Effect of modified tapioca starches on the gelling properties of whey protein isolate

Abstract

The objective of the present work was to investigate the rheological, thermal and microstructural properties of whey protein isolate (WPI)-modified tapioca starch (acetylated tapioca starch (ATS), hydroxypropylated tapioca starch (HPTS) and cross-linked tapioca starch (CLTS)) gels. The rheological results showed that the WPI-modified starch gels had higher storage modulus (Gʹ) values than the pure WPI and WPI-native starch gels. During heating, the WPI-modified starch systems exhibited a continuous increase in Gʹ. Differential scanning calorimetry (DSC) results showed that WPI-modified starch mixtures presented higher thermal transition temperatures than did modified starches. The results of light microscopy (LM) and scanning electron microscopy (SEM) showed that WPI-ATS, HPTS and CLTS systems presented a better gel morphology than WPI-native starch system. This study showed that the gelling properties of WPI can be modulated by the addition of modified starches, with WPI-CLTS system displaying better gel properties than other WPI-modified starch systems.