Jiabao Sun

Title: From Manual to Inspections: A Content and Survey-based Study of Frozen Dessert Machines Cleaning Practices

Abstract:

Frozen dessert machines are commonly used in retail food establishments to produceproducts such as ice cream, milkshakes, and yogurt. These machines require regular cleaning,sanitizing, and maintenance to ensure food safety because they contain multiple components,which may allow bacterial contamination to cause foodborne illness if not cleaned properly.

Listeria is a serious problem because it can survive and grow at refrigerationtemperatures and in a moist environment. If the cleaning and sanitizing steps are improper,Listeria may persist in the machines. In addition, Listeria can form biofilms on the food-contactsurface, which can increase the difficulty of cleaning and sanitizing. Once biofilms develop onthe machines, they can protect Listeria from the cleaning process and increase the risk of productcontamination. In 2023, a Listeria outbreak in Tacoma, Washington, linked contamination tomilkshake machines used in a local restaurant. Investigators identified improper cleaning andsanitizing practices as likely factors.7 These foodborne illness outbreaks emphasize theimportance of effective cleaning, sanitizing, maintenance, and inspection practices.

The FDA Model Food Code and NSF/ANSI 6 provide guidance for cleaning andsanitizing frozen dessert machines, including equipment, food-contact surfaces, and utensils.However, the guidance differs across sections, such as in 4-602.11(c) and 4-602(D).2 Thesedifferent requirements may lead to misunderstandings about how cleaning frequencies should beimplemented by manufacturers, food establishments, and inspectors.

To address these concerns and ensure food safety, this study used a mixed-methodsapproach to analyze frozen dessert machine food safety from two perspectives: manufacturermanual guidance and local health jurisdiction inspector surveys. The study combined qualitative and quantitative analyses of manufacturer manuals and inspector survey responses to identifygaps in cleaning frequency, maintenance schedules, real-world practices, and inspectorconfidence. The findings aim to support improvements in training, guidance clarification, andreal-world cleaning practices.