Structure and digestibility of endosperm water-soluble α-glucans from different sugary maize mutants

Structural modification and characterisation of a sugary maize soluble starch particle after double enzyme treatment

“…The soluble starch particles were isolated from sugary maize in the laboratory following the methods of as described in a previous study (Miao, Li, Jiang, Cui, Lu, et al, 2014). The sugary-1 maize fresh kernels were dehulled, and the endosperm was separated from the germ and soaked in five times its weight of deionised water at 20 • C overnight.…”

“…The flow rate was set at 0.5 ml/min with a mobile phase of distilleddeionised water (pH 6.8, 18.2 M cm) containing 0.02% NaN 3 . A dn/dc value of 0.138 was used in molecular weight calculations, and data processing was performed using ASTRA software (Version 5.3.4.14, Wyatt Technology, Santa Barbara, CA, USA) as described by Miao, Li, Jiang, Cui, Lu, et al (2014). The weight-average molecular weight (M w , g/mol) and z-root mean square radius of gyration (R z , nm) were obtained using the second-order Berry method.…”

“…According to several earlier studies, soluble starch is a typical nano-scale particle ranging from 30 to 100 nm and exhibits a spherical shape (Miao, Li, Jiang, Cui, Lu, et al, 2014;Miao, Xiong, et al, 2014;Putaux, Buléon, Borsali, & Chanzy, 1999). In comparison with amylopectin, soluble starch has an average branch chain length of DP 10-12 with a 7-10% branch density (Inouchi, Glover, & Fuwa, 1987;Miao, Li, Jiang, Cui, Lu, et al, 2014;Putaux et al, 1999;Wong et al, 2003;Yun & Matheson, 1993). Moreover, there is an obvious density increment towards the external region of soluble starch, whereas the molecular density of amylopectin remains uniform during amyloglucosidase hydrolysis (Huang & Yao, 2011).…”

“…The su-1 mutant endosperm cell is deficient in debranching enzyme, which is used to trim abnormal branches that inhibit the formation of starch crystals and granules, and the more highly branched ␣-d-glucan then accumulates (Ball & Morell, 2003;Boyer & Liu, 1983). According to several earlier studies, soluble starch is a typical nano-scale particle ranging from 30 to 100 nm and exhibits a spherical shape (Miao, Li, Jiang, Cui, Lu, et al, 2014;Miao, Xiong, et al, 2014;Putaux, Buléon, Borsali, & Chanzy, 1999). In comparison with amylopectin, soluble starch has an average branch chain length of DP 10-12 with a 7-10% branch density (Inouchi, Glover, & Fuwa, 1987;Miao, Li, Jiang, Cui, Lu, et al, 2014;Putaux et al, 1999;Wong et al, 2003;Yun & Matheson, 1993).…”

“…Soluble starch is similar to glycogen, and it is also a primary amylopectin analogue with a more highly branched structure in the sugary-1 (su-1) mutants of maize, rice, sorghum or barley (Ball & Morell, 2003;BeMiller & Whistler, 2009;Boyer & Liu, 1983;Miao, Li, Jiang, Cui, Lu, et al, 2014;Tetlow, Morell, & Emes, 2004). Starch is generally formed in the amyloplasts of cereal grains, in which the reactions are catalysed by starch synthase, starch branching enzyme, and starch debranching enzyme in the starch biosynthetic pathway (BeMiller & Whistler, 2009;Powell et al, 2014;Tetlow et al, 2004).…”