The paper ‘Latent Anti-nutrients and Unintentional Breeding Consequences in Australian Sorghum bicolor Varieties’ focuses on an alternative analytical approach to better understand anti-nutrients in the sorghum grain used in animal feed. It was written in collaboration with Heather Walker (University of Sheffield biOMICS Facility), Duncan Cameron (University of Sheffield Animal and Plant Sciences [APS]), Robert Falconer (University of Adelaide) and industry partner Aaron Cowieson (DSM Nutritional Products).
Why is this paper important?
Animal feed is formulated with several components which include a base grain, a protein/amino acid supplement and often other additives including enzymes. These enzymes help animals better digest nutrients and reduce environmental emissions, especially phosphorous and nitrogen. Recently, there has arisen a need to investigate components of feed grain that could be reducing the effectiveness of these added enzymes. Specifically, we were interested in polyphenol and tannin anti-nutrients in sorghum grain, which historically has had elevated levels of these compounds. While modern sorghum grain has been bred to significantly reduce levels of large tannin anti-nutrients, there is a need to better understand the variability of polyphenols and related anti-nutrients in modern varieties. We thus sought to characterise and further unravel the composition of polyphenol extracts from three modern Australian sorghum varieties.
How did you do the research?
This research was conducted between CBE and APS departments utilising various pieces of analytical equipment to better understand the composition of the sorghum polyphenol extracts. Using an extraction method previously optimised by former CBE PhD student, Dr Theofilos Kempapidis, extracts were prepared from sorghum grain and then analysed using a variety of methods, including Fourier-transform infrared (FT-IR) spectroscopy and direct injection mass spectrometry. The data from each technique was then processed using multivariate analysis to yield information about the relationships between the different sorghum extracts. This analytical approach allowed us to identify groups of compounds and specific molecules causing variation between the extract types.
What is the potential impact of the study?
Our research has identified latent anti-nutrients in modern sorghum varieties utilising an under-studied analytical approach. The results indicated possible unintentional consequences of past sorghum breeding efforts as researchers sought to eliminate the large tannins that are known to cause issues in animal digestion. While the results confirmed that large tannins of the past had been successfully eliminated, high concentrations of fatty acids and small to medium sized polyphenols, both known to interfere with enzyme activity, were present. Any remaining negative effects in sorghum diets today may be caused by these more varied anti-nutrients. Beyond providing an updated view of sorghum’s anti-nutrient profile, this study also sought to utilise under-studied techniques, like FT-IR and direct injection mass spectrometry, over more complex procedures typically used. The results obtained from the simpler techniques indicated that, depending on the research goals/aims, the use of complex methodologies could be avoided. FT-IR, for example, could easily be incorporated on-line in grain processing facilities.
Tell us more about yourself.
I’m originally from Virginia in the United States and have a diverse background with my undergraduate education in chemistry and history and an MSc from the University of the West of England in Biomedical Science. Before moving to the UK, I was a high school (secondary/A-level) chemistry teacher for two years. I started my PhD at Sheffield with the aim of applying the skills I had obtained from my different degrees to more specific scientific goals. Prior to coming to Sheffield, I had no experience in agriculture or animal nutrition but was eager to get experience in a new field. I’ve enjoyed the interdisciplinary aspect of my PhD project as I’ve been able to collaborate across the university and with industrial partners in Europe.