Profitability
through
Tumbling Techniques

by Chuck Sartell

Tumbling is the physical process of energy transferal within a piece of meat. It improves the distribution of liquid media such as brine; improves meat tenderness; and increases salt-soluble protein extraction and migration to the surface of the meat. Increased moisture holding, yields, and overall product quality are all accomplished in a controlled tumbling environment.

The optimum tumbling system provides as much control as possible, producing high quality, high yield, and the most uniform product that can be achieved. The following process controls contribute to such results.

• Previous air-free injection. No air pockets should exist, eliminating possible air-borne bacteria.
• Proper container fill. This is essential to provide maximum efficiency of the mechanical functions of the tumbling operation. If the container is too full, product fall and movement is restricted; too empty, and too much fall and product tearing will occur. This will cause a different product - too tender and over-tumbled, resulting in protein denaturation.

A sixty percent full-by-volume, 1 lb.-per-liter capacity is recommended. Variation is dependent upon bulk density of the tumbled meat

(boneless - high pump versus bone-in - low pump).

• Action and rest cycles during tumbling.

This is important to allow the meat to rest during the cycle. Usually a 10, 15, or 20 minute action followed by a 5 or 10 minute rest is recommended as a starting point. Depending on the product and the desired end results, the cycle should be adjusted to achieve the desired finished product. Some products may require more rest than action as the vacuum plays the major role.

• RPM of tumbler. Tumbler speed controls the amount of force by which the meat falls within the tumbler. Usually 10 or 12 rpms is recommended. However, slower rpm should be used when final product definition dictates. Any machine purchased should have a variable speed option.
• Tumble direction. The machine should gently push, shove, massage, lift, fold, and tumble the product to achieve maximum effect. Equipment should have reverse capabilities The final 5 minutes of the tumble cycle should be in reverse to clean protein and meat off the back of the fins prior to unloading.
• Vacuum. This may be the most important function on the tumbler. Availability of vacuum is necessary to assure rapid movement of brine throughout the piece of meat, and helps eliminate air pockets or pinholes and voids. As the meat swells, or expands in the chamber, some tenderness is achieved. Usually a vacuum of 70% to 80% of one atmosphere is drawn on the vessel or container; any is an asset, but too much defeats the purpose since moisture is pulled out of the meat at higher levels. New technology utilizes a pulsating vacuum system that exposes the tumbled product to a slow vacuum variation, cycling from 80% to 20% and back up to 80%. Some tumbler models backflush during this cycle with CO₂ or nitrogen, eliminating oxygen from the system and giving product a longer shelf-life.
  

• Temperature control. Some experts feel that you obtain a better color in warmer environment. However, with shelf-life, food safety, and yield concerns, it is not recommended. The product should be ideally tumbled at 33° F to 35° F. When a product is tumbled at 40° F. or higher, there will be a noticeable decrease in bind, yield, and sliceability. It is not recommended that these quality requirements be sacrificed for better color.
• Total tumble time. This is important for uniformity. Once a procedure has been adopted to yield a standard of product quality and definition, the procedure or cycle should be held constant.

The optimum tumbling system will have -

(RPM, direction),

(tumble, rest, and total),

(pulsating),

(direct readout and liquid CO₂ injection),

In some cases, the tumbler may only provide the mechanism for a vacuum chamber as in the case of uniform rub application to roast beef. However, it is a versatile piece of equipment that can pay for itself in a very short period of time with increased yields and improved, uniform product quality.