خانی حسین آبادچی فرهوش، و سرخ کردن فرآیندشی روغن طیکسایداری ا آنها بر پای و ترکیب گالتیک، متیلسید گالثیر ارسی تا بر383 Homepage: http://ifstrj.um.ac.ir Research Paper Investigation of the Impact of Gallic Acid, Methyl Gallate and their Combination on the Oxidative Stability of Frying Oli M. Hosseinkhani Abadchi 1 , R. Farhoosh 2 * Received: 2022.02.04 Revised: 2022.04.17 Accepted: 2022.04.26 Available Online: 2022.05.15 Introduction Thermal process is the most prominent option for treating foods. During the heat treatment, food nutrients response simultaneously but adversely under pH, temperature, moisture, and other provided conditions. It might result in an irreversible transformation of composition and structure that influences oxidative stability and sensory properties. The use of antioxidants is one of the most common methods to prevent edible oils oxidation. Safety concerns of synthetic antioxidants including tert-butylhydroquinone (TBHQ) as food additives have led to increasing demands for natural ones. Phenolic compounds such as Gallic Acid (GA) and Methyl Gallate (MG) represent to possess markedly high activity to scavenge free radicals which are among the most powerful natural sources of oxidative inhibitors in foods. Apart from their antioxidant activity, GA and MG also exhibit multiple biological characteristics such as anti- atherogenic, anti-spasmodic, and anti-microbial activities. This study aimed to investigate the oxidative stability of the in-use sunflower (S) and palm (P) oils as affected by the GA, MG, (GA+MG), and TBHQ to clarify their antioxidant behavior. Materials and Methods Antioxidants Gallic acid, Methyl gallate and TBHQ (Purity>98%) were purchased from Sigma Aldrich, USA. All solvents and chemicals were provided from Merck, Germany and Sigma Aldrich, USA with analytical grade. Antioxidant-free sunflower and palm oil were prepared from Three Goals factory, Neyshabur, and potatoes (Agria variety) from Fariman region, Khorasan Razavi. Results and Discussion Chemical changes, oxidative stability and quality indices of the in-use sunflower oil (S) and palm (P) (65:35 w.t. %) were evaluated during 8-hour heat treatment at 180 °C through GA, MG, GA/MG (25:75, 50:50 and 25:75) and TBHQ. All experiments were carried out in quadruplicate, and data were subjected to analysis of variance (One-way-ANOVA). Mean data were compared based on Duncan's multiple range test at 5% level (p<0.05). Observations of the chemical properties showed that sample S mainly contained Linoleic fatty acid (61.53%) and Oleic acid (25.50%) and for sample P, Oleic acid (41.90%) and the saturated long-chain fatty acid of Palmitic acid (38.9%). Also, the total phenolic content (TPC) and tocopherol (TTC) of sample P were 53.12 and 185)μg.g -1 (, respectively, and sample S were 36.01 and 490 )μg.g -1 (. The results of oxidation stability test were analyzed based on Carbonyl value (CV), Conjugated diene value (CDV) and acidity (FFA) parameters. According to our findings, all parameters increased significantly at different 1 and 2 -M.Sc Graduated Student and Professor, Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, respectively. (*- Corresponding Author Email: rfarhoosh@um.ac.ir) DOI: 10.22067/ifstrj.2022.75114.1144 How to cite this article: Hosseinkhani Abadchi, M., & Farhoosh, R. (2023). Investigation of the Impact of Gallic Acid, Methyl Gallate and their Combination on the Oxidative Stability of Frying Oli. Iranian Food Science and Technology Research Journal, 19(2), 383-397. (In Persian with English abstract). http://doi.org/10.22067/ifstrj.2022.75114.1144 نشری ایرانییع غذایم و صناشهای علو پژوه ه جلد19 ، شماره2 ، خرداد- تیر1402 ص.397 - 383 Iranian Food Science and Technology Research Journal Vol. 19, No. 2, May-June 2023, p. 383-397