SIMULTANEOUS DETERMINATION OF ELEVEN ORGANIC ACIDS IN BLUEBERRY JUICE BY HPLC-DAD

The organic acid content in blueberry juice is an important parameter to evaluate the quality of fruit juice.Eleven kinds of organic acids (oxalic acid,acetic acid,crylic acid,succinic acid,malonic acid,tartaric acid,fumaric acid,citric acid,propionic acid,malic acid and lactic acid) in five kinds of commercial blueberry juice products were determined simultaneously by using high performance liquid chromatography-diode array detector (HPLC-DAD).The determination conditions were as follows:Hypersil C_l8column (5 m,250 mm×4.6 mm i.d.),methanol-0.5% NaH₂PO₄as mobile phase,gradient elution,injection amount 20.0 L,flow rate 1.0 mL/min,column temperature 25℃,and detection wavelenght 210 nm.The 11 kinds of organic acids were identified by retention time and characteristic spectra and quantified by peak area.Results showed that the mass concentrations of the 11 kinds of had good linear relationship with peak areas,with the correlation coefficients of 0.996 2 to 0.999 5;the The average recoveries were 86.3% to 99.7% with relative standard deviations of 2.2%~4.6%(n=7) and detection limits of 0.4 to 2.5 mg/L.The proposed method was used to determine commercial blueberry juice products,and results showed that the contents of the 11 kinds of organic acids in five blueberry juice products had significant difference.The method is simple,quick,sensitive,and reproducible,is suitable for organic acid content analysis in fruit juice,and is practical and instructive for evaluating the quality of blueberry juice and other related products.