Fig.4.37.Arrangement of amylopectin molecules in a starch granule
B Amorphous regions A chains 6um B chains Crystalline regions Reducing end Hilum 6 D glucose units a1-→6 branch points Figure 3.2 Amylopectin and the starch granule.(A)The essential features of the cluster model first proposed by Robin in 1974.(B)The organisation of the amorphous and crystalline regions (or domains)of the structure generating the concentric layers that contribute to the 'growth rings'that are visible by light microscopy.(C)The orientation of the amylopectin molecules in a cross section of an idealised entire granule.(D)The likely double helix structure taken up by neighbouring chains and giving rise to the extensive degree of crystallinity in a granule
Amylose .Linear Glucose Polymer .Smaller Component of Starch MW-105to106
•Linear Glucose Polymer •Smaller Component of Starch •MW - 10 5 to 10 6
Amylose content (% Short Grain 14.8 (Koshihikari) Medium Grain 16.8 (M-202) Medium Grain 17.5 (M-401)
Amylose content (%) Short Grain (Koshihikari) Medium Grain (M-202) Medium Grain (M-401) 14.8 16.8 17.5
dW/d logM Differential M.W.Distribution 20 Rice Mw106 M401 72 15 M202 61 Koshihikari 84 10 Calmochi 174 5 01.0e+7 1.0e+8 1.0e+9 M(g/mol)
1.0e+7 1.0e+8 1.0e+9 M (g/mol) 0 5 10 15 20 dW/d logM Differential M.W. Distribution Rice Mw 106 M401 72 M202 61 Koshihikari 84 Calmochi 174