Maria B. Mielnik

Commercial antioxidants control lipid oxidation in mechanically deboned turkey meat

Effects of commercial rosemary antioxidants on oxidative stability of mechanically deboned turkey meat (MDTM) compared with Trolox C (vitamin E), ascorbic acid (vitamin C) and control without antioxidant were investigated. Antioxidants were added to meat at three levels. Thiobarbituric acid (TBA) assay and dynamic headspace gas chromatography were used to assess the effects of commercial antioxidants on lipid stability of MDTM during 7 months of frozen storage. Increased levels of TBA-reactive substances (TBARS) and volatile carbonyl compounds were noticed in all meat samples during storage, however most distinctly in meat without antioxidants. Retarding effect of antioxidants on the development of oxidation depended on the level and type antioxidants. Trolox C-a water soluble, synthetic derivative of vitamin E possessed the greatest antioxidative activity reflected by the lowest values of TBARS and volatile compounds. Ascorbic acid was less efficient than Trolox C and Biolox HT-W (rosemary), but more potent than most rosemary extracts in suppressing lipid oxidation especially in the long term frozen storage MDTM. The DPPH() method confirmed that antioxidant activity depends on the concentration of active compounds present in the samples available to scavenge the free radicals formed during the storage period. Supplementation of MDTM with antioxidants could be an alternative method to prevent oxidative degradation of the meat during frozen storage when vacuum packaging is not practical.

Prediction of sensory characteristics of beef by near-infrared spectroscopy

Sensory hardness, tenderness and juiciness of M. Longissimus dorsi muscles from 10 beef carcasses at three ageing stages were predicted by near-infrared (NIR) spectroscopic analysis in the reflection (NIRR) and transmission modes (NIRT) during 14 days ageing at 2°C. Predicting the sensory variables hardness and tenderness from NIRR measurements using principal component regression (PCR), yielded correlation coefficients in the range 0·80-0·90. The root mean square errors of prediction for the predictions of hardness and tenderness were in the range 0·5-0·7, given in sensory assessment units. Juiciness was not well predicted. Prediction of sensory variables from NIRT measurements did not give satisfactory results. Including samples from all carcasses, cows and young bulls in the models resulted in good predictions from NIRR measurements of frozen and thawed samples. However, the best prediction results were generally obtained from separate calibrations of the samples from the bulls. The potential of NIR spectroscopy in the prediction of sensory variables in whole meat needs to be further investigated on a larger number of samples with different breeds, animals and process treatments included.

Marinating as a technology to shift sensory thresholds in ready-to-eat entire male pork meat

This study investigated the effect of marinades in improving the eating quality in ready-to-eat boar meat. Neck chops with fat content below 18.9%, skatole ⩽1.1ppm (range 0.03-1.1) and androstenone ⩽5.6ppm (range 0.01-5.6) were used. In a screening experiment different marinades were tested for their ability to mask boar taint (defined as manure and urine odour and flavour). Liquid smoke and oregano extracts appeared to have the best potential for masking, and were studied in detail. Results from the study indicated that marinated chops with skatole content of approximately 0.4ppm appeared similar to castrates in boar taint. Chops with skatole contents above 0.7ppm remained unmasked despite the use of strongly flavoured marinades. Unmarinated chops served at 60°C were more tainted than those served at 15°C, but scored lower for boar taint when reheated, although the concentrations of androstenone and skatole remained the same. The fat content of the chops was not well correlated to the perception of boar taint. The attributes manure and urine were correlated with the level of skatole, but urine attribute was not a good indicator of the androstenone level.

Composition and some quality characteristics of the longissimus muscle of reindeer in Norway compared to farmed New Zealand red deer.

Norwegian reindeer of Finnmark county live under harsh conditions on extensive feed sources. Thus the meat may have special qualities. M. longissimus lumborum from 30 animals was investigated with respect to carcass and meat quality and compositional/nutritional characteristics. Meat from calves had a higher myofibrillar fragmentation index and tenderness, and had lighter, redder and more yellow colour than meat from adult reindeer. Regarding nutritional compounds the meat from calves had lower antioxidant capacity, and higher taurine levels than adults, while the levels of iron, carnosine, anserine, and vitamin E were similar. Carcass weights of the adult reindeer were lower than the weights reported for Swedish reindeer and New Zealand farmed red deer. Reindeer muscles had higher antioxidant capacity, shorter sarcomeres, smaller muscle fibre diameters, higher n-6/n-3 ratios of fatty acids in the intramuscular fat and higher muscle taurine levels relative to values for the same muscle of New Zealand farmed red deer.