Implementação das normas ISO 8196 e 9622 para análise de leite e produtos lácteos

Abstract

With technological advances and the search for alternative methods, the need has arisen to establish standards for the calibration of equipment, ensuring the quality of measurements by comparing the values obtained with accepted reference values. To address the calibration of alternative methods, two specific standards were developed: ISO 8196, which refers the general accuracy of milk analysis methods, and ISO 9622, which focuses on the application of mid-infrared spectrometry in milk samples and other liquid dairy products. The company Lactogal S.A., internship location, has adopted methodologies based on these standards to standardise and improve the calibrations of its equipment. An internal model was established to simplify the calibration process, following guidelines such as the minimum number of samples, handling practices, calibration frequency and evaluation criteria. Based on this model, specific calculations were determined to manipulate the desired components. The evaluation criteria included correlation coefficient, standard deviation of residuals, slope and mean differences. Furthermore, a model was implemented to analyse the stability of the signal of the equipment over time, identifying possible instabilities that could compromise the results. The analysis of the control chart and the established rules allowed the compliance of the system to be verified. The company also improved the parameters used in the interlaboratory tests, which evaluate the precision and accuracy of the equipment in relation to the reference methods. The laboratories of the manufacturing units participated in these tests, using the average differences between the values obtained and the reference values as an evaluation. In conclusion, the implementation of the standards was carried out according to the criteria established by them. In addition, other ways of evaluating the accuracy and precision of the equipment were introduced or improved.

Date of Award	27 Jul 2023
Original language	Portuguese
Awarding Institution	Universidade Católica Portuguesa
Supervisor	Anabela de Lima (Supervisor)