Oxidative stress and postmortem meat quality in crossbred lambs

Abstract

The objective of this study was to evaluate effects of different levels of lipopolysaccharide (LPS)-mediated oxidative stress on fresh meat quality. Crossbred lambs (n = 29) were blocked by weight and fed a standard finishing ration for the duration of the study. Lambs were individually housed and treatment groups were administered one of three intravenous injections every 72 h across a three-injection (9-day) cycle: saline control (Control), 50 ng LPS/kg bodyweight (BW) (LPS50), or 100 ng LPS/kg BW (LPS100). Rectal temperatures were measured to indicate inflammatory response. Lambs were harvested at the Loeffel Meat Laboratory, and 80 mg of pre-rigor Longissimus lumborum were collected in Control and LPS100 treatments within thirty minutes postmortem for RNA analysis. Wholesale loins were split and randomly assigned 1 or 14 d of wet aging. Chops were fabricated after aging and placed under retail display (RD) for 0 or 7 d. Animal was the experimental unit. Lipopolysaccharide-treated lambs had increased (P < 0.05) rectal temperatures at 1, 2, 4, and 24 h post-injection. Transcriptomics revealed significant (Praw < 0.05) upregulation in RNA pathways related to generation of oxidative stress in LPS100 compared to Control. A trend was found for tenderness (Warner-Bratzler Shear Force, WBSF) (P = 0.10), chops from LPS50 having lower shear force compared with Control at 1 d postmortem. Muscle from LPS50 treatment lambs exhibited greater troponin T degradation (P = 0.02) compared to all treatments at 1 d. Aging decreased WBSF (P < 0.0001), increased sarcoplasmic calcium concentration (P < 0.0001), pH (P < 0.0001), and proteolysis (P < 0.0001) across treatments. Following aging, chops increased discoloration as RD increased (P < 0.0001), with Control chops aged 14 d being the most discolored. Chops from lambs given LPS had higher (P < 0.05) a* values compared to control at 14 d of aging. The L* values were greater (P < 0.05) in LPS100 compared to both LPS50 and Control. Aging tended (P = 0.0608) to increase lipid oxidation during RD across either aging period. No significant differences (P > 0.05) in sarcomere length, proximate composition, fatty acid composition, or isoprostane content were found. These results suggest that defined upregulation of oxidative stress has no detriment on fresh meat color, but may alter biological pathways responsible for muscle stress response, apoptosis, and enzymatic processes, resulting in changes in tenderness early postmortem.

H2O2-induced oxidative stress improves meat tenderness by accelerating glycolysis via hypoxia-inducible factor-1α signaling pathway in postmortem bovine muscle

“…Conversely, Chen et al (2021) demonstrated that ROS accumulation ameliorates the meat texture via inducing satellite cell proliferation and collagen synthesis in grass carp muscle. In addition, several studies suggested that ROS, especially hydrogen peroxide (H 2 O 2 ), acts as a secondary messenger molecule to activate apoptosis and caspase-3, which is conducive to the tenderization of lamb and bovine muscle ( Herrera et al, 2021 , Ma et al, 2022 , Wang et al, 2018 ). According to the above literature, there is inconsistency in describing the influence of ROS on meat quality.…”

Polysaccharide of Atractylodes macrocephala Koidz alleviate lipopolysaccharide-stimulated liver inflammation injury of goslings through miR-223/NLRP3 axis

“…During the cultivation of goslings, feed corruption and poor breeding environment could cause widespread bacterial infection. This phenomenon will increase blood levels of endotoxin lipopolysaccharide ( LPS ) in goslings, and LPS exposure could greatly impact both product quality and consumer palatability ( Herrera et al, 2021 ). More importantly, LPS could stimulate the innate immunity and trigger biochemical and cellular responses that lead to the inflammation and toxicity ( Kolomaznik et al, 2017 ).…”