Application of metabolomics in monitoring the qualities of meat and meat products

Meat and meat products have been the most important sources of proteins in the human diet, particularly on directly linking to public health and welfare. Meat quality has attracted much more attention for the meat industry worldwide, as the meat consumption is increasing in recent years, due to the improvement of living standards. Generally, the meat quality depends highly on pre-slaughter factors, including breed, age, muscle types, as well as the ways of post-slaughter processing, where the alteration of metabolites normally occurs all over the stages during meat production. Thus, the intrinsic mechanism of meat quality at the metabolites level has been a highly relevant issue for improving the nutritional value of meat. As a branch of systems biology, metabolomics mainly focuses on the whole metabolome, metabolites of molecular weight below 1 500 Da, to represent in a biological system, whether it being stimulated or disturbed. Recently, the interest in the application of metabolomics has been extended to the field of meat science with constantly rising studies. This present review systematically summarized the main techniques that used in metabolomics, based on the methodology of recent studies, including the Nuclear Magnetic Resonance (NMR) spectroscopy, Gas Chromatography-Mass Spectroscopy (GC-MS), and High-Performance Liquid Chromatography-Mass Spectroscopy (HPLC-MS), as well as the applied methods for data analysis. Five aspects were also overviewed, according to the recent findings in metabolomics associated with meat quality traits. 1) In pre-slaughter factors, animal breed, ages, muscle types, and diet can be recognized as the most significant indictors of meat quality. Most previous studies confirmed that the metabolomics profiling related to age or breed can contribute to the assessment of meat quality, and thereby to provide theoretical support for the development of high-quality meat resources. Moreover, the different types of muscle in an animal have shown the distinct metabolic characteristics of individual energy. In recent reports, these differences in postmortem muscle metabolites were identified to provide useful theoretical information regarding the biochemistry process of muscle to meat conversion. Additionally, metabolomics has shown a promising potential to distinguish the various feeding regime, and dietary addition of mate extract, such as naringin, hesperidin, further to facilitate the creation of novel management schemes for mitigating limitation in meat quality. 2) Metabolomics can offer a new perspective to predict the post-mortem ageing time, shelf-life of meat and meat products. Previous studies also found that the metabolomics can achieved data information on the flavor and taste that related to metabolites changes, particularly occurring on ageing of meat, predicting ageing time, and differentiating various aging conditions. The reason is that the metabolites variation in meat depended mainly on the ageing time and conditions after post-mortem. The growth and enzymatic activity of microorganisms can cause the meat decomposition and formation of metabolites, resulting in the meat spoilage. Hence, those changes have also been reviewed on critical metabolites that exploited for monitoring the shelf-life of meat. 3) In processed meat products, numerous biochemical and biophysical reactions can pose some influence on the final quality during meat handling and cooking. These changes detected by metabolomics can be contributed to the optimization of the processing technology. 4) A potential technique of metabolomics was applied to identify metabolic markers that selected for the substantiation of the claim, and further to aid in the certification of the geographical origin of meat product. 5) Metabolomics has also been developed as a useful tool for the adulteration detection of meat and meat products, showing the reliable meat identification. Finally, an insightful prospect was made, in order to provide a sound theoretical basis for the further application of metabolomics to meat science.