Official control and self-monitoring: Data agreement report in the integrated food safety system of an Italian dairy chain

The dairy industry's silos is a critical point in the safety and quality control system. However, limited scientific evidence is available on measurement agreement between the milk analyses done by official control bodies and the self-monitoring analyses done by milk processing industries. Milk production data from a milk processing plant were collected for four months and analyzed by an official control body and the dairy company for freezing point, total bacterial count, somatic cell count, and for fat, lactose and protein percentages. Correlation and Bland-Altman analysis showed a good agreement between the two determinations for most of the variables (Spearman's rho > 0.82 for Somatic cell count, Fat% and Protein %), while low agreement was found for total bacterial counts (Spearman's rho =0.78). It was found that the difference between total bacterial counts was influenced by collecting route, time between sampling and analysis, and milk temperature inside the truck tank.