Compositional Variation in Sugars and Organic Acids at Different Maturity Stages in Selected Small Fruits from Pakistan

Selected soluble sugars and organic acids were analyzed in strawberry, sweet cherry, and mulberry fruits at different ripening stages by HPLC. The amounts of fructose, glucose and sucrose were found to be: strawberry (1.79-2.86, 1.79-2.25 and 0.01-0.25 g/100 g FW), sweet cherry (0.76-2.35, 0.22-3.39 and 0.03-0.13 g/100 g) and mulberry (3.07-9.41, 1.53-4.95 and 0.01-0.25 g/100 g) at un-ripened to fully-ripened stages, respectively. The strawberry, sweet cherry and mulberry mainly contained tartaric, citric and ascorbic acids in the range of 16-55, 70-1934 and 11-132 mg/100 g; 2-8, 2-10 and 10-17 mg/100 g; 2-118, 139-987 and 2-305 mg/100 g at un-ripened to fully-ripened stages, respectively. Fructose and glucose were established to be the major sugars in all the tested fruit while citric and ascorbic acid were the predominant organic acids in strawberry and mulberry while tartaric acid was mainly present in sweet cherry. The tested fruits mostly showed an increase in the concentration of sugars and organic acids with ripening.