On the internal structure of modified starch particles

Oil in water (O/W) emulsions can be stabilized by adsorbing particles at the oil/water interfaces, i.e. the so-called Pickering type emulsions.1 Starch particles have been used to stabilize O/W food emulsions. Starch particles modified by esterification with dicarboxylic acids to give octenyl succinic anhydride (OSA) starch is an approved food additive that can be used to stabilize oil in water emulsions used in foods and drinks. Unfortunately, the chemical quantification methods can only assess the average total degree of modification but not the location of the modification. In this study, we plan to make use of chain deuterated octenyl succinic anhydride (provided DMAX at ESS) and isotopic contrasts to locate the modification. This knowledge is essential for the understanding the interfacial behavior of the starch particles. Preliminary SANS data from D11 at ILL shows that it is possible to perform SANS measurements on these samples. We expect to use the ZOOM instrument at ISIS that are able to reach sufficiently low q for the size of the particles.