Sources of variation in water vapour permeance of apple fruit

• Published in: Postharvest biology and technology Vol. 17; no. 1; pp. 11 - 17
• Main Authors: Maguire, Kate M, Banks, Nigel H, Lang, Alexander
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-09-1999
• Subjects: APPLES; Cuticle; EVAPORACION; EVAPORATION; Malus domestica; MANZANA; Mass loss; PEEL; PELURE; PERMEABILIDAD; PERMEABILITE; PERMEABILITY; PIEL (VEGETAL); POMME; Water loss; Mass loss; Cuticle; Malus domestica; Water loss
• ISSN: 0925-5214; 1873-2356
• DOI: 10.1016/S0925-5214(99)00034-4

There can be large fruit-to-fruit variation in water vapour permeance within a population of fruit. We quantified contributions of several factors to variation in apple fruit (
Malus domestica Borkh.). In a study on ‘Braeburn’ fruit from six growers in each of five apple growing regions of New Zealand, there were large differences between growers, and marginal regional differences. The water vapour permeance of the fruit was extremely variable within each grower line. There were no relationships between four fruit maturity indicators (starch, background colour, firmness and soluble solids) and permeance, although fruit from the inner canopy had mean water vapour permeance values on average 57% greater than those from the outer canopy. Apple fruit with large numbers of adjacent fruit (three and four contact points) had on average a 54% higher water vapour permeance than those with less contact points. The areas of contacts had a mean water vapour permeance 30% higher than other areas. There was no difference in permeance between the sun and shade sides of apple fruit nor was cuticle thickness related to fruit water vapour permeance. There was no pattern of water vapour permeance of ‘Braeburn’ fruit with respect to blush or vertical displacement (shoulder or cheek). However, there were large variations among fruit within a population. A large proportion of this variation seems to be non-systematic, random error. Further work should be undertaken to determine differences in physical and chemical composition of the cuticle that lead to this variation in water vapour permeance.