Meat quality characteristics of two South African goat breeds after applying electrical stimulation or delayed chilling of carcasses

Differences in Meat Quality of Six Muscles Obtained from Southern African Large-Frame Indigenous Veld Goat and Boer Goat Wethers and Bucks

Various meat quality characteristics of six muscles (Longissimus thoracis et lumborum (LTL), Semimembranosus (SM), Biceps femoris (BF), Supraspinatus (SS), Infraspinatus (IS), Semitendinosus (ST)) from large-frame Boer Goats (BG) and Indigenous Veld Goats (IVG: Cape Speckled and the Cape Lob Ear) were studied. Weaner male BG (n = 18; 10 bucks and 8 wethers) and IVG (n = 19; 9 bucks and 10 wethers) were raised on hay and natural grass, and on a commercial pelleted diet to a live weight of 30–35 kg. All goats were slaughtered at a commercial abattoir and the dressed carcasses were chilled at 4 °C within 1 h post mortem. The muscles were dissected from both sides 24 h post mortem and aged for 1 d and 4 d. Variations in meat characteristics such as ultimate pH, water holding capacity (WHC), % purge, myofibril fragment length (MFL), intramuscular fat (IMF), connective tissue characteristics, and Warner-Bratzler shear force (WBSF) were recorded across muscles. Bucks had higher lightness (L*) and hue-angle values, whereas wethers had increased redness (a*) and chroma values. The muscle baseline data will allow informed decisions to support muscle-specific marketing strategies, which may be used to improve consumer acceptability of chevon.

Carcass Quality Profiles and Associated Genomic Regions of South African Goat Populations Investigated Using Goat SNP50K Genotypes

Simple Summary

South Africa is one of the major goat producing countries on the African continent. However, despite a large number of goats being produced, there is still a growing demand for chevon, which leads to producers being unable to reach demand, resulting in an absence of chevon in retail markets. Carcass quality is an important economic trait that plays a major role in influencing consumer preferences and high nutrient provision. Even though chevon is an easily accessible meat for smallholder farmers and has health benefits, it is still less preferred due to perceptions of low meat quality attributes such as toughness, off-odours and flavour, and unappealing colour. The majority of goat populations are village ecotypes whose genetic potential for meat and carcass quality is unknown.

Abstract

Carcass quality includes a battery of essential economic meat traits that play a significant role in influencing farmer breed preferences. A preliminary study was undertaken to investigate the carcass quality and the associated genomic regions in a small nucleus of animals that are representative of South African goat genetic resources. Samples of the South African Boer (n = 14), Northern Cape Speckled (n = 14), Eastern Cape Xhosa Lob ear (n = 12), Nguni/Mbuzi (n = 13), and Village (n = 20) were genotyped using the Illumina goat SNP50K and were phenotyped for carcass quality traits. SA Boer goats had heavier warm and cold carcass weights (17.2 ± 2.3 kg and 16.3 ± 2.3 kg). Pella village goats raised under an intensive system had significantly (p < 0.05) heavier warm and cold carcass weights (9.9 ± 1.1 kg and 9.2 ± 1.2 kg) compared to the village goats that are raised extensively (9.1 ± 2.0 kg and 8.4 ± 1.9). A total of 40 SNPs located on chromosomes 6, 10, 12, 13, 19, and 21 were significantly associated with carcass traits at (−log10 [p < 0.05]). Candidate genes that were associated with carcass characteristics (GADD45G, IGF2R, GAS1, VAV3, CAPN8, CAPN7, CAPN2, GHSR, COLQ, MRAS, and POU1F1) were also observed. Results from this study will inform larger future studies that will ultimately find use in breed improvement programs.

Effect of different cooking water on flavor characteristics of mutton soup

The mutton flavor is affected by cooking water significantly, and the flavor of mutton is delicious and widely loved by consumers through an extremely simple processing in northwest China, such as Inner Mongolia, Ningxia, and Xinjiang. The flavor shows obvious changes if get out of these areas even use the same raw meat, which may be caused by different cooking water. To determine whether and how the cooking water affect the mutton soup flavor, the elements in water, the flavor was studied by inductively coupled plasma mass spectrometry (ICP-MS), amino acid analyzer, and thermal desorption (TDS)-gas chromatography-mass spectrometry (GC-MS). Specifically, three water samples from different sources, Ningxia (NXW), Beijing (BJW), and ultrapure water from the laboratory (PUW), were used for cooking with Tan sheep's ribs to get different mutton soups. The inductively coupled plasma mass spectrometry (ICP-MS) results showed that the elements and the concentration of solutes in different water sources were significantly different. The NXW batch had the highest Na, Mg, K, and Sr concentrations, and Na in NXW water reached to 50.60 mg/L, which existed as Na+, significantly (p < .05) higher than BJW (8.63 mg/L) and PUW, which were important to the flavor of mutton soup. The PUW batch had the highest content of free amino acids, and the content of glutamic acid (Glu) reached to 17.89 μg/mL. The NXW batch had the highest content of taste nucleotides, and the content of 5´-IMP reached to 68.68 μg/ml. The volatiles of the three batches had significant differences, and only 40 volatiles were detected in all batches. Further flavor studies using electronic nose and electronic tongue showed significant differences in overall aroma and overall taste, especially bitterness, saltiness, and astringency. The results could provide a basis for improving the flavor quality for the mutton soup.

Proteomics analysis to investigate the impact of diversified thermal processing on meat tenderness in Hengshan goat meat

During the thermal processing, proteins of Hengshan goat meat undergo structural modifications such as degradation, oxidation and denaturation, ultimately affect the palatability and acceptability. The results of several objective metrics demonstrated that thermal processing exhibited significant impacts on the tenderness of goat meat. The 551, 84, 72, and 121 proteins were identified in the control and thermal processed groups (boiled, steamed, and roasted), respectively. Compared with the control group, the 101, 98, and 109 differentially-expressed proteins were explored in the treatment groups. Furthermore, the functions of metabolic and skeletal muscle proteome were investigated and discussed. Sensory evaluation and proteomics analysis showed that steaming and boiling treatment had no significant effect on the tenderness of goat meat, while roasting significantly reduced the tenderness, indicating that the available thermal processing methods to ensure the tenderness of goat meat were steaming and boiling treatments. Thus, the established proteomics database of goat meat provided the valuable reference for rational selection of thermal processing methods.

Relationship between population genomic structure and growth profiles of South African goats under different production systems

Goats play a major role in poor marginalized communities of South Africa for food security and socio-economic purposes. Majority of the goats are raised in villages with poor infrastructure and resources, therefore facing challenges that affect growth performance which leads to low mature weights. Investigating growth profiles will shed light on growth performances and will aid in goat improvement and selection. This study investigated the growth profiles and genomic structure of SA indigenous breeds raised in different production systems to unravel the genetic potential of indigenous goat populations. Live weights and morphological body measurements were collected from a total of 83 kids representing the commercial meat-producing SA Boer (n = 14); the indigenous veld goats (IVG) of NC Skilder (n = 14), Mbuzi (n = 13), and Xhosa lob (n = 14) raised under intensive systems; and nondescript village goat populations (n = 14) raised in intensive and others (n = 14) raised in extensive production systems. The remaining 72 of 83 phenotyped goats were genotyped using the Illumina Caprine SNP50K BeadChip. The SA Boer had a higher weight (28.96 ± 0.30 kg) gain as compared to other populations. The Mbuzi population was the smallest (14.83 ± 0.33 kg), while the village goats raised in Pella Village were relatively smaller (17.55 ± 0.37 kg) than those raised on the research farm (19.55 ± 0.36 kg). The study concluded that both genetics and management systems can lead to improved growth performance in goat production. The outputs of this study can be used to identify suitable breeds and potential genotypes for optimal growth and establish optimal goat management systems suitable for communal farmers for improved productivity.

Effect of Carcass Chilling on the Palatability Traits and Safety of Fresh Red Meat

Chilling procedures have been widely used in livestock abattoirs since the development of refrigeration systems. The major criteria when applying chilling regimes is not only complying with regulations, but economic concerns, and also meat safety and quality assurance requirements. Given recent developments, an updated review is required to guide the industry to choose the best chilling method and to inspire the development of new approaches to chilling. Thus in this paper, the quality and microbial safety of beef, lamb, pork, venison, and bison resulting from different chilling treatments has been reviewed, as well as the underlying mechanism(s) for the different impacts on meat quality traits as a result of different chilling regimes. The effect of fast chilling on the tenderness of beef and lamb is a focus, as some new findings, have recently been reported, while multistep chilling is highlighted as it incorporates the advantages of fast chilling to reduce carcass weight loss, resulting in similar quality improvements as found with slow chilling. It is, suggested, that if spray chilling can be combined with the second phase of multi-step chilling, it will benefit the meat industry in terms of both meat quality and safety. Future studies should focus on combinations of chilling methods with new technologies, such as medium voltage electrical stimulation, muscle stretching, or ultrasound and so on, to move meat quality and safety to a new level.