Technical Criteria for Delimiting the Picanha Beef Cut: A Preliminary Study.

The Picanha, obtained from the Biceps femoris muscle, is highly valued worldwide. No official standard precisely defines this cut, leading slaughterhouses to rely on subjective criteria such as weight, length, or the location of the "third vein". Thus, this study aimed to characterize variations along the entire length of the Biceps femoris muscle to identify the location of the separation of Picanha. Four Biceps femoris muscles were sectioned into 12 consecutive steaks (2.5 cm each) along the proximal-distal axis and subjected to physicochemical and histological analyses. Between steaks 6 and 7, the average weight of the cut (∼1.5 kg) was consistent with empirical industry standards, and the "third vein" was identified at steak 6, reinforcing its practical relevance. A decrease in pH was observed along the proximal-distal axis (5.79 to 5.62; P < 0.05). Total fat decreased toward the distal region (P < 0.01), whereas total moisture and collagen content increased (P < 0.05 and P < 0.001, respectively). Sarcomere length exhibited linear and quadratic effects (P < 0.001 and P < 0.05, respectively), with greater values in proximal steaks and progressive shortening toward distal regions. Similarly, Warner-Bratzler shear force showed a quadratic increase (P < 0.01), with steaks 1-6 classified as tender (≤ 4.4 kg) and steaks 7-12 as non-tender. Histological evaluation confirmed structural differences consistent with these findings. Overall, the transition in physicochemical and structural traits occurred around steaks 6-7, corresponding to the location of the "third vein." These results support its use as a practical and biologically meaningful anatomical reference for delimiting the Picanha cut. PRACTICAL APPLICATIONS: The anatomical delimitation of the Biceps femoris muscle was evaluated under controlled experimental conditions using steaks of standardized thickness, which may differ from commercial fabrication practices. The results consistently identified physicochemical and structural transitions around the "third vein", supporting its use as a practical anatomical reference for standardizing the Picanha (sirloin cap or rump cap) and Coxão Duro (outside round or bottom round) cuts in the meat industry and gastronomy.