Optimizing meat quality.

As you may know, the tenderness of meat is affected by various processing conditions related to temperature. Researchers at Mirinz Food Technology and Research Ltd. (PO Box 617, Hamilton, New Zealand), working with the Swedish Meat Research Institute, found that rigor temperature has important effects on meat quality, apart from muscle shortening.

Subsequent studies at Mirinz showed that calpains, the major enzymes responsible for tenderness, degrade faster at temperatures above and below 15 C. Although meat ages faster at temperatures greater than 15 C, reduced calpain levels limit its final tenderness. To achieve meat of consistently high quality, researchers found that a significant amount of attention has to be given to controlling processing temperatures.

On another front, meat with a range of pH values from 5.5 to 6.3 was cooked and evaluated by sensory panelists. The panelists found that intermediate pH meat (5.8 to 6.0) had a less-acceptable tenderness and flavor than meat above and below this range. Irrespective of pH, meat cooked to a low temperature of 60 C was the most acceptable and had the least cooking loss.

Although high pH meat, greater than pH 6.2, is visually unappealing when raw, panelists found it to be the most acceptable overall when cooked. This could be attributed to that meat's remarkably high tenderness. When meat of similar tenderness but various fat levels, ranging from trace levels to 13% fat content, was cooked to 70 C (medium rare) or 80 C (medium), panelists preferred meat cooked to the lower temperature and slightly preferred the meat containing the most fat. Researchers believe an extraordinary amount of fat is needed to result in any improvement in consumer acceptability.

A formal in-house survey assessed staff attitudes toward meat containing various amounts of fat. Staff overwhelmingly preferred lean meat. Although most indicated in the survey that they liked their meat cooked medium rare, when asked to visually assess slices of meat cooked differently, the same staff members tended to select meat cooked to a higher temperature as being best. These results indicate that information needs to be presented to consumers on how meat should be cooked for optimal acceptability.

Further information. Carrick Devine; phone: [phone]; fax [phone]; URL: http://www.mirinz.org.nz.