Avenanthramides as a means to slow rancidity development in oats

Abstract: Cereal grains are an important staple in many diets across the globe. Being one of the most cultivated cereal crops worldwide, especially in Nordic countries, oats are known to have a high dietary fibre content and a nutritional value that makes them highly beneficial for human health. Avenanthramides are a group of phenolic compounds that, among other cereal grains, are only produced in oats. Avenanthramides are known to have strong antioxidant activity and, in this present study, avenanthramides were investigated in relation to rancidification in oats. Avenanthramide-rich oat extracts were added to milled oat flour in accelerated storage trials with a water-methanol mixture containing copper sulphate, and rancidity markers such as peroxide value (PV), lipase activity and hexanal detection were followed over time to investigate the potential of avenanthramides as a means to slow rancidity development. In the two later storage trials conducted, avenanthramide enrichment was found to result in statistically significant decreases in PV, lipase activity and hexanal levels after 24 hours compared to the controls. The findings of this study serve to provide an overview of avenanthramide enrichment as a means of delaying rancidification in oats and can be used to guide further research into how avenanthramide extracts can be used to optimise oxidative stability in oats and other lipid-based foods. Interestingly, in addition to delaying lipid oxidation, avenanthramides also seem to be effective lipase inhibitors, which is perhaps something that can be further investigated in later studies.