Impact of Amino Acid Addition on Aroma Compounds in Papaya Wine Fermented with Williopsis mrakii

The impact of amino acid addition on aroma compound formation in papaya wine fermented with yeastWilliopsis saturnus var. mrakii NCYC2251 was studied. Time-course papaya juice fermentations werecarried out using W. saturnus var. mrakii NCYC2251, with and without the addition of selected amino acids(L-leucine, L-isoleucine, L-valine and L-phenylalanine). Yeast growth and changes in sugars, °Brix, organicacids and pH were similar, regardless of amino acid addition. L-Leucine addition increased the productionof isoamyl alcohol and some esters such as isoamyl acetate, isoamyl butyrate and isoamyl propionate, whileL-isoleucine addition increased the production of active amyl alcohol and active amyl acetate. L-valineaddition slightly increased the production of isobutyl alcohol and isobutyl acetate. L-phenylalanineaddition increased the formation of 2-phenylethanol, 2-phenylethyl acetate and 2-phenylethyl butyrate,while decreasing the production of most other esters. This study suggests that papaya juice fermentationwith W. saturnus var. mrakii NCYC2251 in conjunction with the addition of selected amino acid(s) can bean effective way to modulate the aroma of papaya wine.