Beef broth flavour: relation of components with the flavour developed at different cooking temperatures

Abstract

The components of broths obtained at different cooking temperatures (from 55 °C to boiling under reflux) have been related, through regression analysis, with their sensorial evaluation. An increase in cooking temperature led to a significant rise (P ≤ 0.05) in the concentration of nitrogen in peptides of molecular weight higher than 600 Da (HPPN, higher than 600 Da peptidic nitrogen), nitrogen in non-amino acid substances of less than 600 Da (SNAN, small non-amino acid nitrogen compounds), creatinine, inosine 5′-monophosphate (IMP) and adenosine 5′-monophosphate (AMP) in beef broths. The levels of SNAN, IMP, AMP, guanosine 5′-monophosphate (GMP) and creatine showed a positive and significant relation (P ≤ 0.01) with the sensorial evaluation. Simple linear regression analysis showed that the beef broth flavour is inversely related to the protein nitrogen (PN) concentration. Multiple linear regression analysis suggested that flavour properties of beef broths were more influenced by the IMP concentration than the GMP and AMP concentration and that SNAN is more important than HPPN. Significant correlations (P ≤ 0.01) established between D-ribose content, sensorial evaluation and amino acid nitrogen (AN) concentration suggested that besides amino acids and free sugars, substances from the earlier steps of Maillard reactions are involved in the obtention of suitable beef broth flavour at 85 °C. Nevertheless, the development of off-flavours at cooking temperatures higher than 95 °C, especially warmed-over flavour (WOF), suggests that it is advisable to restrict the reactions that occur at high temperatures. © 2000 Society of Chemical Industry