The isolation method and oxidation modify the physicochemical and technological properties of non-conventional Calathea allouia starch

This study aimed to investigate the effect of different isolation method using water, acidified water (2 % ascorbic acid), and alkalized water (0.1 % NaOH), as well as oxidation with sodium hypochlorite (1–3 % Cl 2 ), on the structural, morphological, physicochemical, and pasting properties of Calathea allouia starch. Starch was evaluated using Fourier transform infrared spectroscopy, X-ray diffraction, thermal analysis, morphological characterization, pasting properties, swelling power, solubility, and retrogradation tests. The isolation method did not significantly affect most physicochemical and functional properties of the starch, and all starches exhibited high purity (99.2–99.6 % dry basis). However, oxidation increased the percentage of carbonyl (CO) and carboxyl (COOH) groups with rising Cl 2 concentration. Additionally, oxidation created pores on starch granule surfaces and increased relative crystallinity, solubility, oil absorption capacity, paste clarity, whiteness, and freeze-thaw stability. Conversely, oxidation reduced all pasting properties except pasting temperature. Retrogradation kinetics revealed that oxidation increased starch paste transmittance, though transmittance decreased with longer storage (4 days) and lower temperatures (from 25 °C to 8 °C). These findings suggest that oxidized C. allouia starch is a more suitable thickening and stabilizing agent than its native counterpart, which may be highly relevant to the food industry. • Starch from the tuberous root of Calathea allouia was isolated using aqueous, alkaline, and acidic methods. • C. allouia isolated with water presented high purity and whiteness. • Oxidation with sodium hypochlorite increases the carbonyl and carboxyl group content in C. allouia starch. • Oxidized C. allouia starch exhibited higher crystallinity and paste clarity. • Oxidation enhanced the physicochemical and functional properties of C. allouia starch.