Study Of Sources And Preventive Measures Of Phthalic Acid Esters In Oil-tea Camellia Seed Oil

PAEs has become a global enviromental pollutants, which is widely existed in air, soil, water, vegetables, fruits, edible oil and so on. In this work, the content and the sources of 6 PAEs in camellia oil were analyzed among the raw seeds, refining, packaging materials of oil by GC. The control measures were discussed. The main results are as follows:1. A method for the simultaneous determination of 6 phthalate acid esters in oil-tea camellia seed oil samples by GC-FID was developed. The six PAEs had a good linear range from 0.1 μg/mL to 14.0 μg/mL, with the correlation coefficients(R2) all above 0.999. The limits of detection of phthalate acid esters in oil-tea camellia seed oil samples ranged from 0.03 μg/mL to 0.05 μg/mL(S/N=3) and the limits of quantification ranged from 0.09 μg/mL to 0.11 μg/mL (S/N=10). The average recoveries of the six targets in spiked oil-tea camellia seed oil ranged from 71.6% to 107.5% with the relative standard deviations (RSDs) from 1.5% to 8.8%.2. In order to analyze the characteristics of phthalic acid esters (PAEs) and the source of PAEs in oil-tea camellia seed,16 samples of oil-tea camellia seed obtained from different regions in China and 9 samples collected from different species were determined. The results indicated that DIBP, DBP and DEHP mainly existed in samples from different regions. The average EPAEs concentrations in oil-tea camellia seed shell are 3.72 mg/kg, which significantly higher than oil-tea camellia seed kernel with the average EPAFs concentrations of 0.144 mg/kg. The pollution of PAEs in oil-tea camellia seed shell is more serious than kernel. The oil-tea camellia fruit has been polluted by the PAEs from environment when it is still in growth. There is a significant difference for single PAE compound accumulated by different parts of oil-tea camellia seed. The average contents of DIBP and DEHP in oil-tea camellia fruit shell is significantly higher than those both in pericarp and kernel. The average content of DIBP in oil-tea camellia fruit shell, pericarp and kernel respectively is 0.051、0.120、0.027 mg/kg. The average content of DEHP in oil-tea camellia fruit shell, pericarp and kernel respectively is 0.035、 0.195、0.053 mg/kg.3. The changes of the content of phthalic acid esters (PAEs) in oil-tea camellia seed oil after different refining process were studied in this paper. The sources that may cause the increase of PAEs content in oil-tea camellia seed oil during refining process were explored on that basis. The results showed that, neutralization and water scrubbing hardly had effect on the content of PAEs in oil-tea camellia seed oil. But the filtering operations of decoloration and winterization will cause the increase of contents of DIBP, DBP and DEHP in different degrees. It was found that filter paper and filter cloth is the main sources of the DIBP, DBP and DEHP. However, the deodorization could decrease the content of PAEs in oil-tea camellia seed oil effectively. After deodorization, the content of DIBP, DBP and DEHP in oil-tea camellia seed oil decreased respectively by 86.2%-97.3%,85.6%～91.7% and 53.2%～76.7%.4.11 samples of oil-tea camellia seed oil were examined by the developed method, the results showed that commercially available oil-tea camellia seed oil contain different levels of DIBP, DBP and DEHP, DBP and DEHP in some of the oil-tea camellia seed oil exceed the requirements. PAEs in the oil-tea camellia seed oil is not entirely from the packaging of plastic, in the production and processing process has been PAEs to move into the oil-tea camellia seed oil. Besides, the impact of plastic packaging for PAEs in oil-tea camellia seed was studied based on the comparison of two experiments. The results indicated that the plastic packaging increases the content of ∑PAEs in oil-tea camellia seed shell. The average content of ∑PAEs in oil-tea camellia seed shell that stored at room temperature with plastic woven bag packaging is increased by 0.056 mg/kg, and it is increased by 0.142 mg/kg that stored at high temperature. High temperature promotes the migration of PAEs from plastic materials to oil-tea camellia seed shell.