Effect of Pichia membranaefaciens in combination with salicylic acid on postharvest blue and green mold decay in citrus fruits

摘要

The separate or combined effects of Pichia membranaefaciens and salicylic acid (SA) on the control of blue and green mold decay in citrus fruits were investigated. Results indicate that combining P. membranaefaciens (1x108 CFU ml-1) with SA (10 micro g ml-1) either in a point-inoculated or dipped treatment provided a more effective control of blue and green mold than separately applying yeast or SA. SA (10 micro g ml-1) did not significantly affect P. membranaefaciens growth in vitro but slightly increased the yeast population in fruit wounds. P. membranaefaciens plus SA effectively enhanced the phenylalanine ammonia-lyase, peroxidase, polyphenoloxidase, chitinase, and beta -1,3-glucanase activities and stimulated the synthesis of phenolic compounds. The combined treatment did not impair quality parameters such as weight loss or titratable acidity, but resulted in low average natural infection incidence and increased total soluble solids and ascorbic acid contents in citrus fruits after 14 d at 20 degrees C.