Strategy to identify and quantify polysaccharide gums in gelled food concentrates
Grün, C.H. ; Sanders, P. ; Burg, M. van der; Schuurbiers, E. ; Adrichem, L. van; Velzen, E.J.J. van; Roo, N. de; Brunt, K. ; Westphal, Y. ; Schols, H.A. - \ 2015
Food Chemistry 166 (2015). - ISSN 0308-8146 - p. 42 - 49.
locust bean gum - polymerase-chain-reaction - guar gum - capillary-electrophoresis - enzymatic determination - starch industry - raw-materials - xanthan gum - identification - additives
A strategy for the unambiguous identification and selective quantification of xanthan gum and locust bean gum (LBG) in gelled food concentrates is presented. DNA detection by polymerase chain reaction (PCR) showed to be a fast, sensitive, and selective method that can be used as a first screening tool in intact gelled food concentrates. An efficient isolation procedure is described removing components that may interfere with subsequent analyses. NMR spectroscopy enabled the direct identification of xanthan gum and the discrimination between different galactomannans in the isolated polysaccharide fraction. An enzymatic fingerprinting method using endo-ß-mannanase, in addition to being used to differentiate between galactomannans, was developed into a selective, quantitative method for LBG, whereas monosaccharide analysis was used to quantify xanthan gum. Recoveries for xanthan gum and LBG were 87% and 70%, respectively, with in-between day relative standard deviations below 20% for xanthan gum and below 10% for LBG.
Phase separation induced fractionation in molar mass in aqueous mixtures of gelatin and dextran
Edelman, M.W. ; Tromp, R.H. ; Weenen, H. - \ 2003
Physical Review. E, Statistical nonlinear, and soft matter physics 67 (2003)2. - ISSN 1539-3755 - 11 p.
locust bean gum - 2-phase systems - temperature - carrageenan - equilibria - protein
An overview of the effects of phase separation of aqueous mixtures of gelatin and dextran on the fractionation in molar mass of these two components is given. Molar mass distributions in coexisting phases were investigated using size exclusion chromatography with multiangle laser light scattering. The initial molar mass of the native material, concentration, and temperature were varied. The results show a strong fractionation in molar mass for both components. The molar mass of the native material and concentration appeared to be the only factors that affected the final molar mass distributions, temperature having no effect. The results show that in the molar mass range where fractionation is the strongest, i.e., roughly below the maximum in the distribution, fractionation is governed by a Boltzmann factor e-¿G/kT, where ¿G denotes the free energy involved in transferring a polymer with a certain length from the enriched to the depleted phase, and in this case turns out to be proportional to the molar mass. Comparison of the results of phase separation with results on dialysis shows that water affinity is not the driving force for the phase separation of gelatin and dextran in aqueous solution. The gelation properties of gelatin in both phases were also determined. The gelation properties of gelatin in the coexisting phases differ from those of native gelatin. In particular, the gelatin in the gelatin-poor phase shows strong differences compared to the native material.