Humectants improve myosin extractability and water activity of raw, cured intermediate moisture meats

Glycerol, propylene glycol and sorbitol were incorporated into salt-based intermediate moisture meats manufactured from porcine M. longissimus thoracis and bovine M. biceps femoris by dry curing and air drying at 4°C. Moisture content and water activity (a(w)) in cured pork were reduced by the addition of propylene glycol and sorbitol. Propylene glycol was more effective than sorbitol in lowering a(w). The extractability of myosin heavy chain, used as an index of alteration of myofibrillar protein, decreased in intermediate moisture porcine meats with the addition of salt and was unaffected by sorbitol. However, use of glycerol and propylene glycol in cured and air-dried pork increased the extractability of myosin heavy chain. Whereas intact myofibrils could not be extracted from salt-cured, air-dried beef, myofibrils could be made from air-dried beef cured in the presence of 10% glycol, 5% propylene glycol and 4% sorbitol. Such myofibrils contracted immediately on addition of Mg(2+)-ATP. In addition, even after storafe for 5 months, including 30 days at 25°C, myosin heavy chain could be extracted from meat cured with this combination of humectants. In comparison with salt curing alone, curing meat with the above three humectants together, plus salt, results in intermediate moisture meats more like fresh meat.