Changes in the content of biologically active polyamines during beef loin storage and cooking.
Dietary polyamines putrescine (PUT), spermidine (SPD) and spermine (SPM) participate in numerous human physiological processes, including tumour growth. Reliable information on their contents in foods is thus needed. Data for processed beef are very limited. Nine experiments with beef loin (longissimus lumborum) were, therefore, carried out. Loin cuts were stored at -18°C for 178 days or beef was stored aerobically, vacuum-packaged (VP) and packaged in a modified atmosphere (MA; 70% N(2) and 30% CO(2), v/v) at +2°C for 9, 21 and 21 days, respectively. The effects of three usual cooking treatments were also tested. Polyamines were determined after extraction with perchloric acid as dansyl derivatives using an HPLC method. Only SPM was detected at initial levels of 23.5-27.5mgkg(-1), PUT and SPD contents were below the detection limits of 1.2 and 1.7mgkg(-1), respectively. SPM content increased during the initial weeks of frozen storage and then gradually decreased to about 70% of the initial values at the end of the storage period (P<0.05). No apparent SPM decrease was observed during aerobic storage for 9 days, while in VP and MA variants the losses were about 20% of the initial values on day 21 (P<0.05). Slightly higher mean SPM losses were observed during boiling and stewing with and without added water. The differences among the cooking treatments were not significant. However, significant differences were observed among the loins used.
Kozová
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Department of Applied Chemistry, Faculty of Agriculture, University of South Bohemia, 370 05 České Budějovice, Czech Republic.
Kalač
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Pelikánová
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