Free amino acids in meat of buffalo young bulls fed faba bean as protein source

Consumers perceive meat as a product with large variability in sensorial qualities. A tight control of meat quality requires understanding of all elements inducing this variability. Among the factors, that influence meat properties, recently free amino acids, peptides, and proteins have become of interest since they are important precursors of taste and flavor. The present study is concerned with the knowledge that free amino acid concentration contribute to understand the variability of the meat sensorial properties and that the animal diet effects on free amino acid profile of muscles. In this study, free amino acids were analyzed on Longissimus thoracis of 16 Italian Mediterranean Buffalo young bulls. Animals were divided into two groups and fed with iso- protein and iso-energy diets, characterized by different protein source in the concentrate: faba bean tannin-free variety (Vicia faba minor L.) vs. whole seed soybean (Soja hispida), FB and SB group respectively. Animals were slaughtered at 350 kg BW. Samples of Longissimus thoracis were collected for free amino acids analysis. The derivatized amino acids were analysed by reverse-phase HPLC in a C18 column (250x4.6 mm). The samples were monitored at 254 nm. The quantification of each amino acids was carried out by external standard method. The statistical analysis was performed considering the variables protein source effect (i = FB, SB). The protein source did not influence the muscle protein percentage (FB: 21.2 g 100 g-1 vs. SB: 21.5 g 100 g-1). The free amino acid profiles of Longissimus thoracis of FB and SB group show that the different protein source significantly increased only the quantity of Glycine (FB: 43.2 mg 100 g-1 vs. 29.4 mg 100 g-1; P<0.01). Among the amino acids with taste properties, Glycine, named for its sweet taste, has the lowest relative sweetness of the amino acids (in order of decreasing sweetness: Tryptophan, Histidine, Phenylalanine, Tyrosine, Leucine, Alanine, and Glycine). Results show that free amino acids had similar values in meat from animals fed faba bean vs. soybean; therefore, faba bean, that leads, by itself, to agronomical and economic advantages, can be used as a protein source alternative to soybean in the diet of young buffalo bulls without modify meat sensorial properties.