Selective and eco-friendly synthesis of lipoaminoacid-based surfactants for food, using immobilized lipase and protease biocatalysts

- Lipoaminoacid synthesis was studied using immobilized enzymes on porous silica.
- Biocatalysts selectivity was studied using lauric acid and glycine as substrates.
- Selectivity and synthesis yield were dependent on the reaction conditions used.
- The best selectivity/yield balance was achieved with glyoxyl-silica protease.

Lipoaminoacids, as surfactants, are an excellent option for food industry due to the currently trends in consumption of functional and natural ingredients. Synthesis of lauroyl glycine lipoaminoacid was carried out with a lipase from Pseudomonas stutzeri and a protease from Bacillus subtilis, which were immobilized in octyl-glyoxyl silica and glyoxyl-silica supports, respectively, comparing their catalytic performance. The enzymatic selectivity towards the lipoaminoacid instead of the dipeptide glycylglycine and synthesis yield were evaluated with respect to the characteristics of the immobilized biocatalysts and synthesis conditions. Three solvents were tested as reaction media for evaluating the expressed activity, stability and catalytic behavior during synthesis. Results indicate that both enzymes favor the lauroyl glycine synthesis over the peptide synthesis, but the immobilized protease has the best balance between selectivity and yield: 40% yield for lauroyl glycine and less than 5% for dipeptide after 96 h of synthesis, at 45 °C and acetone as solvent.