Acid-Blanching and EDTA Reduce Spoilage and Toxigenesis of Canned Mushrooms Inoculated with Proteolytic Clostridium botulinum Types A and B Spores.

A new process involving acid-blanching and addition of EDTA to the canning brine (ABC) was compared with the standard commercial method (SCM) for the control of Clostridium botulinum spores in canned mushrooms. Fresh mushrooms were uniformly inoculated under vacuum with 10 spores of proteolytic strains of Clostridium botulinum Types A and B and processed either by the ABC or SCM method. Compared to the SCM, the ABC process significantly reduced the spoilage and toxigenesis of canned products. At F values of 0.5, 2, and 4, the ABC when compared to the SCM process reduced percent spoilage from 91.4 to 51.5, 17.6 to 6.3, and 12.1 to 2.9, respectively. No botulinal toxicity occurred except at F of 0.5 when the number of toxic cans was reduced from 54.3 to 30.3 by the ABC, compared to SCM.