A Method Research For Determination Of Colourants And Natural Antioxidant Tea Polyphenol In Foods

Food safety problem is an important issue related to the people health in China, also a subject area under continuous attentions in recent years. As the emphasis, the food additive abuse problem, especially the method research for determination of colorants and antioxidants as additives in foods, was emphatically researched in this paper. This paper based on Ultra-high pressure liquid chromatography coupled with ultraviolet detector (UHPLC-UV) and tandem mass spectrometry detector (UHPLC-MS/MS) developed the determination methods of 4 natural pigments,6 artificial colorants and natural antioxidant tea polyphenol in foods. And an innovative pretreatment method based on homemade macroporous resin Solid-phase Extraction (SPE) column was established. The mass fragmentation mechanism and antioxidant activity of natural pigment Carthamins Yellow was also researched in the paper. This paper included 6 parts as follows. 1. The ultra-high pressure liquid chromatography coupled with UV detector and tandem mass was employed for the identification of Carthamins Yellow (CY). According to the Selection Electron Monitoring (SIR) mode chromatogram and tandem mass fragmentation analyses, it was found that the Carthamins Yellow extract mainly consisted of Hydroxysafflor yellow A (34.0%), Safflor Yellow A (27.4%), Anhydrosafflor yellow B (23.2%) and Safflomin C (8.3%). The relative quantities of each component are figured out by area normalization method. Using DPPH·method with the standard matter of Vc to measure the antioxidant activities of CY by UV spectrophotometer. The conclusion was figured out that the antioxidant activities of Vc was 23.36 times of CY. A method based on SPE-UHPLC was established to determinate the four components of Carthamins Yellow in sodas and fruit drinks. SPE column was made by using macroporous resin as filler to absorb and desorb Carthamins Yellow during the pretreatment. The recoveries of each component were between 92% and 116% and R.S.D.s varied from 0.78% to 6.64%.2. Crocin Yellow was determined in soft drinks, sausages and sauces by ultra-high pressure liquid chromatography coupled with ultraviolet detector and analyzed within 5 min. An innovative pretreatment method based on homemade macroporous resin Solid-phase Extraction (SPE) column was established. The SPE column packed with macroporous resins could simplify the sample preparation of multi-matrices and be reused by regeneration steps. Through optimization of solid-phase extraction conditions, the recoveries of Crocin Yellow added to soft drinks, sausages and sauces at three levels ranged from 81.3% to 106.2% and relative standard deviations (R.S.D.s) were within 8.8%. The limits of quantitation of soft drinks, sausages and sauces were 0.5 mg/kg,5 mg/kg and 5mg/kg respectively. The method can satisfy the requirements of domestic detection of crocin yellow.3. The ultra-high pressure liquid chromatography coupled with UV detector and tandem mass was employed for the determination of Black Bean Red and Basella rubra L. Red in soft drinks, sausages and sauces. The pretreatment method was simple. Soft drink samples were diluted with water directly. Sausage and sauce samples were extracted with 0.05% formic acid solution, and petroleum ether was used to remove the fats and oils. Multiple reaction monitoring (MRM) scan mode of the tandem mass detector and UV detector were used to detect Basella rubra L. Red and Black Bean Red. The recoveries of Basella rubra L. Red added to soft drinks, sausages and sauces at three levels ranged from 89.1% to 106.7% and relative standard deviations (R.S.D.s) were within 9.2%, and the recoveries of Black Bean Red ranged from 78.2% to 102.2% and R.S.D.s were within 4.6%.4. The ultra-high pressure liquid chromatography coupled with UV detector was employed for the determination of 5 synthetic pigments in soda drinks. The pretreatment method was the Solid-phase matrix scattered extraction used by polyamide resin powder. The polyamide resin powder adsorbed with synthetic pigments was washed by citric acid solution and methanol:formic acid=6:4 (volume ratio) solution successively. The eluent of 5 synthetic pigments was dried with nitrogen, volumed and then detected by UHPLC-UV. The recoveries of 5 synthetic pigments added to soda drinks at three levels ranged from 83.37% to 106.9% and relative standard deviations (R.S.D.s) were within 6.3%.5. The ultra-high pressure liquid chromatography coupled with mass detector was employed for the determination of Quinoline Yellow in alcoholic beverage and fruit juice samples. The pretreatment method was the solid-phase matrix scattered extraction used by polyamide resin powder. The polyamide resin powder adsorbed with Quinoline Yellow was washed by 1% acetic acid solution and water successively. And Quinoline Yellow was washed off by ethanol:ammonia:water=7:2:1 (volume ratio) solution. The eluent of Quinoline Yellow was dried with nitrogen, volumed and then detected by UHPLC-MS under selective ion reaction (SIR) scan mode. It was found that Quinoline Yellow contained 4 main components KL-1,KL-2,KL-3 and KL-4. The recoveries of 4 components of Quinoline Yellow added to alcoholic beverage at three levels ranged from 69.74% to 108.81% and relative standard deviations (R.S.D.s) were within 6.5%, and the recoveries of 4 components added to fruit juice samples ranged from 69.32% to 104.93% and R.S.D.s were within 7.2%.6. The ultra-high pressure liquid chromatography coupled with tandem mass was employed for the determination of tea polyphenol in meat products, meat enemas and sauces. The pretreatment method was that solid matrices were extracted with 5% methanol solution through the process of vortex and ultrasonic twice. The extractive liquor was treated by centrifugation and constant volume. Petroleum ether was used to remove the fats and oils. Multiple reactions monitoring (MRM) scan mode of the tandem mass detector was used to detect the 3 components of tea polyphenol. The recoveries of the components of tea polyphenol besides of EGCG added to meat products at three and four levels ranged from 77.90% to 103.52% and relative standard deviations (R.S.D.s) were within 8.3%, and the recoveries of 3 components added to meat enemas ranged from 69.11% to 123.56% and R.S.D.s were within 9.9%, and the recoveries of 3 components added to sauces ranged from 70.43% to 94.18% and R.S.D.s were within 12.1%.