Analysis of SPME flavour chemistry for MSA grass and grain fed beef samples

Summary

Quality assurance A proportion of the 472 GC-MS analyses for 26 volatile compounds were quality assured. The identification of the compounds was checked against the mass spectra and linear retention indices for authentic compounds. The peak areas were also checked. Forty three GC-MS runs appear to have suffered from an instrumental fault and were omitted from statistical analysis of the data and some peak areas were corrected. The remaining data was found to be excellent. Training The data produced by these analyses is complex and requires some experience to analyse and quality assure effectively. 
Training has been provided both during a visit to AFBI by Dr Jerrad Legako and through email correspondence. FlavourBlue storage The final quality assured excel database has been stored on the AFBI server, which is backed up regularly. Data analysis and findings It is important to note that the data discussed in this section were acquired by the staff and students of Texas Tech University and that they have academic ownership of these data. While AFBI have been commissioned by MLA to conduct a preliminary analysis of this data, the final analysis must be conducted in collaboration with TTU. I. SPME analysis of volatile compounds from the grilled steak used for MSA consumer panels shows some significant differences due to ageing, cut and diet which shed some light on the nature of the effects of these factors on flavour. II.
Surprisingly, there were few consistent effects of USGrade, marbling, ribfat and other carcase measurements on the flavour volatiles. III. The data confirms previous findings that volatiles from similar pathways generally tend to follow the same trends. This offers the possibility that certain compounds may act as markers for important flavour compounds which are difficult to analyse routinely. IV. There are many findings from this data set that will allow much greater analysis than has been possible in this report and should result in several refereed scientific publications. Implications for MSA The data under discussion in this report is extensive and complex and this report can only address the scientific findings in part. These will be addressed more completely in scientific papers planned by Jerrad Legako and co-workers. Nevertheless, some conclusions can be drawn about the relevance of the findings for MSA. While all the relationships between meat production and flavour are not yet understood, a rational explanation can be proposed for how meat production and processing can influence flavour formation and release and thereby flavour as perceived by the consumer. 
​The findings presented in this report demonstrate that both flavour volatiles and consumer scores are influenced by factors such as muscle/cut, days aged and diet. IMF appears to be an important driver for flavour perception, and it is probable that a certain level of IMF is needed to achieve the most desirable flavour release. Knowledge of the optimum level of IMF for flavour release and the impact of different levels on flavour liking will assist prediction of flavour liking. Differences in consumer liking between different muscles is likely to be influenced by flavour differences as well as tenderness. Only some of this difference is explained through variations in IMF. Days aged is likely to show a curvilinear impact on flavour liking with an optimum level for most consumers. Further information may be available from existing MSA data. Diet has significant effects on flavour, only some of which may be explained by IMF. A controlled experiment with consumers from different countries eating beef from both diets is required.  Section 7.2 proposes how MSA might be developed to include the prediction of flavour and Section 7.3 summarises these findings and how they may be applied to the development of MSA. Recommendations for further work and a flavour workshop are included.