Study of ascorbic acid stabilization conditions in fresh juices

Abstract

For the first time the possibility of using purified pectins to stabilize ascorbic acid (AA) in fresh juices was considered and proved. The purpose of the study was to analyze the possibility of using purified pectins to stabilize AA in fresh juices with a concentration of 1⋅10-6-1⋅10-4g/ml. The work used AA, oxalic acid (OA), as well as beet (BP), citrus (CP) and apple (AP) pectins. There was no interfering effect of pectins on AA determination by differential UV spectroscopy. The specific absorption rate of AA (727) was determined, according to which the AA content in model solutions with auxiliary substances during storage was estimated. The optimal weight ratio AA:AP 1:16 used for blending fresh juices, in which the AA concentration was previously determined by titration with 2.6-dichlorophenolindophenolate sodium, was established. It was revealed that AP contributes to the pH shift to the optimal pH area for AA 4.5-8.0; increase of juice viscosity by 5-148% and storage life by 3.3-59 times. The relative error of definitions did not exceed ±5.6%.