摘要

The aim of the present study was to evaluate the effect of incorporating pig back fat in restructured dry cured ham (RDH) on the lipase and lipoxygenase activities. Fresh raw hams were skinned, boned, cut into meat cubes (4-6x4-6x4-6cm). The meat cubes were restructured respectively with 0, 2, and 4% pig back fat paste into raw restructured ham. After 30 days of ripening, lipase activity in RDH was determined using a fluorescence spectrometer ((ex)=350nm, (em)=445nm), the result was expressed as mu mol of released 4-methylumbelliferone per hour per gram protein. Lipoxygenase (LOX) activity in RDH was assayed in a 96-Well Plate Reader M200, one unit of LOX activity was defined as an absorbance increment per minute per milligram protein at 234nm. Results showed that exogenous pig back fat incorporation from 2 to 4% gave rise to the increased neutral lipase and LOX activities (p<0.05), and the enhanced hydrolysis of neutral lipids and phospholipids, and production of free fatty acids, suggesting that exogenous pig back fat incorporation could improve the quality of RDH. Practical applications: Hams produced from genotypes with high intramuscular fat have more intense and persistent aroma, because intramuscular triacylglycerols are a good trap for most aroma compounds. However, traditional extensive feeding regime give rise to massive consumption of natural resource and this strategy is not always feasible because availability of natural resource is largely influenced by environment. The present work has provided a successful strategy to improve dry cured hams' quality that incorporating exogenous pig back fat directly into raw ham from general confinement feeding, not through traditional extensive feeding, could increase the content of lipid, and enhance the neutral lipase and LOX activities in dry cured meat. Restructured dry cured hams (RDH) with different pig back fat levels were successfully manufactured. This work shown that large differences in the neutral lipase and LOX (Lipoxygenase) activities of RDH can be caused by the exogenous pig back fat incorporation. An increase in pig back fat level from 2 to 4% in RDH significantly enhanced the neutral lipase and LOX activities during ripening.

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