Differential metabolism of hydroxycinnamic acids and their tartartic acid esters by Brettanomyces and Pediococcus in red wines

Lauren Marie Schopp

Hydroxycinnamic acids (caffeic, p-coumaric, and ferulic acids) and their corresponding tartaric acid esters (caftaric, coutaric, and fertaric acids, respectively) are found in red wines. While Brettanomyces and Pediococcus can utilize the free acids, it is not known whether they can metabolize the corresponding tartaric acid esters. Syrah, Pinot noir, Cabernet Sauvignon, and Merlot wines were inoculated with one of four strains of B. bruxellensis (B5, I1a, E1, or B1b) at 105 -106 cfu/mL. In a second experiment, Pinot noir and Syrah wines were inoculated with either strain of P. parvulus (WS-7C or WS-29A) at 106 -107 cfu/mL, and after two weeks, half of the wines were inoculated with B. bruxellensis E1 at 105 cfu/mL. Wine samples were fractioned by C18 solid phase extraction columns with caffeic, caftaric, p-coumaric, coutaric, and ferulic acids analyzed by high-performance liquid chromatography with diode array detection. B. bruxellensis B5 populations declined to less than 30 cfu/mL and metabolized 12% or less of the caffeic, p-coumaric, and ferulic acids. Conversely, strains I1a, E1, and B1b entered exponential growth and reach populations in excess of 107 cfu/mL. Additionally, the three strains metabolized 43-71% of the caffeic acid, 87-98% of the p-coumaric acid, and 37-78% of the ferulic acid. However, strain I1a exponential growth and the onset of the free hydroxycinnamic acids utilization were delayed one to three weeks compared to strains E1 and B1b. None of the B. bruxellensis strains were able to metabolize the hydroxycinnamic acid tartaric acids esters. P. parvulus WS-7C and WS-29A populations slowly declined one log over nine weeks. Both strains were able to convert 25-38% of the caffeic acid and 13-20% of the p-coumaric acid. Neither strain of P. parvulus utilized the ferulic acid or hydrolyzed the hydroxycinnamic acid tartaric acid esters. When the P. parvulus inoculation was followed by inoculation with B. bruxellensis E1, both microorganisms reached higher populations compared to inoculations alone. Both B. bruxellensis and P. parvulus demonstrated strain- and wine- dependent metabolism of the free hydroxycinnamic acids. While B. bruxellensis exhibited preferential metabolism of p-coumaric acid compared to caffeic and ferulic acids, P. parvulus expressed preferential conversion of caffeic acid to the correspondent ethyl phenol.

Differential metabolism of hydroxycinnamic acids and their tartartic acid esters by Brettanomyces and Pediococcus in red wines

Files and links (1)

Abstract

Metrics

Details