Food processing drives the toxic lectin reduction and bioactive peptide enhancement in Pinellia ternata

Abstract

Processing can change the properties and flavors of food. Many plants in the Araceae family can be used as food or medicine, but their raw materials are usually toxic, such as Pinellia ternata tuber (PTT). After processing (processed PTT, PPTT), its toxicity is reduced. However, the mechanism remains unclear. In this study, a novel approach integrating liquid chromatography-mass spectrometry, feature-based molecular networking (FBMN), de novo sequencing, and protein database searching was applied to rapidly discover and characterize peptides in PPTT. Potential antihypertensive peptides were screened using in silico methods, angiotensin I-converting enzyme (ACE) inhibitory assay, and molecular docking analysis. A significant decrease was observed in toxic lectins after processing. Meanwhile, a total of 1954 mass spectral nodes were discovered in PPTT, of which 130 were annotated as peptides by FBMN. These peptides, ranging from 2 to 21 amino acids, were rapidly identified using PEAKS. Notably, 98 peptides were derived from lectins, most of which increased after processing. Approximately 30% of identified peptides were screened for potential high antihypertensive activity in silico. Five peptides exhibited inhibitory effects on ACE, with two showing IC₅₀ values of 131 and 185 μM. Dynamic profiling indicated that 7–9 days of processing is optimal for reducing toxicity and enhancing efficacy. More importantly, these peptides were also found in commercial PPTT, confirming their bioactivity contributions. These findings provide insights into the mechanism by which food processing drives the toxic lectin reduction and bioactive peptide enhancement in PTT, providing a novel approach to rapidly discover bioactive peptides, which can be extended to other foods in Araceae family.