Physico-chemical characteristics of ground meat relevant for patty forming and end product quality

Relevant final product quality factors for chicken meat burgers after frying and during consumption are for instance shape, shrinkage and bite. These parameters are not only determined by meat composition but also by the different processing steps. The interacting effects of process conditions and meat composition are extremely important for defining the final product properties. In the present work the relationship between patty formation, physical characteristics of chicken meat dough and final product quality will be demonstrated. The release of free protein during chopping was determined by Near Infra Red (NIR) spectroscopy and related to meat dough elasticity. Thermal and mechanical properties of the meat dough were examined by respectively Differential Scanning Calorimetry (DSC) and rheological characterization, performed in the same temperature ranges as applied during patty forming (varying from -6°C till +5°C). The effects of processing on ground meat structure were examined by light microscopy. Final quality of oven-heated products was examined by Texture Profile Analysis (TPA). TPA and microscopy results showed recovery of the dough structure within the first hours after forming. However, part of the deterioration that occurred after low temperature (-8°C) moulding appeared irreversible. A strong relation between temperature and final texture due to moulding was found. This can be explained by the thermal profile during melting (DSC) in combination with the dough mechanical characteristics. The results show, that a critical temperature range exists, where small variations in temperature may lead to a significant variation in hardness and cohesiveness. Products heated from meat doughs formed at lower temperatures (-8°C) showed a lower hardness and cohesiveness. During dough rest the mechanical behaviour of the dough, formed at relatively low temperatures, recovered. However, cohesiveness of heated products after forming at relatively low temperatures was always significantly lower than that of products being formed at relatively higher temperatures.