Principal component analysis for particle size‐based classification of gorgon nut flour and their morphological, structural, thermal and pasting characteristics

Abstract

SummaryThe effect of differential particle size on morphological, structural, thermal and pasting properties of raw gorgon nut flour was studied. Flour was sieved into five size fractions (250–75 μm). XRD spectra were of “A” type with strong diffraction peaks at 15 & 23, and an unresolved doublet at 17 & 18 degree. A strong negative correlation was observed between relative crystallinity and amylose content. The peak glass transition temperature (70.13–78.81 °C) and enthalpy (12.06–60.96 J g−1) differed significantly. Among all fractions, the peak viscosity, trough viscosity, onset temperature, enthalpy, peak & conclusion temperature, and amylose content were inversely correlated to setback, breakdown, relative crystallinity, pasting temperature, and pasting time of gorgon nut flour. Principal component analysis categorised flour fractions into three distinct sub‐groups viz. coarse (<250 μm), medium (<180 μm), and fine (<106 μm), exhibiting diverse behaviour. It could be inferred that peak viscosity and setback of finer fractions could be considered as the key property of gorgon nut flour. The finer fractions may be appropriate for sauces and soups whereas, coarser fractions may be used to prepare stronger dough for baked products.