The effect of RN gene on yields and quality of extended cooked cured hams.

The effect of RN(-) allele on minimally processed hams as manufactured in France is now well established. In the present study, meat from 35 rn(+) and 51 RN(-) pigs on the basis of their glycolytic potential (GP) was used to assess the effect of the RN(-) allele on a model system and on yields and quality of cooked hams cured with a 40% brine addition containing the most common meat processing ingredients. Quality parameters were also measured on the fresh loins and a glucose assay was carried out on meat juice from both hams and longissimus dorsi (LD) muscles. With respect to GP, glucose content of LD juice gave the best prediction of RN status with 10% misclassified samples in comparison with 20% as determined from ham juice. Lower pH and higher drip loss and L* values were measured on the LD from RN(-) pigs (p⩽0.001). Technological yields obtained on the model system and on extended cooked cured hams were lower in meat from RN(-) pigs (p⩽0.001). However, pH value was more influential on the yield of the model system while protein content and particularly the amount of extractable sarcoplasmic proteins were more determinative on cured hams probably due to the effect of tumbling. All other quality traits were lower in hams from RN(-) pigs (p⩽0.001). Meat from RN(-) pigs can be used for the manufacture of extended cured products, but under similar processing technologies, quality and yield will remain inferior to what would provide pork of normal quality.