Relationships Between Anthocyanins, Total Phenolics, Carbohydrates, Acidity and Colour of Saskatoon Berries

Abstract

The relationships between levels of anthocyanins, total phenolics, pH, titratable acidity, sugars and colour of several cultivars of Saskatoon berries (Amelanchier alnifolia), harvested at three stages of maturity, were studied. Anthocyanins, total phenolics, sugars, sugars-acids ratios and anthocyanins-phenolics ratios increased with ripening of the berries. Titratable acidity and pH differed among the cultivars but showed little change with berry development. Anthocyanin contents of the berries ranged from 25.1 to 178.7mg/100g of fruit, while total phenolics and soluble solids ranged from 0.17 to 0.52% and 9.6 to 18.7%, respectively. Significant correlation with anthocyanins was obtained for total phenolics content, titratable acidity, pH and sugar-acid ratio. The correlation coefficients between total phenolics and sugar-acid ratio, pH and total phenolics, and pH and titratable acidity were −0.787, −0.743 and −0.941, respectively. The relationships between surface colour and compositional factors of the berries showed low significance. These results suggest that high levels of anthocyanins in Saskatoon berries are associated with high total phenolics and acids and low pH and sugar-acid ratios.