Microbial Levels in Apple Must and Their Association with Fruit Selection, Washing and Sanitization



This study evaluated the effect of the operations of selection, cleaning and sanitizing with sodium hypochlorite, on the populations of yeasts and lactic acid bacteria present in apple cider must, elaborated from commercial and industrial fruit. The microbial load differed between the cultivars and classes of fruit. The total populations of yeasts and lactic acid bacteria were higher in the industrial fruit. The operation of selection avoided cross-contamination and the presence of organic compounds that might react with the chlorine. Washing the apples decreased the populations of these microorganisms by one logarithmic cycle. Hierarchical cluster analysis indicated that sanitization was effective at a concentration of 100 mg/L for 5 min. The sanitizer was not effective in totally eliminating the microorganisms in populations greater than 104 CFU/mL. Selection and washing help reduce natural microbiota, making sanitization more effective, and positively affecting food safety and the quality of unpasteurized cider.

Practical Applications

This article presents the results, and a thorough discussion, of the use of pre-fermentation operations that can be used to reduce the microbial load of apple must, which is to be turned into cider. Among all the various techniques and controls, the three that were most noteworthy were analyzed (selection of fruits, washing and sanitizing with chlorine, followed by rinsing). These operations are critical control points, and if they are planned and monitored then can reduce or eliminate microorganisms (pathogens or not), eliminate or reduce the need for sulfite, facilitate the cleaning and disinfection of the environment and equipment, increase food safety, and ensure the production of high-quality unpasteurized cider.