title: Enzyme activity and biochemical changes of three date palm cultivars with different softening pattern during ripening.
abstract: The physicochemical composition changes during palm ripening were studied. The activities of invertase and cell wall-modifying enzymes, namely pectin methylesterase (PME), β-galactosidase (β-Gal), endo-1,4-β-D-glucanase (EGase), and cellulase were monitored during growth and ripening of Shahani, Piarom and Deiry cultivars with different textures. Also, we estimated the concentrations of six organic acids by HPLC. Reducing sugars, most of organic acid, pH and TSS increased up to the full-ripe stage of all date types. On the contrary, moisture, macro and microelements and proteins decreased during the same period. Despite a considerable rise in invertase activity (200 units) during ripening of Shahani, no significant trend could be discerned in Deiry cultivar (8 units) at different stages. Our results also showed that cell wall enzymes were increased in activity during ripening and these increases were coincident with fruit softening. Furthermore, our results showed that the composition and the variation of the chemical compositions mainly depended on the cultivar and maturity stage.
authors.affiliation: Department of Horticultural Science, Shiraz University, Shiraz, Iran.
authors.forename: Somayeh
authors.initials: S
authors.lastname: Rastegar
authors.affiliation: Department of Horticultural Science, Shiraz University, Shiraz, Iran.
authors.forename: Majid
authors.initials: M
authors.lastname: Rahemi
authors.affiliation: International Center for Science and High Technology and Environmental Sciences, Kerman, Iran.
authors.forename: Amin
authors.initials: A
authors.lastname: Baghizadeh
authors.affiliation: Department of Horticultural Science, Shiraz University, Shiraz, Iran.
authors.forename: Mahdiyeh
authors.initials: M
authors.lastname: Gholami
mesh_terms: D002241:Carbohydrates / Q000737:chemistry; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism*; D002473:Cell Wall / Q000737:chemistry* / Q000378:metabolism; D002480:Cellulase / Q000378:metabolism*; D005511:Food Handling / Q000379:methods; D005638:Fruit / Q000737:chemistry / Q000254:growth & development*; D006863:Hydrogen-Ion Concentration; D065749:Phoeniceae / Q000737:chemistry / Q000254:growth & development*; D014867:Water / Q000737:chemistry*; D001616:beta-Galactosidase / Q000378:metabolism*
chemical_list: D002241:Carbohydrates; D014867:Water; D002265:Carboxylic Ester Hydrolases; C022323:pectinesterase; D001616:beta-Galactosidase; D002480:Cellulase