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.