A comparative study of mayonnaise and Italian dressing prepared with lipase-catalyzed transesterified olive oil and caprylic acid

Viscoelastic properties of mayonnaise and Italian salad dressing prepared with olive oil and enzymatically synthesized structured lipid (SL) from caprylic acid and olive oil were studied using an SR5000 dynamic stress rheometer. Storage modulus (G ') and loss modulus (G ) were determined as functions of frequency, temperature, and stress. Frequency sweeps did not show significant differences between dressings prepared with olive oil or SL. For all mechanical spectra, G ' values were consistently higher than G values. Both Italian dressing and mayonnaise samples displayed similar gel-like characteristics. Mayonnaise and Italian dressings made with olive oil separated when they were brought to room temperature from refrigeration temperatures. SL-based mayonnaise did not separate. Only minor separation was observed in SL-based Italian dressing. A change in the crystallization properties of the two oils was probably responsible for the differences observed after refrigeration. Both SL-based and unmodified olive oil-based mayonnaise and Italian dressing samples had similar viscoelastic character.