Abstract
Changes in the chemical composition of four guava cultivars were studied during development and ripening of the fruits. Guava fruit was analysed at three developmental stages for chemical composition, total sugars (fructose, glucose and sucrose), ascorbic acid, total soluble solids, total pectin and polyphenols. Investigation showed that total sugar contents were significantly increased with fruit growth and development in all cultivars. The maximum level varied from 13.7 to 30.6 mg per 100 ml of juice. Individual sugar contents increased gradually with fruit growth and development. The maximum level varied from 5.64 to 7.67, 1.90 to 8.00 and 6.20 to 7.78 mg per 100 mi of juice for fructose, glucose and sucrose, respectively, in all cultivars. Ascorbic acid was significantly increased with fruit growth and development in all cultivars. The maximum level varied from 88.2 to 113.3 mg per 100 g. Total soluble solids gradually increased with fruit development in all cultivars, which differed in their final value (11.1-13.2 degrees B). Polyphenols significantly decreased with fruit growth and development in all cultivars, which differed in their final value (0.20-0.30%). Total pectin for Shambati and Shendi cultivars significantly increased with fruit growth and development, while for Pakistani and Ganib it reached its maximum when the fruits were 106 days old, and thereafter it declined rapidly. The maximum level varied from 0.62 to 1.00%. (C) 1997 Elsevier Science Ltd.