Quantitative Methods for Anthocyanins.

Abstract

SUMMARY— The method developed consists of extracting the anthocyanins with ethanol‐1.5N hydrochloric acid (85:15) and measuring the O.D. of the extract, diluted with the extracting solvent, at 535 nm. The total anthocyanin content was calculated in absolute quantities with the aid of the extinction coefficients established for the four major cranberry anthocyanins dissolved in the alcoholic solvent system.

Study on the development of pomegranate juice processing technology: Clarification of pomegranate juice

“…The TPS and total titratable acidity (as citric acid) were determined according to the AOAC methods [13]. Total anthocyanin pigment (by pH-differential, as mg cyanidin-3-glucoside/L juice), turbidity (Abs 700 value) and colour density (((Abs 420 + Abs 523 )-2 (Abs 700 )) 6 dilution factor) measurement were made as described by Fuleki and Francis [14] and Wrolstad [15]. The values reported are means of duplicate analyses which showed only little variation (l 5%).…”

Phenolics in cereals, fruits and vegetables: Occurrence, extraction and analysis

“…However, according to Moore et al [257,258] the acid may bring about changes in the native form of anthocyanins by breaking down their complexes with metals and co-pigments. The acidic extracts of anthocyanins are first concentrated under vacuum and then may be extracted with petroleum ether, ethyl acetate or diethyl ether in order to remove lipids and unwanted polyphenols [259,260]. The extract can also be partially purified, using ion exchange resins, as described by Fuleki and Francis [261].…”

Sorghum flour fractions: Correlations among polysaccharides, phenolic compounds, antioxidant activity and glycemic index

“…Total anthocyanin concentration was performed by the pH differential method described by Fuleki and Francis (1968), with modifications according to Awika, Rooney, and Waniska (2004). The samples were read at 300 and 700 nm.…”