Study On The Accuate Determining Methods Of Rapeseed Oil Content

The rapeseed is one of the most important four greatest oil crops in our country. That rapeseed oil accounts for above 35% of our country people edible consuming plant oil. It is the most important and edible plant oil of our country. So improving the rapeseed determining level is of greatly practical significance to developing the rapeseed production of our country and to promoting the rapeseed import and export trade. This text is mainly to do a complete introduction and comparison of rapeseed determining method and its applied values, do the best for the improvement of our country rapeseed determining method with oil content.This thesis made use of a 3 levels+ a completely random combination design, and taking the main four factors that affected determining result of Soxhlet extractor method as the decision factor. That main four factor include specimen degree of thickness( namely the screen size, from thick to thin is 20#,30#,40#,50#,60#), extraction time( from short to long is 6h, 8 h, 10 h), the extraction dissolvent[ anhydrous ether, petroleum ether(60℃ -90 ℃ ), petroleum ether(30℃ -60℃ )] and the breed which oil content is different from low to high is V01, V02, V09). Then we study the accuracy and reliability of GB determining oil content method in detail. Finally, we draw the conclusion as follows:1, On the condition of different extraction dissolvent and different extraction time, The determining result of varying specimen that contain the high and low oil content breed would take on the trend from low to high in pace with the change of screen size from thick to thin. But after 50#, the result would take on the different trend. Some assume the trend go up, others are on the contrary.2, On the condition of different extraction time and different screen size, The determining result of varying specimen that contain the high and low oil content breed would take on the trend------anhydrous ether> petroleum ether(60 ℃ -90 ℃ )> the petroleum ether(30 ℃ -60 ℃ ),according to the varying of extraction dissolvent. That is, the best extraction dissolvent is anhydrous ether, then petroleum ether (60 ℃ -90 *C); the last bad one is petroleum ether (30 ℃ -60 ℃).3,On the condition of different extraction dissolvent and different screen size, The determining result of varying specimen that contain the high and low oil content breed would take onthe trend------10 h>8 h> 6h in pace with the varying of extraction time. That mean, at the rangefrom 6h to 8h, the extraction effect becomes more and better.4, During determining process, The experiment result shows that extraction result have the relation to soak time, if soak time is elongated, the determining result may have marked improvement.5, To sum the result of multiple-factor or factorial experiment, at the prerequisite of unknown oil content rapseed , the best determine condition is using anhydrous ether to extract the 50# specimen in 10h.So auther consider the GB method should be amended to adept the need of high oil content breeding and international market competition.Through the contrast of GB method and the method that let the intact seed was extracted first, and then grind into fine powder. We can find out that the second method would decend the final result to the low oil content variety, such as V01; but to the medium and high oil content breed, such as V02, V09, it would improve effect. So we suggest that use second method to test the seed to high oil content specimen.This study contrast Chinese determining oil content method------GB/ T 2906 — 1982 andJapanese standard grease analysis method 1.5 —1996 which is compiled by Japan oil and chemistry institute. Through the contrast of result, we find out that the Japanese results are always higher than Chinese. Investigating its reason, maybe there are some reasons as follows: (1) Extraction number is different. Our country adopt the method that extract the seed in an at one time on the condition of 105 ℃s, ones hour drying. Otherwise, what Japan uses two-stage extraction methods, every time only use 4h to extract seed. It may increase the result after two times extraction.(2)The Japanese sample thickness degree is thiner. It is a main reason for existing difference in result. (3) The calculation formula is different. So, through the study, the author suggests that we should make the advantage of Japanese two-stage extraction method to improve the GB method.We use Soxhlet Extractor Method as the standard determining oil content method, to study the accuracy and reliability of Nuclear Magnetism Resonance Method and Near Infrared Spectroscopy Method in detail. Then find out: The Nuclear Magnetism Resonance Method technology is maturater as long as controlling the determination condition strictly.the result of it is in accord with GB method; Near Infrared Spectroscopy Method have some advantage,such as little sample dosage, determining speed is faster and not need damnify the sample. But the accuracy of determining result needs to make the further verification. So we need use the GB method in the...