Effects of Saccharides on Anthocyanin Pigment from Juice of Campbell Early Grapes

Studies on Qualities of Grape Juice (Part 4)

Abstract

Many saccharides as well as some inorganic salts and organic acids were found to enrich the color density at 520nm of anthocyanin solution (pH3.0) from juice of Campbell Early grapes and to stabilize the enriched color density for forty days at room temperature. (1) All of the sugars tested had hyperchromic effect (enrichment of the absorbance at 520nm). A linear relation was obtained between the enriched absorbance at 520nm(ΔE 520nm) and the sugar concentration (0-2.0M). The trisaccharide had the most hyperchromic effect, followed bydisaccharide, monosaccharide. Thus it was proved that the hyperchromic effect enhanced with increasing molecular weight of sugars. (2) In the case of monosaccharides, the hyperchromic effect (enrichment of absorbance at 520nm) increased in the following order: sugar-alcohols (D-sorbitol and D-mannitol)<ketohexose (D-fructose)<aldopentose (D-xylose)<aldohexoses (D-glucose, Dmannose and D-galactose). (3) Many saccharides effectively maintained the enrichment of absorbance at 520nm during room storage, (4) The stability of anthocyanin pigment in the presence of sugars was markedly influenced by storage temperature: The pigment was favorably held at cold temperature (6°C) and room temperature; the pigment breakdown was accelerated at higher temperature (55°C).