RESUMEN
Despite the importance of intramuscular fat (IMF) to eating quality, as yet no methodology has been widely adopted by the whole of industry in Australia to measure it routinely. Thus, a study was conducted to investigate the potential for a Near Infra-Red (NIR) device to predict the IMF content of the loin from spectra collected on the topside which is externally located on a hanging carcase and therefore easily accessible. To this end, NIR spectra were collected from topsides (m. semimembranosus) of 258 lamb carcases over 5 data collections and a sample of muscle was collected from the loin and the topside for IMF determination using a wet chemistry method. Subsequent Partial Least Square (PLS) models suggested the ability to predict the absolute IMF content of loins was poor (R2 = 0.28, RMSE = 1.26), yet there was a moderate ability to predict the IMF content of the topside (R2 = 0.56, RMSE = 0.82). Partial Least Square Discrimination Analysis (PLS-DA) models to classify cuts based on the IMF eating quality threshold of 4.5% yielded better predictive outcomes with accuracies of 66.7% and 76.7% for loin and topside respectively. However, further research to assess the relationship between the IMF of the loin and topside and reduce the impact of differences in overall absorbance between data collections will improve predictive outcomes.
Asunto(s)
Tejido Adiposo , Músculo Esquelético , Carne Roja , Oveja Doméstica , Espectroscopía Infrarroja Corta , Animales , Músculo Esquelético/química , Espectroscopía Infrarroja Corta/métodos , Australia , Tejido Adiposo/química , Carne Roja/análisis , Análisis de los Mínimos CuadradosRESUMEN
Intramuscular fat (IMF) content is critical in the determination of eating quality. At present the Australian lamb industry has no ability to measure IMF as carcases are not split and processing speeds of up to 15 animals per minute prohibit the use of traditional methods. Consequently, the potential for a hand-held Near- Infrared (NIR) device to predict the IMF content of lamb topside in-situ was investigated. Models demonstrated that there is an ability to predict the IMF content of topside (R2 = 0.58, RMSEP = 0.85) using NIR spectra collected at 24 h post-mortem and loin (R2 = 0.50, RMSEP = 0.91). However, the models were limited by the range and distribution of the lamb population measured. Thus, further research is required to determine whether these models can be improved by increasing the range of data in the calibration models and considering alternate methods of analysis which are suitable for skewed populations.
Asunto(s)
Tejido Adiposo , Músculo Esquelético , Carne Roja/análisis , Espectroscopía Infrarroja Corta/veterinaria , Mataderos , Animales , Australia , Oveja Doméstica , Espectroscopía Infrarroja Corta/métodosRESUMEN
A preliminary investigation was conducted to determine the potential for a handheld Raman spectroscopic device to predict sensory traits determined by an untrained consumer panel. Measurement of 45 beef loins (M. longissimus lumborum) was conducted using a 671nm handheld Raman spectroscopic device. Samples were then held frozen until testing by an untrained sensory panel. Sections were also excised to determine shear force values and other indicators of meat quality. Derived models suggest that the Raman spectroscopic device can predict juiciness and tenderness, with correlations between predicted and observed values (ρ) of 0.42 and 0.47, respectively. Spectra indicated that these predictions were characterised by the fatty acid concentration, the hydrophobicity of proteins and the orientation of collagen. However, future research is required to determine the repeatability and robustness of these models on a larger independent data set.
Asunto(s)
Bovinos , Carne Roja/análisis , Espectrometría Raman/métodos , Adolescente , Adulto , Animales , Colágeno , Ácidos Grasos/análisis , Humanos , Persona de Mediana Edad , Proteínas Musculares/análisis , Músculo Esquelético/química , Resistencia al CorteRESUMEN
Multiple studies were conducted at 3 abattoirs to determine the potential of a dual function GR/Impedance probe to measure GR soft- tissue depth (depth at the 12th rib, 110mm from the mid line of the carcase) of typical lamb carcases processed in Australia. Lamb carcases (1016) were measured approximately 25min post slaughter with the probe and a GR knife as the most commonly used measurement. Modelling indicated that variation in the measurement using the probe compared to the measurement using the knife occurred with increasing carcase weight and fatness as well as between different abattoirs. Consequently, the probe in its current design cannot provide the repeatable measurement required by industry.