Determination of Collagen as a Quality Index in Bologna from Northwestern Mexico

Six popular brands of commercial bolognas in the State of Sonora, México, were analyzed. The resulting values were compared to a control that was made based on the Mexican Standard Regulations. The products were analyzed for general composition. Hydroxyproline was quantified to calculate the collagen content. Free collagen protein, collagen/protein, and moisture/protein ratios were also calculated. Chemical analysis of commercial bolognas revealed that none of the products fulfilled the standards, especially, for protein content since none of them reached the minimum limit (14%). Moisture/protein ratios for all commercial brands were higher than the control. In the case of hydroxyproline and collagen contents, the commercial brands presented lowest values (0.14–0.26% and 1.1–2.1%, respectively). Free collagen protein for all bologna brands (7.9–9.5%) was different from the control (13%). The collagen/protein ratio for only one brand was not different from the control. In conclusion, the results of this study showed that none of the analyzed bolognas fulfilled the amount (proximate analysis) and the quality (collagen assay) of the protein established by the Mexican standards.