The effects of fat content and thickeners, propylene glycol alginate (PGA; 1.40%) and guar gum (1.55%), on sensory and instrumental quality descriptors on reduced mayonnaises (15 and 30% fat) with and without added aroma compounds, citral (semi-polar) and oyroligneous acid (polar), were investigated. One mayonnaise, 82% fat, without added thickener or aroma compounds, was used as reference. Sensory evaluation (quantitive descriptive analysis; QDA), rheological analysis (yield stress, maximum viscosity, G' and G"), measurements of particle size and headspace GC-MS analyses were carried out. Correlations between the results were developed. Perceived and instrumental texture, and perceived smell and flavour, changed differently in magnitude and direction due to fat content and type of thickener.