Food grade silica nanoparticles cause non‐competitive type inhibition of human salivary α‐amylase because of surface interaction

Abstract

Given the potential of ingested particles to interact with enzymes in oral cavity, we compared different grades of SiO2 particles (food‐grade and non‐food grade nanoparticles (FG‐SiO2‐NP, NFG‐SiO2‐NP), and food grade microparticles (FG‐SiO2‐MP)) for their interaction with human salivary α‐amylase (HSA). There were differences in the agglomeration behavior and relative abundance of silanol and siloxane groups among different grades of SiO2 particles where FG‐SiO2‐NPs contained less cyclic siloxane groups but more silanol groups. Secondary structure and function of HSA were negatively impacted by FG‐SiO2‐NPs. In order to verify if this inhibition is mediated through surface interactions, pristine particles were compared with those interacted with pure protein (bovine serum albumin‐BSA) and with food matrix (milk) for HSA inhibition. BSA coating of SiO2 particles ameliorated HSA inhibition, but milk interacted ones showed an enhanced the HSA inhibition because of the presence of milk protease suggesting the relevance of surface interactions in manifesting potential negative impacts of silica particles used in food.