Comparative Antioxidant and Protective Effects of Ultrasound-Assisted Ethanolic and Aqueous Extracts of Silybum marianum Seeds versus Silymarin Against Heat-Induced Oxidation in Soybean Oil

Beheshti Saravi, Mehdi; Golestan, Leila; Ebrahimzadeh, Mohammad Ali

doi:10.22034/jfss.2026.598473.1024

Comparative Antioxidant and Protective Effects of Ultrasound-Assisted Ethanolic and Aqueous Extracts of Silybum marianum Seeds versus Silymarin Against Heat-Induced Oxidation in Soybean Oil

Articles in Press

Document Type : Original Article

Authors

Mehdi Beheshti Saravi ¹

leila golestan ²

Mohammad Ali Ebrahimzadeh ¹

¹ Department of Food Science and Technology, Ayatollah Amoli Branch, Islamic Azad University, Amol, Iran

² Department of Food hygiene, SR.C.,Islamic Azad University, Tehran, Iran.

10.22034/jfss.2026.598473.1024

Abstract

Lipid oxidation is a major challenge in maintaining the quality of polyunsaturated fatty acid-rich oils such as soybean oil. Oxidation can cause rancid flavors, nutrient loss, and formation of undesirable secondary products during storage and heating. Although synthetic antioxidants such as BHA can delay oxidation, the search for plant-based antioxidants has increased. Silybum marianum seeds contain phenolic compounds and flavonolignans, but limited information is available on whether ultrasound-assisted aqueous and ethanolic seed extracts can protect soybean oil against heat-induced oxidation in comparison with purified silymarin and BHA. Therefore, this study evaluated UAE-prepared aqueous and ethanolic extracts of S. marianum seeds, their in vitro antioxidant activities, and their protective effects in soybean oil during accelerated oxidation at 70 °C for 12 days. The ethanolic extract showed higher total phenolic and flavonoid contents than the aqueous extract. Silymarin showed the strongest activity in the in vitro assays, while the ethanolic extract generally showed greater activity than the aqueous extract. In the oil system, the 800 ppm ethanolic extract produced the lowest peroxide value throughout storage and reduced the day-12 peroxide value to 94.12 meq O₂/kg, compared with 255.20 meq O₂/kg in the control. It also showed the strongest inhibition of secondary oxidation and the slowest increase in acid value among the extract treatments. Overall, the results indicate that ultrasound-assisted ethanolic extraction of S. marianum seeds can provide an effective plant-based antioxidant for improving the oxidative stability of soybean oil under accelerated heating conditions.

Graphical Abstract