Journal article
Characterization of oat proteins and aggregates using asymmetric flow field-flow fractionation
Lund Centre for Field-Flow Fractionation, Department of Food Technology, Engineering and Nutrition, Lund University, P.O. Box 124, 221 00, Lund, Sweden. ray.runyon@food.lth.se1
The soluble proteins and protein aggregates in Belinda oats were characterized using asymmetric flow field-flow fractionation (AF4) coupled with online UV-vis spectroscopy and multiangle light-scattering detection (MALS). Fractions from the AF4 separation were collected and further characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE).
The AF4 fractogram of the oat extracts revealed three peaks which were determined to be monomeric forms of soluble proteins, globulin aggregates, and β-glucan, respectively. The early eluting monomeric proteins ranged in molar mass (MM) between 5 and 90 kg/mol and in hydrodynamic diameter (D h) from 1.6 to 13 nm.
The MM at peak maximum of the globulin aggregate peak was found to be ∼300 kg/mol and the D h was measured to be ∼20 nm. SDS-PAGE of the collected fraction across this peak revealed two bands with MM of 37 and 27 kg/mol which correspond to the α and β subunits of globulin indicating the elution of globulin aggregates.
A third peak at long retention time was determined to be β-glucan through treatment of the oat extract with β-glucanase and by injection of β-glucan standards. The amount of soluble protein was measured to be 83.1 ± 2.3 wt.%, and the amount of albumin proteins was measured to be 17.6 ± 5.7 wt.% of the total protein in the oats.
The results for Belinda oat extracts show that the AF4-MALS/UV platform is capable of characterizing the physicochemical properties such as MM and hydrodynamic size distribution of proteins and protein aggregates within a complicated food matrix environment and without the need to generate protein isolates.
Language: | English |
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Publisher: | Springer Berlin Heidelberg |
Year: | 2013 |
Pages: | 6649-55 |
ISSN: | 16182650 and 16182642 |
Types: | Journal article |
DOI: | 10.1007/s00216-013-7115-7 |
Analytical Chemistry Avena Biochemistry, general Characterization and Evaluation of Materials Chemistry Chemistry and Materials Science Environmental Monitoring/Analysis Field-flow fractionation Food Analysis Food Science Fractionation, Field Flow Laboratory Medicine Light scattering Mass Spectrometry Oats Plant Proteins Protein aggregation Seeds