The Application of Foliar Urea on the Concentration of Amines in Wine

A great variability in the concentration of amines in wines exists as there are many factors which have an influence on the formation of these substances. Among these factors, the content of nitrogenous compounds in the grape stands out and depends on the nitrogenous fertilization. Fertilization with foliar urea does serve as a help to complete and guarantee the nitrogen requirements of the vineyard. Treatment with foliar urea significantly increased ( < 0.05) the concentration of histamine in the Tempranillo wines compared to the control sample (sample without foliar urea treatment), reaching higher concentrations than the threshold level where it could provoke toxic effects in the consumer (8–20 mg/l). In the case of the volatile amines with secondary amino groups, the concentration of pirrolidine increased by 37% in the treatment with 2 kg of nitrogen per hectare (kg N/ha) and 61% in the treatment with 4 kg N/ha.