Quinolizidine Alkaloid Profiles in Lupin-Based Products: Monitoring of the Italian Retail Market and Efficacy of the Debittering Process

The increasing interest in plant-based diets has driven the demand for sustainable legumes such as lupins. However, their broader utilization is limited by the presence of quinolizidine alkaloids (QAs), secondary metabolites toxic to human health. Despite severe health risks, European legislation lacks harmonized maximum levels, necessitating comprehensive market surveillance. This study evaluates the occurrence of 14 specific QAs across 28 commercial samples collected from the Italian market using a validated LC-MS/MS method. Concurrently, the impact of a laboratory-scale debittering process was examined on a subset of eight dried seed samples to monitor toxin reduction efficiency. The total alkaloid content exhibited significant variability across food categories. Dried lupins samples showed the highest concentration (mean: 13,676 mg/kg), whereas lower levels were detected in lupin flours (mean: 253 mg/kg), brined lupins (mean: 86.1 mg/kg), and ready-to-use products (mean: 70.3 mg/kg), with lupanine being the predominant alkaloid across most matrices. Data on finished lupin-based products confirm the efficacy of industrial processing techniques in significantly reducing the alkaloid content. In parallel, laboratory debittering process demonstrated high QA reduction efficiency, ranging between 94% and 99%. Nevertheless, if initial QA levels were high, most of the debittered lupin seeds still retained residual alkaloid levels exceeding commonly accepted safety thresholds. This highlights the importance of establishing harmonized regulatory limits within the European Union and implementing continuous analytical monitoring programs, both at the field level and on commercial products, to guarantee consumer safety.