Impact of food additives (sodium carbonate and ammonium bicarbonate) on interactions between astringent compounds and an oral cell model

Many foods contain additives like sodium carbonate and ammonium bicarbonate to ensure safety, preserve quality, or extend shelf life. Recent studies suggest these additives may influence interactions between astringent compounds and oral cells. Using a tongue epithelium cell model, we investigated how these salts affect interactions between astringent compounds (phenolic and non-phenolic) and oral constituents. The salts reduced the interaction of green tea flavanol-rich extract (GTE) with salivary proteins and altered interactions with tannic acid and alum. The effects varied depending on the specific astringent compound, salt, and oral constituents, with ionic strength playing a role. The reduced adsorption of flavanols from GTE may be due to oxidation induced by these additives, raising concerns about their use. However, sodium carbonate and ammonium bicarbonate can modify astringent molecule interactions, potentially influencing the astringency of certain products.