Relationship of physically separable lean with chemical lean in pig carcasses

This study was conducted to examine the relationships between 'physically separable lean' (carried out by the Kulmbach reference technique) and 'lean' determined by moisture or lipid analysis (called chemical lean). Five major cuts (ham, shoulder, loin, belly and neck), originating from the Hungarian cross-breed 'Hungahyb', were dissected and the weights recorded. The moisture and lipid contents of three tissue groups (lean, intermuscular fatty tissue and remainder) were determined by common laboratory methods. Adequate estimators (predictors) were then developed for the assessment of standardized or non-standardized lean content in the 'boneless cut' (without skin and subcutaneous fatty tissue). It was shown that the concept of moisture-standardized lean is analogous to that of the fat-standardized one. It appears that unbiased estimators could be obtained if the interdependences between the chemical composition (moisture or lipid content) of the lean, the 'residue' (intermuscular fatty tissue + remainder) and that of the 'boneless cut' are included in the respective equations. If these interdependences are neglected and only the corresponding means are used in these equations, biased estimates have been obtained for the standardized or non-standardized lean content in the 'boneless cut'. Difficulties arising at practical application of these concepts are also discussed in this paper.