Vitamin E Can Offset Beef Oxidation
Steaks from beef cattle fed a diet heavy in wet distillers grains may develop an off-color or off-flavor sooner in the grocery store, but the addition of vitamin E to cattle's feed appears to reduce the problem, according to University of Nebraska-Lincoln research.Steaks from beef cattle fed a diet heavy in wet distillers grains may develop an off-color or off-flavor sooner in the grocery store, but the addition of vitamin E to cattle's feed appears to reduce the problem, according to University of Nebraska-Lincoln research.
Wet distillers grains, a byproduct of the ethanol and corn-processing industries, are an economical cattle feed, and one that Nebraska is particularly well-suited to take advantage of, given its steady corn supply and well-established cattle industry.
"Distillers grain is a great feed for cattle," said UNL meat scientist Chris Calkins.
However, UNL research found that wet distillers grains increase the amount of polyunsaturated fatty acids -- PUFAs -- in beef. And that leads to faster oxidation.
The quicker oxidation doesn't seem to matter with vacuum-sealed beef, but in the UNL research, it did affect meat that was repackaged onto foam trays, covered in plastic wrap and set out in simulated grocery store displays.
"It causes the meat to turn brown more quickly and it can develop off flavors," Calkins said. "We simulated retail display, so additional work is needed to measure the color and flavor changes under actual retail conditions. Some popular cuts of beef are likely sold before color and flavor differences would occur."
"It's hard to describe off-flavor. There was a different flavor in some steaks that some panelists didn't like -- usually when vitamin E was not included in the diet," said Calkins of the reaction of tasters in the research.
Tenderloins and flat-iron cuts were most susceptible to the discoloration and off flavors. Ribeyes seemed more resistant to the oxidation.
The higher percentage of wet distillers grains fed to beef, the greater the impact. The livestock tested were fed a diet consisting of up to 30 percent of distillers grains on a dry matter basis. "Not everyone is feeding that much distillers grains in the diet, which may be low enough to minimize color and flavor issues," Calkins said.
"We have some preliminary results now that suggest there's a way to address those potential problems," the Institute of Agriculture and Natural Resources scientist said.
The solution is to add vitamin E to beef cattle's diets during their finishing phase, he said.
"It suppresses or controls that oxidation," Calkins said.
The vitamin E must be added to the feed to get it into the membranes where some of the PUFAs gather; simply injecting it into meat wouldn't be expected to work.
Calkins said his research next will attempt to determine how much vitamin E must be added to the feed to be effective. To test the concept, initial research used a relatively high dose that would cost $1 to $1.50 per head. Since this represents an additional cost to producers, Calkins said, it's important to arrive at a cost-effective recommendation that results in a product that meets consumers' expectations.
"We need to be really careful that we can assure our customers that the shelf life of the product is going to be as good as it's always been," Calkins said.
Calkins said he also will explore the impact of different types of packaging on how quickly meat turns from the bright red consumers look for to a less-appetizing brown.
He also will try to test these laboratory results in a retail setting.
"To date, there have not been a lot of complaints on shelf life of beef even though we know a good percentage of the cattle are being fed distillers grains," said Calkins. "So we need to know the magnitude of the problem under commercial situations. It's to our advantage to be pro-active in identifying potential problems and offering solutions."
The research will continue with cattle on feed this summer, with further results to be gathered through next fall and winter.
Calkins' research is supported by the Nebraska Beef Council, the National Cattlemen's Beef Association, and under UNL's Agricultural Research Division, a part of the university's Institute of Agriculture and Natural Resources.