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

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 degrees C). 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 degrees C and relatively unstable at 23 and 40 degrees C with varied extents of degradation. At room temperature (23 degrees C), 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 degrees C, 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 degrees C, but unstable at 40 degrees C. Therefore, low-temperature storage is recommended for maintaining the quality and efficacy of hawthorn fruits and its preparations. (c) 2005 Elsevier Ltd. All rights reserved.