Effect of L-isoleucine and L-phenylalanine Addition on Aroma Compound Formation During Longan Juice Fermentation by a Co-culture of Saccharomyces cerevisiae and Williopsis saturnus

  • T.T.T. Trinh Food Science and Technology Programme, Department of Chemistry, National University of Singapore, 4 Science Drive 4, Singapore 117543
  • W.Y. Woon Food Science and Technology Programme, Department of Chemistry, National University of Singapore, 4 Science Drive 4, Singapore 117543
  • B. Yu Firmenich Asia Pte Ltd, Tuas, Singapore
  • P. Curran Firmenich Asia Pte Ltd, Tuas, Singapore
  • S.-Q. Liu Food Science and Technology Programme, Department of Chemistry, National University of Singapore, 4 Science Drive 4, Singapore 117543

Abstract

Some amino acids are known to be precursors of aroma-active compounds produced by yeast metabolism. This
study examined the effect of the addition of L-isoleucine and L-phenylalanine on the volatile profiles of longan wine
fermented by a co-culture of Saccharomyces cerevisiae var. bayanus EC-1118 and Williopsis saturnus var. saturnus
CBS254 inoculated at a ratio of 1:1 000 cfu/mL with the aim of enhancing longan wine aroma. Significantly higher
concentrations of active amyl alcohol (2-methyl-1-butanol), 2-phenylethyl alcohol and their corresponding acetate
esters were found in the longan wine with added L-isoleucine and L-phenylalanine respectively, compared with the
control (without added amino acids). The biosynthesis of other volatile compounds was either similar or minimally
different, although the formation of some acetate esters, such as isoamyl acetate, hexyl acetate and ethyl acetate,
was decreased. These results suggest that the added amino acids play an important role in enhancing the production
of targeted aroma compounds in longan wine fermented with mixed yeasts, and that the addition of selected amino
acids can be a valuable tool to modulate the formation of aroma compounds in longan wine.
Published
2016-12-12
Section
Articles