Submitted to: Journal of Meat Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 1, 1999
Publication Date: N/A
Interpretive Summary: Toughness in low-fat ground beef is one of the reasons this product has limited consumer appeal. Manufacture of ground beef immediately following slaughter of the animal (hot processing) will produce very tender beef patties. It is not fully understood why this should occur, since the rapid chilling (necessary to process uniform patties) results in shortening of the muscle. With steaks and roasts, this condition would produce toughenin rather than tenderization. This study was conducted to further understand the influence of hot processing and grind size on tenderness and other properties of 10 percent fat, cooked beef patties. Grind size (1/8-inch and 5/32-inch) did not greatly affect patty properties. Greater tenderness occurred for hot processed patties even when they were compared to traditionally processed patties having 20 percent fat. Muscle fibers underwent considerable shortening in hot processed patties, and yet hot processed patties possessed very small particles when evaluated by a taste panel. Thus, because the hot processed muscle became shorter and harder, it may have resisted being forced through the grinder plate in grinding. This could lead to a "whittling" effect on the muscle producing smaller particles and ultimately greater tenderness.
Technical Abstract: This study was conducted to further understand the role that hot processing and grind size exert on cooked beef patty tenderness and other properties. Low-fat (10 percent) hot-processed (HP) and cold-processed (CP) beef were ground either through a 0.32 or 0.40 cm plate. A 20 percent fat CP product was also manufactured through a 0.32 cm plate. HP patties had higher pH, shorter sarcomere lengths, higher tenderness scores (including greater number of smaller particles during chewing) lower shear force values, higher flavor scores, less well-done cooked color, longer cooking times and higher cooking yields than CP patties (P <0.01). The use of a 0.32 cm rather than a 0.40 cm plate improved tenderness properties, especially for HP patties. Other properties were not greatly influenced by grind size. Sensory evaluation of patties showed indication that the greater tenderness of hot processed patties may be due to the presence of smaller meat particles. Highly contracted muscle, providing resistance to grinding, could be responsible for the small meat particles.