精炼工艺对玉米油微量成分变化的影响

以在超级脱胶结合白土预脱色-复脱色以及双塔脱臭脱酸工艺生产线上取样的玉米毛油、脱胶油、脱蜡油、脱色油、脱臭油为研究对象,对其游离脂肪酸、磷、金属离子、色素、生育酚含量及过氧化值进行测定,考察精炼工艺对玉米油微量成分变化的影响。结果表明:双塔脱臭脱酸工艺可以明显降低玉米油中游离脂肪酸含量;超级脱胶工艺可去除玉米油中约95%的磷脂;脱胶和脱色可明显降低金属离子含量;大部分色素在脱色工段被去除;经脱臭后,成品油中总生育酚损失19. 9%;脱胶使玉米油过氧化值升高,脱色和脱臭可使过氧化值明显降低。说明应根据玉米毛油品质选择合适的精炼工艺,以最大限度地保留有益微量成分,去除有害成分,做到适度精炼。

Effects of refining process on trace components in corn oil

With corn oil samples including crude oil, degummed oil, dewaxed oil, bleached oil and deodorized oil from production line of super degumming combined with pre-bleaching-re-bleaching, deodorization and deacidfication using twin towers as research subjects, the contents of free fatty acid, phosphorus, metal ions, pigment and tocopherol, and peroxide value were determined in order to investigate the effects of refining process on trace components in corn oil. The results showed that free fatty acid content decreased obviously after deodorization and deacidification using twin towers. About 95% phospholipids were removed after super degumming. The contents of metal ions decreased obviously after degumming and bleaching. Most pigment was removed after bleaching. After deodorization, 19.9% tocopherol was lost. The peroxide value increased after degumming, but it significantly decreased after deodorization and bleaching. Therefore, suitable refining process should be selected according to the quality of crude oil. In this way, benefit minor compounds could be reserved, simultaneously, harmful minor compounds were removed, and moderate refining was achieved.