Dry-cured hams are produced commercially in sizeable volume primarily in the Southeastern section of the United States. Production has increased rapidly in this area for many years (Kemp et al., 1981). This type of ham has been described in detail by Dunker and Hankins (1951).
In dry-curing, the curing agents are rubbed on the ham surface in a dry form. For large cuts, the cure ingredients should be applied several times during the curing period. The dry-curing procedure is slow and requires a large amount of hand labor (Forrest et al., 1975). Research has attempted to reduce the dry-cure processing time to a minimum while attempting to improve and standardize quality (Graham and Blumer, 1971a). Nitrate has been used traditionally in dry-curing. Work by Kemp et al. (1974, 1975) has shown that intact hams cured either with nitrate, nitrite, or a combination of these compounds, were similar in quality. Kemp et al. (1979) also reported that there were no differences in quality of boneless dry-cured ham produced with or without nitrate.
Tumbling a product has been reported to improve distribution of cure ingredients and to obtain a more desirable cured color (Krause et al., 1978). In this research, the tumbling technique was applied to the dry-cured boneless ham and a "lard coating" technique was used to reduce internal mold growth and retard moisture loss during storage. Product was placed in a plastic freezer bag to keep the hams clean and to reduce moisture loss.
The objective of this research was to evaluate the new curing and storage procedure and to determine the effect of nitrate and storage time on the residual nitrite, TBA values, composition, pH, total aerobic plate counts, and sensory properties of tumbled boneless dry-cured hams.