Using vibrational infrared biomolecular spectroscopy to detect heat-induced changes of molecular structure in relation to nutrient availability of prairie whole oat grains on a molecular basis.
BACKGROUND
To our knowledge, there is little study on the interaction between nutrient availability and molecular structure changes induced by different processing methods in dairy cattle. The objective of this study was to investigate the effect of heat processing methods on interaction between nutrient availability and molecular structure in terms of functional groups that are related to protein and starch inherent structure of oat grains with two continued years and three replication of each year.


METHODS
The oat grains were kept as raw (control) or heated in an air-draft oven (dry roasting: DO) at 120 °C for 60 min and under microwave irradiation (MIO) for 6 min. The molecular structure features were revealed by vibrational infrared molecular spectroscopy.


RESULTS
The results showed that rumen degradability of dry matter, protein and starch was significantly lower (P <0.05) for MIO compared to control and DO treatments. A higher protein α-helix to β-sheet and a lower amide I to starch area ratio were observed for MIO compared to DO and/or raw treatment. A negative correlation (-0.99, P < 0.01) was observed between α-helix or amide I to starch area ratio and dry matter. A positive correlation (0.99, P < 0.01) was found between protein β-sheet and crude protein.


CONCLUSIONS
The results reveal that oat grains are more sensitive to microwave irradiation than dry heating in terms of protein and starch molecular profile and nutrient availability in ruminants.
Ministry of Agriculture Strategic Research Chair in Feed R&D, Department of Animal and Poultry Science, College of Agriculture and Bioresources, The University of Saskatchewan, 51 Campus Drive, Saskatoon, SK S7N 5A8 Canada ; The United Graduate School of Agricultural Sciences, Iwate University, Morioka, Iwate 020-8550 Japan.
M D Mostafizar
MD
Rahman
Ministry of Agriculture Strategic Research Chair in Feed R&D, Department of Animal and Poultry Science, College of Agriculture and Bioresources, The University of Saskatchewan, 51 Campus Drive, Saskatoon, SK S7N 5A8 Canada ; Institute for Global Food Security, Queen's University Belfast, Clooreen Park, Malone Road, BT95HN Belfast, UK.
Katerina
K
Theodoridou
Ministry of Agriculture Strategic Research Chair in Feed R&D, Department of Animal and Poultry Science, College of Agriculture and Bioresources, The University of Saskatchewan, 51 Campus Drive, Saskatoon, SK S7N 5A8 Canada.
Peiqiang
P
Yu
Dry roasting; Feed processing; Microwave irradiation; Modeled cereal grains; Molecular structure; Nutrient availability