Characterisation of the chemical composition of scab-resistant apple pomaces

Abstract

SummaryPomaces obtained during the production of cloudy or clear juice from scab-resistant apple cultivars (28 harvested in 2006, and 23 harvested in 2007) were studied as a source of nutritionally important components. It was shown that the average yield of pomace during the production of cloudy juice was 6.4% (w/w), and 4.9% (w/w) for clear juice pressing. The average total dietary fibre (TDF) contents were 48.4% (w/w) and 52.4% (w/w) for cloudy and clear juice pomaces, respectively. Ten pomaces from cloudy apple juice production, and 12 obtained from clear juice production, contained ≥ 2,000 mg kg−1 of polyphenols.‘Ariwa’ and ‘Rajka’ are apple cultivars suitable for juice production and their pomaces are characterised by having high contents of TDF [50.9% (w/w) and 51.1% (w/w), respectively], with aboveaverage polyphenol and quercetin glycoside concentrations. The mean contents of quercetin glycosides for pomaces from all apple cultivars was 994 mg kg−1 after clear juice production, and 908.2 mg kg−1 after cloudy juice production. ‘Topaz’, which became a popular commercial apple cultivar in Europe, was the best source of health-promoting components. Its pomace was the richest source of polyphenols among all 28 cultivars studied. It contained ≥ 2,000 mg kg−1 quercetin glycosides in both its clear and cloudy juice pomaces.