Effect of amylose deposition on potato tuber starch granule architecture and dynamics as studied by lintnerization

Abstract

The effect of amylose deposition on the amylopectin crystalline lamellar organization in potato starch granules was studied by mild acid, so-called lintnerization, of potato tuber starch transgenically engineered to deposit different levels of amylose. The starch granules were subjected to lintnerization at different temperatures (25, 35, and 45°C) and to two levels of solubilization, ∼ 45 and 80%. The rate of the lintnerization increased with temperature but was suppressed by amylose. The molecular size of the lintner dextrins increased with temperature, but this effect was suppressed by the presence of amylose. At high temperatures and low-amylose content, the degree of branches was high with the concomitant increase in size in the dextrins. A portion of the branches was resistant to debranching enzymes possibly due to specific structural formations. The effects of temperature suggested a unique granular architecture of potato starch, and a model showing the dependence of temperature on the dynamic arrangement of amylopectin and amylose in the crystalline and amorphous lamellae for the potato starch is suggested.

Influence of amylopectin structure and degree of phosphorylation on the molecular composition of potato starch lintners

“…In amylose‐free and low‐amylose containing starches, the apparent annealing effect was more pronounced than in normal potato starch. All three starches had similar amylopectin structures and phosphate content, and it was thus concluded that it was the presence of amylose that retarded the effect . Interestingly, in an earlier work comparing amylose‐free maize (A‐type allomorph) and potato starches, it was found that the temperature had an effect on the composition of the lintnerized starch only in the potato sample .…”

Understanding Starch Structure: Recent Progress

“…The "Maltese cross" also remains [48], which shows that the organized molecular segments are confined to the crystallites. The crystallites are formed by short, external chain segments of amylopectin with a degree of polymerization (DP) approximately 10-20 glucosyl units [49][50][51][52]. As two chains unite into a double-helix with 6 glucose residues per turn of each strand and a pitch of 2.1 nm [53], the length of these double-helices is about 4~6 nm.…”

Understanding the role of water-ionic liquid mixtures on the gelatinization and dissolution of maize starches

“…Unlike amylose, however, there is great additional variation with respect to the unit chain lengths and branching patterns. Chain length, expressed in DP, is used to quantify the molecular weight In addition, each macromolecule contains a single C-chain which carries the sole reducing end group (Figure 1.3) (Wikman, Blennow & Bertoft, 2013). …”

“…The less dense amorphous shells contain amylose and less ordered amylopectin, whereas the semi-crystalline material consists of regular repeat of alternating amorphous and crystalline lamellae. At higher level organization, the semi-crystalline rings are associated with the amylopectin structures (Wikman, Blennow & Bertoft, 2013). The amylopectin molecule is highly branched with its side chain branches forming rigid double helices that associated into clusters (Figure 1.5).…”

“…In high amylose starches, amylose may contribute to the crystallinity of granules (Buleon et al, 1998;Hoover, 2001). As amylose has a low degree of branching, dissolved amylose has a tendency to form insoluble semi-crystalline aggregates depending on the placement of the branches in the structure, the existence of amylose chains transversely oriented through the crystalline lamellae has been suggested (Wikman, Blennow & Bertoft, 2013). To date the organization of amylose and amylopectin in the growth rings and the lamellar architecture of the crystalline layers within these rings is still not fully understood (Donald, 2001;Perry & Donald, 2000).…”