**15. Experimental procedure**

The target concentration range of 3 mg/ml was obtained by weighing and dissolving the necessary amount of crystal BSA in double distilled water and then diluting it properly. The optical density (OD) was then measured with a UVspectrophotometer at a wavelength of 280 nm. A regular curve was created by plotting the resulting value against concentration. The SDS-PAGE system was used to quantitatively estimate individual components in a protein mixture.

## **16. Determination of critical micelle concentration (CMC) of BSA**

Required quantity of powdered BSA was weighed and dissolved in double distilled water and then suitably diluted to obtain a desired concentration range of 100–800 mcg/ml. The surface tension of those samples was measured by using drop count method, and a plot of Concentration VS Surface tension was constructed (**Figure 2**).

### **17. Measurement of the gas percentage hold up**

Different concentrations of feed are prepared for deciding percentage gas holdup while keeping the same Protein surfactant ratio. As gas went through the column, the percentage gas hold up was determined in a batch of oil. The liquid pool's height was assessed. After turning off the gas supply, the height of the liquid *Separation of Bovine Serum Albumin (BSA) Protein by Foam Fractionation Technique DOI: http://dx.doi.org/10.5772/intechopen.99943*

**Figure 2.** *Surface tension vs. concentration of bovine serum albumin (BSA).*

**Figure 3.** *Percentage of gas hold up at defferent ci and fixed PSR.*

pool was measured once more. The percentage of entrapped gas bubbles in the liquid column was measured and tabulated as percent gas hold up. The percentage gas hold up was plotted against the gas flow rate (GFR). The temperature in the lab was held at 25°C (**Figure 3**).
