Effects of oven temperature and degree of doneness in flavor development of beef steaks

Development of flavor and flavor dynamics can be impacted by various factors. Meat cookery involves many transformative processes. As meat is being cooked – water levels decrease at the surface, texture changes, proteins coagulate and protein solubility changes, endogenous proteolytic enzymes get inactivated, lipid degradation occurs and finally color and flavor change. These phase changes, along with heat and mass transfer changes in beef dry heat cookery determines the final flavor perception of a grilled beef steak. Flavor development is dependent on two factors, reactant mixture (flavor precursors like amino acids, fatty acids, thiamine and other compounds) and reaction conditions (cooking temperature, relative humidity, time amongst others). These two factors have a strong chemical interdependent relationship with respect to different layers of a meat product or any other composite porous food product upon cooking. The effect of eighteen cookery treatment combinations consisting of oven cooking temperature (OT) (177°C, 246°C and 343°C) and internal temperature (IT) (57°C, 63°C, 68°C, 74°C, 79°C, 85°C) on free amino acids (AA) concentrations, fatty acids (FA) and volatile flavor compounds (VFC) of three steak layers were explored. Six free AA were impacted by a two-way OT × layer interactions (P ≤ 0.05). Seven free AA were impacted by the main effect of layer (P ≤ 0.05). Six free AA as well as total free AA content were impacted by the main effect of different OT (P ≤ 0.05). Three free AA were impacted by the main effect of different IT (P ≤ 0.05). There is evidence indicating that water soluble precursors like free AA can vary greatly in content within beef steak layers at different OT and IT. It is shown how protein fragmentation into free AAs, OT and IT can interplay among themselves to help us understand flavor development better at each location within a steak. This work also sheds light on the dynamics of generation and retention of free AAs and can give be used as a future resource on this topic. FA can be classified into two groups – Neutral lipids (NL) and Polar Lipids (PL). For NL, two groups were impacted by a three-way interaction of OT × IT × layer (P ≤ 0.05). Two-way interactions for OT × IT (P ≤ 0.05) were also detected on a content basis for seven fatty acid groups. Moreover, arachidonic acid was impacted by the main effect of layer (surface, mid, center) within a steak (P ≤ 0.05). For PL, MUFA percentage were impacted by a two-way interaction OT × IT (P ≤ 0.05). Other than this, no PL were impacted either by interactions or main effects (P > 0.05). These results indicate differences in NL thermal oxidation in beef steak at different OT, IT and layers. This is potentially because of phase transitions (recrystallization and melting) across treatments and layers for NL. This work can help in predictive studies of FA retention contents at different section of grilled steak at different OT and IT. VFC concentrations investigated for all treatments and six VFC were impacted by a three-way interaction of OT × IT × layer (P ≤ 0.05). Three VFC were impacted by a two-way interaction OT × IT (P ≤ 0.05). Nineteen VFC were impacted by a two-way interaction OT × layer (P ≤ 0.05). Twenty-five VFC were impacted by a two-way interaction IT × layer (P ≤ 0.05). Twenty-three VFC were impacted by main effect of layer (P ≤ 0.05). Nine VFC were impacted by main effect of IT (P ≤ 0.05). However, VFC were not impacted by main effect of OT (P > 0.05). These differences suggest variances in beef flavor development in beef steak at different OT, IT and layers. This reflects how the influence of OT and IT impacts VFC at different depths within steak layer (surface, middle, center). Finally, this research can be very useful in food service industry to assess and predict the sensory attributes at diverse OT and IT. Better understanding of variable flavor profiles can help in better perception of an eating experience with a precise flavor profile in mind. This work can also give clues to both desirable and undesirable eating regimens.