Good afternoon!

A part of my master's degree involves determining the HLB of vegetable oils that I will work with to develop a formulation. I have found it difficult to determine this parameter following the current methodology. Below, I describe it briefly:

The aqueous (FA) and oil (FO) phases will be heated separately to a temperature of 70-75°C. FA consists of water and Tween 80®, whereas FO is composed of passion fruit seed oil and Span 80®. Once heated, the FA will be poured into the FO and homogenized with a magnetic stirrer at 5000 rpm until cooling to room temperature. After preparation, the samples will be transferred to a graduated Falcon tube and allowed to stand at room temperature for 24 and 48 hours. For classification and determination of the EHL required for passion fruit seed oil, the classification described below will be used:

N = normal, without alteration; CL = light creaming; CI= intense creaming; SF= phase separation.

I started with a concentration of 5% surfactant, but I did not obtain stability in the formulations. I gradually increased the surfactant concentration and am currently at 15%, without success. The works that I have found, determined the HLB with only 5%, and those that did not achieve this concentration, raised it to around 10%.

That said, I would like help looking for possible alternative methodologies or advice to overcome this difficulty.