Polyphenol components and radical scavenging activity of Geneva (crab apple)

Abstract

The polyphenol components and radical scavenging activity of Geneva (Malus niedzwetzkyana) fruit were determined. Geneva is a Canadian native crab apple with deep red skin and flesh, and is grown in the Asahi region, Yamagata prefecture. The contents of malic acid and polyphenols in Geneva fruit juice were higher than those of several other apple juices such as Fuji, Ohrin, and Kogyoku, but the Brix value of Geneva was lower than those of other apples. Chlorogenic acid, (+) catechin, (-) epicatechin, procyanidin B2, procyanidin B1, and phloridzin were identified as major polyphenol compounds in Geneva by HPLC and ESI-MS spectrometry. The DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity of Geneva fruit juice was the highest of all the apple juices, and the activities of all juices were proportionate to their total polyphenol contents. It was concluded that the major components responsible for high DPPH radical scavenging activity were chlorogenic acid, catechins (monomeric forms), and procyanidins (oligomeric and polymeric forms).