Fermentation quality and aerobic stability of low moisture-crimped wheat grains manipulated by organic acid-based additives

Abstract

AbstractPreservation of moist grain anaerobically by so-called crimping has many advantages. Generally, preservation has been successfully performed when grain is harvested at 30–40% moisture content (MC). However, there is a trend towards using drier than the optimal MC of the raw material. This leads to an increasing need to control aerobic spoilage of the material and also to experimental challenges in assessing the quality and stability of low-MC crimped grain. The objective of the current work was to evaluate fermentation quality, microbial composition and aerobic stability (AS) of drier than the optimal crimped grain ensiled with different additives and to use these materials to compare three different AS evaluation methods. Crimped wheat grain with 28% MC was ensiled using eight additive treatments based mainly on formic and propionic acids including a control without any additive. The low MC resulted in no lactic acid fermentation, but significant ethanol formation occurred in the control. The treatments used resulted in clear differences in microbial quality and AS of the feeds, and use of formic and propionic acid-based additives provided a clear benefit in improving the AS of crimped wheat grain. The correlation between increasing temperature and carbon dioxide (CO2) production under aerobic conditions was very close, indicating that CO2produced by aerobic bacteria can be used as a method of evaluating AS. Visual inspection of mould growth resulted in somewhat different ranking of the treatments.