Beef carcass electrical stimulation: a zymographic approach for evaluate tenderization

• Grant number: 24/15648-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2024
• End date: October 31, 2025
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Production
• Principal Investigator: Saulo da Luz e Silva
• Grantee: Marília Cristina Ródio Durante
• Host Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil

Abstract

Tenderness is the main organoleptic characteristic of beef, directly influencing consumer acceptance. Knowing that the proteolytic system formed by calpains and calpastatin is the main candidate for determining post-mortem meat tenderness, measuring this system becomes crucial for understanding the process. Zymography, a simple and low-cost technique compared to other methodologies, has the potential to assist in understanding and predicting meat tenderness. The main objective of this proposal is to associate zymography with other techniques and characteristics related to beef tenderness and quality using samples with different levels of tenderness. At the time of slaughter, the carcasses (n = 20) will be divided in half (n = 40), with the left half-carcass being subjected to electrostimulation (ES), while the right half-carcass will be kept as the respective control (CON). The ES protocol used will be a single-frequency wave of 300 V AC, 15 Hz, kept on for 4 seconds, off for 2 seconds, with a total application time of 60 seconds. Samples will be collected from the Longissimus thoracis (LT) and Supraspinatus (SS) muscles 24 h postmortem (called 0d) and after 7, 14 and 21 days of steak aging. Data on shear force, color, cooking losses and myofibrillar fragmentation index (MFI) will be evaluated by analysis of variance considering the fixed effects of treatment (CON and ES), muscle (LT and SS), aging time and first and second degree interactions. Aging time will be used as a repeated measure. The means will be compared by Tukey's test, and the significance values will be reported and discussed when considered significant. For the zymography and immunodetection analysis, which will be determined in samples 24 hours post-mortem, regressions will be investigated, with the response variable being tenderness at 14 days. In addition, correlations will be made between these analyses and the MFI results. The present project is expected to elucidate important aspects regarding the determination of the rate and potential extent of tenderness of beef from Bos taurus indicus animals, from electrostimulated or non-electrostimulated carcasses.