| Phthalic acid esters(PAEs)is an environmental hormone substance,although there is no acute toxicity to the human body,the long-term accumulation of chronic toxicity in the human body,especially the toxicity of reproductive development can not be ignored.In the study of the contamination of PAEs in edible oils,it is found that,whether it is oil raw materials,or in the process of edible oil processing and production,vegetable oil will inevitably be contaminated by PAEs,resulting in the consumption of edible vegetable oil products in the PAEs exceeding the standard.Therefore,the study on the removal of PAEs from edible vegetable oil is of great significance to ensure the safety of edible oils.In this paper,the steam distillation deodorization of sunflower seed oil under different steam distillation conditions was carried out firstly,the effects of deodorization temperature and deodorization time on the removal rates of PAEs in sunflower seed oil and the steam distillation deodorization conditions based on different degree of removal of PAEs were studied.The result showed that deodorization temperature and deodorization time had a significant effect on the removal rate of PAEs and PAHs,VE and sterol retention rates,and the generation rate of trans fatty acid(TFA)in the fixed vacuum and steam quantity.At the laboratory level,the optimum deodorization conditions of 260 ?,40 min and 220-240 ?,100 min,can make the residual amounts of PAEs and PAHs in sunflower seed oil lower,BaP and PAH4 residues were in line with the national standard limit,taking into account the high retention rate of VE and sterols and the low generation rate of trans fatty acids,at the same time,the value of acid,peroxide,smoke point,color have reached the national standard of sunflower seed primary oil quality requirements;After 260 ?,100 min deodorization,the residual amount of BaP and PAEs was lower than the EU limit,and the PAEs and PAHs in oil were removed deeply,and high quality sunflower seed oil was obtained.Secondly,the effects of two stages steam distillation(SD2)and two stages molecular distillation(MD2)on phthalic acid esters(PAEs)elimination were investigated and compared in the present work using sea buckthorn(Hippophae rhamnoides L.)pulp oil,which was heavily polluted by plasticizer,as raw material.After SD2,the DBP residue was 0.293 mg/kg,significantly lower than the national standard limit level,DEHP residue was 3.700 mg/kg,still higher than the national standard limit level;after treated with MD2,the concentrations of DBP and DINP could be lowered below the limit values set by China,even if the initial concentrations of DBP and DEHP in R-SPO were 1.626 and 10.933 mg/kg respectively.Results show that compared to SD2,MD2 could remove the high concentration of PAEs from SPO effectively,and had a good removal effect on other harmful components such as PAHs,3-MCPDEs and GEs from edible vegetable oil,and there was no significant change in fat fatty acid composition of oil samples.However,it would cause more serious loss of the nutrients such as VE,sterols and flavonoids in SPO.The results indicated the precise removal technology of PAEs in edible vegetable oil with high concentration of PAEs,which was of great significance to the development of oil precision processing technology and the improvement of the safety quality of edible vegetable oil.Then,using ethanol as extraction solvent,the liquid-liquid extraction of PAEs in edible vegetable oil was carried out,and the effects of ethanol extraction on the content of active components such as VE and sterols in oil were investigated,as well as the influence of the content of harmful factors such as trans fatty acids,in order to find the method of removing high concentration PAEs in oil except distillation.Liquid-liquid extraction and removal of PAEs from edible vegetable oil was carried out with 95 ethanol used as extraction solvent,and the liquid ratio,extraction temperature,extraction time and extraction times of the extract were optimized by single factor test and orthogonal test.The results showed that under the condition that the material liquid ratio was 1:5,the temperature was 55 ?,and the time of was 50 min,three times solvent extraction could remove 96% DBP and 93% DEHP from edible vegetable oil.In order to reduce the influence of adsorbent on the removal effect of PAEs for edible vegetable oil,ethanol was used to extract the PAEs in the adsorbent and purify the adsorbent,and the residual amounts of DBP,DEHP,DINP,and ?8PAEs in H-2 activated carbon were reduced to 0.546,0.476,0.673,and 2.691 mg/kg respectively after extraction and purification three times under the condition of material liquid ratio 1:5,temperature 55 ? and time 50 min.Compared with the non-purified activated carbon,the removal rate of DBP,DEHP,DINP and ?8PAEs with purified activated carbon under the same decolorization process conditions increased by 17,33,25,and 25 percentage points respectively.Through solvent purification adsorbent,the removal efficiency of PAEs in adsorption decolorization process can be improved.On the conclution,the deodorization temperature and deodorization time had a significant effect on the comprehensive quality of sunflower seed oil,and the removal rates of PAEs would increased and the retention rate of nutrient would decreased with the increasing of deodorization temperature and prolonging of deodorization time;compared with SD,MD had increased the efficiency of the removal rates of PAEs from edible oil significantly,and the other harmful components in oil samples such as PAHs,3-MCPDEs,and GEs could be removed better,but that would cause serious loss of vitamin E,sterols and other nutrients in the oil;liquid-liquid extraction by ethanol can remove the PAEs effectively from the edible vegetable oil under optimal conditions and,it has been proven that extracted solvent ethanol can be recycly used.But,this method also caused the loss of vitamin E,sterols and other nutrients in edible oil;the removal rates of PAEs for edible oil during decolorization process can be improved by extracting and purifying the adsorbent with ethanol.The results of this paper provide a selection basis for the removal methods of different PAEs pollution levels from edible vegetable oil,which is of great significance for optimizing the production process and ensuring the quality and safety of edible oil. |
PDF Full Text Request