Fresh and frozen meat largely the same

Irene Midling Andreassen

24. November 2011

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New research shows that there are only minor differences in quality between fresh reindeer meat and meat that has been frozen and thawed. As a consequence, it might be possible to sell reindeer meat from the meat counter all year long.

Reindeer are only slaughtered in season, and access to fresh reindeer meat is consequently limited to fall and winter. In grocery stores, reindeer meat is therefore mainly sold frozen.

In the research project in question, both fresh and thawed meat were packaged through modified atmosphere packaging (MAP), which entails that the packaging is sealed before the air is sucked out and replaced with carbon dioxide and nitrogen. The meat was then refrigerated for 21 days at 4°C in packaging with a CO2 emitter, which generated CO2 during storage and absorbed humidity from the meat, something that extended the product’s shelf life.

Meat from Kautokeino

In February 2010, fresh rump steaks of approximately equal weight were transported from the town of Kautokeino in the far north of Norway. The slabs of beef were stored for three days at 4°C. Half of the slabs were then sliced and stored in a refrigerator, while the remaining slabs were frozen. After being frozen for six months at -40°C, these slabs were thawed, sliced, and stored in a refrigerator in the same manner as the fresh meat.

Considerably higher acidity in thawed meat

Thawed and stored meat showed considerably lower pH levels than fresh and stored rump steaks. This is because frozen/thawed meat is less able to resist changes in acidity during storage.

Fluid loss is undesirable

In both storage experiments, the greatest fluid loss was measured during the first two weeks. Fresh meat lost considerably more fluid during storage than frozen/thawed meat. This can be explained by the fact that the frozen rump steaks had already lost some fluid during the thawing process. However, fluid loss is undesirable no matter when it occurs, both from a financial standpoint and because it makes the product less juicy.

“Heat treatment at 65°C caused slices of fresh meat to lose somewhat more fluid than thawed samples,” explains project manager Maria Mielnik. “The difference was not significant, however. Nor was there any evidence that refrigerated storage in a modified atmosphere affected the cook loss.”

Large amounts of antioxidants in reindeer meat

Reindeer meat contains relatively large amounts of antioxidants. This experiment showed that the amount of antioxidants in reindeer meat did not decrease during the freezing process or during refrigerated storage. This suggests both that reindeer meat keeps well and that the packaging adequately protected the meat against the detrimental effects of oxygen.

Colour differences

Colour analyses revealed considerable change in colour following the freezing process. Frozen meat was darker, less red, and more yellow than fresh meat. During storage, thawed meat also gradually faded and received a more bluish hue.

Bacterial growth

Microbiological results from this experiment suggest that fresh reindeer meat stored in MAP with a CO2 emitter may have a longer shelf life than meat that is frozen, thawed, and stored. The spore count on the surface of frozen/thawed meat was nevertheless considerably lower at the beginning of storage, but after a week the spore count had doubled and was then at approximately the same level as fresh meat. It is worth noting, however, that the number of bacteria did not exceed the prescribed limit. In neither case was there any sign of nonstandard appearance, odour, or taste after three weeks of refrigerated storage at 4°C.

In short, the main differences between fresh and frozen meat, stored in MAP with a CO2 emitter, concerned colour and bacterial growth, but these differences were not major.

“Our conclusion is therefore that both fresh and thawed meat are suitable for MAP storage with a CO2 emitter,” Mielnik says. “The selling of reindeer meat from the meat counter can therefore become a year-round activity. At the same time it is vital that the package labelling states whether the meat has been frozen or not.”

The project is co-funded by the Committee for Research Funds from the Reindeer Husbandry Agreement and Nofima.

Food and health   Raw materials and process optimisation  

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