Changes of trace components in soybean oil during refining
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.
soybean oilconventional single temperature deodorizationcooling deodorizationtrace componentzero trans fatty acid