Effect of Replacing Soybean Concentrate with Bulgur (Wheat Groats) Flour on Quality and Storage Stability of Beef Burger

Replacing soybean concentrate with Bulgur flour in beef burger manufacture was studied. The results showed that the components of Bulgur were carbohydrate (82.65 %), protein (13.47%), moisture (11.59%) and fat (1.8%). Dietary fiber content was 31.33 % NDF and 1.98% ADF. Water absorption, fat absorption and emulsion stability were 173.74%, 175.87% and 39/100g, respectively. Soybean concentrate had high level of isoflavones comparing with Bulgur flour. Genistein , biochanin A, daidzien and formononetin in soybean concentrate were higher 13, 6, 12 and 8 times than that in Bulgur flour. Percentage of DPPH radical scavenging activity in Bulgur and soybean was 28.84% and 54.42%, respectively. Five different formulations of beef burger were prepared, 3 containing 10%, 15% and 20% Bulgur flour , one having 20% soybean concentrate and the last one was 100% meat .The moisture, protein, fat, ash and carbohydrate contents ranged from 66.37 to 72.72, 59.13 to 70.86, 21.48 to 24.34, 3.78 to 4.81 and 0. 17 to15.48%, respectively in the beef burger samples. Cooking loss and shrinkage increased after 3 months of freezing at –20°C, meanwhile decreasing in WHC was traced. The TBA values of the different burger products and after storage 3 months at –20°C ranged from 0.008 to 0.018 mg malonaldehyde per 1 kg sample. The TVC ranged from 3.5× 103 to 6.0 × 104 CFU/g before and after frozen storage. Enterobacteriaceae was 7.2x102 to 5.1x103 CFU/g in samples at zero time and not detected after one month of storage at –20°C. E.coli, Coliform and Staphylococcus aureus were not detected in all samples before and after 3 months of frozen storage . All roasted samples were judged acceptable by the panelists, 10% and 15% beef burger with Bulgur had the highest acceptability.