Effect of non-enzymatic browning on oysters during hot air drying process: Color and chemical changes and insights into mechanisms

• Published in: Food chemistry 2024-10, Vol.454, p.139758, Article 139758
• Main Authors: Hu, Yuanyuan, Zeng, Xiangbo, Jiang, Kaiyu, Luo, Ying, Quan, Zhengze, Li, Jinjin, Ma, Yurong, Guo, Xiaoming, Zhou, Dayong, Zhu, Beiwei
• Format: Article
• Language: English
• Subjects: Color change; Hot-air drying; Lipid oxidation; Non-enzymatic browning; Oyster
• ISSN: 0308-8146; 1873-7072; 1873-7072
• DOI: 10.1016/j.foodchem.2024.139758

Hot air drying (HAD) is an extensive method used on oysters and it causes the most intuitive change, a color change. However, the mechanism of color change remains unclear. This study showed that oysters underwent browning during the HAD process. The colorimetric parameter L* decreased while a* and b* increased, all of which were well described by the first-order color kinetic model. Mechanistically, the HDA process induced the oxidative browning of phenols and the generation of Maillard reaction products (5-hydroxymethylfurfural and hydrophilic pyrrole). Meanwhile, the HAD process caused lipid oxidation, leading to the reduction of phosphatidylethanolamine and the generation of reactive carbonyl compounds (aldehydes and α-dicarbonyl compounds). Moreover, the accumulation of hydrophobic pyrroles, a lipid-induced Maillard-like reaction product, was observed. These results suggest that, in addition to phenolic oxidation, sugar- and amino acid-mediated non-enzymatic browning reactions, lipid-mediated Maillard-like reactions play important roles in oyster darkening during the HAD process. •Effects of non-enzymatic browning on oysters during HAD process are investigated•Changes in L*, a*, b* of oysters during the HAD process are consistent with first-order kinetic models•Lipid-mediated Maillard-like reaction plays a crucial role in color change of oysters•Maillard reaction, phenolic oxidation, and lipid-related NEBRs work together to darken oysters