Effects Of Wine Phenolic Compounds On Aroma And Related Mechanisms

The sensory properties of wine(aroma,astringency,mouthfeel)can be impacted by some chemical parameters,such as phenolic compounds,non-volatile compounds and volatile compounds.Phenolic compounds are unstable compounds that are released when the grapes are crushed or pressed and continue throughout the winemaking process.These phenolic compounds may interact with aroma compounds,thus altering their volatility and influencing the release rate of aroma compounds.In this experiment,phenolic compounds of Cabernet Sauvignon wine were taken as the research objects,to study their effects on compounds with different aroma characters.Phenolic compounds were analyzed by using HPLC-MS,UV-VIS and DLS,and the aroma compounds were identified by using GC-MS,and the interaction mechanism of phenolic compounds and aroma compounds by using 1H-NMR.The main results of this study are as follows:1.Based on the GC-MS data results,four types of aroma characters were selected:"green","fruital","floral" and "aged aroma",and the concentrations of 22 aroma compounds were determined.In addition,after adding commercial tannins to Cabernet Sauvignon wine and a synthetic wine system containing four types of aroma compounds,it was confirmed that tannins have a significant effect on aroma compounds.By comparing the three polyphenol components(F1,F2 and F3),it was found that the total phenolic and total flavanol content of F3 were higher than those in F1 and F2;and the%G and mDP of F2 proanthocyanidins were larger than those of F3;and the particle size and Pdi of F3 were larger than those of F1 and F2 components,but the dispersibility was not as good as that of F1 and F2 components.2.The effect of different concentrations of polyphenol components on aroma compounds shows that:the three polyphenol components could affect the release of aroma compounds to varying degrees.Various concentrations of phenolic acid,monomeric/oligomeric,polymeric could inhibit the release of ethyl butanoate,ethyl 3-methylbutanoate,ethyl hexanoate,whiskey lactone and 4-ethylphenol.When the concentration of phenolic acid was lower than the concentration of prophenolic acid in wine,the release of "green" aroma compounds was significantly inhibited.When the concentration of phenolic acid and polymeric was 4 times the normal concentration,the release of "fruital" aroma compounds was inhibited,but the release of four "floral"aroma compounds(?-citronellol,nerol,?-damascenone,geraniol)was promoted.In addition,the monomeric/oligomeric with six concentration gradients were found to promote the release of ?-citronellol,nerol,?-damascenone,geraniol and "green" aroma compounds,and to inhibit the release of ethyl butanoate,ethyl 3-methylbutanoate,ethyl hexanoate,and "aged" aroma compounds.3.The effect of different reaction times on aroma compounds shows that:The effect of phenolic compounds on the four types of aroma compounds was in the order of"floral" aroma compounds>"green" aroma compounds>"fruital" aroma compounds>"aged" aroma compounds.When there were three groups of polyphenol components in the solution system,"floral" aroma compounds preferentially combined with polymeric,"green" aroma compounds preferentially combined with phenolic acid and monomeric/oligomeric,"fruital" aroma compounds preferentially combined with monomeric/oligomeric and polymeric.4.The results of the interaction mechanism between phenolic compounds and aroma compounds show that:Epicatechin could interact with ethyl butanoate,rose oxide,whiskey lactone and IBMP intermolecularly.The-H on ethyl butanoate was easy to combine with-OH on epicatechin,which caused the chemical shift to the right and the intermolecular interaction to become weak.After mixing epicatechin and rose oxide,its-H chemical shift value was decreas ed,this is because around the double bond of the polar group through the ?-? stacking effect makes carbon on proton changed,far easier to track overlap with hydrogen causes the vibration of the hydrogen is abate,so as to make the intermolecular interaction force.Some chemical shifts at both epicatechin and the whiskey lactone increased,moving towards the low field,and the intermolecular interaction became stronger.The chemical shifts of both epicatechin and IBMP were changed,indicating that epicatechin and IBMP had intermolecular interactions.In conclusion,the study of the effects of phenolic compounds on aroma provides data support for the regulation of wine aroma,and lays a theoretical basis for the addition of commercial tannin and the regulation of aroma in the later wine processing process.