140 Modern Food Microbiology mung seeds with 98% of 750 nondisinfected and only 1.8% of surface-disinfected seeds containing a number of mold genera including aflatoxigenic species although no aflatoxins were found.1 On alfalfa seeds, only 21% of 500 contained yeasts and molds Since sprouts are eaten without being heated or cooked, problems arise when the sprout seed stock contains foodborne pathogens such as Salmonella or E coli 0157:H7 Because of the excellent nutrient state of germinating seeds as noted above, the pathogens grow very well In an effort to control pathogens, sprout seeds are treated in various ways to destroy these forms The United States Food and Drug Administration (FDA) recommends the use of 20,000 ppm calcium hypochlorite for 15 to reduce pathogens, and this treatment does not significantly reduce germination efficiency or sprout length Pathogens The pathogen of greatest concern in RTU vegetables is C botulinum and reasons for this concern are pointed out by several studies In one, five RTU vegetables (butternut squash, mixed salad, rutabagas, romaine lettuce, and a stir-fry mix) were inoculated with a 10-strain cocktail—five each of proteolytic and nonproteolytic spores.3 The products were sealed in polystyrene trays with an oxygen transmission rate (OTR) (see Chapter 14) of 2,100 ml and incubated at 5, 10, or 25◦ C All five vegetables became toxic at some point during their storage The time to toxin detection for nonproteolytic strains in butternut squash was days at 10◦ C with CO2 at 27.8%; and for proteolytics in this product, days at 25◦ C with 64.7% CO2 In butternut squash at 5◦ C with an inoculum of nonproteolytic strains of 103 /g, toxin was detectable in 21 days At the time of toxin detection in all samples, O2 was