Elicitation and treatment with precursors of phenolics synthesis improve low-molecular antioxidants and antioxidant capacity of buckwheat sprouts.

BACKGROUND

Recently, an increase of interest in the modification of food products on each step of production (breeding, production technology, storage condition) is observed. Nutritional properties as well as level and activity of bioactive compounds in plant-origin food may be modified using a range of technological and biotechnological practices and elicitation should be mentioned between them.

METHODS

Elicitation with willow bark infusion supported by feeding with the phenylpropanoid pathway precursors were used for improving the quality of buckwheat sprouts. Special emphasis has been placed on the metabolomic and biochemical changes and the mechanism of overproduction of low-molecular antioxidants.

RESULTS

The accumulation of phenolics is caused by stimulation of two main enzymes the phenylpropanoid pathway (tyrosine ammonia-lyase and phenylalanine ammonia-lyase). Tyrosine ammonia-lyase activities were effectively induced by feeding with tyrosine (about four times that of the control), whereas phenylalanine ammonia-lyase activity was the highest in the elicited control sprouts and those fed with shikimic acid (an increase by 60% compared to the control). Shikimic acid feeding (both elicited and non-elicited sprouts) effectively improved the total phenolics (by about 10% and 20%, respectively), condensed tannins (by about 30% and 28%, respectively), and flavonoids (by about 46% and 70%, respectively). Significant increase of vitexin, rutin, chlorogenic acid and isoorientin contents was also observed. The treatments increased the ascorbic acid content, too. Total antioxidant capacity of sprouts was most effectively increased by feeding with shikimic acid and further elicitation.

CONCLUSIONS

The studies transfer biotechnology commonly used for the induction of overproduction of secondary metabolites in plant cell line systems to low-processed food production. The obtained results could be used for better understanding of the effect of elicitation and precursor feeding on antioxidants production and contribute to improving the buckwheat sprouts quality.