Antioxidant, color and sensory properties of sorghum bran in pre-cooked ground beef patties varying in fat and iron content

The effect of currently used antioxidants and sorghum bran in pre-cooked beef patties was evaluated at two different fat levels (10 and 27%, w/w). Pre-formulated ground beef was purchased at a retail store on three different processing days. Within each fat level, ground beef portions were weighed and randomly assigned to control, butylated hydroxanisole (BHA) and butylated hydroxytoluene (BHT) (0.001%), rosemary (0.25%) or sorghum bran (0.25, 0.5 or 1.0%). After mixing in the appropriate antioxidant, 200-g patties were formed, and pH and objective color measurements for each raw patty were performed. Patties were cooked to an internal temperature of 73oC. Cooked patties were packaged and stored at 4oC. Two patties per treatment were sampled after 0, 1, 3 and 5 d of storage and analyzed for 2-thiobarbituric acid reactive substances (TBARS), non-heme iron, pH, instrumental color and trained flavor and texture descriptive attributes. The addition of BHA/BHT and rosemary extract to patties reduced non-heme iron, TBARS values, and cooked beef fat flavor attributes, but increased beef/brothy flavor attributes relative to control patties (P<0.05). As sorghum bran level increased, cooked beef patties were darker (P<0.05), less yellow (P<0.05), had higher non-heme iron (P<0.05), lower TBARS (P<0.05) and higher sandy/gritty (P<0.05) sensory texture. Cooked patties containing antioxidants did not differ in other sensory attributes (P>0.05). Fat mouthfeel of control patties were higher than treated patties (P<0.05). Sorghum bran delayed lipid oxidation by reducing TBARS values and cooked beef fat flavors, and when used at 0.25 and 0.5%, minimal effects on color and sensory attributes were observed. Our results suggested that sorghum bran can be a desirable natural antioxidant in pre-cooked ground beef.