Effect of sieve particle size on functional, thermal, rheological and pasting properties of Indian and Turkish lentil flour

Abstract

The influence of particle size (74–210 μm) on compositional, functional, rheological, thermal and pasting properties of two commercial lentil flour samples (Indian and Turkish) was investigated. Reduction of particle size significantly affected the composition of the flour. Turkish lentil flour fractions had higher bulk density (480–600 kg/m3) than Indian one. Particle size did not influence the water holding capacity of flour, however, the process temperature increased those parameters significantly. Instrumental color parameters a and b reduced abruptly and the lightness value, L increased while the particle size was reduced from 210 to 74 μm. Laser diffraction analysis showed bimodal particle size distributions of lentil flour. Two distinct thermal transitions exhibited by lentil samples and the glass transition temperature varied among samples. Non-isothermal heating of lentil particle dispersions demonstrated a gradual decrease in the peak complex viscosity with decreasing particle size. Pasting parameters and micrographs of lentil fractions showed a significant difference between two samples. The obtained results could be useful for the food industry to manufacture lentil-based food products with a defined particle size to obtain desirable functional and rheological characteristics.