Assessing chemometric models developed using Raman spectroscopy and fatty acid data for Northern and Southern Australian beef production systems.

A total of 960 beef carcases from northern and southern Australian production regions were assessed by examining the subcutaneous fat. Carcases from four different production systems within each region were assessed, by Raman spectroscopy and the fatty acid composition determined to develop models that best classified the various production systems. As a result, 12 Partial Least Square Discriminant Analysis models were developed. A two-class model based on fatty acid composition was able to correctly classify 99% of grass and grain fed animals. The best Raman spectroscopic model correctly classified 94% of grass vs grain carcases produced in the northern region. For the southern production region, the models had the following classification accuracies; southern long-term grain fed (98%), southern short-term grain fed (95%), southern grass (96%), southern grass supplemented (97%), and the southern model classified grass vs grain (97%). Raman spectroscopy is considered a useful rapid method for classification of beef carcases based upon production system.

Preliminary investigation into the use of Raman spectroscopy for the verification of Australian grass and grain fed beef.

Australian grass and grain-fed beef products attract premium prices at sale and several beef processors market beef underwritten by production system claims. This preliminary investigation assessed the feasibility of using Raman spectroscopy to detect differences in the chemical composition of subcutaneous fat from cattle raised in extensive and intensive production systems. Raman spectra, fatty acid composition, ß-carotene composition and objective colour measurements were measured on 150 grass and 150 grain-fed cattle. Spectral differences at peaks including 1069 cm-1, 1127 cm-1, 1301 cm-1 and 1445 cm-1 suggest that Raman spectra is able to detect differences in saturated fatty acids, which were significantly higher in carcases from grain-fed cattle. Differences in spectra at 1658 cm-1 were observed, however further research is required to investigate the cause of this spectral feature. Overall, this study indicated that Raman spectroscopy is a potential tool for the authentication of beef carcases from grass and grain-fed production systems.

Measurement of drip loss in alpaca (Vicugna pacos) meat using different techniques and sample weights.

Drip loss is an indicator of water holding capacity in fresh meat that can be measured using the bag method and the newer EZ method. However, to our knowledge, no previous study has investigated the application of these methods to assess drip loss of fresh alpaca meat. Over a year, 160 alpaca (Vicugna pacos) loins were sampled using the two different drip loss methods. There was no difference (P = 0.490) in drip loss percentage between the bag (3.39 ±â€¯0.24%) and EZ method (3.16 ±â€¯0.22%). The 24 h pH had a significant (P = 0.03) impact on drip loss percentages, such that as pH increased the drip loss percentage decreased. A greater (P < 0.001) drip loss was found using the bag method if the sample weighed 80 g (4.04 ±â€¯0.15%) compared to 60 g (3.38 ±â€¯0.12%).