PHYSICOCHEMICAL CHARACTERIZATION AND DIFF ERENTIATION OF THE COMMERCIAL TYPES OF RAW SAUSAGE LONGANIZA-DE-ARAGON

The raw sausage longaniza de Aragon, was characterized by physico-chem ical parameters such as moisture, ash, fat, total protein, nitrates, n on-protein nitrogen, free fatty acids, hydroxyproline, pH, curing conv ersion index and water activity, in 105 samples representative of comm ercial drying-related type, geographical origin, manufacturer, packagi ng, retail type and legal category. With a view to solve the legal pro blem of differentiating the dry sausage from fresh and semi-dry sausag es (the characteristics of the latter overlapping with those of both d ry and fresh sausage, though closer to the latter according to manufac turing process and consumption habits), a multivariate discriminant an alysis was performed. As a result, the use of water activity was propo sed instead of moisture content for the legal differentiation of dry f rom all non-dry longaniza, since an a(w) value of 0.895 constitutes a sharper limit between both types of sausage than the 40% moisture cont ent currently used. Analysis of variance was used to study the effect of sampling variables (type, geographical origin, manufacturer, packag ing, retail type and commercial category) upon physico-chemical parame ters. It is worth mentioning the effect of drying-related type, retail and packaging on parameters related to ripening process, thus allowin g the differentiation of the three sausage types: dry, semi-dry and fr esh. The effect of manufacturer was also noticeable and, although to a lesser extent, that of retail type and category on hydroxyproline and protein content. This indicated a higher protein content of longaniza prepared by butchers; although of a lower quality, as revealed by the higher collagen content.