Resistance to acid hydrolysis of lipid-complexed amylose and lipid-free amylose in lintnerised waxy and non-waxy barley starches

Morrison, William R., Tester, Richard F., Gidley, Michael J. and Karkalas, John (1993) Resistance to acid hydrolysis of lipid-complexed amylose and lipid-free amylose in lintnerised waxy and non-waxy barley starches. Carbohydrate Research, 245 2: 289-302. doi:10.1016/0008-6215(93)80078-S


Author Morrison, William R.
Tester, Richard F.
Gidley, Michael J.
Karkalas, John
Title Resistance to acid hydrolysis of lipid-complexed amylose and lipid-free amylose in lintnerised waxy and non-waxy barley starches
Journal name Carbohydrate Research   Check publisher's open access policy
ISSN 0008-6215
1873-426X
Publication date 1993-07
Sub-type Article (original research)
DOI 10.1016/0008-6215(93)80078-S
Volume 245
Issue 2
Start page 289
End page 302
Total pages 14
Place of publication Oxford, United Kingdom
Publisher Pergamon
Language eng
Formatted abstract
Waxy barley starches (0.8-4.0% lipid-complexed amylose = L · AM, 0.9-3.4% lipid-free amylose = F · AM) and non-waxy barley starches (6.1-7.2% L · AM, 23.1 ± 25.9% F · AM) were lintnerised by steeping in 2 M HCl at 35°C for 140 h. Material solubilised from the waxy starches was estimated to be 70.7% of their amylopectin (AP) plus 3.7% of their L · AM and F · AM, and material solubilised from the non-waxy starches was estimated to be 70.7% of their AP plus 28.9% of their L · AM and F · AM. The polysaccharide components of the insoluble residue were characterized by HPLC, GPC, and λ(max) of the polyiodide complex. It was concluded that short chain-length (CL 16) material was from external chains of AP, intermediate material (modal CL 46) was from retrograded F · AM, and longer chain residues (CL 77, 120-130) were from lipid-complexes segments of L · AM. The starch lysophospholipids were completely hydrolysed to free fatty acids which remained complexed with L · AM residues. This was shown by the 13C CP/MAS-NMR spectrum which had a clear resonance at 31 ppm from mid-chain methylene carbons of fatty acids in complexes. The C-1 signal of the L · AM residues also included a feature at 104 ppm indicative of single V6 AM helices. The wide-angle X-ray diffraction patterns of the residues of non-waxy starches were Cc-type (= mixed A+B types), whereas the spectra of the original starches were A-type. It is suggested that, during the early stages of lintnerisation, amorphous F · AM was partially hydrolysed into material (CL < 120) that retrograded into double helices (with B-type crystallinity) that were resistant to hydrolysis. Evidence for some B-crystalline polymorph was also obtained from the 13C CP/MAS-NMR spectra, which were consistent with a mixture of double helices and V-type glycosidic conformations, with only a small proportion of non-ordered regions. Broad DSC endotherms were found for both waxy (50-110°C) and non-waxy (50-110°C) lintner residues, which were assigned to disordering of double helices from short chains (modal CL 16) for waxy residues, together with disordering of longer chains (modal CL 46) in double-helix residues of F · AM and also V-helix residues of L · AM for non-waxy starch residues.

Cereal starches are unusual in that they contain significant quantities of monoacyl lipids throughout the granules. Way barley starches (0.8-4.0% lipid-complexed amiylose = L-AM, 0.9 3.4% lipid-free amylose = F · AM) and non-waxy barley starches (6.1-7.2% L · AM, 23.1-25.9% F · AM) were lintnerised by steeping i 2 M HCI at 35°C for 140 h. Material solubilised from the waxy starches was estimated to be 70.7% of their amylopectin (AP) plus 3.7% of their L · AM and F · AM, and material solubilised from the non-waxy starches was estimated to be 70.7% of their AP plus 28.9% of their L · AM and F · AM.
Keyword Cereal starches
Inclusion complexes
Alpha amylases
Potato starch
complexes
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: Centre for Nutrition and Food Sciences Publications
 
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Created: Wed, 16 Mar 2011, 20:37:58 EST