Pectins from the albedo of immature lemon fruitlets have high water binding capacity

The white part of citrus peel, the albedo, has a special role in water relations of both fruit and leaves from early on in fruit development. In times of drought, this tissue acts as a water reservoir for juice sacs, seeds and leaves. When water was injected into the albedo, free water was undetecta...

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Veröffentlicht in:Journal of plant physiology. - 1979. - 161(2004), 4 vom: 14. Apr., Seite 371-9
1. Verfasser: Schröder, Roswitha (VerfasserIn)
Weitere Verfasser: Clark, Christopher J, Sharrock, Keith, Hallett, Ian C, MacRae, Elspeth A
Format: Aufsatz
Sprache:English
Veröffentlicht: 2004
Zugriff auf das übergeordnete Werk:Journal of plant physiology
Schlagworte:Journal Article Hexuronic Acids Water 059QF0KO0R galacturonic acid 4JK6RN80GF Pectins 89NA02M4RX
Beschreibung
Zusammenfassung:The white part of citrus peel, the albedo, has a special role in water relations of both fruit and leaves from early on in fruit development. In times of drought, this tissue acts as a water reservoir for juice sacs, seeds and leaves. When water was injected into the albedo, free water was undetectable using magnetic resonance imaging. Microscopy showed tightly packed cells with little intercellular space, and thick cell walls. Cell wall material comprised 21% of the fresh albedo weight, and contained 26.1% galacturonic acid, the main constituent of pectin. From this, we postulated that pectin of the cell wall was responsible for the high water-binding capacity of the immature lemon albedo. Cell wall material was extracted using mild procedures that keep polymers intact, and four pectic fractions were recovered. Of these fractions, the SDS and chelator-soluble fractions showed viscosities ten and twenty times higher than laboratory-grade citrus pectin or the other albedo-derived pectins. The yield of these two pectins represented 28% of the cell walls and 62% of the galacturonic acid content of immature lemon albedo. We concluded that, from viscosity and abundance, these types of pectin account for the high water-binding capacity of this tissue. Compositional analyses showed that the two highly viscous pectic fractions differ in galacturonic acid content, degree of branching and length of side chains from the less viscous albedo-derived pectins. The most striking feature of these highly viscous pectins, however, was their high molecular weight distribution compared to the other pectic fractions
Beschreibung:Date Completed 29.06.2004
Date Revised 30.09.2020
published: Print
Citation Status MEDLINE
ISSN:1618-1328