Effects of Temperature and Humidity on the Quality and Textural Properties of Melon Fruits During Development and Ripening

Abstract

The quality of melon fruit depends on the environmental growth conditions. We evaluated the effects of temperature and humidity in the greenhouse on the quality and textural properties of melon fruit during development and ripening. The greenhouse humidity and air and soil temperatures were monitored over two growth seasons of three melon varieties. The average air and soil temperatures were higher in spring than in autumn, whereas average air humidity was lower in spring. The contents of free amino acid, soluble protein, and soluble sugar in melon fruit were significantly higher in spring than in autumn. The contents of sucrose phosphate synthase and sucrose synthase were also significantly higher in spring than in autumn. In both seasons, the contents of water-soluble pectin and ionic soluble pectin increased during fruit maturation, whereas the content of covalent soluble pectin decreased. The cellulose and hemicellulose contents of the three melon cultivars decreased to different degrees during ripening. The contents of ploygalacturonase, pectinesterase, and β-galactosidase first increased and then decreased over time. The cellulase activity in the three cultivars increased steadily and peaked at maturity, suggesting that cell wall-modifying enzymes play important roles in the transformation of fruit texture.