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International Agrophysics
publisher:Institute of Agrophysics
Polish Academy of Sciences
Lublin, Poland
ISSN: 0236-8722


vol. 14, nr. 1 (2000)

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Watermelon epicuticle changes related to friction test parameters
Puchalski C.1, Brusewitz G.H.2
1 Department of Agricultural Production Technology, Agricultural University of Cracow, Ćwiklińskiej 2, 35-959 Rzeszów, Poland
2 Department of Biosystems and Agricultural Engineering , 0klahoma State University, Stillwater, OK 74078, U.S.A.

vol. 14 (2000), nr. 1, pp. 113-119
abstract A surface friction method was used to apply a mechanical load to the watermelon fruit's epicuticle. By varying the degree of abrasion intensity, four increasingly larger degrees of epicuticle were identified. These altered stages were related to unique features on the friction force vs. displacement curve, marks on the watermelon, and marks on the abrasive surface. Failure threshold distance and epicuticle layer removal distance were good indicators of resistance to abrasion and were affected by roughness of the abrasive surface, sliding speed, normal force and measurement location on the sample. The magnitude of changes in the fruit's epicuticle structure varied with harvest date and between the two watermelon cultivars.
keywords abrasion, friction, watermelon, wax, resistance