Comparative study of emulsifying properties in acidic condition of soluble polysaccharides fractions obtained from soy hull and defatted soy flour

PORFIRI, M.C.; CABEZAS, D. M.; WAGNER, J.R.

JOURNAL OF FOOD SCIENCE AND TECHNOLOGY-MYSORE

ASSOC FOOD SCIENT TECHN INDIA

Año: 2016 vol. 53 p. 956 - 967

0022-1155

The presentstudy compares the emulsifying properties in acidic conditions of hull solublepolysaccharides (HSPS), soybean soluble polysaccharides (SSPS) and itsmixtures. These fractions were obtained from byproducts of soybean processingindustry (soy hull and residual fiber after isolation of soy cotyledon protein,respectively). Although SSPS is already characterized, HSPS is a novel fractionwhich has not been studied in deep and it is still unexplored as emulsifier. Dispersionsof both fraction and a mixture 50:50 of them at pH 3.0 were used as aqueousphase (1.0-3.0% w/w) in coarse and fine oil-in-water emulsions (oil massfraction= 0.3). Its stability was evaluated through the evolution ofbackscattering profiles (%BS), particle size distribution and mean particlediameters. The rheology of the emulsions was also analyzed. Both fractionsprovided stability to creaming when increasing the polysaccharide concentrationand energy of homogenization. While coarse emulsions were unstable systems,fine emulsions were stable enough and allowed a deeper analysis of thedestabilizing processes. A bridging flocculation phenomenon in the presence ofHSPS and HSPS/SSPS mixtures is suggested, which influences the creaming andrheological behavior. Also, coalescence index increases according HSPS andHSPS/SSPS concentrations, but particle sizes reached were smaller than in SSPSemulsions. Fine emulsions with 3% of HSPS/SSPS mixtures yielded the bestresults on the overall stability at 28 days. So, functional properties of the fractionsmay improve by the formulation of emulsions consisting in mixtures of them.These results are of interest to themanufacturing of acidic foods, taking advantage of obtaining byproducts from residual materials.