Validation and adaptation of an ion-exchange HPLC-DAD method for simultaneous analysis of organic acids in artisanal goat coalho cheese

This study adapted and validated an HPLC-DAD method for the simultaneous quantification of eight organic acids in artisanal goat coalho cheese. The sample preparation used ion-exchange resin that ensures high selectivity for the complex protein matrices. The optimized method demonstrated excellent linearity (R2 > 0.998), precision (RSD < 4.5%), and recoveries ranging from 70% to 107%. The method was successfully applied to monitor the organic acid profiles in cheeses matured for 1, 20, 40, or 60 days, made with raw or pasteurized milk, with or without the addition of Limosilactobacillus mucosae CNPC007. Lactic acid was the predominant metabolite, negatively correlated with moisture, while acetic acid was inversely correlated with yield. These correlations reflect biochemical and technological transformations influenced by autochthonous culture. Overall, the validated method proved to be a robust, practical, and cost-effective tool for quality control and biochemical understanding of artisanal cheeses, broadening the possibilities for goat dairy products evaluation.