Changes in biogenic amine contents, non-protein nitrogen and crude protein during curing and thermal processing of M. longissimus, pars lumborum of pork

Abstract

Changes in histamine, putrescine, cadaverine and tyramine, weight, dry matter, crude protein and non-protein nitrogen were studied during immersion-curing (brine with NaNO2 and NaCl content of 0.6 g/l and 99.4 g/l, respectively and brine with NaNO2 and NaCl content of 0.6 g/l and 199.4 g/l, respectively) and boiling and grilling (70 °C core temperature) of both “fresh” and “stored” (storage 5 days at 4 °C) pork loin chops. Amine concentrations were significantly higher in “stored” pork; this difference was preserved during most of the processing techniques. Correlations of amines with nonprotein nitrogen were weak and not significant, but strong and significant for putrescine: cadaverine (r=0.89) as well as putrescine: tyramine (r=0.95). Amine reductions for “fresh” pork were not pronounced. In “stored” pork both cooking in water (water/meat = 1:1, weight base) and curing in the less concentrated brine resulted in mean reductions of 65, 77, and 68% for putrescine, cadaverine and tyramine, respectively. Boiling of cured samples yielded reductions of 50–77, 74–80, 67–71, and 77–91% for histamine, tyramine, putrescine and cadaverine, respectively.