Syneresis

BARRERA, GABRIELA NOEL; PALAVECINO, PABLO MARTÍN; RIBOTTA, PABLO DANIEL

Basic Protocols in Starch Characterization

Springer Nature

Año: 2022;

The term syneresis describes the phenomenon whereby a polymeric matrix expelled liquid from it. Syneresis is a complex molecular process where an increase of the number of macromolecular junctions leads to network rearrangement causing the interstitial liquid release. In starch systems, syneresis is specifically the phenomenon associated with water expelling out from gelatinized starch systems during cooling, storage, and freeze-thawing as a consequence of the starch retrogradation. The water phase separation from the retrograded starch polymeric-matrix is associated with a food quality issues; therefore, the syneresis level is used as a stability indicator of starchy foods. Mainly two procedures are used to quantify the released liquid from starch systems: centrifugation and vacuum methods, although the experimental procedures in both cases have not been standardized yet. Both methodologies use an external force to expel the water out from the polymeric network and the weight of the removed water is used as a syneresis measure. This chapter provides a general overview of syneresis in starch systems by presenting the main aspects of this phenomenon. The two main analytical methods to determine the degree of syneresis are presented and a protocol for the centrifugation method and the vacuum method is proposed taking several measurement conditions into account. Additionally, some recommendations are given for controlling the measurement conditions in order to prevent imprecise estimates of syneresis.