Color Attributes and Glycolytic Energy Metabolites of Meat From Light and Heavy Bovine Feedlot Carcasses Stimulated With Low-Voltage Electricity

Abstract

This study investigates the influence of timing and duration of low-voltage electrical stimulation (ES) as well as carcass weight, which are important factors affecting muscle glycolysis and meat color attributes. Longissimus samples from 147 cattle, representative of typical South African feedlot cattle, were assigned to 10 treatment groups according to the combination of carcass weight (small or heavy), time of ES (early [7 min] or late [45 min] postmortem), and duration of ES (30 or 60 s). Early ES and longer ES duration (60 s) produced the highest (P < 0.05) meat lightness (L*). The combination of early ES and heavier carcasses produced the highest (P < 0.05) chroma (C*) 2 d postmortem (butchery period). These results were corroborated by the energy metabolites, such that early stimulation produced the highest amount (P < 0.05) of muscle lactate, glucose, and glucose-6-phosphate, as well as the lowest glycogen, creatine phosphate, and adenosine triphosphate early postmortem. This shows that the application of low-voltage ES on heavier carcass is advantageous in terms of meat color, but the advantages diminish as ageing progressed from 2 to 14 d postmortem.

The Effects of Different Zilpaterol Hydrochloride Feed Supplements and Extended Aging Periods on the Meat Quality of Feedlot Bulls

“…Zilpaterol hydrochloride (ZH) supplementations (ZH-A or ZH-B) in the feed during the finisher period increased slaughter mass, cold carcass mass and dressing percentage of feedlot bulls compared to the negative control groups (CT), which agrees with previous studies [7][8][9]15,[18][19][20][21][22][23][24][25]. Subcutaneous carcass fat thickness was reduced in ZH-supplemented bulls, which resulted in higher carcass weight losses post-mortem compared to the CT.…”

“…This involved the mechanical stunning of bulls using a pneumatic stunner (captive bolt), followed by suspension from their hocks and exsanguination. The carcasses were electri-cally stimulated (110 V, 17 Hz, 5 m/s; Jarvis Product Corporation, Alberton, South Africa, Pty Ltd.) during hoisting, followed by evisceration and skinning [12,15].…”

“…The carcasses were placed in a chiller (2-4 • C) at approximately 45 min post-mortem. Muscle samples were collected from the carcasses after chilling for 24 h. Samples were excided from the Longissimus dorsi muscle (LD; muscle generally used for meat science studies) between the 9th and 12th ribs on the left side of each carcass [12,15]. Muscle samples were labelled, vacuum packed and stored at −1 to 0 • C for different aging periods (7, 14, 28, 56 and 120 days) until meat quality analyses were performed.…”

Variations in Low Electrical Stimulator Voltage Settings Minimally Influence Beef Longissimus Muscle Slice Shear Force Values

“…Therefore, objective color measurement (L*, a*, and b*) of LM served as a more consistent indicator of actual differences among treatments and plants. Previous studies reported that application of ES resulted in the appearance of more youthfulness of lean, more desirability of overall maturity scores, and improved CIE L*, a*, and b* values of lean color compared with the controls (McKeith et al, 1981;Tatum et al, 1999;Roeber et al, 2000;McKenna et al, 2004;Nazli et al, 2010;Agbeniga and Webb, 2021). This is relatively consistent with the findings of this study, as carcasses receiving ES had a redder lean color compared with control carcasses.…”

“…ES also enhances lean color, texture, and lean maturity of beef carcasses (Savell et al, 1978a;Cross, 1979;Roeber et al, 2000). Improvement in tenderness with ES has been attributed to increased adenosine triphosphate (ATP) metabolism and prevention of sarcomere shortening during carcass chilling (Gilbert and Davey, 1976;Agbeniga and Webb, 2021). Moreover, the contractile forces during ES can damage cellular integrity and liberate calcium from the sarcoplasmic reticulum, which can activate the calpain system to enhance the postmortem tenderization process (Ducastaing et al, 1985;Uytterhaegen et al, 1992).…”