Physicochemical and rheological characteristics of commercial chili sauces as thickened by modified starch or modified starch/xanthan mixture Original Research Article

Physicochemical and rheological properties of various commercial chili sauces were characterised in this study. It was found that all studied sauces were acidic. Fourier transform infrared spectroscopy and colour staining experiments showed that the studied sauce could be categorised into two groups: one containing only starch and the others having both starch and xanthan within their ingredients. The rheological measurements showed that all sauces had a weak gel-like characteristic with strong shear thinning behaviour. In particular, the sauce with the weakest network contained only starch. Flow experimental data, fitted with the Herschel–Bulkley model, also revealed that the sauce with the lowest total solid content had undetectable yield stress, the lowest consistency coefficient, and the highest flow behaviour index, hence the weakest network structure amongst the studied sauces. The xanthan–starch mixture was shown to be beneficial as they could interact synergistically in acidic condition to enhance the gel-like characteristics and shear thinning behaviour of chili sauces.