Impact of pre and post-harvest treatment with chemicals preservatives on Botrytis gray rot disease and fruit quality of strawberry

Abstract

This study focuses on the evaluation of some chemical food preservatives to control gray mold disease in strawberry fruits. Six compounds, i.e. acetic acid, sodium benzoate, benzoic acid, sodium citrate, citric acid and potassium citrate were tested at concentrations 10, 20, 40 and 80 mM for inhibiting mycelial growth of the pathogen. In vitro studies, data obtained showed that all treatments significantly (P ≤ 0.05) inhibited the mycelial growth of the pathogen. Sodium benzoate especially at concentration of 80 mM caused complete mycelial growth inhibition of the pathogen. Under laboratory conditions, dipping the strawberry fruits in solutions of these compounds were effective in reducing the disease severity. Also, applications of these compounds as fruits spraying gave a significant reduction of the disease. Sodium benzoate had a better effect on the disease in vitro and in vivo. Laboratory estimates showed that treated fruits with the tested compounds contained a high percentage of total soluble solids (TSS) compared to untreated fruits and healthy control. Also, titratable acidity (TA) increased in treated fruits compared to the healthy fruits; as a result, TSS/TA ratio was increased. Furthermore, treated fruits contained a high level of total phenol contents (TPC) compared to untreated fruits. All studied treatments improved the quality attributes of strawberry fruits, i.e. T.S.S, TA%, TSS/TA ratio and TPC. It is concluded that these compounds were effective on the disease, so they can be used as safe alternatives to fungicides in treating fruits to protect them from the fungal decay during storing or marketing.