Heat treatment affects epicuticular wax structure and postharvest calcium uptake in 'Golden Delicious' apples

• Published in: HortScience Vol. 29; no. 9; pp. 1056 - 1058
• Main Authors: Roy, S. (Horticultural Crop Quality Laboratory and Electron Microscopy Laboratory, ARS, USDA, Beltsville, MD.), Conway, W.S, Watada, A.E, Sams, C.E, Erve, E.F, Wergin, W.P
• Format: Journal Article
• Language: English
• Published: Alexandria, VA American Society for Horticultural Science 01.09.1994
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; CALCIO; CALCIUM; CERAS; CHLORURE DE CALCIUM; CIRE; CLORURO CALCICO; Food industries; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; INFILTRACION; INFILTRATION; MANZANA; MICROSCOPIA; MICROSCOPIE; Physiological diseases. Varia; Phytopathology. Animal pests. Plant and forest protection; POMME; SOLUCION; SOLUTION; TECHNOLOGIE APRES RECOLTE; TECNOLOGIA POSTCOSECHA; TRAITEMENT THERMIQUE; TRATAMIENTO TERMICO; ULTRAESTRUCTURA; ULTRASTRUCTURE; Heat treatment; Calcium; Rosaceae; Cuticle; Malus domestica; Postharvest disease; Surface analysis; Inorganic element; Calcium Chlorides; Absorption; Dicotyledones; Angiospermae; Plant wax; Scanning electron microscopy; Pome fruit; Under pressure; Uptake; Fruit industry; Apple; Chemical treatment; Epicuticular wax; Structure modification; Spermatophyta; Infiltration; Physiological disorder
• ISSN: 0018-5345; 2327-9834
• DOI: 10.21273/hortsci.29.9.1056

'Golden Delicious' apples (Malus domestica Borkh) were pressure-infiltrated at harvest with a 4% CaCl2 solution either without prior heat treatment or following 4 days at 38C. Examination of the apple surfaces from both treatments by low-temperature scanning electron microscopy revealed that heat treatment changed the pattern of epicuticular wax. The epicuticular wax of nonheated fruit exhibited numerous deep surface cracks that formed an interconnected network on the fruit surface. The epicuticular wax of heat-treated fruit did not exhibit a similar network of deep cracks. This apparent obstruction or elimination of deep cracks may limit the CaCl2 solutions from entering the fruit. The heated fruit contained significantly less Ca than the fruit that were pressure infiltrated with CaCl2 solutions but not heated. These results indicate that cracks on the fruit surface may be an important pathway for the penetration of CaCl2 solutions