Effect of Different Alkali Types on the Physicochemical Properties of Camellia oleifera Seed Starch

Abstract

To improve the resource utilization of Camellia oleifera , this study investigated the influences of alkaline extraction agents (NaOH and Na 2 CO 3 ) on the structure and physicochemical characteristics of C. oleifera seed starch. C. oleifera seed starch was a typical C‐type starch with spherical granules about 2.5 µm in diameter, which was composed of 80% amylopectin (DP 10‐40) and 20% long‑chain amylose (DP 900‐1000). The starch extracted with Na 2 CO 3 at pH 9 exhibited higher extraction yield, total starch content, relative crystallinity, and gelatinization enthalpy. In comparison, NaOH extraction caused slight degradation of starch molecules, accompanied by increased paste viscosity, swelling power, and resistant starch content. Compared to conventional starches, C. oleifera seed starch demonstrated greater shear resistance, higher resistant starch content, and lower transparency. Na 2 CO 3 was more suitable for high‐yield and high‐purity starch preparation, while NaOH treatment favors the acquisition of starch with higher viscosity and resistant starch content. This study revealed the impacts of alkaline types on the structure and physicochemical properties of Camellia oleifera seed starch, providing a targeted technical basis for the selective extraction and high‐value utilization of this specialty starch resource.