Physical parameters, oleoresin and volatile oil contents of five pepper (pepper Nigrum l.) cultivars as influenced by maturity

Abstract

The experiment was undertaken to identify the appropriate stage of harvesting of berries to prepare quality pepper for whole use or for extraction purpose to get better oleoresin and essential oil yield. Harvesting of berries from five pepper cultivars was carried out at 3.5, 4.5, 5.5, and 6.5 months after 70% set of the berries. The experiment was arranged in a randomized complete block design with three replications at Teppi Agricultural Research Sub-center, South-western Ethiopia. Generally, peppercorn boldness and color improved with delayed harvest; 5.5 months after fruit set being the optimum. Five of the cultivars showed comparable oleoresin and volatile oil contents. The oleoresin content ranged from 13.63 to 16.01% whereas the volatile oil content ranged from 3.18 to 3.53%. Both were found to be within the acceptable ranges. The highest oleoresin (19.41%) and volatile oil (4.95%) yields were obtained from earlier harvest (3.5 months after fruit set) and decreased as harvest stages delayed. In general, it is recommended that the spikes be harvested 3.5 months after 70% fruit set to get higher oleoresin or volatile oil yield and 5.5 months after fruit set if it is intended for use as whole or in ground form.

Keywords: Black Pepper; Essential Oil; Oleoresin; Peppercorn; Volatile Oil