Frozen storage stability of beef patties incorporated with extracts from ulam raja leaves (Cosmos caudatus)

•Use of aqueous extract of ‘ulam raja’ (UREX) in beef patties.•Beef patties were stored for 10weeks at −18°C.•Patties assessed for lipid oxidation, physical and sensory characteristics.•UREX was as good as green tea in retarding fat oxidation.•UREX did not affect sensory quality. In Malaysia, fresh ulam raja leaves (Cosmos caudatus) are eaten raw with rice. In this study, beef patties incorporated with extracts of ulam raja (UREX) and commercial green tea extract (GTE) added individually at 200 and 500mg/kg were stored at −18°C for up to 10weeks. Lipid oxidation, cooking yield, physicochemical properties, textural properties, proximate composition and sensory characteristics of the beef patties were compared between those incorporated with UREX, GTE and the control (pure beef patty). Incorporation of UREX or GTE at 500mg/kg into beef patties reduced the extent of lipid oxidation significantly (P