General points to consider when manufacturing processed pork
There are processing features which influence product quality and are important to keep in mind before considering reducing salt or using a potential substitute. The more relevant ones are presented here.
Meat to be processed should be at a temperature of 0-3 °C to avoid bacterial growth and to keep the bacteria count as low as possible (maximum permitted count can be between 102 and 104 per gram of meat). A low initial bacteria count is essential to keep the count low throughout the manufacturing process. In addition, high hygiene standards must be maintained during the process in order to avoid contamination (Feiner, 2006).
Correct preparation of the brine is essential, in both injected and immersion-cured products. The optimum temperature of the brine is between -2 °C and 2 °C and it should be kept low to avoid multiplication and/or metabolic activity of possible contaminating micro-organisms. The brine should be prepared shortly before it is going to be used because some of the additives break down over time. The order in which additives are added is important.It should be: phosphates ( (soy) protein ( starch ( salts ( carrageenan. Phosphates should be added first because they require a large volume of free water to dissolve. If instead salts are added before the phosphates, there may be insufficient free water for the phosphates to dissolve. After phosphates, sugars and injectable protein should be added. However, it is recommended that salts are added before hydrocolloids; this is because salt reduces the surface tension of water and therefore enhances the dispersibility of carrageenan and starch. It is best not to reuse brines for injection into meat. However if the brine is going to be reused it must be stored at low temperatures (0 °C) and kept for only a short time because it becomes contaminated with blood, proteins and enzymes.
Meat to be processed must be fully thawed prior to injection and there must be no semi frozen areas in the meat. This is because there will be frozen areas where distribution of the injected brine is incomplete and so there will be poor uniformity in the product .
As we have seen, the principal binding agent in reformed meats is myosin. Formation of the myosin gel is heat-dependent and it occurs as the meat is cooked. Air has to be removed before cooking to ensure good coating of the meat pieces by the soluble myosin. When the reformed meat pieces are coated and the myosin gel forms, the reformed meat will retain its shape provided a strong air-free gel has been formed. Because the solubilised protein is extracted from the interior onto the exterior of the meat piece it naturally displaces air from the meat surface, but it is important not to inject air with the brine or to incorporate air when shaping a reformed meat. The individual muscles to be processed for reformed whole-muscle ham products should also be free of any surface fat. This is because fat on the meat surface reduces coating by the solubilised proteins and therefore binding, resulting in poor slice cohesion. Connective tissue does not bind as strongly with myosin as muscle proteins. Therefore, selecting well-trimmed raw meat will improve cohesion of the final product. Cohesion is particularly important in thinly sliced product, such as vacuum packed wet-cured ham slices.
Uniform salt uptake
When the aim is to reduce the average salt content in dry-cured hams, the first step that has to be achieved is reduction of the variability in salt uptake; salt should reach all parts of the meat (including fatty tissue and bone) to obtain a stable product. Within normal limits, salt uptake is independent of the brine concentration, but depends more on ham characteristics (pH, weight, fatness) and on processing procedures (trimming, salting conditions such as time, and temperature). Thus the procurement of raw material according to these characteristics and good control of these processing parameters will allow reductions in salt uptake variability (Wood, 1966; Gou et al., 2009).
What impact would slow or variable salt diffusion have on the quality of the product?
List some of the processing features which influence product quality