Changes in glyoxal and methylglyoxal content in the fried dough twist during frying and storage.

摘要

Glyoxal (GO) and methylglyoxal (MGO) are important precursors for advanced glycation end products (AGEs) in foods and in vivo, which are also known as reactive carbonyls. Accumulation of AGEs may result in health risk. The effect of frying time and temperature on GO and MGO formation during fried dough twist processing was investigated. The changes in GO and MGO content of fried dough twist were also examined under the different storage condition. Sample extraction, derivatization, and cleanup conditions were evaluated to provide a sample preparation method for GO and MGO analysis by RP-HPLC-DAD. Quantification limits of GO and MGO were 0.01 and 0.02 mg/L for fried dough twist, respectively. The average recovery rate was 89 % with detection relative standard deviation of lower than 5.7 %. During frying and prolonged storage, GO and MGO contents in fried dough twist ranged from 6.5 to 11.8 mg/kg and from 5.1 to 12.0 mg/kg, respectively. The results indicated that content of GO and MGO in fried dough twist depended on the frying time and temperature. For GO, no significant differences (p < 0.05) among the all types of samples were found during the whole process of storage, with the exception of storage temperature after 60-day storage. Changes in MGO occurred during the 60-day storage, indicating storage temperature, oxygen content, lighting, and storage duration, exert a significant effect on the development of the MGO