Antimicrobial Plectranthus amboinicus emulsions prepared with amphiphilic cellulose stearate

This work focuses on creating tiny oil droplets (nano-emulsions) from a cheap sugarcane bagasse residue to deliver the active ingredients in a plant extract (Plectranthus amboinicus) for use in medicine and food. Instead of expensive synthetic materials, scientists have proposed using a special type of fat (cell–stearate) made from recycled plant waste for this purpose. The extract’s main components successfully produced nano-emulsions (NEMs) around 27–59 nm in size. The oil emulsifier (cell–stearate) has specific properties that keep the oil droplets separate and prevent them from clumping together. This is confirmed by measurements showing how the stabilizer changes the surface properties of the droplets, allowing them to mix better with water. The prepared nano-emulsion was in nano-range between 27.23 and 59.29 nm. The degree of substitution (DS) and HLB of cell–stearate was 0.17 and 7.26. The cell–stearate provided a protective layer around the extract droplet surface, which prevented droplets from coalescing. This hypothesis is supported by the contact angle measurement for the O/W emulsion formed by cell–stearate being 57°, which is lower than the value for emulsions formed by the emulsion of the extract with water, 105°. This study demonstrates a cost-effective way to produce a natural emulsifier for tiny oil droplets containing valuable plant compounds, potentially leading to new applications for recycled cellulose materials.