Study On Aroma Components And Oleanolic Acid Of Chaenomeles Fruits

To study aroma characteristics and pharmacological constituents of Chaenomeles fruits, aroma components of Chaenomeles fruits were extracted with the method of Simultaneous Distillation and Extraction (SDE) and identified by GC-MS. Using Ultrasonic Extraction Method to extract oleanolic acid from Chaenomeles fruits, and extracting parameters were optimized by Response Surface Methodology(RSM).The content of oleanolic acid was detected by HPLC and the optimum extracting conditions were found.According to the analysis of GC-MS, 62, 60 and 53 different compounds were identified from three different cultivars of Chaenomeles fruits-Changjun, Shi Zitou and Yulan separately, and among them 21 components were identical. The compound of the highest relative content in these Chaenomeles fruits was 4-Methyl-5-penta-1,3-dienyltetrahydrofuran-2-one,but their relative contents were different (Changjun 11.38%, Shi Zitou 25.71% and Yulan 17.72%). What's more, other compounds with strong fruit aroma such asà-Farnesene; 2-Hexenal, (E)-; 2-Hexen-1-ol, 1-Hexanol;β-ionone were also identified from these Chaenomeles fruits. Aroma components of Chaenomeles fruits mainly included alcohols, ketones, aldehydes, esters and hydrocarbons and among them alcohols, ketones, aldehydes and esters were critical compounds that contributed to the particular flavor of Chaenomeles fruits. Many components such as 2-Heptenal, (Z)- ; Megastigma-4,6(E), 8(E) -triene; Megastig-matrienone were not reported in studies of aroma components of Chaenomeles fruits .There were differences in aroma components of Chaenomeles fruits of the same cultivar from three regions of Baihe County. According to the analysis of GC-MS, 86 different compounds were identified from these Chaenomeles fruits and among them 28 components were identical. The dominant components included 4-Methyl-5-penta-1,3-dienyltetrahydrofu -ran-2-one ;à-Farnesene; 1-Hexanol;3-Hexen-1-ol,(Z)-;et al, but their relative contents were different. Besides, many other components such as Hexanoic acid, hexyl ester; 3-Furaldehyde; Megastigma-4,6(Z),8(E)-triene; E- 11-Hexadecenoic acid, ethyl ester were also identified. The great differences among these Chaenomeles fruits indicated that the environment was one of the important factors influencing aroma components of Chaenomeles fruits. The total trend of aroma components of Chaenomeles fruits during different storage time were that esters and alkenes were increasing along with the storage time while alcohols, ketones and aldehydes were decreasing. At the beginning of the storage, the dominant aroma components of Chaenomeles fruits were 4-Methyl-5-penta-1,3-dienyl tetrahydrofu ran-2-one, 4-(2,6,6-Trimethyl- cyclohex-1-enyl)-butan-2-ol,3-Hexen-1-ol, (Z)- et al. After 40 days storage at 8℃, the main components and their relative contents were alkenes(21.07%), esters(18.73%) and alcohols(16.34%). After 90 days storage, the relative content of ethyl esters of aliphatic acids increased significantly to 34.86%, among which the critical one was 3-Nonenoic acid, ethyl ester(21.67%). In addition, the relative content ofα-Farnesene increased from 3.63% at the beginning of the storage to 35.22% after 90 days storage.The study for the method which HPLC mensurated the content of oleanolic acid in Chaenomeles fruits indicated that chromatograph conditions were HiQ Sil C18(4.6mm×250 mm) column, mobile phase methanol-water-acetic acid-triethylamine(87:13:0.04:0.02),flow rate 0.8mL/min,detection wavelength 210nm,column temperature 30℃. Under above conditio -ns, oleanolic acid in Chaenomeles fruits was separated well. The results showed that HPLC was simple, accurate and could be used for the quality study of oleanolic acid in Chaenomeles fruits.The method of ultrasonic extraction were used to extract oleanolic acid from Chaenomel -es fruits, parameters of temperature, the ratio of solid to liquid and extracting time were optimized by Response Surface Methodology(RSM).The optimum extracting conditions were as follows: using water-free ethanol, the ratio of solid to liquid 1:16, temperature 53℃, extracting time 45 min. Under above conditions, the content of oleanolic acid in Chaenomeles fruits was 1.40mg/g.