Nutritional characterization of naked and dehulled oat cultivar samples at harvest and after storage

• Non-caloric nutrients reveal oat biodiversity.
• Avenanthramides represent an important marker of biodiversity.
• Storage depletes more the bound than the free polyphenols.
• B-glucan is stable or increases with storage.
• The relevant antioxidant capacity of oats suggests a wider use in food preparations.

In the present study, 15 dehulled and 15 naked oats were used for a comparative analysis of macronutrients, β-glucan, free (FPs) and bound (BPs) polyphenols and avenanthramides (AVNs). The naked and dehulled oat cultivar samples (cvs.) did not show any significant difference in protein and lipid percentages and only small differences in starch. As regard the β-glucan, no significant difference in the average values between naked and dehulled cvs. was observed. Concerning polyphenols, BPs showed higher levels than FPs, but the antioxidant capacity (ORAC) of the FPs was superior to that of the BPs. Naked oats showed a concentration of AVN that was three fold higher than that of dehulled oats. Regarding the storage, AVNs resulted to be the most sensitive non-caloric nutrients to storage conditions, as a depletion was detected in most of the analyzed cvs. Overall, our results suggested that there is a great variability, in term of AVN content, between naked and dehulled oat cvs. and that storage conditions must be adapted for groups of cvs. in order to reduce their loss. Moreover, high levels of β-glucan found in some cvs. may help us to develop commodities, which meet the EFSA requirements for health claims.