Controlled nitrogen atmosphere for the preservation of functional molecules during silos storage: A case study using old Italian wheat cultivars

In the last decades, finding new methods to preserve the quality of wheat during post-harvest storage has become of primary importance to guarantee high-quality food products. Attacks by rodents and microorganisms, as well as humidity and high temperatures, are well-known factors affecting the qualitative and quantitative features of stored grains. The use of a controlled atmosphere saturated with different gases (such as carbon dioxide-CO2 and nitrogen-N2) is known to decrease the growth of microorganisms. Furthermore, the use of N2 is free of pollutants, thus being an environmental-friendly method. In this study, the use of a controlled atmosphere saturated with N2 was investigated as a method to preserve the nutraceutical qualities in two old Italian wheat cultivars (i.e. Verna and Cappelli). In particular, vitamin E (α-tocopherol), polyphenols and antiradical activity were quantified to highlight the differences between traditional storage methods and the use of a controlled atmosphere saturated with N2. The data obtained showed that the use of a N2-saturated atmosphere reduced the loss of functional molecules, especially vitamin E, in both cultivars, during long storage periods. Moreover, the present system is suitable for the storage of seeds of old varieties cultivated under organic agriculture. Overall, the results validate the efficacy of the storage method with N2 and suggest its possible use for wheat on an industrial scale.