Synthesis and characterization of octenyl succinic anhydride modified starches for food applications. A review of recent literature

Starch is esterified with octenyl succinic anhydride (OSA) to yield a hydrocolloid with amphiphilic properties, octenyl succinylated starch (OS-starch). OS-starch finds wide application in the food industry mainly as emulsifier, encapsulating agent and fat replacer. As a result of the new hydrophobic groups introduced and concomitant changes produced in the granules structure, OSA modified starches typically show reduced gelatinization temperature and enthalpy, lower digestibility, higher swelling power, and increased paste viscosity and paste clarity. Traditionally, OS-starches have been synthesized in aqueous slurry under mild alkaline conditions, resulting in reaction taking place mainly on the surface and amorphous regions of starch granules. However, in the last years, alternative methodologies and modifications to the conventional method (e.g. in situ mechanical and ultrasonic assistance, and hydrothermal, mechanical, enzymatic and chemical pretreatments of starch) have received much attention; aiming to increase reaction efficiency, reduce reaction time, attain a more even distribution of ester groups within the granules, and/or produce OS-starches with enhanced or specific properties. Considering the importance of octenyl succinylation methodology on the resulting OS-starch structure, functional properties, and uses derived from them, in the current review OS-starch production routes, products properties and main food applications described in the literature within the last five years have been summarized.