大豆油中微量成分在精炼过程中的变化

Changes of trace components in soybean oil during refining

旨在实现大豆油的精准适度加工和开发零反式脂肪酸的双温脱臭工艺,分析了大豆油常规单温脱臭(脱臭温度240~260℃)精炼的原油、中和油、脱色油、脱臭油和降温脱臭(脱臭温度240~260℃降至220℃左右)精炼的脱臭油中生育酚、甾醇等有益微量成分和反式脂肪酸、3-氯丙醇酯等有害微量成分的含量变化。结果表明:大豆油常规单温脱臭精炼工艺下,生育酚和甾醇在各精炼工段均有损失,总损失率分别为15.01%~22.35%、11.51%~21.54%,其中生育酚主要在脱臭工段损失,损失率达10.53%~19.85%,而甾醇在中和、脱臭工段损失严重,损失率分别为5.81%~13.17%、1.22%~9.18%;精炼大豆油中反式脂肪酸含量为0.761%~1.487%;3-氯丙醇酯含量在中和工段减少,在脱色工段波动,在脱臭工段明显上升,精炼大豆油中3-氯丙醇酯含量为0.300~1.048 mg/kg;随着脱臭温度的降低,反式脂肪酸含量递减,生育酚和甾醇含量总体有所提升,当脱臭温度降至220℃时,接近零反式脂肪酸目标(<0.3%)。综上,采用先低温长时脱臭,再高温短时脱臭的双温脱臭工艺,可在保证精炼大豆油质量的同时,接近零反式脂肪酸的目标。

Aiming to achieve accurate and moderate processing of soybean oil and develop a double-temperature deodorization process with zero trans fatty acid,the content changes of beneficial trace components such as tocopherol and sterol and harmful trace components such as trans fatty acid and 3-chloropropanol ester in crude oil,neutralized oil,decolorized oil and deodorized oil refined by conventional single temperature deodorization(deodorizing temperature 240-260℃)and deodorized oil refined by cooling deodorization(deodorizing temperature 240-260℃was reduced to about 220℃)were analyzed.The results showed that under the conventional single temperature deodorization refining process,both tocopherol and sterol were lost in each refining section,with a total loss rate of 15.01%-22.35%and 11.51%-21.54%,respectively.Among them,tocopherol was mainly lost in the deodorization section,with a loss rate of 10.53%-19.85%,while sterol was severely lost in the neutralization and deodorization sections,with loss rates of 5.81%-13.17%and 1.22%-9.18%,respectively.The content of trans fatty acid in refined soybean oil ranged from 0.761%to 1.487%.The content of 3-chloropropanol ester decreased in the neutralization section,fluctuated in the decolorization section and significantly increased in the deodorization section.The content of 3-chloropropanol ester in the refined soybean oil was 0.300-1.048 mg/kg.The content of trans fatty acid decreased,and the contents of tocopherol and sterol overall increased with the decrease of deodorizing temperature.When the deodorizing temperature decreased to 220℃,the goal of zero trans fatty acid(<0.3%)of soybean oil was close to being realized.In conclusion,adopting double-temperature deodorization process of first low-temperature long-term deodorization and then high-temperature short-term deodorization can achieve the goal of zero trans fatty acid while ensuring the quality of refined soybean oil.