Solutions to Difficulties of Home Curing Pork

N. G. Marriott and P. P. Graham*
REVISED 2000 PUBLICATION 458-872
Virginia Cooperative Extension
VIRGINIA POLYTECHNIC INSTITUTE
AND STATE UNIVERSITY VIRGINIA STATE UNIVERSITY

Virginia Cooperative Extension programs and employment are open to all, regardless of race, color, religion, sex, age, veteran status, national origin, disability, or political affiliation. An equal opportunity/affirmative action employer. Issued in furtherance of

Cooperative Extension work, Virginia Polytechnic Institute and State University, Virginia State University, and the U.S. Department of Agriculture cooperating. J. David Barrett, Director, Virginia Cooperative Extension, Virginia Tech, Blacksburg;

Lorenza W. Lyons, Administrator, 1890 Extension Program, Virginia State, Petersburg.

VT/028/1000/1M/210866/458872

 I. Introduction

For centuries, meat has been preserved by drying, salting and smoking. Chinese ancestors have used salt to cure and preserve meat since the 13th Century B.C. Preservation by smoking is believed to have been developed inadvertently by primitive tribes who lived in caves and burned fires for warmth and to discourage predatory animals. The American Indian preserved meat prior to settlement by Europeans through hanging it in the top of a tepee to maximize contact with campfire smoke. During the past, meats have been cured to reduce spoilage. These meats were unevenly cured or dried and were frequently salty or too heavily smoked. After the development of refrigeration systems, meat has been cured primarily for the development of color and flavor desired by many consumers.

 Curing is the addition of salt, sugar, nitrates, nitrites and sometimes phosphates and ascorbates to meats for preservation, color development, and flavor enhancement. The functions of each ingredient used in curing are:

 Salt:

Sugar:

Nitrates and Nitrites:

  1. Contribute to the characteristic cured flavor.
  2. Contribute the characteristic reddish-pink color of cured meat.
  3. Prevent growth of a food poisoning microorganism known as Clostridium botulinum which can occur in foods that require heat processing.
  4. Retard the development of oxidative rancidity and rancid taste.
  5. Prevent warmed-over flavor in reheated products.

Phosphates:

Ascorbates:

II. Why Dry Cure?

Dry curing was the original method of preserving meat through a dry rub method of cure application. This method, which was brought forward from early civilization to the 21st century, involves mixing the cure adjuncts and subsequently rubbing the mixture on the external surfaces of the meat to be cured. Penetration of cure adjuncts primarily from the lean surfaces occurs via osmosis (created by salt). Therefore, this method involves long periods of storage with one or two additional applications of curing ingredients (a process known as “overhauling”). Although this cure method requires 1-2 months (or longer) for larger pork cuts such as hams and involves a large amount of shrinkage, it is considered a popular method for curing hams in Virginia. In fact, the Virginia Style Cured Ham was one of the first agricultural products exported from North America and continues to be exported every year. The Virginia ham is distinguished as a product with a distinct and unique flavor preferred by many throughout the world. The distinct advantages of a country cured ham by introduction of a dry rub cure are:

III. Curing Mechanism

When cure is administered, the salt diffuses inward, to form a complex with the meat proteins. The slower the diffusion inward, the longer the outflow of water and soluble proteins from the muscle. The basic mechanism involved in meat curing involves the action of nitrates and nitrites. Although other reactions and steps are involved in the curing mechanism, the following sequence of events provides a simplified explanation of the process. Nitrate is converted to nitrite by a reducing action of microorganisms that are present within the meat tissues. Reduction of nitrite to nitrous acid and ultimately to nitric oxide is effected either by microorganisms or by the muscle’s own enzyme system. Nitric oxide binds to myoglobin, the meat pigment protein, to provide the characteristic cured meat color. This cured color is fixed by application of heat during the smoking process.

IV. Effect of Curing On the Nutritive Value

The biological value of meat proteins is not lowered by curing and the B-complex vitamins are essentially unaffected. However, minimal losses of water soluble vitamins can occur through weeping. During storage, cured meats deteriorate through discoloration, oxidative rancidity, and microbial changes. These conditions will be discussed later. Nitrates up to 3 1/2 oz. per 100 lbs. of meat are permitted in a limited quantity in dry cured meat because of their importance in flavor, color fixation, and retardation of bacterial growth. Since nitrates may be toxic when eaten in large quantities, care should be exercised to use only the recommended amount as supplied in the commercial cure to be used. Commercial cures may be purchased from farm supply stores and some drug and food stores. A frequently used dry cure mixture utilizes 8 pounds of salt, 2 pounds of sugar and 2 ounces of sodium nitrate (dry cure only). These ingredients are mixed thoroughly and frequently divided into three equal parts for application at three intervals.

V. Problems - Solutions of Home-Cured Pork

Although home curing of pork may be successfully conducted if the proper steps are taken, certain precautions should be taken to improve the finished product. The following problems that are discussed can frequently occur. However, as the discussion suggests, solutions exist to maintain an acceptable product.

Lack of uniformity of size and shape of cured cuts - Uniformity can be improved by selecting cuts or live hogs from a specific weight range. Most hogs are slaughtered when their live weight ranges from 240-270 pounds. This size hog produces uncured hams that weigh 16-20 pounds. Picnics from hogs in this weight range weigh 8-10 pounds and the uncured belly averages 15-18 pounds. Uniformity of shape of each cut can be provided by separation of all cuts from the same location. An example of correct fabrication procedures of pork cuts to be cured is:

Recommended precautions include pork slaughter and curing hams during cold weather when these insects are inactive. Proper cleaning of the aging and storage areas is essential since the cheese skipper feeds and breeds on grease and tiny scraps of meat lodged in cracks. (Cracks should be sealed with putty or plastic wood after cleaning. Screens should be installed to prevent entrance - especially of flies, ants and other insects that carry mites.) Double entry doors are recommended to reduce infestation of insects. After cleaning and sealing cracks, a surface spray should be applied to the floor so that the thin layer of insecticide will kill insects that crawl over the deposit. Spray aging rooms once every three months with a pyrethrin-based spray to reduce infestation. Follow mixing and application directions on the pesticide label. This insecticide may be applied with a paint brush if the room is stocked with meat. If applied as a spray, remove all meat products from the storeroom before spraying. Allow the spray to dry before any meat is returned to the store room. If any product becomes infested after precautions have been taken, it should be removed from the storeroom and the infested area should be trimmed. The trim should be deep enough to remove larvae that have penetrated along the bone and through the fat. The un-infested portion is safe to eat, but should be prepared and consumed promptly. The exposed lean of the trimmed areas should be protected by greasing it with salad oil or melted fat to delay molding or drying. Ham trimmings can be used as seasoning or incorporated in ham sausage.

 

 

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