Influence of foliar riboflavin applications to vineyard on grape amino acid content

- Grape and must nitrogen concentration can potentially affect wine quality.
- Riboflavin is widely distributed in nature and is essential in key redox reactions.
- Foliar application of riboflavin to vineyard had effect on grape nitrogen composition.
- Some oenological parameters had differences when riboflavin treatments were applied.
- Must high amino acid content was observed with riboflavin foliar application.

Nitrogen is an important element for grapevine and winemaking, which affects plant development, grape juice fermentation and has a potential effect in modulating wine quality. The aim was to study the influence of foliar applications of riboflavin (vitamin B2) to vineyard on grape nitrogen composition. This vitamin has a reported capacity to protect different plant species, but its application to favor grape and grape juice quality had not previously been studied. This work reports the oenological properties and the effect on amino acid concentration of grape juices obtained from grapes treated with riboflavin at two different doses compared to control. Results showed that probable alcohol, malic acid, color intensity and hue had significant differences when the riboflavin treatments were applied. Most of the amino acids presented the highest concentrations when the lowest riboflavin dose was used. These results are promising in terms of fermentation development and grape juice nitrogen composition.