Assay of lipase and esterase activities in fresh pork meat and dry-cured ham

Abstract

Lipase and esterase activities in post-mortem pork muscle and adipose tissue were assayed. Acid lipases showed optimal activity in the presence of 0.8 mg bovine serum albumin (BSA)/ml and 0.05% (by vol.) Triton X-100, while neutral/basic lipases required 5 mg BSA/ml and no addition of Triton X-100. All lipases had an optimal temperature of 37° C except neutral muscle lipase, which was optimally active at 45° C. A wider range of optimal temperatures of 30–45 and 15–45° C was found for muscle acid esterase activity and neutral esterase activity, respectively. In adipose tissue, higher temperatures of 60° C and 45–75° C were found for maximal acid esterase and neutral esterase activities, respectively. Lipolytic and esterolytic activity assays in muscle and adipose tissue were conducted at four different stages in the processing of Spanish Serrano dry-cured ham. Recovered activities of muscle enzymes were more than 40% of the original activity, even at the end of the drycuring process. In adipose tissue, recovered esterase activity was also around 50% of the original activity at the end of the process, while lipolytic activity was significant only during the post-salting stage.