*2.7. Physicochemical Properties and the Energy Value of the Cookies*

The weight, diameter, thickness and spread factor of the cookies were determined with and without the biosurfactant [23,24]. The total diameter was determined by using four randomly selected specimens placed side by side. The cookies were then turned 90◦ and the diameter was measured again. The final diameter was expressed as the mean of the two measurements divided by four. The thickness was determined by stacking four cookies and expressed as the total height divided by four. The spread factor was determined by dividing the diameter by the height.

The physicochemical properties of the cookies were determined using the analysis methods of the Association of Official Analytical Chemists [25]. The moisture content was determined gravimetrically considering the mass loss from the specimens submitted to heating in an oven at 105 ◦C until a constant weight was reached. The concentration of total protein was calculated using the Kjeldahl method, which consists of the acid digestion of organic matter followed by distillation, the quantitative determination of nitrogen by titration and multiplication of the obtained value by a factor of 6.5. The gravimetric method was used for the determination of the fixed mineral residue (ash) based on the loss of mass from the specimens submitted to incineration at 550 ◦C. The Bligh and Dyer [26] extraction method was employed to quantify the lipids. The energy value was determined by the sum of the values of carbohydrates, lipids and proteins multiplied by 4, 9 and 4, respectively [27].
