Research On The Detection Method Of Anthocyanins, Ascorbic Acid And Isoascorbic Acid In Blueberry And Products

Blueberry, also known as bilberry, is perennial deciduous or evergreen trees belonging to Ericaceae Vaccinium spp.The fruit of blueberry is berry, which exhibits nearly round, dark blue and covered with hoarfrost. Blueberry contains anthocyamins, and is one of the rare bule foods in the world.Anthocyanin is a class of water-soluble polyphenols, whose anthocyanin sugar has been combined with glycosidic bonds. Anthocyanin as a natural edible pigment has aroused great attention, especially considering the alternative of synthetic dyes. Extracting natural anthocyanin expresses particularly importance because anthocyanin usually adds to foods and cosmetics for its capacity of scavenging free radicals and lipid-lowering effect.Our thesis studied the separation and purification of anthocyanin. The experiment results indicate that the optimized binary mobile phase is phase A:0.2%trichloroacetic acid aqueous solution and phase B:acetonitrile. The pigment content of the sample was measured as well. Furthermore, blueberry anthocyanins contained six different kinds of anthocyanins, which were identified by liquid chromatography-tandem mass spectrometry.Our thesis mainly focused on the detection methods of anthocyanins, ascorbic acid and isoascorbic acid in blueberry and buleberry products, and the extraction of anthocyanins in blueberry fruit. The extracted anthocyanins were pure verifying by mass spectrometry. The pigment, ascorbic acid and isoascorbic acid content in blueberry and buleberry products were also measured. Acetonitrile-0.1%phosphoric acid aqueous solution (90:10, v/v) was intended as both the mobile phase and the extracting solution, and then used Venusil HILIC column (250x4.6mm,5μm,100A) to separate ascorbic acid and isoascorbic acid. The experimental results showed that the average recovery of ascorbic and isoascorbic acid were96.61%and96.53%, while the detection limit of ascorbic and isoascorbic acid were0.35μg/mL and0.42μg/mL, respectively.The Venusil HILIC chromatographic column could be intended to simultaneously measure the ascorbic and isoascorbic acid content in blueberry foods. Moreover, the proposed method could be applied to determine the ascorbic and isoascorbic acid content in fortified foods, because it exhibited many advantages, such as convenient pre-treatment, accurate results, high sensitivity, good reproducibility, and easy operation, etc.