With sausage and deli products the epitome of convenience for many consumers, protein processors continue to develop new ways to take advantage of this segment of the marketplace. But what are these products without the casings that envelope them and (if edible) give them just the right bite and snap?

Certainly, protein processors have a wide variety of options to choose from when deciding upon casings for their product. Casings can be classified as natural or artificial, and each of these classifications provides several options for the processor.

Natural casings include hog, sheep and beef intestines, while artificial casings include collagen, cellulose and plastic varieties.

But how can a processor narrow down and eventually select the right casing for the job? According to a Worldwide Food Expo/American Meat Institute Show presentation in October 2009 by Lynn Knipe, processed meats extension specialist at Ohio State University, there are several factors that play into the selection process, including:

  • Product appearance
  • Stuffing and linking method
  • End user cooking method
  • Desired shelf life
  • Cost

The advantages to using natural casings include the traditional appearance and texture they provide, their ability to absorb smoke well, and their variable permeability. On the down side, natural casings lack good machinability and uniformity in thickness, diameter and color, and they require refrigeration.

Collagen casings resolve the issues that natural casings have with uniformity and storage concerns; they can be straight or curved and can be used right out of the box. But the cooking performance isn’t as forgiving as other options.

For processors considering cellulose casings, the main advantage to this type is their permeability to smoke, while the disadvantage is that cellulose casings require peeling.

Plastic casings are another option for processors who are producing hams, pates and lunch meats and don’t want the product exposed to possible pathogenic contamination after it is cooked. While some plastic casings, such as those used for dry sausage, are permeable to moisture and smoke, most are not. Also, on some plastic casings, flavor or color coatings are added to simulate traditional processing results on the product.