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

The 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 mu m). 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 degrees 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 mu m), medium (<180 mu m), and fine (<106 mu m), 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.

Automated summary

The study investigated the impact of different particle sizes on the morphological, structural, thermal, and pasting properties of raw gorgon nut flour. The flour was divided into five size fractions (250-75 μm). XRD spectra showed strong diffraction peaks at 15 & 23 degrees and an unresolved doublet at 17 & 18 degrees, indicating an A-type crystal structure. There was a significant negative correlation between relative crystallinity and amylose content. The finer fractions of gorgon nut flour exhibited higher peak viscosity and setback, making them suitable for sauces and soups, while the coarser fractions were more appropriate for baking products with stronger dough.