Effect of natural antioxidants on lipid oxidation in mayonnaise compared with BHA, the industry standard

Mayonnaise is an oil in water emulsion (O/W) consisting 70-80% oil. Lipid oxidation is a major cause of quality deterioration in mayonnaise. The effectiveness of antioxidants in a hetrophasic systems is highly dependent on their polarity and partitioning properties.

The aim of the present study was to determine the effect of a hydrophilic [green tea extract (GTE)] and a lipophilic [tocopherol mixture (TOC)] and BHA on lipid oxidation in mayonnaise during 60 days of storage at 38 °C and to examine the interactions between GTE and TOC, to determine possible synergistic or antagonistic effects in antioxidant activity.

The oxidative stability was studied by measuring hydroperoxides, volatile organic compounds (VOCs) and colour of mayonnaise during storage. Comprehensive analysis of VOCs was done by static headspace extraction and separation by two-dimensional gas chromatography time of flight mass spectrometry. Sensory analysis was also carried out to study the effect of storage time and antioxidant type on sensory properties of mayonnaise and to investigate the predictive ability of volatile compounds for sensory terms.

Addition of GTE (500 ppm) and TOC (500 ppm) increased the formation of hydroperoxides and certain VOCs. The combination of GTE with TOC improved the antioxidant efficacy compared to the individual extracts. However, sensory evaluation demonstrated that GTE promoted the development of unpleasant fishy and rancid aroma. The volatile compound methional, was significantly and positively correlated with fishy and rancid flavour. Regarding colour analysis, GTE showed the highest increase in darkening and browning during storage.