Microbiological and chemical quality of ice used to preserve fish in Lisbon marketplaces

Ice is widely used to preserve fish on markets, playing a major role in the food industry. If manufactured, stored or distributed in inadequate sanitary conditions, it can represent a considerable health risk for both consumers and professionals. The present study characterizes ice used in marketplaces, on microbiological and chemical parameters. The aim was to assess potential risks on occupational exposure and consumer safety and therewith plan orientation guidelines. Sampling took place in 18 marketplaces in Lisbon, with ice samples collected at three different stages— production (n = 29), storage (n = 30), and product-contact (n = 29). No significant contamination was found in production and storage stages, demonstrating that ice production and storage procedures are adequate regarding sanitary conditions. With exception for Salmonella, significantly higher concentrations of microbial parameters were identified in product-contact stages, specifically Total Coliforms (548 MPN/100 mL), Escherichia coli (1 MPN/100 mL), Enterococci (29 MPN/100 mL), Staphylococcus aureus (271 CFU/100 mL), HPC at 5 , 22 , and 37 (>301 CFU/mL). Our study also shows that the majority of samples from ice production and storage comply with national regulations regarding drinking water quality. Yet, occupational health and consumer risks may still exist at the final product-contact stage, as significant contamination was detected.. Practical applications The present study can be used as a model for ice quality monitoring in fish preservation, serving as a tool for quality control and fast contamination detection during the several process stages. This monitoring model is an important contribution for assuring the safety of the preserved products, as well as, occupational health improvement and consumer risk protection.