Study On Preparation Technology And Analytical Method Of Lycopene

Lycopene as one of the carotenoids is an efficient antioxidant that quenches single oxygen and free radical. In this work, the extracting conditions of lycopene oleoresion have been investigated, the purification and the analytical method of lycopene have been established, and the stability of lycopene has been studied. The conclusions are as follows:1. The factors that effected results of the extraction of lycopene oleoresion from tomato paste were extracting agent, extracting time, extracting temperature, mass ratio of liquid-solid. The experiment results showed that ethyl acetate is a good extractant The suitable extracting conditions of lycopene oleoresion have been obtained: the sugar in tomato paste is removed by 95% alcohol; the extracting temperature is 50℃; The extracting time is 30min; the mass ratio of ethyl acetate and tomato paste is 3:1. The results gained showed that the extracting technology of lycopene oleoresion could be applied to industrial production.2. The preparation and purification of lycopene from tomato paste have been studied by column chromatography using PRP-6 resin as adsorbing material with 50-80 μ m granularity and 20-30nm aperture.The rough lycopene prepared through extraction, freeze, crystallization, and filtration was separated by column chromatography. The eluent was the mixture of alcohol-dichloromethane (V/V, 1:9, 3:7, 5:5), The needle lycopene was obtained from the eluent kept in refrigerator (<12℃) for 8h. The trans-lycopene has been characterized by UV-Vis, HPLC, IR, MS, and NMR. The mass percentage of lycopene is 99.8%. The resolution ratio of lycopene on the PRP-6 resin is 90%.3. The novel analytical method of lycopene by HPLC was established using Sudan Ⅰ as standard substance in place of lycopene. The linear ranges of calibration curves of lycopene and Sudan Ⅰ are 0~ 42 μ g/ml and 0~38 μ g/ ml respectively. The slope relationship between Sudan Ⅰ and lycopene is 3.857. The relative standard deviation is 1.8%~4.1%, and the recovery is 101%-112%. The determination results of some samples by this method are identical with the results by External Standard Method.4. The stability of lycopene has been investigated in detail. It has been proved by the study that lycopene is degraded sharply in either chlorhydric acid solution or in the sodium hydrate solution. Vitamin C, vitamin E, and BHT can not protect lycopene from degradation. In the same environment, the stability of lycopene oleoresion is superior to that of lycopene.