Qiaozhi Zhang,Zhijie Huang,Huatao Li,Congnan Cen,Ruixing Zheng,Cao Lili,Shufen Zhang,Yanbo Wang,Linglin Fu
As a complex reaction, biological consequences of the Maillard reaction (MR) on dietary proteins need to be deciphered. Despite previous studies on the structural and antigenic properties of ovalbumin (OVA) by MR, associated changes induced by specific MR intermediates and their downstream products are largely unknown. This study focused on the impacts of glycation by α-dicarbonyl compounds (α-DCs), intermediates of MR and precursors of advanced glycation end-products (AGEs), on the structural and IgE-binding properties of ovalbumin (OVA) under simulated heating. Methylglyoxal (MGO), glyoxal (GO), and butanedione (BU) were selected as typical α-DCs to generate glycated OVA with different AGE-modifications (AGE-Ms). The results showed that reactions between OVA and α-DCs generated OVA-AGE with various degrees of modification and conformational unfolding, and the reactivity of α-DCs followed the order GO > MGO > BU. Depending on the precursor type, the levels of 10 specific AGEs were verified, and the amounts of total AGEs increased with heating temperature and α-DC dosage. Compared to native OVA, glycated OVA showed reduced IgE-binding levels but with sRAGE-binding ligands, the extent of which was associated with the contents of total AGEs and Nε-carboxymethyllysine, and changes in certain protein conformational structures. High-resolution mass spectrometry further identified different AGE-Ms on the Lys and Arg residues of OVA, confirming variations in the glycation sites and their associations with the immunoreactive epitopes of OVA under different conditions.
The inhibitory effects of four hydrocolloids, including alginic acid, pectin, carboxymethylcellulose sodium salt, and chitosan on the formation of two typical toxic advanced glycation end products N Ɛ -(carboxymethyl) lysine (CML) and N Ɛ -(carboxyethyl) lysine (CEL) were investigated in chemical models and fish patties. All the four hydrocolloids were found to significantly inhibit CML and CEL formation in chemical models, and among them, pectin and alginic acid were the most effective inhibitors. In roast fish patties, the addition of pectin and alginic acid at 0.9% reduced the content of CML by 43.6% and 44.9%, and CEL by 32.4% and 32.6%, respectively. Moreover, alginic acid plus a polyphenol epigallocatechin gallate (EGCG) showed stronger inhibitory effect against CML and CEL formation than alginic acid alone. Further study showed that alginic acid and pectin decreased the formation of glyoxal (GO) and methylglyoxal (MGO), two key intermediates of CML and CEL, in the chemical models and fish patties. In addition, compared with EGCG, the addition of alginic acid in fish patties showed less impact on color, odor, and sensory properties. These findings suggest that alginic acid is a potent inhibitor against the formation of AGEs with less impact on food quality.
危险品化学品经营许可证（带存储）