Bioactive amines in fresh beef liver and influence of refrigerated storage and pan-roasting

The profile and levels of ten bioactive amines in fresh beef liver was determined and associated with physico-chemical parameters of quality. Furthermore, the influence of refrigerated storage at 0 ± 1 °C and 7 ± 1 °C and of pan-roasting on beef liver quality and safety was investigated. Fresh beef liver was characterized by pH of 6.71-6.92, TVB-N of 98.58-154.72 mg N/100 g and negative H2S. It contained high levels of spermine (up to 119 mg/kg), and low levels of spermidine, putrescine, tyramine and histamine. Therefore, beef liver constitutes one of the richest dietary source of spermine. During refrigerated storage, there were significant physico-chemical changes: the pH decreased, TVB-N increased, and hydrogen sulfide was moderate. The levels of most of the naturally occurring amines increased at rates which were faster at higher storage temperature. Two amines which were not initially detected, reached detectable levels - tryptamine and cadaverine. The proposed bioactive amines based indices of quality to access liver quality were not appropriate to follow gradual quality changes. A shelf life of up to 6 and 4 days during storage at 0 ± 1 °C and 7 ± 1 °C, respectively, is recommended. During pan-roasting at 180 °C for 10 min, the levels of the polyamines increased significantly.