https://doi.org/10.17113/ftb.61.01.23.7537

Supplement

Formation of Maillard Reaction Products in Aged Sorghum Vinegar during Ageing and Protective Effects of Pure Vinegar Melanoidin Against CCl₄-Induced Rat Hepatic Damage

Xiaomin Tang¹, Xiaoyu Yin¹, Majida Al-Wraikat¹, Yaqiong Zhang¹, Saiping Zhou¹, Yingxue Tang¹, Yanyan Zhang² and Junfeng Fan^1*

¹Department of Food Science and Engineering, College of Biological Sciences and Technology, Beijing Key Laboratory of Forest Food Processing and Safety, Beijing Forestry University, 100083 Beijing, PR China

²College of Food Science and Engineering, Beijing University of Agriculture, 102206 Beijing, PR China

Article history:

Received: 26 October 2021

Accepted: 1 February 2023

Keywords:

food safety; 5-HMF; advanced glycation end products; hepatoprotective effect; oxidative damage; reactive oxygen species

Summary:

Research background. The processing method generally affects the toxicity and biological activity of aged sorghum vinegar. This study investigates the changes in the intermediate Maillard reaction products of sorghum vinegar during ageing and the in vivo hepatoprotective effects of pure melanoidin obtained from it.

Experimental approach. High-performance liquid chromatography (HPLC) and fluorescence spectrophotometry were utilized to quantify intermediate Maillard reaction products. The CCl₄-induced liver damage in rats was used to evaluate the protective role of pure melanoidin in rat liver.

Results and conclusions. Compared with the initial concentration, the 18-month ageing process caused a 1.2- to 3.3-fold increase in the concentrations of intermediate Maillard reaction products, i.e. 5-hydroxymethylfurfural (HMF), 5-methylfurfural (MF), methylglyoxal (MGO), glyoxal (GO) and advanced glycation end products (AGEs). The concentrations of HMF in the aged sorghum vinegar were 6.1-fold higher than the 450 μM limit standard for honey, implying the need for shortening the ageing of the vinegar in practice for safety concerns. Pure melanoidin (M_r>3.5 kDa) demonstrated significant protective effects against CCl₄-induced rat liver damage, as evidenced by normalized serum biochemical parameters (transaminases and total bilirubin), suppressing hepatic lipid peroxidation and reactive oxygen species, as well as increasing glutathione amount and restoring antioxidant enzyme activities. Histopathological analysis revealed that melanoidin in vinegar reduced cell infiltration and vacuolar hepatocyte necrosis in rat liver. The findings demonstrated that a shortened ageing process should be considered in practice to ensure the safety of aged sorghum vinegar. Vinegar melanoidin is a potential alternative for the prevention of hepatic oxidative damage.

Novelty and scientific contribution. This study demonstrates that the manufacturing process had a profound influence on the generation of vinegar intermediate Maillard reaction products. In particular, it revealed the in vivo hepatoprotective effect of pure melanoidin from aged sorghum vinegar, and provides insight into the in vivo biological activity of melanoidin.