Effect of theanine and polyphenols enriched fractions from decaffeinated tea dust on the formation of Maillard reaction products and sensory attributes of breads

• Theanine and polyphenols enriched fractions (TEF and PEF) from tea dust were studied.
• PEF and TEF inhibited fluorescent AGEs formation in glycoxidation model systems.
• Extent of Maillard reaction in the enriched breads was analyzed.
• PEF lower the level of fluorescent AGEs formed during baking.
• The best bread formulation from nutritional and sensorial aspects was with 30% PEF.

The antiglycoxidative properties of theanine (TEF) and polyphenols enriched fractions (PEF) prepared from tea dust were tested in a model system composed of bovine serum albumin (BSA) and methylglyoxal (MGO). PEF caused a decrease in available free amino groups of BSA in presence and absence of MGO, suggesting the simultaneous occurrence of glycoxidation reaction and phenols-protein interaction. The presence of PEF and TEF inhibited formation of fluorescent advanced glycation end-products (AGEs).Moreover, theanine (TB) and polyphenol-enriched bread (PB) were formulated. A significant increase in free amino groups was observed in TBs with a dose–response effect, while addition of PEF in bread produced a significant decrease (p < 0.05). PEF efficiently reduced fluorescent AGE formation in breads compared with TEF. The results are in line with the simplified model systems. PEF used as food ingredient allows obtaining a tasty food possessing health promoting properties and lower content of potential harmful compounds (AGEs).