Protein Molecular Structures and Protein Fraction Profiles of New Coproducts from BioEthanol Production: A Novel Approach

• Published in: Journal of agricultural and food chemistry 2010-03, Vol.58 (6), p.3460-3464
• Main Authors: Yu, Peiqiang, Niu, Zhiyuan, Damiran, Daalkhaijav
• Format: Article
• Language: English
• Subjects: Biofuels and Bioproducts Chemistry; Biological and medical sciences; Ethanol - chemistry; Ethanol - metabolism; Food industries; Fundamental and applied biological sciences. Psychology; Industrial Microbiology; Plant Proteins - chemistry; Plant Proteins - metabolism; Protein Structure, Secondary; Triticum - chemistry; Zea mays - chemistry
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf904179m

The objectives of this study were to determine the protein molecular structures of the new coproducts from bioethanol production, quantify protein structure amide I to II and α-helix to β-sheet spectral peak intensity ratio, and illustrate multivariate molecular spectral analyses as a novel research tool for rapid characterization of protein molecular structures in bioethonal bioproducts. The study demonstrated that the grains had a significantly higher ratio of α-helix to β-sheet in the protein structure than their coproducts produced from bioethanol processing (1.38 vs 1.03, P < 0.05). There were significant differences between wheat and corn (1.47 vs 1.29, P < 0.05) but no difference between wheat dried distiller grains with solubles (DDGS) and corn DDGS (1.04 vs 1.03, P > 0.05). The grains had a significantly higher ratio of protein amide I to II in the protein structure than their coproducts produced from bioethanol processing (4.58 vs 2.84, P < 0.05). There were no significant differences between wheat and corn (4.61 vs 4.56, P > 0.05), but there were significant differences between wheat DDGS and corn DDGS (3.08 vs 2.21, P < 0.05). This preliminary study indicated that bioethanol processing changes protein molecular structures, compared with original grains. Further study is needed with a large set of the new bioethanol coproducts to quantify protein molecular structures (α-helix to β-sheet ratio; amide I to II ratio) of the bioethanol coproducts in relation to nutrient supply and availability in animals.