M.A. Thesis:

Study on the possibility of using pistachio oil in mayonnaise formulation

Abstract Great nutritional and medical benefits of pistachio oil and the popularity and high consumption of mayonnaise have led to investigate the possibility of using pistachio oil in mayonnaise formulation in the present study. To this end, mayonnaise with different percentages of pistachio and sunflower oils (9 treatments) was prepared and their physical, chemical, rheological and sensory properties were examined. The results of chemical tests within 60 days of storage indicated that all samples were in good condition in terms of peroxide value and the acidity rate of all samples was in the standard range (0.7-1.2). Also, the physical stability of the emulsion for samples containing 10 to 20 percent of oil was relatively good. L index of Lovibond colorimetric test which shows the rate of the sample’s brightness was lower in the samples containing pistachio oil compared to sunflower oil. Investigation of rheological propertiesand the flow behavior of mayonnaise revealed that all samples follow Herschel-Bulkley model and had pseudoplastic behavior which is desirable for mayonnaise. N index of all samples was less than 0.6. Sensory evaluation of samples was carried out using 5-point hedonic method and samples containing pistachio oil received a higher score relative to sunflower oil. The sample containing 20% of pistachio oil obtained the high score of 4.5. The achieved results demonstrate that pistachio oil can be used in the formulation of mayonnaise and in this way, pistachio byproducts can be expanded through the introduction of new product.

Keywords: Keywords: pistachio oil, mayonnaise, sensory properties