Effect of exposure to light on physico-chemical quality attributes of sliced dry-cured Iberian ham under different packaging systems.

Dry-cured Iberian ham slices were stored under vacuum and under two different atmospheres (N(2)=70% N(2)+30% CO(2); Ar=70% Ar+30% CO(2)) and exposed to lightness or darkness. Physico-chemical, sensory and microbial analysis was carried out throughout 60 days storage. Vacuum samples showed the highest a*-value compared to N(2) and Ar after 30 (P<0.05) and 60 days (P<0.05). The influence of illumination during storage was evident after 60 days of storage, L* and a*-values being lower (P<0.01) in hams exposed to light than those kept in darkness, which can be ascribed to the lower nitrosylmioglobin content in samples exposed to light after 60 days (P=0.001). Ham slices stored in darkness showed the lowest TBARS values (P<0.05) and hexanal content (P<0.05) after 60 days. Slices of ham packed in vacuum showed lower TBARS values than N(2) and Ar batches (P=0.001), these samples being perceived as more rancid (P<0.05). The rest of the sensory attributes were not generally affected by gas mixture or illumination (P>0.05).

Modified atmosphere packaging and vacuum packaging for long period chilled storage of dry-cured Iberian ham.

Dry-cured Iberian ham slices were stored under vacuum and under four different modified atmospheres (60/40=60%N(2)+40%CO(2); 70/30=70%N(2)+30%CO(2); 80/20=80%N(2)+20%CO(2); argon=70%argon+30%CO(2)) at 4+/-1 degrees C during 120 days. Gas composition, moisture content, pH, colour, pigment content, and lipid stability were measured, as well as sensory and microbial analysis were carried out throughout storage. A loss of intensity of red colour (a(*)-values) was observed during storage in ham slices (P<0.05). Consistently, MbFe(II)NO content also decreased throughout storage (P>0.05). Slices of ham packed in 40%CO(2) (60/40) and 30%CO(2) (70/30) showed lower a(*)-values than the rest of the batches after 60 days (P<0.05), though differences were not evident after 120 days (P>0.05). TBARs values showed an upward trend during the storage of packaged slices (P<0.05). Vacuum-packed slices showed the lowest TBARs values and those packed with 40%CO(2), the highest. Sensory attributes did not vary significantly (P>0.05) throughout storage under refrigeration and packed either in vacuum or in modified atmospheres. No safety problems were detected in relation to the microbial quality in any case.