Flavonoid Accumulation in Wine Grapes

Consumption of “superfoods” is associated with a reduced risk of degenerative disease, but what makes these fruits and berries superb? These protective benefits are often associated with flavonoids a group of diverse plant phenolic compounds, most well known as pigments. Flavonoids are produced in the shikimate/phenylpropanoid pathway in plant tissues. Anthocyanins, a group of low molecular weight flavonoids, are highly soluble pigments that accumulate in grape skin cells, which contribute to the black and red color of grapes. Flavor properties of grapes and wine are all influenced by anthocyanin compound accumulation. One of the most valuable fruit crops cultivated worldwide, grapes produce wine, juice, raisins and table grapes, and are a practical model to study the regulation of anthocyanin accumulation. My research is based on the hypothesis that, although many genes play a role in pigment accumulation during grape development; identifying specific genes that control flavonoid accumulation is useful for efforts to modulate flavonoid content. Specific objectives include, investigating what are the key metabolites present in flavonoid biosynthesis throughout developing grape berries? By comparing metabolic imaging experimental results of in Cabernet Franc and Riesling grape samples, we can determine which compounds are involved in flavonoid gene regulation in red versus green wine grape’s tissue (epidermis, flesh, and seed). We analyze the metabolic profiles using MALDI imaging (matrix-assisted laser desorption ionization mass spectrometer), a relatively new and unique technology to determine the accumulation pattern of compounds present in grape tissue to continue validating the metabolite biosynthetic pathway in wine grapes.