Abstract
Biosurfactants are amphipathic molecules with capacity to reduce the surface and interfacial tension of aqueous solutions, arousing great industrial interest due to the diversity of structures and production from renewable sources, allowing the obtention of products with unique characteristics. In the food industry, for example, the use of biosurfactants produced by some yeasts is very promising, since they do not present any risk of toxicity and pathogenicity, and can be applied in emulsification, for improvement of mass texture, as antimicrobial agents and in the replacement of fats. Thus, the aim of this work was to produce a biosurfactant by the yeast Candida utilis UFPEDA1009 with potential application as an emulsifier in foods. The yeast was grown in mineral medium containing 6% canola frying oil and 6% glucose, under 150 rpm agitation for 88 h at 28 °C. After the production process, the surface and interfacial tension, yield and Critical Micelle Concentration (CMC), as well as the particle size distribution of emulsions were determined. The surface and interfacial tensions obtained were, respectively, 35.33 ± 0.19 and 2.53 ± 0.02 mN/m, with biosurfactant yield varying from 13.10 ± 0.04 to 48. 05 ± 0.21 g/L. The biosurfactant CMC was 0.6 g/L. The emulsions showed small particle sizes, with uniform shape and more separated particles, appearing resistance to coalescence. In general, it was observed that the increase in the concentration of the biosurfactant resulted in the decrease of the particle size, that is, the higher the concentration of a given biosurfactant, the greater the stability of the emulsion. The microbial surfactant was incorporated in the mass of a biscuit formulation in substitution of the animal fat, which showed improvements in the texture profile of its mass. Therefore, the biosurfactant produced is promising for application in food formulations as an emulsifier.
