Impact of inulin molecular weight on physiochemical and techno-functional properties of Chlorella protein isolate and hydrolysed peptides' Maillard conjugates.

Abstract

Background: With the rise of alternative proteins, microalgae are on the verge of commercialization to meet global demand for protein-rich foods. The functionality of alternative protein becomes crucial for protein-fortified product development. Modification via Maillard-type glycation can be employed to improve functional properties. Maillard reaction is a scalable, fast and simple method for enhancing functionality.

Results: The findings indicated that glycation had altered the surface morphology and increased particle size. With varying molecular weight of inulin higher solubility was observed, particularly for sample CHP 1:1L at pH 4.0, which demonstrated highest increase in solubility compared to the native protein, overall, solubility remained moderate. Moreover, high-molecular-weight inulin has positively affected emulsification stability for glycoconjugates of both Chlorella protein isolate and hydrolysates, H-CHP 1:1H demonstrated most stability at pH 5.0 with an emulsification stability index (ESI) of 2203 min (1.5 days). Notably, the antioxidant capacity of both CHP and H-CHP conjugates was high, with CHP 1:1M showing a Trolox equivalent of 0.33 mg mL^-1 mg^-1 (a 450% increase) and H-CHP 1:1L showing 0.61 mg mL^-1 mg^-1 (a 308% increase), respectively.

Conclusion: The results obtained from this study expand understanding of glycoconjugates' structure and function behaviour, promising its utility as functional ingredients. The enhanced emulsification stability, water/oil holding and antioxidant ability of these conjugates promises its application in structured matrices, emulsion and fat containing formulations. © 2026 Society of Chemical Industry.