Localisation of amylose and amylopectin in starch granules using enzyme-gold labelling

Citation
Nj. Atkin et al., Localisation of amylose and amylopectin in starch granules using enzyme-gold labelling, STARCH, 51(5), 1999, pp. 163-172
Citations number
31
Categorie Soggetti
Food Science/Nutrition
Journal title
STARCH-STARKE
ISSN journal
00389056 → ACNP
Volume
51
Issue
5
Year of publication
1999
Pages
163 - 172
Database
ISI
SICI code
0038-9056(199905)51:5<163:LOAAAI>2.0.ZU;2-4
Abstract
The independent localisation of amylose and amylopectin in a range of dry a nd hydrated native starch granules with varying amylose content (0-70 %) ha s been indirectly visualised using enzyme-gold cytochemical markers. Increa sing amylose content was clearly demonstrated to result in distinct changes in granule architecture. In the absence of amylose (waxy maize starch) a f ramework of closely packed concentric layers of amylopectin exists in the g ranules. Low amylose content (potato starch) results in alternating layers of densely packed amylopectin and amylose molecules. High amylose content ( amylomaize starch) granules were shown to possess an amylopectin centre sur rounded by an amylose periphery encapsulated by an amylopectin surface. Elo ngated granules without the amylopectin centre were also observed in high a mylose starches suggesting a relationship between amylopectin, amylose and granule shape. A model of starch granule architecture is proposed where inc reased compartmentalisation of amylose and amylopectin is observed in granu les containing increasing levels of amylose.