This study investigated if changes in physical state due to sous-vide cooking significantly alter the lipemic response to food. Canadian AAA boneless beef strip loins containing the longissimus lumborum muscle (n=3) were randomly assigned to different degrees of doneness (DOD: raw/20, 50, 60, 70 and 80°C). Lipid bioaccessibility was assessed utilizing the TIM-1 simulated gastrointestinal tract and changes in network structure were analyzed. The total cumulative free fatty acid (FFA) bioaccessibility (%) shows significant differences (P<0.05) depending on the DOD, with the maximum lipid bioaccessibility occurring in samples cooked to 60°C. Furthermore, the denaturation of actin significantly correlates with the total cumulative FFA bioaccessibility whereby the striploin cooked to 60°C presented the maximum bioaccessibility and digestion rate. This research shows the importance of changes to the structural networks of foods and their ability to alter lipid digestion and can aid in the development of foods that tailor FFA release.