Lipid oxidation and colour in pressurised and heated chicken samples were evaluated. In a preliminary test, raw and overcooked (100 • C/60 min) minced chicken thighs were pressurised (500 MPa/50 • C/30 min). Samples were stored at 4 • C in contact with air. Thiobarbituric acid reactive substances (TBARS) were quantified at 1, 6 and 9 days. Pressure induced oxidation in chicken, but overcooking generated many more secondary oxidation compounds. In a second experiment, raw minced chicken thighs were pressurised (500 MPa/−10, 5, 20 and 50 • C/30 and 60 min) or cooked (90 • C/15 min). Samples were vacuum stored at 4 • C. TBARS were measured at 1 and 9 days, whereas colour parameters (L, a, b and E) were determined at 1 day. No differences in TBARS values were observed between untreated and pressurised samples, whereas cooked samples presented the highest values. Pressurisation for 30 and 60 min generated similar TBARS contents. At 9 days, oxidation values did not increase. Pressurisation and cooking induced marked colour changes. Pressurised samples were lighter and less red than untreated ones. Samples pressurised at 50 • C were the palest and, together with cooked samples, presented the lowest a values. Therefore pressurised chicken thigh cannot be marketed as a fresh product but can be incorporated as an ingredient in ready-to-eat meals.
The effect of oscillatory high pressure processing on mesophile and psychrotroph populations of mechanically recovered poultry meat (MRPM) was evaluated. Vacuum-packaged samples were subjected to cycles by alternating moderate pressure (60 MPa) and high pressure (450 MPa) at 20 ЊC, once or several times so that the total time under high pressure was 15 min. A continuous treatment at 450 MPa for 15 min at 20 ЊC was also performed. Oscillatory treatments did not generate significantly higher decreases in counts of both populations than continuous pressurization. Reductions from 3.2 to 3.8 log CFU g 1 were found for mesophiles. Psychrotrophs proved more sensitive: one of the cyclic treatments induced a lethality of 5.2 log CFU g 1 . Pressurization improves the microbiological quality of MRPM.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.