Maillard reaction-based conjugation of Spirulina protein with maltodextrin using wet-heating route and characterisation of conjugates

Abstract

Spirulina protein concentrate (SPC) was extracted from Spirulina biomass and its structure and technofunctional properties were modified through Maillard reaction with maltodextrin (MD). Wet-heating route was adapted and Maillard reaction was controlled within initial to intermediate stage by avoiding or minimising the formation of melanoidins. A glycation degree of up to 29.1 % was achieved after reaction between SPC and MD, and molecular weight of the SPC increased accordingly. The solubility of SPC was improved only in the pH range around its isoelectric point after conjugation. The antioxidative property of the SPC-MD conjugate was also improved as the DPPH radical scavenging activity increased 19.7 to 30.2 %. Oil-in-water emulsion stabilised by SPC-MD conjugate produced at 6 h had significantly reduced droplet size, increased surface charge, and higher physical stability in temperature range 25-60 °C. The outcome of this research will help broaden the application of SPC in food as emulsifier and encapsulating shell material.

Keywords: Conjugation; Emulsions; Maillard reaction; Maltodextrin; Solubility; Spirulina protein concentrate.