Validation of a Washing and Sanitizing Procedure for Cantaloupes at a Mexican Packing Facility.

In-plant validation of an alternative washing and sanitizing method was conducted at a cantaloupe packing operation in Mexico. This method consisted of a spray water wash followed by spraying warm (55 to 60°C) 2% L-lactic acid solution and was compared with the existing method of spray washing the melons with tap water followed by immersion in a chlorinated water tank. Surface samples (100 cm²) were collected from 160 melons subjected to each processing method and tested for counts of aerobic bacteria, coliforms, and Escherichia coli. The aerobic plate counts from cantaloupes washed in the dump tank ranged from 3.6 to 5.2 log CFU/cm² and were significantly higher (P < 0.05) than those from melons treated with the alternative spray method, which ranged from 1.8 to 2.6 log CFU/cm². Coliform counts for cantaloupes treated in the dump tank were 0.2 to 2.2 log CFU/cm² and were below the detection level (-6.0 log CFU/cm²) on cantaloupes treated by the spray method. Growth of E. coli was observed in 2.5% of the samples of cantaloupes treated in the dump tank and in none of the samples of cantaloupes treated by lactic acid spray (P < 0.05). These results support the elimination of dump tanks in cantaloupe packing operations established by the Mexican government for certification of finns exporting cantaloupes to the United States. When a sanitizer is to be applied to the product, lactic acid seems to be a viable option, at least for products such as cantaloupes whose quality is not affected by an acid wash. [ABSTRACT FROM AUTHOR]