Thermo-functional characterization of the carbohydrate-rich fractions of pea (CRFP) as influenced by particle size

This study examined the impact of particle size on the thermal and functional properties of the carbohydrate-rich fraction of pea (CRFP). Four CRFP samples were analyzed: >32<53 μm, >53<75 μm, >75 μm, and a whole fraction (control). The investigation focused on physical, thermal, pasting, functional, amylose, amylopectin, and retrogradation properties. The >75 μm fraction displayed a bimodal particle size distribution, while the others had a single mode. The >32 < 53 μm CRFP fraction had least initiation temperature (T_i = 45.82 ± 1.1 °C), concluding temperature (T_c = 59.22 ± 0.9 °C), enthalpy (ΔH = 2.94 ± 0.3 j/g) and gelatinization temperature range (ΔT = 20.90 ± 1.2 °C). Pasting temperatures showed no significant differences (P < 0.05), though the >75 μm fraction did not paste. Amylose content was highest in the finest fraction (>32 < 53 μm) and lowest in the coarsest fraction (>75 μm). Swelling capacity increased with particle size. All samples showed similar crystalline patterns characteristic of C-type starches, with the coarsest fraction displaying an additional crystalline peak. Raman spectroscopy revealed consistent structural features across all fractions. Overall, the particle size of CRFP influenced its thermo-functional properties, offering a promising approach for its industrial applications.