Assignment of a Reference Value Independent from the Participants and Its Implications Regarding Performance Evaluation in Proficiency Testing on the Determination of Raw Milk Freezing Point
Source abstract
Abstract
Milk adulteration may cause losses or quality problems in the dairy industry, with implications regarding consumers’ health. The addition of water is one of the most common adulterations, which can be detected by determining the freezing point of milk. A proficiency testing (PT) program is in place in Chile concerning the determination of the freezing point of raw milk. A limited number of laboratories participate regularly to assure the validity of their measurements. The reference values were obtained independently through a calibration test, as recommended by ISO 13528:2022 in those cases where a small number of participants are evaluated. The uncertainty of the reference values assigned to nine PT rounds that included three PT items was investigated. A modification has been proposed for their calculations, which consists of the incorporation of the CRM uncertainty. This involves assessing the participants’ performance using the z’-score across all laboratories utilizing the thermistor method, which presents a slightly higher likelihood of inaccurate evaluation (2.9% of total participations). The assigned values demonstrated compatibility with the participants’ results. It is recommended that the same standard deviation for proficiency assessment be utilized for evaluating the performance of participants.
Source: crossref · Quality: baseline
Research context
OpenAlex topics: Nutrition, Health and Food Behavior · Freezing and Crystallization Processes · Food Quality and Safety Studies
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
Laboratory for Measurement Quality Assurance (LACM), Institute of Food Sciences and Technology, Faculty of Agricultural and Food Sciences, Universidad Austral de Chile, Valdivia 5090000, Chile
Department of Analytical Chemistry, Center of Agri-Food and Wine Research (IVAGRO), Faculty of Science, University of Cadiz, 11510 Puerto Real, Spain
Institute of Food Sciences and Technology, Faculty of Agricultural and Food Sciences, Universidad Austral de Chile, Valdivia 5090000, Chile
Funding
Laboratory for Measurement Quality Assurance LACM®, Institute of Food Sciences and Technology, Austral University of Chile · Erasmus Mundus Master on the Quality in Analytical Laboratories (EMQAL) at the University of Cadiz (Spain)
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