio (XA), disinfectants concentrations (XB) and disinfection time (XC)), with 3-levels each (XA: 1:1, 1:5, 1:9 (kg:L); XBSH: 0, 100 and 200 mg/L; XBPAA: 0, 40 and 80 mg/L; XC: 1, 10, 19 min), and eight responses were considered (total mesophilic aerobic bacteria (TMAB), total yeasts and molds, dry matter, ash content, total phenolic compounds, total carotenoids, DPPH and ABTS assays). After, other batch of mango peels was washed according to the optimized conditions predicted. Besides aforementioned parameters, Enterobacteriaceae, Bacillus cereus and total protein were evaluated. Significant statistical models were found for all responses, excluding yeast and molds, ash content and ABTS assay (in PAA Design). The increase of XB and XC positively impacted microbiological quality. However, in the SH Design, when higher levels of XA were applied, shorter XC were required to achieve the highest microbial load reductions. High XB and XC levels impaired total carotenoids and antioxidant activity. More studies are needed to understand the impact of washing conditions on total phenolic compounds. The SH and PAA optimal washing conditions were XA = 1:9 (kg:L), XB = 200 mg/L, XC = 90 s and XA = 1:1 (kg:L), XB = 27 mg/L and XC = 19 min, respectively. Their application significantly improved microbiological quality and did not impair phytochemical composition and antioxidant activity. Results showed that PAA is a sustainable alternative to SH.