Recent research on inherent molecular structure, physiochemical properties, and bio-functions of food and feed-type Avena sativa oats and processing-induced changes revealed with molecular microspectroscopic techniques

ABSTRACT

Avena sativa oat is a cereal widely used as human food and livestock feed. However, the low metabolized energy and the rapid rumen degradations of protein and starch have limited the use of A. sativa oat grains. To overcome this disadvantage, new A. sativa oat varieties have been developed. Additionally, heat-related processing has been performed to decrease the degradation rate and improve the absorption of amino acids in the small intestine. The nutritive value is reflected by both chemical composition and inherent molecular structure conformation. However, the traditional wet chemical analysis is not able to detect the inherent molecular structures within an intact tissue. The advanced synchrotron-radiation and globar-based molecular microspectroscopy have been developed recently and applied to study internal molecular structures and the processing induced structure changes in A. sativa oats and reveal how molecular structure changes in relation to nutrient availability. This review aimed to obtain the recent information regarding physiochemical properties, molecular structures, metabolic characteristics of protein, and the heat-induced changes in new A. sativa oat varieties. The use of the advanced vibrational molecular spectroscopy was emphasized, synchrotron- and globar-based (micro)spectroscopy, to reveal the inherent structure of A. sativa oats at cellular and molecular levels and to reveal the heat processing effect on the degradation characteristics and the protein molecular structure in A. sativa oats. The relationship between nutrient availability and protein molecular inherent structure was also presented. Information described in this review gives better insight in the physiochemical properties, molecular structure, and the heat-induced changes in A. sativa oat detected with advanced molecular spectroscopic techniques in combinination with conventional nutrition study techniques.

KEYWORDS:

• Molecular spectroscopy
• physiochemical properties
• molecular structure
• metabolic characteristics
• heat processing-induced changes
• spectral solution
• Avena sativa oats

Acknowledgments

The author is grateful to Lisa Miller for synchrotron beamtime support at ALS and NSLS, discussion and/or collaborations, and Randy Smith (NSLS-BNL, New York) and Hans Bechtel (ALS, Berkeley) for helpful synchrotron data collection at ALS and NSLS. The authors thank Dr. Aaron Beattie (Crop Development Center, University of Saskatchewan) for providing different varieties of oat and barley multi-year samples and Zhiyuan Niu (Department of Animal and Poultry Sciences, University of Saskatchewan) for the technical support in lab analyses and animal studies.

Funding

The SRP Chair (PY) research programs are financially supported by various grants from the Ministry of Agriculture Strategic Research Chair Program, the Natural Sciences and Engineering Research Council of Canada (NSERC-Individual Discovery Grant and NSERC-CRD Grant), the Prairie Oat Grower Association, the Saskatchewan Agricultural Development Fund, SaskMilk, Saskatchewan Forage Network (SNK), Western Grain Research Foundation (WGRF), SaskPulse Growers, etc. The National Synchrotron Light Source in Brookhaven National Laboratory (NSLS-BNL, New York, USA) and Advanced Light Source in Berkeley National Laboratory (ALS-BNL) are supported by the U.S. Department of Energy. Canadian Light Source Inc. at University of Saskatchewan (Saskatoon, Canada) is supported by various Canadian federal and provincial funds.