Impact of Up- and Downregulation of Metabolites and Mitochondrial Content on pH and Color of the Longissimus Muscle from Normal-pH and Dark-Cutting Beef

Abstract

Limited knowledge is currently available on the biochemical basis for the development of dark-cutting beef. The objective of this research was to determine the metabolite profile and mitochondrial content differences between normal-pH and dark-cutting beef. A gas chromatography–mass spectrometer-based nontargeted metabolomic approach indicated downregulation of glycolytic metabolites, including glucose-1- and 6-phosphate and upregulation of tricarboxylic substrates such as malic and fumaric acids occurred in dark-cutting beef when compared to normal-pH beef. Neurotransmitters such as 4-aminobutyric acid and succinate semialdehyde were upregulated in dark-cutting beef than normal-pH beef. Immunohistochemistry indicated a more oxidative fiber type in dark-cutting beef than normal-pH beef. In support, the mitochondrial protein and DNA content were greater in dark-cutting beef. This increased mitochondrial content, in part, could influence oxygen consumption and myoglobin oxygenation/appearance of dark-cutting beef. The current results demonstrate that the more tricarboxylic metabolites and mitochondrial content in dark-cutting beef impact muscle pH and color.

Novel Insights into the Differences in Nutrition Value, Gene Regulation and Network Organization between Muscles from Pasture-Fed and Barn-Fed Goats

“…Therefore, the richer Leu and Ile in the meat from pasture-fed goats may be the key reason for the better flavor. In addition, pasture-fed has been proved to have a positive impact on the image and nutrition of goat meat [31], and flesh color is closely related to pH [32]. The color of pasture-fed meat is commonly deeper for a high content of myoglobin and the content of intramuscular fat is lower, which were also proven in our study.…”

Protein Biomarkers of Bovine Defective Meats at a Glance: Gel-Free Hybrid Quadrupole-Orbitrap Analysis for Rapid Screening

“…It was previously reported that respiration machinery has an enhanced functionality in high pHu muscles. 17 , 18 , 24 , 26 As a result, increased oxygen consumption would favor its transportation by specific proteins such as HBB, explaining its overabundance in the high pHu sample ( Table 1 ). In contrast, the iron transportation TF protein was less abundant in this assayed meat group.…”

You Are What You Eat: Application of Metabolomics Approaches to Advance Nutrition Research

“…One study related to the biochemical changes and their impact on meat color was undertaken by Ramanathan et al [115]. Their goal was to determine the differences in metabolite profile and mitochondrial content between normal-pH and dark-cutting beef.…”

“…Additionally, darkcutting beef had greater mitochondrial content and higher levels of neurotransmitters such as 4-aminobutryic acid and succinate semialdehyde. The authors speculated that the mitochondrial content and downregulation of metabolites involved in glycolytic pathways resulting in lower lactic acid formation during anaerobic metabolism would result in a high-pH of dark-cutting beef [115].…”