This study investigated the effects of replacing beef fat with walnut oil and walnut cake on the fatty acid composition and nutritional value of beef patties. Nine groups were prepared: four with differing levels of walnut oil, four with walnut cake, and one control without substitution. Fatty acid composition was determined by gas chromatography, and nutritional indices were cal- culated. Substitution with walnut derivatives reduced saturated fatty acids (SFA) and increased unsaturated fatty acids (UFA), including both monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA), with a marked increase in oleic acid (C18:1 n-9) and linoleic acid (C18:2 n-6). Beef patties composed with walnut oil showed a more favourable profile than those with cake, as reflected in lower atherogenic (AI) and thrombogenic indices (TI), and higher values of the hypocholesterolaemic/hypercholesterolaemic ratio (HH), nutritional value index (NVI), and health-promoting index (HPI). The best results were observed in beef patty BP4 (100% fat replacement with walnut oil), which had the highest UFA and PUFA/SFA ratio, and the lowest AI and TI values. eng http://creativecommons.org/licenses/by-nc-sa/4.0/legalcode Beef patty, Walnut oil, Walnut cake, Fatty acid profile, Nutritional quality Fatty acid composition of beef patties with replacement of beef fat by walnut oil and cake https://unilib.phaidrabg.rs/o:8590 doi:10.18485/meattech.2025.66.3.39 2025-12-01 info:eu-repo/semantics/article application/pdf 505317 bytes Meat technology - Special Issue 66/3 2025 volume: 66 number: 3 startpage: 242 endpage: 248 Institute of Meat Hygiene and Technology Slijepčević, Amila Raščić, Leila Čorbo, Selma Đinović-Stojanović, Jasna Janković, Saša Čaušević, Amir Begić, Munevera