Modification of Gelling Properties of Salt Soluble Beef Proteins by the Addition of Whey Protein Concentrate

SZERMAN NATALIA; VAUDAGNA SERGIO R.; SANCHO ANA M.; GONZALEZ CLAUDIA B.

Ljubljana, Slovenia.

Congreso; First European Food Congress (EFFoST 2008); 2008

European Federation of Food Science and Technology (EFFoST)

Salt-soluble muscle proteins (SSP) form heat-induced gels that contribute to texture, water holding capacity (WHC), binding and appearance of beef products. Currently, whey protein concentrate (WPC) is incorporated to meat products to minimize the use of conventional additives (sodium chloride-NaCl; tripolyphosphates-TPP) improving yield and quality. Based on this research, the objective of the present study was to evaluate the potential modification of SSP-gelation properties by the addition of WPC (native and modified). SSP were extracted from Semitendinosus muscle using two different salt concentrations: 0.4M and 0.6M NaCl. Protein content was tested by Biuret technique. SSP and WPC protein profile was analyzed by SDS/PAGE. Protein thermal behavior was analyzed by differential scanning calorimetry (25-90°C, 5°C/min). Mixed gels were prepared according to previous results and heated at 70°C. Texture profile analysis was performed on gels using a cylindrical probe (35mm, compression 30%, 0.5mm/s). WHC was determined by centrifugation (800xg, 15min, 4ºC). Electrophoretic patterns obtained from the SSP extracted at 0.4M and 0.6M NaCl were similar. However, at higher ionic strength miofibrilar proteins solubilization was slightly increased. Native and modified WPC presented similar protein profiles. Denaturation patterns of SSP showed two Td points (myosin: 54-58°C and actin: 71-83°C). Native and modified WPC presented one peak, corresponding to b-lactoglobulin thermal denaturation (75.8°C and 76.9°C, respectively), which is increased by NaCl. The incorporation of the salts (alone or in combination) produced an increment of gel hardness and cohesiveness. The replacement of TPP by any of the WPCs, produced gels with similar hardness and cohesiveness. Gels WHC was improved by the addition of WPC, NaCl or TPP. Summing up, the use of any of the additives improved quality properties of the model gels, supporting previous results.