Capsaicin Extraction,Isolation and Purification

Capsicum annuum L. is used world-wide as a natural condiment in food and vegetable with nutrition. Pungency (hot flavour) is the most important quality attribute of the fruit. The substances responsible for pungency are capsaicinoids which are a series of analogues differing in the structure and character. The most representative is capsaicin (69% of the total). Capsaicin is characterized by a high biological activity and is used for many industries such as pharmaceutics, food, military and so on. By the end of this time, capsaicin has been being studied by lots of scientists all over the world because of its important value. China is rich in the resource of capsicum. The study of natural capsaicin is very important for the development of the agricultural economy of our country. In this paper, on base of the modern technology of extraction and separation, the process of extraction and purification capsaicin from chilli (Capsicum annuum L. ) is studied.The work in this paper is describe as follows:(1) An accurate and rapid RP-HPLC method was established for the quantification of capsaicin. The chromatographic conditions was studied for the seperation capsaicin from other capsaicinoids.The method for quantifying capsaicin was determined by using MeOH-H₂O (70 : 30, V / V) system with 0.6 mL/min as the mobile phase, detected at 280nm, 25℃. The range of linear is enlarged. The method is rapid, accurate and reliable. At the same time, spectrophotometric analysis of capsaicin was studied for comparison with chromatography;(2)The optimum process of extracting capsaicin from chilli with ethanol was studied . The optimum extraction process was selected with orthogonal test . Experiments were made by using L₉(3⁴) orthogonal design with extractive yield of capsaicin as the index, investigating the ethanol concentration, temperature, extracting time and the ratio of solid to liquid. Optimum extraction condition was determined as follows: temperature 60℃, time 1h, 70 vol.% EtOH as extracting solvent, stock ratio 1 : 12 (m / V), three times;(3)A microwave-assisted extraction procedure was developed forcapsaicin, using a household microwave oven. Ethanol was chosen as solvent. Under appropriate MAE conditions, such as ethanol concentration of 65 vol.%, power of 455W, MAE for 2.5min, liquid/solid ratio of 10 .' 1(V / m), the extraction yield can reach high in a short time. Compared with Soxhlet extraction, ultrasonic extraction, extraction at room temperature and water heat extraction, MAE is more efficient;(4) The silica gel chromatography at normal pressure was used to purify capsaicin from Capsicum annuum L.. The operation conditions of silica gel chromatography were optimized; The capacity of loading and the increasing recovery of capsaicin were performed; The crude sample of capsaicin extracts could be separated and purified by this technology, the purity of capsaicin reached more than 93% from 25% with the recovery more than 85%; when the procedure was combined with recrystallization of petroleum ether, the purity of capsaicin can reach more than 95%;(5)The purification procedure of capsicum extraction by macro porous resins was established. NKA- II resin was found to be suitable for seperating capsaicin after experiments on six different kinds of resins. The adsorption properties of NKA- II were studied. The parameters of static and dynamic adsorption are determined.