A t-test ranking-based discriminant analysis for classification of free-range and barn-raised broiler chickens by 1H NMR spectroscopy

[Display omitted] •1H NMR metabolic profile for free-range and barn-raised broilers.•Screening t-test ranking showed significant differences in metabolite concentration.•Free-range broilers have more anserine and carnosine and less amino acids.•A univariate discriminant model based on the ratio of two NMR peaks was built.•This model showed 100% of correct classification and is more robust than PLS-DA. Intensive systems of raising chickens in barns prevail worldwide for financial reasons. In contrast, free-range chickens are raised in better welfare conditions, and preferred by consumers due to their distinctive taste/flavor, having higher market prices. Thus, free-range chickens have been the target of frauds. In this study, 1H NMR metabolic profiles of breasts of free-range and barn-raised broilers (108 individuals) were compared by two discriminant models, based on t-test ranking and partial least squares (PLS-DA). Both models provided 100 % of correct classification in both training and test sets, being the univariate model based on t-test screening simpler and more robust. Among other differences, barn-raised broilers presented lower carnosine and anserine concentrations, and higher free amino acids contents. Univariate discrimination was based on the ratio of two NMR signals assigned to β-alanine and carnosine + anserine, respectively. As an additional advantage, this profiling method could be adapted to other measurement platforms.