title: Specific Changes of Exocarp and Mesocarp Occurring during Softening Differently Affect Firmness in Melting (MF) and Non Melting Flesh (NMF) Fruits.
abstract: Melting (MF) and non melting flesh (NMF) peaches differ in their final texture and firmness. Their specific characteristics are achieved by softening process and directly dictate fruit shelf life and quality. Softening is influenced by various mechanisms including cell wall reorganization and water loss. In this work, the biomechanical properties of MF Spring Crest's and NMF Oro A's exocarp and mesocarp along with the amount and localization of hydroxycinnamic acids and flavonoids were investigated during fruit ripening and post-harvest. The objective was to better understand the role played by water loss and cell wall reorganization in peach softening. Results showed that in ripe Spring Crest, where both cell turgor loss and cell wall dismantling occurred, mesocarp had a little role in the fruit reaction to compression and probe penetration response was almost exclusively ascribed to the epidermis which functioned as a mechanical support to the pulp. In ripe Oro A's fruit, where cell wall disassembly did not occur and the loss of cell turgor was observed only in mesocarp, the contribution of exocarp to fruit firmness was consistent but relatively lower than that of mesocarp, suggesting that in addition to cell turgor, the integrity of cell wall played a key role in maintaining NMF fruit firmness. The analysis of phenols suggested that permeability and firmness of epidermis were associated with the presence of flavonoids and hydroxycinnamic acids.
authors.affiliation: Department of Biosciences, University of Milan, Via Celoria 26, 20133, Milano, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Onelli
authors.affiliation: Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza n. 1, 20126, Milan, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Ghiani
authors.affiliation: Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza n. 1, 20126, Milan, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Gentili
authors.affiliation: Department of Horticulture, Washington State University, TFREC, Wenatchee, 98801, WA, United States of America.
authors.forename: S
authors.initials: S
authors.lastname: Serra
authors.affiliation: Department of Horticulture, Washington State University, TFREC, Wenatchee, 98801, WA, United States of America.
authors.forename: S
authors.initials: S
authors.lastname: Musacchi
authors.affiliation: Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza n. 1, 20126, Milan, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Citterio
mesh_terms: D002473:Cell Wall / Q000502:physiology*; D003373:Coumaric Acids / Q000378:metabolism*; D005419:Flavonoids / Q000378:metabolism*; D061353:Food Storage; D018506:Gene Expression Regulation, Plant; D010940:Plant Proteins / Q000235:genetics; D000068239:Prunus persica / Q000254:growth & development* / Q000502:physiology*
chemical_list: D003373:Coumaric Acids; D005419:Flavonoids; D010940:Plant Proteins