A Crison Basic 20+ pH meter (Crison S.A. Barcelona, Spain) was used to measure the pH of salad dressings. For the total titratable acidity (TTA) determinations, 10 g of each sample were mixed with 40 mL of distilled water and titrated with a 0.1 N NaOH solution until a pH value of 8.30. Total titratable acidity was expressed as g acetic acid/100 g of dressing. The water activity (aw) of samples was measured by an Aqualab dew point hygrometer model 4 TE (Decagon Devices, Inc., Washington, USA) at 25 ºC. The sodium chloride analysis was carried out by an automatic Chloride Analyser (Sherwood Scientific Ltd., Cambridge, UK) and the results were expressed as g NaCl/100 g of sample.
To study the stability of salad dressings against creaming, 5 g of each sample were transferred to a cylindrical glass container, sealed with a plastic cap and stored until analysed. The extent of creaming was calculated by employing Eq. ( 1): H% = (Ht/H0) x 100
(1)
where Ht represents the visible separation layer and H0 is the initial emulsion height.
Finally, the colour parameters (L*, a*, and b*) of salad dressings were measured by a spectrocolorimeter (CM-3600d, Minolta Co., Tokyo, Japan) with an observer 10º and illuminant D65. The Whiteness index (WI) was calculated by Eq. ( 2) and colour variations (2)
(3)
To study the stability of salad dressings against creaming, 5 g of each sample were transferred to a cylindrical glass container, sealed with a plastic cap and stored until analysed. The extent of creaming was calculated by employing Eq. ( 1): H% = (Ht/H0) x 100
(1)
where Ht represents the visible separation layer and H0 is the initial emulsion height.
Finally, the colour parameters (L*, a*, and b*) of salad dressings were measured by a spectrocolorimeter (CM-3600d, Minolta Co., Tokyo, Japan) with an observer 10º and illuminant D65. The Whiteness index (WI) was calculated by Eq. ( 2) and colour variations (2)
(3)