Predicting Intramuscular Fat Content in Pork and Beef by near Infrared Spectroscopy

Abstract

Prediction ability of near infrared (NIR) spectroscopy for intramuscular fat content (IMF) determination was studied. The material comprised 126 muscle samples; 46 pig longissimus dorsi and semitendinosus and 34 beef longissimus dorsi muscle samples. The IMF content was chemically determined in duplicate using two different chemical methods; fat extraction according to Folch et al. and Soxhlet extraction with hydrolysis according to SIST ISO 1443. Folch extraction underestimated IMF content compared to Soxhlet extraction with hydrolysis (-0.32%, P < 0.0001). Similar repeatability was obtained for Folch and Soxhlet extraction with hydrolysis (0.17% and 0.18%, respectively, P < 0.0001). Sample spectra were scanned from 400–2500 nm by the NIR Systems model 6500 spectrophotometer (Silver Spring, MD, USA) and analysed by WinISI II on minced and intact (pork only) samples. Modified partial least squares regression was used to develop models and to obtain calibration statistics: coefficient of determination in calibration( R2 C) and cross-validation ( R2 CV) and standard error in calibration ( SEC) and cross-validation ( SECV). We prepared different models (for a single muscle/common, by applying NIR spectrum or the whole spectrum, on intact and minced samples). Obtained models proved the remarkable prediction ability of NIR spectroscopy to determine IMF content ( R2 CV between 0.84 and 0.99; SECV between 0.14% and 0.53%) and confirms the potential of NIR spectroscopy to replace laborious chemical procedures. Regarding the factors studied, calibrations were less accurate for intact than for minced samples; the use of an NIR spectrum compared to the whole spectrum had no important effect on the prediction ability. According to calibration statistics, the prediction using a common equation for several muscles seems more reliable than the equations within the muscle, but the latter showed lower bias.

Use of near infrared spectroscopy for intramuscular fat selection in rabbits

“…In our case, RPD and RER were higher than those limits. Results on the accuracy of calibration equation for predicting fat content are similar to previous works in rabbit (Masoero et al, 1994;Pla et al, 2004), poultry (Abeni and Bergoglio, 2001), beef and pork meat (Prevolnik et al, 2005). Table 2 shows descriptive statistics of IMF content measured by chemical analysis and predicted by NIRS.…”

Comparison of PRKAG3 and RYR1 gene effect on carcass traits and meat quality in Slovenian commercial pigs

“…Drip loss was determined after 24-and 48-hour storage at 4°C and expressed as a percentage of the initial weight. The intramuscular fat content of LD was estimated in minced samples using NIRS (NIR System Model 6500 Spectrometer, Silver Spring, MD, USA) as described in Prevolnik et al (2005).…”

A Review of Optical Nondestructive Visual and Near-Infrared Methods for Food Quality and Safety

“…The best results were from Prevolnik et al [137] where the coefficient of determination value was over 0.9. Very poor results were obtained by Tornberg et al [134] when no preprocessing was used with VIS (400-800 nm) whereas NIR (800-2500 nm) provided almost twice as good results.…”

“…The intramuscular fat is important quality factor which has been studied for beef [130,136,137] and pork [133,137]. Sierra et al [136] studied the composition and content of intramuscular fat has been studied by using NIR transmittance 850 to 1050 nm.…”

“…One reason for difference could be different wavelength areas: Tornberg et al [134] used visible range 400-800 nm, Barlocco et al [138] used NIR (800-2500 nm), Savenije et al [132] used VIS/NIR (400-2500 nm), and Liao et al [133] used VIS/NIR (350-1100 nm). The homogeneity of samples varies [133,137,138]; for example, Liao et al [133] and Savenije et al [132] used intact pork samples. Minced pork samples were used, for example, in [137,138].…”