THE EFFECT OF PRESSURE AND PHOSPHATES ON YIELD, SHEAR, AND COLOR OF MARINATED BROILER BREAST MEAT

Authors: Smith, Douglas; Young, Louis

Submitted to: European Symposium on Quality of Poultry Meat
Publication Type: Proceedings
Publication Acceptance Date: 4/20/2005
Publication Date: 5/25/2005
Citation: Smith, D.P., Young, L.L. 2005. The effect of pressure and phosphates on yield, shear, and color of marinated broiler breast meat. Proceedings 17th European Symposium on Quality of Poultry Meat. p. 139-144.

Interpretive Summary: As much as 50% of the broiler chicken meat produced will be marinated in some form prior to consumption. Typical commercial marinades are made of water, salt, and phosphates, and this is added to the chicken meat in a large rotating barrel-like tumbler. During tumbling, vacuum pressure is applied, as it helps the marinade to penetrate into the meat. This marination process may improve yield, decrease weepage in the package, improve tenderness, and lighten the color somewhat of the white meat. There are questions, however, of exactly how the phosphates in the marination solution interact with the vacuum pressure to provide these benefits. Also, some individuals in the US prefer, and some country’s regulations require that phosphates not be added to chicken meat. For these reasons this experiment was designed to determine the role of phosphate marinades, vacuum pressure, and their interaction on meat quality. Results show that the use of phosphates greatly increases cook yield (which probably would also improve juiciness of the meat) and slightly lightened the meat. Vacuum pressure during tumbling was no better than a lack of pressure (other than normal atmospheric pressure) or the opposite of vacuum, positive pressure. Pressure, either vacuum or positive, also does not interact with phosphates to either improve or decrease meat quality. Phosphates in marinades are important for cooked meat yield, but there is no reason to apply vacuum pressure during tumbling.

Technical Abstract: A significant portion of raw poultry meat in the U.S. is marinated prior to consumption, usually with a mixture of water, salt, and phosphates that are vacuum tumbled with the meat. This study was designed to determine whether pressure, phosphate, or both were responsible for the increase in marinated weight and retention during cooking after marination. In each of three replicate trials, 60 broiler breast fillets were assigned to tumbler vessels with pressures equivalent to either vacuum (381 mm Hg below ambient, VT), ambient (AT), or positive (PT, 776 mm Hg above ambient), with or without phosphate in the marination solution (added at 15% by weight to raw meat weight - either 91% water, 6% salt, and 3% phosphate or 94% water and 6% salt, respectively) in a 3X2 design. All tumblers were operated at 15 RPM for 20 min at a temperature of 30 C. Raw fillets were weighed, color measured via colorimeter, marinated, stored 1 h, reweighed, cooked, reweighed, color re-measured, held overnight, and two strips per fillet sheared via the Warner-Bratzler method (WBSHR). Phosphate had no significant (P<0.05) effect on % marinade uptake; the type of pressure application was significant, however, as AT (12.8%) samples picked up more marinade than PT (11.4%), but neither was different from VT (12.0%). There was no effect of pressure or phosphate on % drip loss (mean = –1.06%). For cook yield, there was no effect due to pressure treatment; phosphate, however, significantly increased yield (86.1 vs. 76.6%). For WBSHR, kg force to shear for VT (9.2) was higher than either PT (5.6) or AT (5.5) for the phosphate treatment, but shear force for PT (9.3) was higher than VT (6.0) or AT (6.2) for the non-phosphate treatment. There were no differences in raw color due to pressure or phosphate treatments, but phosphate increased cooked L* from 70.6 to 71.6, and decreased cooked a* from 1.57 to 0.95 (no practical significance). Overall, the type of pressure application during tumbling has no effect on % drip loss, cook yield, or color values, and only minor effect on % marinade uptake, and the major effect obtained with phosphate is increase in yield. Based on these data, processors may improve yield with phosphate in marination where allowed, but vacuum pressure during tumbling provides no advantage compared to ambient or positive pressure.