Analysis of Phenolic Acids in Citrus Fruits by HPLC

• Main Authors: Wen-Yuan Li, 李文瑗
• Other Authors: Yung-Chung Chang
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/73441654616976345272

碩士 === 國立宜蘭大學 === 食品科學系碩士班 === 98 === The aim of this study was to devise a method for identification and quantification of phenolic acids and their distribution in six varieties of citrus fruits in Taiwan (Murcott, Orange, Lemon, Grapefruit, Kumquat and Pomelo) samples. The reversed-phase HPLC method for simultaneous determination of twelve phenolic acids was developed. The method was validated and it was suitable for the analysis of phenolic acids in selected samples. Soluble phenolic acids fraction were extracted with 80% methanol after pretreatment. Bound phenolic acids fractions were liberated using first alkaline and then acid hydrolysis followed by extraction with diethyl ether/ethyl acetate (1:1). All fractions were quantified separately by HPLC. Operating conditions were as follows: column temperature, 50℃ ; flow rate: 1 ml/min; detected at 280 nm . Chromatographic separations were performed on a Nucleodur 100-5 C18ec (250 × 4.6 mm ). For gradient elution mobile phase A (4% acetic acid in water) and B (methanol) were employed. As a result, the linearity range of phenolic acids is 0.5-500 ppm（R2 = 0.9991-0.9999）, limit of detection 0.05-10 ppm , recovery 65.47%-104.3%, reproducibility(coefficient of variation) of migration time ≦ 4.14% and of integration area ≦ 3.48% . Sample analysis results show the six citrus fruits are different in phenolic acids and their amounts. Both peel and pulp of citrus fruits, the soluble phenolic acids content is highest, and then is alkaline hydrolysis-bound phenolic acids content, but only trace amounts in acid hydrolysis-bound phenolic acids fraction. The ferulic acid, p-coumaric acid, caffeic acid and sinapic acid are common abundant in citrus fruits. The peel of Murcott has highest summation of tree type phenolic acids content (648.31 ± 2.81 mg /100 g d.w.) then others citrus fruits, but orange is the top in pulp (117.07 ± 5.58 mg /100 g d.w.). The order of phenolic contents of each phenolic acids extracted fraction is same as their phenolic acids content in all selected samples. Six citrus fruits are soluble phenolic acids fraction > alkaline hydrolysis-bound phenolic acids fraction > acid hydrolysis-bound phenolic acids fraction.