Studies on preparation and emulsifying properties of guar galactomannan ester of palmitic acid

Various degrees of palmitoylated guar galactomannan (PGGM) are prepared by a heterogeneous method. Both differential thermal analysis and X-ray diffra ction spectra show substituted palmitoyl chains played a role in the new cr ystallization and the molecular aggregated structure of GGM was changed. Fu rthermore, the emulsifying properties of both water-soluble and oil-soluble PGGM were investigated in detail. It is demonstrated that PGGM has good em ulsifying activity, even in high salt concentration or in acidic pH. In add ition, the emulsifying properties of water-soluble PGGM-protein mixture was also studied systematically. It is proven that water-soluble PGGM is a kin d of good oil in water (o/w) emulsion stabilizer. With water-soluble PGGM-c asein mixture (0.1 wt %) as emulsifier, clove oil-water (v : v, 1 : 9) emul sion had good stability within 4 weeks at room temperature, and the breakag e of emulsion was not brought about. (C) 1999 John Wiley & Sons, Inc.