caa a22 4500 463156064 CHVBK 20180406164734.0 cr unu---uuuuu 170326e20070901xx s 000 0 eng 10.1007/s00217-006-0491-x doi (NATIONALLICENCE)springer-10.1007/s00217-006-0491-x Various instrumental and biochemical parameters as ageing indicators of beef Longissimus dorsi muscle and their relation to creatine and creatinine content [Elektronische Daten] [Tomaž Polak, Lea Gašperlin, Božidar Žlender] The main dietary source of creatine is red meat. Its ageing is accompanied by deep changes in chemical composition and structure of muscle tissues. The effect of ageing (nonaged—i.e. 24h post mortem vs. 14 and 28 days post mortem at 1°C) on the content of creatine and creatinine, on the creatine/creatinine ratio and on other ageing indicators, such as instrumentally measured colour values, pHultimate values, length of myofibrilar fragments and total free amino acid content of beef Longissimus dorsi muscle. Muscles originated from eight commercially slaughtered Simmental bulls, 19-20 months old. Generally, all parameters measured were influenced by ageing time at the 5% level or less. Approximately 0.1 unit higher pH values and 1 unit higher colour L *, a * and b * values of ageing samples compared to nonaged was found. Length of myofibrilar fragments being in average the highest (69μm) for nonaged samples, 34μm for 14 days aged and the lowest (17μm) for 28 days aged sample. Higher content of total free amino acids released during 14 and 28 days of storage (10.19 and 18.71μmol/g) than from nonaged beef (19.75μmol/g) was found. Creatine content significantly declined with increasing days of ageing (nonaged 6.05mg/g, 14 days 5.86mg/g, 28 days 5.66mg/g). On the contrary, the total content of creatine (creatine+1.159×creatinine) was not markedly affected by 14 days of ageing (nonaged 6.27mg/g, 14 days 6.14mg/g), although significant difference between nonaged and 28 days aged groups (5.95 mg/g) was observed. It was assumed that the creatinine/creatine ratio might be a good indicator of ageing rate for beef (R 2=0.974). Springer-Verlag, 2006 Creatine nationallicence Creatinine nationallicence Free amino acid content nationallicence Colour nationallicence Texture nationallicence Myofibrilar fragment length nationallicence Beef nationallicence Ageing nationallicence Polak Tomaž Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1111, Ljubljana, Slovenia aut Gašperlin Lea Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1111, Ljubljana, Slovenia aut Žlender Božidar Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1111, Ljubljana, Slovenia aut European Food Research and Technology Springer-Verlag 225/5-6(2007-09-01), 849-855 1438-2377 225:5-6<849 2007 225 217 https://doi.org/10.1007/s00217-006-0491-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00217-006-0491-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Polak Tomaž Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1111, Ljubljana, Slovenia aut NATIONALLICENCE 700 1- Gašperlin Lea Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1111, Ljubljana, Slovenia aut NATIONALLICENCE 700 1- Žlender Božidar Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1111, Ljubljana, Slovenia aut NATIONALLICENCE 773 0- European Food Research and Technology Springer-Verlag 225/5-6(2007-09-01), 849-855 1438-2377 225:5-6<849 2007 225 217 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer