Characterization of juice in fruits of different Chaenomeles species

Abstract

The juice in fruits of 21 genotypes of Japanese quince ( Chaenomeles japonica), 1 genotype of Chinese quince ( C. cathayensis), 1 genotype of flowering quince ( C. speciosa) and 1 genotype of a hybrid taxon ( C. × superba), representing plant breeding material, was extracted and characterized. The content of juice in the fruits varied between 41% and 52%, on fresh weight basis. The juice was very acidic (pH 2.6 and a titratable acidity of 3.5% calculated as anhydrous citric acid, on average) and transparent (52 NTU, on average), with low density and viscosity. The content of soluble solids was also low (7.1°Brix, on average). Proteins constituted 26 mg/100 ml juice on average, but no soluble polysaccharides were present. A high content of vitamin C (59 mg/100 ml juice, on average) and phenols (284 mg/100 ml juice, on average), beside the high acidity of the juice, suggests that chaenomeles juice may be an interesting raw material as ingredient for the food industry and a source of valuable substances. A principal components analysis separated the Japanese quince genotypes from the other genotypes studied, thus indicating a clear difference in the characteristics and chemical composition of the juice.