| Chrysanthemum morifolium Ramat (CMR), is a traditional ‘medicine food’ in China. Itis rich in flavnoids, chlorogenic acid and volatile oil which have anti-bacteria, anti-oxidation,anti-inflammatory properties, hypolipidemic and cardiovascular protection effect. The CMRconcentrate, can serve as functional ingredients, natural flavor enhancer and hyperchromicagent. However, the problems of low efficiency, components degration, flavor loss andsolvent residual may exist in the processes. So far, there are seldom systematic reports aboutpreparation optimization and physicochemical properties of CMR concentrate.This paper studied the optimal conditions for preparing CMR water extract byultrasonic-microwave (UME) synergizing countercurrent extraction method. The optimalconditions were as follows: at the ratio of1:30(g:mL）with microwave power of250W/2.50g and ultrasonic power of50W/2.50g, treated with microwave and ultrasonic for240s(extracted for420s) per unit, combined with two-stage countercurrent method. The totalflavnoids yield reached64.70mg/g, chlorogenic acid yield4.21mg/g, and total solid contents53.52%, which increased by10.92%,10.97%and23.67%respectively compared withtraditional heat reflux extraction (RE).The vacuum concentrating parameters were studied. When concentrated the CMR waterextract to28Brix°at temperature of65℃, the ideal CMR concentrate was obtained, in whichtotal flavoinds content was48.37mg/mL with a remaining rate of81.14%, chlorogenic acidcontent was2.63mg/mL with a remaining rate of82.09%.The effect of different extraction methods (UME, UE and RE) and concentration processon volatile flavor substances from chrysanthemum was studied. It showed that all the threeextraction processes had a negative effect on quantites of hydrocarbons. There wererespectively32,28,32new compounds in UME, UE and RE, which were mainly enols.Ultrasonic-microwave synergetic extraction preserves alcohols, aldehydes, ketones andoxygen heterocyclic hydrocarbons well, by which the types of volatile substances increasedfrom47to57. Besides,6-methyl-3,5-heptadiene-2-one, a distinctive Chrysanthemum flavorcomponents could only be detected in UME. The concentration treatment preserved most ofvolatiles in UME. There were46volatile flavor cmpounds in Chrysanthemum concentrate,16of which were by-products of concentration process.The rheology study showed that, for CMR concentrate at12Brix°-28Brix°, flow rateindex n＜1.0and G”＞G’, which indicated the concentrate had a pseudoplastic and viscousliquid property. With the increase of concentrations, the CMR concentrate had higher flowingactivation energy and tended to be more elastic. At the concentrations of12Brix°-28Brix°and temperatures of4℃-50℃, the relationship among temperature, concentration andviscosity can be described by the following equation: C2.73E11exp(3854.39T)。During90days’ storage time, microbacteria quantities at4℃,30℃and40℃wererespectively over regulated criteria at the75th-90th day,30th-45th day and45th-60th. Itwas easier for components deterioration when the storage temperature went higher. When stired at4℃, content of total flavnoids and chlorogenic acid dropped8.5%and12.39%,respectively; while at30℃, dropped19.15%and40.26%, and at40℃dropped6.25%and58.85%. The color value L*, a*and b*decreased during the storage. Generally speaking, theconcentrate kept it’s original color when stored for90days at4℃, for less than50days at30℃or for less than20days at40℃. The study showed that Chrysanthemum concentratewithout any antiseptic additives, should be stored at low temperature and could be stored forat least75days under4℃. |
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