Effect of storage temperature on phenolics stability in hawthorn (Crataegus pinnatifida var. major) fruits and a hawthorn drink

摘要

The stability of five major phenolics, namely (-)-epicatechin (EC), procyanidin B_2 (PC-B_2), chlorogenic acid (ChA), hyperoside (HP) and isoquercitrin (IQ), in hawthorn fruits and a canned hawthorn drink were evaluated during 6 months of storage in the dark at three different temperatures (4, 23 and 40℃). HPLC with a diode-array detector was used to determine the contents of the individual compounds. The results showed that the studied phenolics in the hawthorn fruits and the drink were both stable at 4℃ and relatively unstable at 23 and 40℃ with varied extents of degradation. At room temperature (23℃), marked degradations of EC and PC-B_2 were observed in both the fruits and the drink with around 50% and 30% decrease after a 6-month storage, respectively. A more significant decrease of the phenolics was observed at 40℃, especially for EC and PC-B_2, which were almost completely degraded after a 6-month storage. HP, IQ and ChA were relatively stable at 23℃, but unstable at 40℃. Therefore, low-temperature storage is recommended for maintaining the quality and efficacy of hawthorn fruits and its preparations.