Solubilised proteins may offer phosphate-free meats
colour and texture of meat during storage may offer an alternative
to phosphates, says new research.
While the phosphate treated meats performed better on scores of lipid oxidation, the research, by scientists from Oklahoma State University, may offer an insight into future trends for meat ingredients to boost colour and palatability of stored meat. Phosphates are employed by the processed meat industry to maintain the "juiciness" of meat by binding water to the meat, and additives such as E450 (diphosphates), E451 (triphosphates) and E452 (polyphosphates) are commonly used. However, reports have indicated that phosphates may pose health concerns to certain segments of the population, most notably people with kidney problems and diabetics. "All current post-mortem treatments have drawbacks such as health or cost effects, so there is always a search to find a new tenderness treatment," explained lead author Dustin Vann. "Phosphates present health concern to certain segments in our society." "Improving steak palatability without the use of additives such as phosphates would be a valuable advancement for [these] segments of our society," he said. Writing in the Journal of Food Science, the Oklahoma researchers tested a protein solution containing solubilised myofibrillar proteins (five per cent of fresh weight) used as additives to paired beef strip loins. This was compared to beef with phosphate additives (4.5 per cent solution). Rosemary extracts (Herbalox) were added to both samples. They report that lean colour of the meat was enhanced for both samples and that by the end of the study both samples were still a dark red colour, "which would still be considered acceptable to the consumer," they wrote. "The overall average of 6.13 [out of seven] for protein-enhanced steaks is slightly lower than the phosphate values [6.47] but not significantly different," they added. One area where the protein-enhanced meat underperformed was in measures of lipid oxidation of the meat. Oxidation of the lipid content of meat produces off-flavours and odours, and the researchers reported that, while the phosphate-enhanced meat had measures below the detectable limit after both five and nine days, the protein-enhanced meat exceeded detectable limits after five days. "Antioxidant levels in the enhancement solution could be a contributing factor to higher lipid oxidation in protein-enhanced steaks," said the researchers. A panel of 20 trained tasters evaluated the enhanced meats on days five, seven, and nine and found that, while the phosphate steaks were classified as slightly more juicy compared to the protein-enhanced steaks (5.7 versus 5.1, respectively, on a scale on one to eight) both steaks were still classified as "slightly juicy" by the panellists. Overall, for the three categories of juiciness, tenderness and connective tissue, the phosphate-enriched steak was classified by the panellists as "slightly desirable", while the protein-enhanced steaks were "acceptable". While the general conclusion that the phosphate-enriched steaks performed slightly better than the protein-enriched steaks, the health concerns over phosphates may boost the acceptability of the solubilised proteins. Further research is also needed to evaluate and optimise the potential of the solubilised proteins. Source: Journal of Food Science Volume 72, Number 1, Pages C72-C77 "Evaluation of solubilised proteins as an alternative to phosphates for meat enhancement" Authors: D.G. Vann, C.A. Mireles DeWitt
