Implication of phenolic reactions in food organoleptic properties

The reaction between (+)-catechin and glyoxylic acid was investigated as a model system of color changes usually observed during conservation and ageing of fruit-derived foods. The reaction was monitored by LC/DAD and LC/ESI-MS analysis and the formation of various phenolic compounds initially absent in the mixture was observed. the detected compounds, colorless bridged derivatives which were converted later to more polymerized compounds were observed. Another type of compounds exhibiting absorption maxima near 300 nm and presenting a shoulder around 350 nm were also detected. The role of all these compounds in the formation of xanthylium salts with absorption maxima ranging from 440 to 460 nm was demonstrated. Thus, xanthylium salts with various structures were shown to be formed in the studied model solution. Other compounds with strong absorption around 560 nm were also detected. ndicated the role of these compounds and the studied model solution in the color change observed during storage and especially the browning phenomenon observed in the case of grape-derived foods. Moreover, some compounds were detected through LC/ESI-MS analysis in grape-derived beverage indicating the probable occurrence of such interaction in fruit-derived foods and the implication of phenolic reactions in the organoleptic properties of fruit-derived foods.