Characterization and In Vitro digestibility of rice protein prepared by enzyme-assisted microfluidization: Comparison to alkaline extraction
Microfluidization followed by density-based separation was employed to extract protein from broken rice by disrupting protein-starch agglomerates. Follow-up enzyme treatments (amylase and glucoamylase) were performed to further improve the purity of the protein-rich fraction. High protein recovery (...
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Published in | Journal of cereal science Vol. 56; no. 2; pp. 482 - 489 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
Kidlington
Elsevier Ltd
01.09.2012
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | Microfluidization followed by density-based separation was employed to extract protein from broken rice by disrupting protein-starch agglomerates. Follow-up enzyme treatments (amylase and glucoamylase) were performed to further improve the purity of the protein-rich fraction. High protein recovery (81.87%) and purity (87.89%) were obtained. The protein composition, solubility, structural properties, and in vitro digestibility of rice proteins prepared by enzyme-assisted microfluidization (EM-RP) and alkaline extraction (AE-RP) were compared. EM-RP was mainly composed of glutelin, which had low solubility and native structure. By contrast, large quantities of prolamin and globulin appeared in the AE-RP except glutelin, leading to the richness of glutamic acid/glutamine, leucine, aromatic and charged amino acids in the AE-RP. Compared to AE-RP, EM-RP showed higher digestibility due to the richness of glutelin (an easy-to-digest protein), as evidenced by higher nitrogen release during pepsin-trypsin digestion. The presence of prolamin (an indigestible protein) in AE-RP decreased protein digestibility although alkaline extraction improved its hydrolysis. These results suggest that enzyme-assisted microfluidization could be an effective technique to non-destructively and selectively extract rice glutelin.
► Microfluidization followed by density-based separation extracts rice protein. ► Carbohydrate-hydrolyzing enzyme treatments improve protein purity. ► Rice glutelin with native structure is non-destructively and selectively obtained. ► Rice glutelin shows better in vitro digestibility than alkali-prepared protein. |
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ISSN: | 0733-5210 1095-9963 |
DOI: | 10.1016/j.jcs.2012.06.008 |