Characterization of the mitochondrial proteome of Longissimus lumborum muscles of Nellore cattle with different final pH ranges and packaged in modified atmosphere

• Grant number: 22/05092-0
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: July 01, 2022
• End date: August 31, 2024
• Field of knowledge: Agronomical Sciences - Animal Husbandry
• Principal Investigator: Carmen Josefina Contreras Castillo
• Grantee: Monique Marcondes Krauskopf
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Associated research grant: 17/26667-2 - Beef quality in Bos indicus cattle: biological markers for meat attributes in different ultimate pH ranges, AP.TEM

Abstract

Brazilian beef production is predominantly in an extensive system, with food based on pastures and, despite its high productivity, the quality of the final product is extremely important. This production system is associated with a lower growth rate, low fat deposition and late age at slaughter, lower glycogen reserve and consequently lower lactate production, negatively affecting meat color characteristics, the main attribute evaluated by the consumer at the time. of purchase. Changes in the postmortem muscle pH decline have been considered the main factor responsible for the observed changes in the color and stability of meat color, the high pH in meats is related to the increase of mitochondrial activity, activity that influences the color and its stability through the rate of oxygen consumption and metmyoglobin reducing activity, processes responsible for affecting the proportion of different forms of myoglobin on the surface of meat. To minimize color changes and meat stability, modified atmosphere packaging is a tool to improve color and prevent meat discoloration during the retail exposure period, in addition to prolonging shelf life. Although knowledge about the effects of high pH on meat color and color stability is advanced, there are still some points to be elucidated, such as the role of mitochondrial proteins in the underlying mechanisms of color development and their stability in meats with different ranges. of final pH packed in packaging with high O2 content. (AU)