MEASURING FAT CONTENT OF GROUND BEEF STREAM USING ONLINE VISIBLE/NIR SPECTROSCOPY

Abstract

Thirty blocks of frozen beef from three truckloads each of nominal 50% and 15% fat meat were studied. The 27kgblocks were ground and formed into a continuous stream on a conveyor using a custom molding head attached to the grinder.A Perten diodearray type NIR/visible spectrometer was used to take reflectance measurements from the stream, which movedat 1.0 m/min. Spectral measurements were made each 3.3 cm, and samples were collected from the stream such that eachsample was represented by two successive measurements. Fat content of each sample was determined by ether extraction,and a prediction model was developed relating fat content to spectral measurements. Standard error of prediction (SEP)values for the calibration and validation data sets were 1.00% to 1.68% and 2.15% to 2.28% fat, respectively. Predictionsfor the fat content of an entire block gave SEPs of 0.70% to 1.05% fat. The results show that the molding head is effective,that the Perten machine is suitable for online measurements, and that the accuracy of predictions is high.