Quality of meat for portioning processes

By Michael Fielding on 8/31/2015

The markets in the poultry industry have changed significantly just over the past 15 years. In efforts to satisfy demand while also improving efficiency, a greater number of broilers have been grown to heavier weights generally ranging from 6 to 10 lbs. The percentage of birds (number of head) greater than 6 pounds has grown from about 23 percent in 2000 to more than 50 percent in 2015. This results in approximately 70 percent of broiler meat coming from these heavy debone market broilers.
The breast meat from broilers in this heavy market is deboned and commonly used in further processing. This meat is portioned into more appropriate sizes depending on its final use. Portioned products are used in many foodservice products such as meat for center of the plate chicken, chicken sandwich, whole muscle nuggets, strips and popcorn chicken. Portioned meat is also often found in retail cases marketed as fresh or frozen. Portioning allows processors to add value to the product as well as maximize the usage of the breast meat produced.

Multiple methods of portioning

Portioning can be done using many different methods, but the basics are that the fillets are cut horizontally, vertically, or both. The portioning process can either be an automated process (more common) or manual, and can use a variety of techniques for cutting including band-saw blades and water jet technology. In automated systems, a mold or template, using vacuum or pressure, can be utilized for horizontal/vertical cut combinations. These processes are useful in cutting meat into very specific sizes and/or weights. This is necessary as there are often narrow customer specifications on the finished product.
Beyond the ability of portioning processes to produce specific portions, quality of the product must also be kept in mind. One such quality factor is the tenderness of the meat in the finished product. Breast fillets already can be susceptible to toughening, but portioned meat can be affected greater in some situations.
In today’s market, broilers are often deboned immediately out of the chiller, which is about 2 hours postmortem, and it is at this time when the meat can be the toughest due to early deboning and that interaction with rigor development (or muscle cell metabolism).
Portioning following deboning in the early rigor period (2 to 4 hours postmortem) can lead to further toughening when cut vertically, across muscle fibers. The reason is that there is sufficient energy in the muscle that can allow the muscles to contract when cut (deboned). Therefore, the muscle fibers shortened and that results in the toughened meat when cooked. Fortunately, horizontally cutting does not further impact tenderness because fibers are not impacted due to direction of cut. Delaying portioning after deboning until after 4 hours postmortem can prevent that further toughening. However, from an efficiency standpoint, portioning after deboning is likely.

Solving the toughening effect

A solution to this toughening effect as a result of early deboning and portioning is marination.
Marination is adding a marinade consisting of water, salt and potential other ingredients such as chicken broth, sodium phosphate or starches. This can be done through injection and/or tumbling. The salt in the marinade along with any phosphate that could be present is the most functional ingredient in terms of providing a tenderness improvement. Salt works to solubilize proteins and bind water and this helps to increase tenderness.
However, these benefits, specifically tenderization, depend on various factors like deboning times, duration of time between deboning and marination, type of product, type and concentration of ingredients, level of marinade used, and method of marination (e.g. tumbling or injecting).

The “woody breast” phenomenon

The quality of the incoming meat also may affect the portioning process and/or final product. In recent times, the poultry industry has observed an emerging meat quality issue referred to as woody breast.
Woody breast occurs when the breast fillet is very hard and rigid, appearing somewhat contracted. The severity of this woody condition can vary, but the moderate and severe cases can certainly cause issues in portioning. Not only are these rigid, but the shape of the fillet is affected. Therefore, the ‘workability’ of these fillets can be decreased because the meat just is not flexible, especially in the first couple of days after processing.
Depending on the type of portion needed, it could be difficult to get the correct needed shape. Should the workability of these fillets be an issue, the fillets could be aged for a couple of days, which would allow the fillet to soften, or become less rigid, so that portioning could be an easier process. If woody breast is present, it may also be advantageous to cut the fillet into small portions for products such as popcorn chicken which are more bite-size in nature, with a coated surface. This may help to reduce any negative sensory attributes that may be present with this type of meat. Another alternative is to divert the meat into other products which can be cut more easily (not relying on fillet to be flexible), or even into ground type products.

Another quality issue of concern

Another issue that can be potentially problematic is a ridge that can be noticeable at the caudal (tail) end of the fillet. This ridge may be more prominent if woody breast occurs as well. However, it can still be present in normal, non-woody, breast. This ridge is most likely due to fillet shape of the fillet.
As broilers have gained in breast meat yield, the width of the fillet across the tip of the keel bone can be wider creating a U-shaped breast. Once the fillet is removed from the frame, and laid flat, a ridge (the regions on either side of keel area) can be present. Often when fillets are portioned, a “native”-shaped fillet will be cut from the tail end of the fillet leaving the top portion for other cuttings such as nuggets and strips.
If the ridge is in this “native” portion because of its location on the whole fillet, then the portion will have an uneven shape. The ridge would appear in the middle of the new cut portion and would result in uneven cooking, problems when placing product on a bun, etc. Using a flattener to flatten this portion could be helpful in making the thickness of the fillet more uniform especially across the width of the fillet.

Conclusion

Portioning as a whole is a very common practice in today’s poultry industry especially in the U.S. It is also a necessary practice as the industry continues to use large broilers for this debone market.
With portioning, a variety of products can be produced from a single broiler (i.e., butterfly fillet). However, final product quality and workability of the product can be affected by the state of the meat that is used. Understanding the quality of the incoming meat is important in producing high quality portions.