Automated determination of vitamin C in some fortified foodstuffs

Abstract

An automated method for the determination of ascorbic acid has been applied to a variety of vitamin fortified food products. The method is based on the reduction of 2,6-dichloroindophenol by ascorbic acid and shows a detection limit of 0.006 mg/ml with a linear absorbance relationship to 0.200 mg/ml. The method was applied to vitamin fortified cereal products, soya protein snacks and beverage concentrates over a broad range of vitamin levels. The results compared favourably with potentiometric titrztion for the majority of products studied. It has been shown that the automated procedure is the method of choice for the determination of ascorbic acid in the large number of food products studied.

Harvesting, Processing, and Cooking Influences on Vitamin C in Foods

“…The DCIP assay can be modified to minimize the effects of the interfering basic substances, but the measurement is still only of the reduced form. Egberg et al (9) adapted the photometric DCIP assay to an automated proce dure for continuous analysis of vitamin C in food extracts. In most plant foods, the predominant form of ascorbic acid present is the reduced compound.…”

Fluorometric Assay for Total Vitamin C Using Continuous Flow Analysis

“…Titration of acid extracts of food products with 2,6-dichloroindophenol (DCP) and the DCP photometric assay are the most common methods for the determination of reduced ascorbic acid (RAA) in foods. Recently, Egberg et al (1973) reported a photometric DCP method for RAA in foods which was adapted for continuous flow analysis using Technicon Auto-Analyzer (Technicon Instruments Corp., Tarrytown, NY 10591) equipment. However, the presence of reducing substances, such as sulfhydryl compounds, reductones and reduced iron limit the use of the DCP techniques for RAA in foods and biological fluids.…”