Synthetic casings have recently been found to prevent the penetration of carcinogenic compounds in
meat products during smoking, in contrast to natural casings. In this paper, physical characteristics of 48
chorizos encased in natural (ChN) and synthetic (ChS) casings, during 11 days of direct smoking, were
compared by means of texturometry, colourimetry, moisture, Scanning Electron Microscopy and Fluorescence
Stereo Microscopy analyses. The lightness (L*) of ChS is lower (p ¼ 0) than ChN. During 5 days,
ChS presented higher hardness and browning index, and less redness (a*), yellowness (b*) and chroma
than ChN (p < 0.05). At 7 days, no differences (p > 0.05) were found in a*, b*, hue angle or chroma. Except
at 1 day, no differences (p > 0.05) were found in their moisture. Physical characteristics were suitable in
both cases, but synthetic casing reduces production time, prevents the penetration and accumulation of
soot particles in mass cavities, and enables the standardization of chorizo.