Biogenic amines in silage. 2. The dynamics of the formation of biogenic amines in silage

When analysing a series of laboratory silages made from orchardgrass, red clover and oats, the fluctuating dynamics of biogenic amines were observed. For levels of putrescine and cadaverine, a rapid exponential increase culminating approximately 30-50 days after ensiling is typical. A small decrease, reaching the minimum at approximately the 100th day, is sometimes followed by a second increase in amine concentrations achieving its maximum approximately 200-230 days after ensiling. Irregular curves of the dynamics probably originate in the simultaneous decarboxylation and deamination reactions along with other relevant amine degradation processes. The dynamics of other biogenic amines-spermidine, spermine and histamine are more difficult to predict. The changes in histamine levels resembled those in the diamines. Some 200 days after ensiling, considerable increases in this toxic amine were observed. The dynamics of some quality criteria, especially the degree of proteolysis, were in many cases similar to those of the amines.