Use of Near-Infrared Spectroscopy to Discriminate DFD Beef and Predict Meat Quality Traits in Autochthonous Breeds

Abstract

The potential of near-infrared reflectance spectroscopy (NIRS) to discriminate Normal and DFD (dark, firm, and dry) beef and predict quality traits in 129 Longissimus thoracis (LT) samples from three Spanish purebreeds, Asturiana de los Valles (AV; n = 50), Rubia Gallega (RG; n = 37), and Retinta (RE; n = 42) was assessed. The results obtained by partial least squares-discriminant analysis (PLS-DA) indicated successful discrimination between Normal and DFD samples of meat from AV and RG (with sensitivity over 93% for both and specificity of 100 and 72%, respectively), while RE and total sample sets showed poorer results. Soft independent modelling of class analogies (SIMCA) showed 100% sensitivity for DFD meat in total, AV, RG, and RE sample sets and over 90% specificity for AV, RG, and RE, while it was very low for the total sample set (19.8%). NIRS quantitative models by partial least squares regression (PLSR) allowed reliable prediction of color parameters (CIE L*, a*, b*, hue, chroma). Results from qualitative and quantitative assays are interesting in terms of early decision making in the meat production chain to avoid economic losses and food waste.

Keywords: Asturiana de los Valles; DFD classification; NIRS; Retinta; Rubia Gallega; meat quality.

Figure 1

NIR spectrum acquisition system. (a) LabSpec 5000 fitted with a fiber optic contact probe (ASD Inc., Boulder, CO, USA); (b) absorbance spectra of all samples included in the study (1000–2500 nm). Different color lines represent each different spectra.

Figure 2

PLS-DA analysis after absorbance (log 1/R): 2D scatter plot of scores of total meat spectra data from: (a) Total (1000–2500 nm); (b) Asturiana de los Valles (AV; 1000–1800 nm); (c) Rubia Gallega (RG; 1000–1800 nm); and (d) Retinta (RE; 1000–1800 nm) sample sets. Graphical representation of PC1 (91%, 32%; 98%, 48%; 93%, 66%; and 74%, 14%, respectively) vs. PC2 (8%, 4%; 1%, 4%; 3%, 3%; and 25%, 25%, respectively). Red dots: DFD samples; blue squares: Normal samples.

Figure 3

Left: Mean absorbance (log 1/R) spectra of Normal (blue) and DFD (red) meat samples from: (a) Total sample set after averaging 110 Normal and 18 DFD spectra (1000–2500 nm); (c) purebreed Asturiana de los Valles (AV) after averaging 43 Normal and 7 DFD spectra (1000–1800 nm); (e) purebreed Rubia Gallega (RG) after averaging 30 Normal and 7 DFD spectra (1000–1800 nm); and (g) purebreed Retinta (RE) after averaging 40 Normal and 4 DFD spectra (1000–1800 nm). Right: PLS-DA analysis after absorbance (log1/R): graphical representation of regression coefficients (B) of wavelengths in DFD meat spectra data from: (b) total (1000–2500 nm), (d) AV (1000–1800 nm); (f) RG (1000–1800 nm), and (h) Retinta (1000–1800 nm) sample sets. Significant variables are highlighted in black.