Background

New marketing techniques and marketing techniques of the past have focused on varying lean to fat ratios in ground beef and subprimal specific grinds (chuck, round, sirloin). As society affluences have risen over the last few years in some social circles, a desire for premium grinds such as prime or Certified Angus Beef, “Kobe” burgers and grass-finished ground beef, has become apparent in many markets. At the same time, there are many people who have suffered due to the decline in the country’s economic situation. These people are looking for a cheaper source of protein while still desiring the traditional meat science principles of tenderness, juiciness and flavor in the protein that they consume. There is however, limited information on the comparisons of the flavor profiles, shelf-life and general meat quality aspects of marketing techniques. It would be beneficial for the industry as well as consumer groups to know the implications for using varying source of grinding meat. Consumers desire a flavorful product. All health aspects aside, if a product is not flavorful, there will not be a demand for it.

Methodology

“Non-traditional” grinds included seven different fat percentages: 6.2, 8.1, 10.5, 19.3, 21.3, 28.4 and 29.0%. The “traditional” grinds included three different fat percentages: 9.6, 11.4 and 16.3%. The products were purchased from commercial meat fabrication facilities or from collaborating partners in those current supply chains. Grinding material was passed through a commercial meat grinder/stuffer (Handtmann, Lake Forest, IL). Following grinding either 1 lb loaves or 1 lb chubs were packaged. For MAP, the loaves were packaged into 2S Styrofoam trays (Cryovac, Duncan, SC) with absorbent diapers and overwrapped with oxygen-permeable polyvinyal chloride film (O2 transmission = 23,250 mL/m2/24 h, 72 gauge). Two sets of this packaging were prepared. The first set was the overwrap (OW) set and they went directly into retail display (Hussman, Bridgton, MO). The second set was Modified Atmosphere Packaging (MAP). These loaves were placed into a master bag with a Multipak-torre Ministretch with perforated film and a Multisorb – FreshPax (Buffalo, NY) and flushed with an industry standard low oxygen gas mix, (approximately 0.4%CO, 30% CO2, 60% N2). These master bags were then held in storage for approximately 8 days to simulate the average transportation and storage. The master bags were then opened and the packages were placed in the retail display. The third packaging treatment was clear plastic retail chubs (CH). The chubs were held in dark storage for 3 days to simulate transport from the manufacturing facility to the retail store. On the third day the chubs were placed on retail display.

Immediately following placement into the retail display (d 0) and every day through d 5 of retail display, Commission International de l’Eclairage (CIE) lean L* (muscle lightness), a* (muscle redness) and b* (muscle blueness) values were evaluated using a Hunter Miniscan XE Plus (model MSXP-4500C; Hunter Laboratories, Reston, VA) with illuminant setting D65 at 10° and a 3.5-cm aperture.

A modified version of Buege and Aust (1978) thiobarbituric acid (TBA) reactive substance assay was used to evaluate lipid oxidation. Samples were frozen after the appropriate days of retail display and samples from each replication were composite. Samples were homogenized with distilled water. A 2mL homogenate will be combined with 4mL TCA/TBA reagent and 100μL BHA. Samples will be heated in boiling water for 15 min and then chilled in ice water for 10 min and re-centrifuged. The peak absorbance of 540 nm of the supernatant was used to determine a value to be plugged into a regression equation generated from a set of standards on a DU 640 Life Science UV/ vis Spectrophotometer (Beckman Coulter, Fullerton, Ca).

Ground beef samples from each grind and each packing treatment and each display day were frozen at 0 ±2°C until sensory analysis was performed. Patties were formed from 150 g of meat with a basic kitchen hamburger patty press. Prior to sensory evaluation, patties were thawed (4°C for 12-18h), weighed, and placed in a pre-heated George Foreman clam-shell-style grill (Model GRV120, Macon, MO) and monitored with thermocouples until a final internal temperature of 76°C (AMSA, 1995) was reached. Cooked patties were weighed to determine the percentage cooking loss by dividing the weight lost during cooking by the pre-cooked weight. Patties were divided using an apple cutter producing eight pie-shaped samples and then placed in 1 oz. sample cups and placed into a warming oven until served to a six-member trained sensory panel. In a cubicle illuminated with red incandescent light, each of the trained panel members evaluated one sample from each ground beef patty and noted scores on the evaluation form. Each product combination was presented twice over the multiple day sensory evaluation period to assure there was no day of serving effect. Panel members were asked to take a bite of a salt-free saltine cracker and sip apple juice to aid in cleansing the palate and expectorate the sample in the cup provided. An eight-point scale was used for the evaluations of initial and sustained juiciness, cohesiveness, beef flavor, and off flavor (1= extremely dry, extremely crumbly, extremely bland, no off flavor to 8= extremely juicy, extremely cohesive, extremely intense beef, and extreme off flavor). Panelists noted appropriate off flavor descriptors provided on form if scores were noted for an off flavor. Intense training on off-flavor perception as well as tenderness, juiciness, cohesiveness and flavor was completed prior to the beginning of the sensory panel period.

Fatty acid analyses were conducted on frozen samples at the time of sensory evaluation utilizing fatty acid methyl ethyl (FAME) procedure. The FAME peaks were then integrated so that peaks could be labeled for analysis.

Findings

For packaging, the MAP had the greatest L*, a* and b* colorimetric values, the greatest level of oxidative rancidity and least initial juiciness and greatest off flavor over all treatments. Therefore, while color may be desirable, the ground beef quality suffers. The CH had the lowest amount of oxidative rancidity and with the exception of the low color values, it may be the best way to package traditional and non-traditional ground beef products.

Day 0 of retail display yielded the greatest a* and b* values with the lowest amount of oxidative rancidity. Detrimental effect did not start showing up until day 3 of retail storage. At day 3, there was an increase in oxidative rancidity, off flavor and a decrease in initial juiciness. The traditional grinds and non-traditional grinds both had good quality characteristics, but they varied with specific quality over different grinding treatments. The 9.6 and 11.4% fat traditional grind products were similar for quality attributes. Those had the greatest percentage of n3 fatty acids, the greatest amount of saturated fatty acids and the least percentage of monounsaturated fatty acids. Those were also the most cohesive in sensory evaluation by a trained panel. The 16.3% fat traditional grind had the least oxidative rancidity, the greatest percentage of monounsaturated fat and the least percentage of polyunsaturated fat.

The non-traditional grinds varied with maturity, marbling and production systems. The least amount of fat was a mature animal and had the greatest off flavor, the greatest percentage of n6 fatty acids and the greatest percentage of polyunsaturated fatty acids. The 8.1% fat non-traditional grind was a specific production system and it yielded the greatest a* values, greatest percentage of polyunsaturated to saturated fatty acids, the least percentage of saturated fatty acids and the highest percentage of monounsaturated fatty acids. The 10.5 and 19.3% fat non-traditional grind had the least amount of oxidative rancidity. The 21.3% fat non-traditional grind had the greatest amount of oxidative rancidity, as did the 29.0% fat non-traditional grind. The 6.2% fat non-traditional grind was a production system and yielded meat with the least amount beef flavor and greatest amount of off flavor, but this did have the highest level of polyunsaturated fatty acids and least amount of oxidative rancidity. The 29.0% fat non-traditional grind had greater percentages of monounsaturated fatty acids, greater cohesiveness, greater polyunsaturated to saturated fatty acid ratio, least polyunsaturated fatty acids and greater cook loss than many of the other traditional and non-traditional grinds.

Implications