Analysis On The Quality And Safety Of Fish Oil In Refining Process

Fish oil contains EPA,DHA and other polyunsaturated fatty acids,which has a wide application prospect in the field of food,health care products and medicine,etc.Refining is the key procedure in the fish oil processing,with the improvement of living standards,a better refining technology is needed to satisfy people's higher demand of it's quality.For this,this paper mainly studied the variation of main nutrients in fish oil and the safety evaluation,aimming to provide a theoretical basis for fish oil refining,results are as follows:?1?With the refining process,the moisture content,acid value?AV?,peroxide value?POV?,thiobarbituric acid value?TBA?,unsaponifiables had a declining trend,while the iodine value?IV?,saponification value had a arising trend.The deacidification process and decoloring process had a significant impact on the physicochemical properties of fish oil.The physicochemical properties of refined fish oil were as followed:moisture content of 0.08%,AV of 0.51 mgKOH/g,IV of 139.67 g/100g,POV of 0.65 mmol/Kg,TBA of 0.148 mg/Kg,saponification value of 97.12 mg/g,unsaponifiables of 0.82%,which attained the first level of polyene fish oil industry.?2?Studied the variation of vitamins and fatty acids in fish oil during refining process,the results showed that:vitamins decreased with the refining proceeding and the contents of VD₂,VD₃ and VE in refined fish oil were 0.004 mg/100mg,0.001mg/100mg and 0.7 mg/100mg,respectively.Fish oil contains 20 kinds of fatty acids,including 7 kinds of saturated fatty acids,4 kinds of monounsaturated fatty acids and 9kinds of polyunsaturated fatty acids.All these fatty acids changed little with the refining process,which showed the refining process didn't have much impact on them.And in the refined oil,the content of EPA is about 10%,the content of DHA is about 16%.?3?With fish oil refining proceeding,cholesterol decreased,the removal rate was57.6%,while the total acid removal rate of the total cholic acid was 97%.Trans fatty acids content rised from 0.21%?crude oil?to 1.42%?refined oil?.The refining temperature and time had a significant influence on trans fatty acids.Heavy metals arsenic?As?,cadmium?Cd?,lead?Pb?and mercury?Hg?decreased with the refining process,refined oil reached the standard of fish oil industry.?4?Sudied the variation of Polychlorinated biphenyls?PCBs?and organochlorine pesticides?OCPs?in the fish oil refining process by Gas chromatography-mass spectrometry?GC-MS?.Both materials were not found in fish oil,which showed the fish oil was not contaminated.?5?Three plasticizers of DIB,DBP and DEHP were detected in fish oil,the contents of them in crude oil were 0.06 mg/kg,0.05mg/kg and 0.04 mg/kg and with the refining process going,they rised.In refined fish oil,the contents of them were0.19mg/kg,0.24mg/kg and 0.06 mg/kg.We found that industrial additives used in the refining process were the main pollution sources.?6?The effects of light,temperature,oxygen on oxidation stability of refined fish oil were studied,results were as follows:Light was the main factor in the impact of fish oil oxidation,under the action of light,the acid value?AV?rose from 0.66 mgKOH/g to8.59 mgKOH/g,peroxide value?POV?rose from 0.83 mmol/Kg to 28.8 mmol/Kg,TBA rose from 0.16 mg/Kg to 1.52 mg/Kg,whereas iodine value?IV?decreased from136.2g/100g to 101.6 g/100g,and natural light was greater than the direct light.Temperature was another main factor affecting oxidation of fish oil.The AV rose from 0.66 mg KOH/g to 2.88mgKOH/g,POV rose from 0.83 mmol/Kg to 5.23mmol/Kg,TBA incresed from 0.16 mg/Kg to 0.45 mg/Kg,while IV decreased from136.2 g/100g to 123.1g/100g.Under the participation of oxygen,the acid value of fish oil rose to 3.42 mg KOH/g from 0.66 mg KOH/g,POV rose from 0.83 mmol/Kg to 7.11 mmol/Kg,TBA incresed from 0.16 mg/Kg to 0.52 mg/Kg,while IV decreased from 136.2 g/100g to 120.1g/100g.