The present invention concerns a new yeast extract comprising from 25% to 55% by weight of 5′-ribonucleotides, including 5% to 20% by weight of adenosine 5′-monophosphate (5′-AMP) and 5% to 20% by weight of guanosine 5′-monophosphate (5′-GMP) in a 5′-AMP/5′-GMP ratio ranging from 0.85 to 1.25, the percentages by weight being expressed in relation to the dry weight of the yeast extract. The invention also concerns the use of such an extract for the masking of bitter and sour tastes and sweetener, protein and metallic off-notes in a product, as well as a process for masking said tastes and said notes.本發明關於一種新的酵母萃取物包含重量百分比25%-55%的5’-核糖核苷酸 (5’-ribonucleotides),其中5’-核糖核苷酸包含5wt%-20wt%的5’-單磷酸腺苷 (5’-AMP) 和5wt%-20wt%的5’-單磷酸鳥苷 (5’-GMP),5’-AMP/5’-GMP的比值為0.85-1.25,重量百分比表示為相較於酵母萃取物的乾重。本發明也關於此酵母萃取物用於掩蓋產品中苦味、酸味及甜味劑、蛋白質及金屬芳香物的異味的用途,以及掩蓋所述味道和所述氣味的方法。