Emulsifying power of mannan and glucomannan produced by yeasts
Subject of study was the colloid chemical properties of the biopolymers mannan, synthesized from strain Rhodotorula acheniorum MC, and glucomannan, synthesized from strain Sporobolomyces salmonicolor AL1. Their emulsifying capacity was studied in model systems of aqueous solutions in concentrations from 0.5% to 2.5% with regard to the aqueous phase. Emulsions of the direct type (oil/water) with 50% oil content were obtained. A disperse system with 2.5% glucomannan had 100% intact emulsion in the centrifugation test, while for the system with mannan, this indicator was 72%. Lab cream emulsions were obtained with glucomannan and with the emulsifiers Rofetan N/NS and Arlacel 165 used in the cosmetics industry. It has been established that under standard testing conditions, cream-like emulsions with 2.0% glucomannan have stability indicators comparable to these of 5.0% rofetan N/NS and 5.0% Arlacel 165. The samples with different concentrations of glucomannan showed a pseudo-plastic behaviour, as the highest viscosity was shown by the emulsion with 2.0% stored at 45°C. The newly synthesized exopolysaccharides had a distinct emulsifying power and can be applied in the cosmetic and food industries.
Document Type: Research Article
Affiliations: 1: University of Food Technologies, Department of Organic Chemistry, 26 Maritza Blvd., 4002 Plovdiv 2: Laboratory of Applied Microbiology, Institute of Microbiology, Bulgarian Academy of Science, 26 Maritza Blvd., 4002 Plovdiv 3: Bulgarian Cosmetologists Association, 4002 Plovdiv, Bulgaria
Publication date: October 1, 2007