Study of dissected lamb muscles by visible and near infrared reflectance spectroscopy for composition assessment

Near infrared reflectance spectroscopy (NIRS) was used to study the reflect ance properties of intact and minced lamb muscles in two presentations to t he instrument to predict their chemical composition. A fetal of 306 muscles were examined from 51 lambs, consisting of the following muscles: longissi mus dorsi, supraspinatus, infraspinatus, semimembranosus, semitendinosus an d rectus femoris. Modified partial least squares (MPLS) regression models o f chemical variables yielded R-2 and standard error of cross-validation (SE CV) of 0.76 (SECV: 10.4), 0.83 (SECV: 5.5) and 0.73 (SECV: 4.7) for moistur e, crude protein and intramuscular fat in the minced samples expressed as g /kg on a fresh-weight basis, respectively. Calibrations for intact samples had lower R2 and higher standard error of cross validation (SECV) compared with the minced samples.