Studies on Blackening of Pepper (Piper nigrum, Linn) During Dehydration



Histochemical studies carried out in fresh green pepper berries at different stages of maturity showed that phenolic compounds distributed throughout the berries at a very young stage were confined to the epicarp and mesocarp alone at full maturity. The blackening that occurs in pepper on drying or on injury also showed a similar distribution pattern. Flavanols were not found in the young stage but appeared in the innermost cells of mesocarp covering endocarp after fertilization. Spores of Glomerella cingulata, present even in healthy pepper berries, were found to be the source of phenolase enzyme taking part in the blackening. Phenols in pepper were enzymatically oxidized and gave rise to black color when the cells were disturbed by dehydration or maceration.