Mathematical modelling of the accumulation of carbohydrates and organic acids throughout the ripening process of Hungarian sour cherry cultivars

Abstract

Changes in sugar and acid content of Hungarian sour cherries during the ripening period can be described by a mathematical model. The Hungarian sour cherry cultivars can be utilised not only as raw material for the food industry, but also for fresh consumption. Changes in the main sugar and organic acid components in the fruit of sour cherry cultivars bred in Hungary (‘Erdi jubileum’, ‘Erdi bőtermő’, ‘Maliga emleke’, ‘Kantorjanosi 3’ and IV-3/48) were determined with the aid of HPLC analysis at nine sampling dates during the ripening process. The main carbohydrate components of the fruit of the Hungarian cultivars tested were glucose (48.73–81.57 mg/g), fructose (30.99–60.26 mg/g) and sucrose (11.67–50.37 mg/g). In the course of ripening the changes in the glucose and fructose contents could be described using a saturation model, and changes in the sucrose content with an exponential model. The main organic acid components were malic acid (220.38–382.72 mg/g), succinic acid (104.54–209.90 mg/g), tartaric acid (89.04–182.01 mg/g) and ascorbic acid (4.60–17.49 mg/g). In general the decrease in the organic acid components could be described using a decreasing saturation model, while the vitamin C content either increased in the course of ripening according to a logistic model or exhibited a decline that could be described with a quadratic function. Consequently, there were substantial differences in the sugar and acid profiles of the various Hungarian sour cherry cultivars, some of which can be recommended for use as parents in breeding for better chemical quality.