Inhibitory effect of natural plant crude extracts on the pathogenic bacteria of blueberry during storage and transportation

To screen out the natural preservative with good fresh-keeping effect on blueberry fruit during storage and transportation.In this study, 21 kinds of plant crude extracts were used to investigate the antimicrobial activities of 3 pathogenic fungi isolated from blueberry during storage and 2 common foodborne pathogenic bacteria in the logistics by Oxford cup method and the minimal inhibitory concertration ( MIC) and minimal bactericidal concentration ( MBC) of these plant extracts were determined.Besides, the effect of concentration of extracts on the inhibition rate of pathogens was studied and the bacteriostatic activity of the compound extracts were tested.The results showed that clove has the strongest inhibitory ability, and the average inhibitory circle diameters of Botrytis cinerea, Alternaria alternata and Penicillium sp. were 47.58, 39.68, 40.54 mm, respectively, and the MICs of clove against these 3 fungi were 15.63, 31.25, 31.25 mg/m L, the MBCs were 31.25, 62.5, 62.5 mg/m L. The antibacterial effect of Schisandra chinensis against Staphylococcus aureus and Escherichia coli was obviously higher than the other extracts, the average inhibitory circle diameter on the 2 kinds of bacteria was 42.08, 28.49 mm, the MICs were 31.25, 62.5 mg/m L, the MBCs were 62.5, 125 mg/m L. Two extracts of clove and Schisandra chinensis, which were the strongest inhibitory effect on Blueberry pathogenic fungi and bacteria, respectively, were screened out and the Change of these two kinds of extract concentration gradient inhibition effect on different pathogens are different, the larger effect of high concentration, besides, clove and schisandra compound ratio greater than 5 ∶ 5 can be used as a better blueberry preservative application reference.