Thermal-Oxidation Stability of Soybean Germ Phytosterols in Different Lipid Matrixes

• Main Authors: Jingnan Chen, Dami Li, Guiyun Tang, Jinfen Zhou, Wei Liu, Yanlan Bi
• Format: Article
• Language: English
• Published: MDPI AG 2020-09-01
• Series: Molecules
• Subjects: soybean germ phytosterols; phytosterols oxidation products; thermal-oxidation stability; lipids medium
• Online Access: https://www.mdpi.com/1420-3049/25/18/4079

The stability of soybean germ phytosterols (SGPs) in different lipid matrixes, including soybean germ oil, olive oil, and lard, was studied at 120, 150, and 180 °C. Results on the loss rate demonstrated that SGPs were most stable in olive oil, followed by soybean germ oil, and lard in a decreasing order. It is most likely that unsaturated fatty acids could oxidize first, compete with consumption of oxygen, and then spare phytosterols from oxidation. The oxidation products of SGP_S in non-oil and oil systems were also quantified. The results demonstrated that at relatively lower temperatures (120 and 150 °C), SGPs’ oxidation products were produced the most in the non-oil system, followed by lard, soybean germ oil, and olive oil. This was consistent with the loss rate pattern of SGPs. At a relatively higher temperature of 180 °C, the formation of SGPs’ oxidation products in soybean germ oil was quantitatively the same as that in lard, implying that the temperature became a dominative factor rather than the content of unsaturated fatty acids of lipid matrixes in the oxidation of SGPs.