Optimal allyl isothiocyanate concentration on Botrytis cinerea during the postharvest storage of blackberries and mechanism of blackberry color changes at high concentration of allyl isothiocyanate

Botrytis cinerea is one of the most important postharvest pathogens causing economical loss in blackberry. To control B. cinerea effectively with safe agent, optimal allyl isothiocyanate (AITC) concentration was determined. Freshly harvested blackberries were placed in a plastic container and treated with AITC at 0, 0.5, 1, 2, 5, and 10 μL L-1 for 12 h at 4 °C, and then stored for 14 d at 4 °C and 80 % relative humidity. The B. cinerea incidence of AITC-treated blackberry samples after storage was lower than that of the control. Treatment with AITC at concentrations ≥ 5 μL L-1 resulted in a decrease in the total anthocyanin and phenolic contents, antioxidant activity, and surface color. The sucrose, glucose, and fructose levels decreased after treatment with 10 μL L-1 AITC, suggesting changed energy metabolism. Higher AITC concentrations (5 and 10 μL L-1) resulted in decreased levels of monogalactosyldiacylglycerol, digalactosyldiacylglycerol, and sulfoquinovosyldiacylglycerol. By contrast, lysophosphatidylethanolamine (LPE) and lysophosphatidylcholine (LPC) increased in the fruit treated with 5 and 10 μL L-1 AITC, indicating cell membranes damage related phospolipids. In summary, 2 μL L-1 AITC was the optimal concentration for blackberry treatment to reduce B. cinerea contamination and extend the fruit shelf-life. In addition, red color of blackberry correlated with LPC and phatidylcholine, which can serve good indicator of reduced cell membrane integrity. This is the first report of metabolomics-based study on controlling B. cinerea during blackberry postharvest storage using AITC.