Pericarp as a new berry trait to define dry recovery and quality in black pepper (Piper nigrum L.)

Abstract

Black pepper is one of the oldest known spices cultivated for its berries. Pericarp is considered as a significant determinant of colour intensity, texture and yield of black pepper. However, pericarp thickness has not yet received its due importance as a trait selection criterion in breeding black pepper for enhanced productivity and quality. In this study, we examined the hypothesis that thick pericarp is associated with high dry berry recovery without any reduction in primary (starch, protein and reducing sugars) and secondary metabolite contents (piperine, oleoresin and phenols) in the pericarp, which imparts odour, flavour and pungency for which black pepper is known for. Eighteen black pepper genotypes were characterised for pericarp thickness, dry recovery and biochemical constituents such as piperine, oleoresin, protein, phenols, reducing sugars and starch content in pericarp and grouped them into thin and thick pericarp groups. Pericarp thickness ranged from 1.22 to 2.04 mm and pericarp dry recovery from 26.30 to 43.24 %. The pericarp contained 0.38 to 0.66 % and 1.60–4.35% of piperine and oleoresin, respectively. Wide variation was also observed for phenols, protein, reducing sugars and starch content in pericarp. Pericarp fresh weight, dry recovery, piperine and starch content differed significantly between thin and thick pericarp group genotypes. Thin pericarp in black pepper is more advantageous than thick pericarp for realizing high dry recovery (%). For white pepper production thin pericarp genotypes may have advantage in terms of recovery and processing as there is hardly any difference between thin and thick pericarp for primary and secondary metabolite contents.