TY - JOUR

T1 - Surface Moisture Induces Microcracks and Increases Water Vapor Permeance of Fruit Skins of Mango cv. Apple

AU - Athoo, Thomas O.

AU - Winkler, Andreas

AU - Owino, Willis O.

AU - Knoche, Moritz

N1 - Funding Information: Funding: This study was funded by a grant (KN 402/21-1 from the Deutsche Forschungsgemein-schaft) to M.K. and a stipend from the German Academic Exchange Service (DAAD) to T.O.A. The publication of this article was funded by the Open Access fund of Leibniz Universität Hannover. Acknowledgments: We thank Gaston Odiwuor, David Votha, Simon Sitzenstock, Yun-Hao Chen and Bishnu P. Khanal for technical help, Patrick and Stellamaries Musyoka for their permission to sample fruit in their orchard and Sandy Lang for useful comments on an earlier version of this manuscript.

PY - 2022/6

Y1 - 2022/6

N2 - Exposure to surface moisture triggers cuticular microcracking of the fruit skin. In mango fruit cv. apple, microcracking compromises postharvest performance by increasing moisture loss and infections with pathogens. This study reports the effects of exposing the fruit’s skin to surface moisture on the incidence of microcracking and on water vapor permeance. Microcracking was quantified microscopically following infiltration with a fluorescent tracer. Water mass loss was determined gravimetrically. Moisture exposure increased cuticular microcracking and permeance. During moisture exposure, permeance increased over the first 4 d, remained constant up to approximately 8 d, then decreased for longer exposure times. Fruit development followed a sigmoid growth pattern. The growth rate peaked approximately 103 days after full bloom. This coincided with the peak in moisture-induced microcracking. There were no increases in water vapor permeance or in microcracking in control fruit that remained dry. When experimental moisture exposure was terminated, microcracking and water vapor permeance decreased. This suggests a repair process restoring the barrier properties of the fruit skin. Histological analyses reveal a periderm forms in the hypodermis beneath a microcrack. Our study demonstrates that surface moisture induces microcracking in mango cv. apple that increases the skin’s water vapor permeance and induces russeting.

AB - Exposure to surface moisture triggers cuticular microcracking of the fruit skin. In mango fruit cv. apple, microcracking compromises postharvest performance by increasing moisture loss and infections with pathogens. This study reports the effects of exposing the fruit’s skin to surface moisture on the incidence of microcracking and on water vapor permeance. Microcracking was quantified microscopically following infiltration with a fluorescent tracer. Water mass loss was determined gravimetrically. Moisture exposure increased cuticular microcracking and permeance. During moisture exposure, permeance increased over the first 4 d, remained constant up to approximately 8 d, then decreased for longer exposure times. Fruit development followed a sigmoid growth pattern. The growth rate peaked approximately 103 days after full bloom. This coincided with the peak in moisture-induced microcracking. There were no increases in water vapor permeance or in microcracking in control fruit that remained dry. When experimental moisture exposure was terminated, microcracking and water vapor permeance decreased. This suggests a repair process restoring the barrier properties of the fruit skin. Histological analyses reveal a periderm forms in the hypodermis beneath a microcrack. Our study demonstrates that surface moisture induces microcracking in mango cv. apple that increases the skin’s water vapor permeance and induces russeting.

KW - cuticle

KW - microcracks

KW - periderm

KW - permeance

KW - russeting

KW - skin

KW - wax

UR - http://www.scopus.com/inward/record.url?scp=85132743321&partnerID=8YFLogxK

U2 - 10.3390/horticulturae8060545

DO - 10.3390/horticulturae8060545

M3 - Article

AN - SCOPUS:85132743321

VL - 8

JO - Horticulturae

JF - Horticulturae

IS - 6

M1 - 545

ER -