Matrix-dependent bioaccessibility of bioactive amines in Milano dry-fermented sausages after in vitro digestion

Dry-fermented sausages often contain high levels of biogenic amines, but they are rarely implicated in outbreaks of histamine intoxication. This study investigated the in vitro bioaccessibility of histamine, tyramine, and other bioactive amines in dry-fermented sausages with different amine levels and assessed the potential impact of the meat matrix on amine availability. For that, seven types of commercial dry-fermented sausages were screened by HPLC-fluorescence. Two Milano-type products with low (356.8 mg/kg) and high (1140.7 mg/kg) amine contents were selected for standardized INFOGEST in vitro digestion. Despite a 3.2-fold difference in initial concentration, digestion markedly reduced amine bioaccessibility, providing similar potentially absorbable fractions. Histamine, tyramine, and total amines showed significantly lower bioaccessibility in the Milano-High sample (29%, 25.7%, and 16.4%, respectively) compared with the Milano-Low sample (72.4%, 34.3%, and 39.1%, respectively), indicating an inverse relationship between total concentration and bioaccessible fraction. Polyamines such as spermine and agmatine were not detected after digestion. Multivariate analyses demonstrated convergence of amine profiles after digestion, regardless of initial levels. In silico modeling of porcine myosin suggests that amine protonation at intestinal pH may influence the protein-amine electrostatic interactions and limit their release. Risk assessment incorporating bioaccessibility indicated lower effective exposure than estimates based solely on total content. These findings demonstrate that total amine concentration alone is insufficient to predict toxicological impact, even though they provide a hypothesis to explain the reduced bioaccessibility and highlight the critical role of matrices in modulating the intestinal availability of biogenic amines in dry-fermented sausage.