Study On Chlorophyll Content Determination And Application In Rapeseed

China is a major consumer as well as a major producer of rapeseed in the world. Rapeseed oil is our first source of oil. The annual acreage and production of rape rank first in the world. The quality and processing cost are connected by the content of chlorophyll. The chlorophyll content of rapeseed directly impact on the level and quality of rapeseed oil, which is also have relation with the processing cost. So it gets more attention by breeders and people who do oil processing.Many countries, such as Japan, Canada, Australia, have made the content of chlorophyll as an important technological basis for rapeseed gradation.High chlorophyll rapeseed may form chlorophyll without magnesium under high temperature and humidity, which, on the one hand, has impact on quality of rapeseed oil appearance, it will deepen the color as dark green and the complex technology of decoloring will increase the processing cost, on the other hand, the chlorophyll without magnesium is a photosensitizer, which can trigger radical response and promote fat oxidation reaction which results in oil rancidity metamorphism, stability reduce, greatly shorten the shelf life of products. So it is important to establish a kind of technology to detect the chlorophyll content that meet our national condition and also the international standard.In this paper, we do a research on the extraction reagents, extraction technology and the condition of detection equipment. We also establish the method of mixed solvent extraction with grinding, and multi-wavelength spectrophotometry detection. By using this method, we detected chlorophyll content of national census samples from 2004～2006 and samples which were collected abroad. The major findings of paper are as followed:1. By reasearching on extraction condition, grinding fineness, chlorophyll extraction reagent, the method of extraction, extraction time, temperature and so the stability of chlorophyll during extraction, A rapid and simple method using solvent grind coupled with ultraviolet-visible absorption spectroscopy for the analysis of chlorophyll a rapeseed is presented. when the sample grinding fineness is 40 mesh, extract the chlorophyll by petroleum ether mixed with ethanol, add grinding ball into the special stainless steel, shock aclinicly for an hour by shocker, filtrate it by the medium speed qualitative filter and then, detect the absorbance using spectrophotometer at the wavelength of 625nm, 665nm and 705nm. Under optimum condition,the reproducibility of the method was 1.62%A for chlorophyll a.The detection limit(3d)was 0155 mg/L for chlorophyll a. The recovery was in a range of 94.4～98.0%.Meanwhile, the performance of the method was compared with the traditional method and excellent agreements were observed between the methods. The method have been promulgate as a Chinese agricultural standard: NY/T1287-2007《Rapeseed—Determination of chlorophyll content—Spectrometric method》.2. Using the established standard method, tested the 120 samples of rapeseed which collected from the main producing areas in China and 26 different rapeseeds which collected from the main producing countries such as Canada, Australia, analyzed and compared the chlorophyll content of rapeseed with different cultivated regions in China, different kinds of seed capsule color, different harvest years of domestic and oreign, initially proved the difference and the distribution of chlorophyll content,chlorophyll content. The chlorophyll content of winter rapeseed is 1～10 mg/kg was significantly lower than the chlorophyll contentof spring rapeseed which is 10～40 mg/kg. The colour of rapeseed coat with different kinds have little influence to the chlorophyll, however, the chlorophyll content of China rapeseed was significantly lower than that of Canada, Australia and other countries. This paper also discussed the impact of the determination of reasons.