Consistent tender beef may arrive with the help of injection technology and simple calcium salt
By Dan Murphy, Contributing Editor
As an item of social significance, a tough steak doesn't exactly rank right up there with crime in the streets. But for beef packers and their foodservice customers, consistent tenderness is as essential to product satisfaction as a knife, fork and steak sauce.
Problem is, some steaks just don't make the grade-including many carrying the USDA Choice label.
"Even with the most careful quality grading, we know that a percentage of Choice beef is going to be tough," says Gary Smith, distinguished professor and holder of the Monfort Endowed Chair at Colorado State University. "Some researchers estimate it's about 10 percent; others claim it's closer to 18 percent or even 20 percent of all Choice beef."
Several landmark studies confirm Smith's statistics-and then some. The 1990 National Beef Tenderness Survey estimated that 20 percent of loin steaks, 40 percent of chuck steaks, and up to 50 percent of round steaks were "slightly tough" or tougher.
The 1992 National Beef Quality Audit concluded that one out of every four beef steaks "just doesn't taste right." A 1993 study by Texas A&M University meat scientists calculated that one tough beef carcass can negatively affect as many as 542 consumers. Although only 0.1 percent of all beef steaks are returned for replacement (or refund) because of toughness, researchers noted that "most consumers who have a bad eating experience don't complain-they just don't come back."
Unfortunately, the problem of inconsistent beef tenderness isn't confined to the meat on the menu.
A former associate director of beef improvement and education at the National Cattlemen's Association once said: "Tenderness is the biggest problem in the beef industry. We need to find a way to ensure that when people choose beef, they have a good eating experience."
According to J.O. Reagan, the director of Product Technology Research for the National Live Stock and Meat Board, results of the beef industry "Customer Satisfaction" study clearly indicate that both beef tenderness and flavor were closely related to the consumers' overall liking scores for beef.
What causes toughness in beef? Good question. Too bad we don't have all of the answers.
In 1984, an extensive review of more than 20 years of research by a team from USDA's Meat Animal Research Center in Clay Center, Neb., found that the amount and type of connective tissue and variations in overall marbling were most often associated with inconsistent tenderness. But those two factors accounted for only one-fifth of the confirmed samples.
"We really couldn't account for 80 percent of the variation in [beef] tenderness," points out Mohammad Koohmaraie, head of the center's Meat Research Unit. Thus, a research project was initiated to identify the source of this 80 percent variation in tenderness.
This resulted in a better understanding of the mechanisms that regulate tenderness and the discovery of calcium-activated tenderization (CAT).
Despite the lack of clear consensus on how to control tenderness, the industry as a whole appears to recognize that this is the primary quality problem today.
As such, an arsenal of weapons has been enlisted to improve overall beef tenderness. Among the technologies currently available are post-mortem aging; electrical stimulation; mechanical tenderizing; and the use of plant-based enzymes, such as papain.
But these options have only gone so far in solving the tenderness problem.
"Mechanical tenderizing and enzyme treatment are self-limiting and can be detrimental to product quality," explains Tony Mata, a consultant to the Meat Board. "It's difficult to control the enzymatic activity of papain. Plant based enzymes hydrolyze (chew up) any protein in their path. Therefore, the possibility exists of turning meat into mush."
None of the tenderizing technologies that are currently being used in industry are completely effective in eliminating tenderness problems. With the advent of a definitive protocol for injection of a simple food-grade calcium chloride solution into selected beef muscles, the industry may have at last acquired an effective weapon in its ongoing battle to put a palatable portion of beef on the nation's dinner plates.
"It's a simple process, really," explains Koohmaraie, the pioneer investigator of the technology. "Beef is injected with 5 percent of a 2.2 percent solution of food-grade calcium chloride, vacuum-packed, then stored for seven days before further processing."
Along with Koohmaraie, the other researchers were Tommy L. Wheeler, food technologist at USDA's Clay Center facility, and Mark F. Miller, animal scientist at Texas Tech University's Department of Animal Science. The group studied the effectiveness of the "calcium-activated tenderization" process. Their study data showed that it is feasible to inject the calcium chloride 24 hours after slaughter-basically, when carcasses have been fully chilled-and still achieve significant improvement in tenderness.
"The CAT process actually stimulates the natural post-mortem tenderization process that takes place in beef cattle," Koohmaraie notes. "And calcium chloride does not seem to 'over-tenderize' beef cuts that are already tender."
How does CAT work? Basically, the calcium chloride activates an enzyme system called calpain, which is naturally found in beef tissue, although levels of calpain vary genetically animal to animal. Like papain, calpain hydrolyzes (breaks down) meat protein. Unlike papain, calcium-activated calpain performs its mission exclusively on specific portions of muscle fibers without over-tenderizing.
In short, the CAT process appears to be well-suited to make significant strides toward addressing the beef industry's nagging consumer satisfaction problems. But as is the case with a more than a few other "can't-miss" proposals the industry has been handed, there is still both skepticism and inertia to overcome.
And there are questions concerning CAT including:
-- Regulatory: USDA regulations permit the use of calcium chloride (maximum concentration of 8.8 percent) at up to 3 percent of green weight.
However, the research indicates that CAT works best (tenderness and flavor) when injecting 5 percent of a 2.2 percent solution of calcium chloride. Higher concentrations and/or injection levels have shown to result in off flavors or excessive purge.
A small amount of salt (i.e., 0.01 percent in the finished product) will be needed to inject 5 percent of an added substance from a regulatory stand point.
Labeling must disclose the presence of calcium chloride and its nutritional value (except for exempt product), and an approved PQC program must be in place. Calcium chloride is used in many food processing applications and is readily available in commercial grades and quantities.
-- Injectability: The CAT process works only if the calcium salt is thoroughly distributed throughout the meat tissue.
"It is not possible to hand-inject calcium chloride and achieve the tenderizing effect you want," stresses Scott Seymour, the technical support manager for Des Moines, Iowa-based Townsend Engineering Co., which supplied the injectors used in a calcium chloride pilot program. "This process really doesn't work in a tabletop situation or at the restaurant level. You really need to be injecting subprimals at the packer level."
-- Microbial counts: Injection of calcium chloride 24 hours after slaughter did not significantly affect microbial counts vs. controls.
-- Color: Salts tend to be pro-oxidants, and thus tend to cause some discoloration when added to fresh meat. However, the lower levels of calcium chloride used in the study did not significantly affect color scores.
"With a typical three- to five-day retail shelf life [for fresh beef], you won't have a problem," Koohmaraie says. "Longer than that may cause slight discoloration, but beef is typically not held in the case longer than five days. "We really don't have a solid commercial interest in the calcium chloride process-not yet," he acknowledges. "But for those 'naturally' tough steaks out there, we know this process is going to help."
Recently, a large-scale CAT pilot program was conducted in Corpus Christi, Texas. (See story, page 40.)
This program confirmed reports from previous studies regarding the improvement in tenderness that can be obtained from CAT. These findings are of special significance because they were obtained using product from a commercial operation and with the participation of 1,500 consumers in an actual restaurant setting.
As promising as CAT appears to be, it will not ensure that 100 percent of the steaks will be tender. However, there are other related technologies that if used in conjunction with CAT will significantly improve consumers' perception of beef tenderness.
Detailed guidelines for the application of CAT technology have been published and can be obtained from the National Live Stock and Meat Board ("Guidelines of the Application of Calcium Chloride to Enhance Beef Tenderness." Item #11-415.)
ASSOCIATED ARTICLE:
Texas Taste Test
By Dan Murphy, Contributing Editor
Consumers say tenderizing with calcium chloride is no bum steer
by Dan Murphy, contributing editor
In order to further explore the effectiveness and palatability of calcium-activated tenderization (CAT), the National Live Stock and Meat Board, in conjunction with the Texas Beef Council, coordinated a pilot CAT program in Corpus Christi, Texas.
"We were very pleased to find out that under an actual consumption environment using product from a commercial operation, consumers can perceive the improvement in tenderness that is contributed by calcium chloride," says Tony Mata, coordinator of the project and consultant to the Meat Board. "The program also proved that CAT is ready for commercialization."
The project took place at the Land and Seas Restaurant in Corpus Christi, a family-type establishment serviced by Sam Kane Beef Processors, the packinghouse that supplied the beef strip loins used in the study.
Other participants in the study included Des Moines, Iowa-based Townsend Engineering and Houston-based TETRA Technologies Inc.
During a period of about five weeks, diners were served (on a blind basis) with one of three types of steaks: Control, papain-treated or CAT steaks. Fifteen-hundred consumers voluntarily agreed to fill out a questionnaire.
"This consumer study was designed to bridge the gap between research done at the academic level and the actual commercialization of the calcium chloride technology," explains Terry Stokes, executive vice president for the Texas Beef Council. "The diners didn't know if the steaks they ate were tenderized. At the end of the meal, they filled out short questionnaires asking them to rate the eating characteristics of their steaks."
The results indicated that the steaks treated with calcium chloride were significantly more tender. Juiciness was not significantly different between the three types of steaks served. Flavor, in fact, was rated somewhat higher on the CAT steaks. Furthermore, consumers indicated they would pay slightly more for the CAT steaks than for the other two types.
CAT improved the tenderness scores by about 8 percent, according to the Corpus Christi data.
"But the real value of CAT lies in the fact that it reduced the incidence of tough steaks by about 50 percent," Mata notes. "It does nothing to the majority of steaks because they are tender to begin with. But it certainly is an effective technology to improve the tenderness of those steaks which will tend to be tough."
Stokes acknowledges: "Treating steaks with calcium chloride is not going to be some kind of silver bullet. But this technology is one way to provide a solution to the problem of tough beef."
ASSOCIATED ARTICLE:
Trying for a Little Tenderness
Strategies to improve beef's eating satisfaction
-- Improve in-plant procedures for electrical stimulation of carcasses.
-- Standardize carcass chilling procedures to minimize cold shortening.
-- Establish a standard for minimum aging time.
-- Discourage cutting steaks from tougher cuts traditionally used as roasts.
-- Use mechanical tenderization when needed at both retail and foodservice.
-- Encourage rapid cooking of steaks at the foodservice level to reduce cooking loss and improve tenderness.
Source: National Cattlemen' s Association
1994 National Beef Tenderness Plan