Color changes in irradiated cooked pork sausage with different fat sources and packaging during storage.

Pork sausages were prepared with lean pork meat, fat from different sources [backfat (BF), corn oil (CO) or flaxseed oil (FO); 10% of lean meat], NaCl (2%), and ice water (10%). The emulsified meat batters were stuffed into casings (3 cm in diameter) and cooked to an internal temperature of 72°C. Cooked sausages were sliced and vacuum- or aerobic-packaged individually. Sausages were irradiated at a 0, 2.5, or 4.5 kGy dose and stored in a 4°C refrigerator for 8 days. Aerobic-packaged, irradiated cooked sausages prepared with BF and FO showed higher Hunter L-values than nonirradiated controls at day 0, but the difference disappeared at day 8. Irradiation increased the Hunter a-value in vacuum-packaged cooked pork sausages regardless of the fat source used, and the increase of the Hunter a-value was dose-dependent. In contrast, the Hunter a-value decreased by irradiation in aerobic-packaged cooked pork sausages prepared with BF or FO. The Hunter a-value of cooked pork sausage with aerobic packaging was significantly reduced at day 8. Hunter b-values increased at Day 8 in irradiated cooked pork sausages except for the sausage prepared with CO at 2.5 kGy. Cooked pork sausages prepared with CO were lighter, and sausage prepared with FO was redder and more yellow (p<0.05) in vacuum packaging.