VOLATILE COMPOUNDS PROFILE IN BEEF WITH DIFFERENT ULTIMATE pH RANGES

Volatile organic compounds (VOCs) are associated with the aroma and flavor of meat. Concomitantly, pH affects the formation of flavor compounds, and knowledge about the effects of different ultimate pH (pHu) on VOCs formation in meat is scarce. Therefore, the objective of this study was to evaluate the VOCs profile in aged grilled meat with different pHu ranges. Meat samples were collected in a commercial slaughterhouse. Muscles (Longissimus lumborum) from non-castrated Nellore bulls (Bos indicus), with 18-35 months-old were classified according to the pHu: 5.40 – 5.79 (normal, n=5); 5.80 – 6.19 (intermediate, n= 4) and > 6.20 (high, n=3), and portioned (2,5 cm), vacuum packaged, and stored at 2 ºC (±1 °C) for 3 or 21 days. For analysis, the beefs were grilled at 71 °C (internal temperature), weighed (15 ± 2g), and placed in glass vials. The extraction of VOCs was conducted by using the headspace/solid phase microextraction technique (HS/SPME). To adsorb the compounds, the vials were kept in a water bath at 60 °C , with the fiber (carboxen/polydimethylsiloxane) exposed for 45 min. Afterwards, the VOCs were desorbed in the GC-MS for analysis. Compounds were identified by comparing their mass spectra, and the Linear Retention Index (LRI) with literature data. Data analysis was performed using multivariate analysis by MetaboAnalyst. A total of 36 VOCs were identified, which were aldehydes, ketones, pyrazines, alcohols, and other compounds. Aldehydes were the most abundant compounds. The beef with normal pHu presented more VOCs, and differed from beef with intermediate and high pHu, which showed relatively similar VOC profiles after both aging times (3 and 21 days). This may be related with the different interaction between amino acids and lipids to form the VOCs during the cooking process. In general, the pHu influenced the COVs in beef, providing insights for further studies.