Appropriate Harvesting Stage of Long Pepper (Piper retrofractum Vahl) to achieve Thai Herbal Phamacopeia

Abstract

Long pepper (Piper retrofractum Vahl) has been used as herb and spice for centuries in many countries, including Thailand. The aim of this study was to determine the appropriate harvesting stage for long peppers which provides an optimum characteristics and chemical properties as stated Thai Herbal Phamacopoeia. The experiment was conducted at The Eastern Fruit Tree Development Center, Chanthaburi Province during December 2014-April 2015. The long pepper fruits were harvested at four different stages of maturation; green (91-98 days), orangish green (99-104 day), greenish orange (105-112 days) and orange (113-119 days). The fruits were collected to determine both physical and chemical properties. Their qualities were compared with standard of long peper mentloned in the Thai Herbal Phamacopoeia. Results showed that the size of dry green, orangish green, greenish orange and orange colour fruits in length were 3.7-3.8 cm and in diameter were 5.8, 6.3, 6.8 and 7.1 mm respectively. Quality of most long pepper in this study achieved the Thai Herbal Phamacopoeia. However, the green harvesting stage showed better properties than the others especially water soluble extractive, ethanol extractive and piperine. Its chemical contents in moisture, total ash, acid insoluble ash, water soluble ash, water soluble extractive, ethanol extractive, volatile oil, and piperine were 6.07% (w/w), 5.7% (w/w), 0.2% (w/w), 2.1% (w/w), 15.7% (w/w), 10.1% (w/w), 0.5% (w/v), 3.91% (w/w), respectively.