Another type of tenderizing machine is the automatic meat pre-massaging unit described in patent US 7578732 B2. The automatic meat pre-massaging unit, consists of two single hammers (or a pair of two single hammers) causing a stretching effect on the muscle fibers, multiplying the inter-fibrillar free spaces allowing for the brine to enter into these spaces during the first steps of massaging (hammer effect). During this process results an important reduction of total mass- aging time and , consequently, an increase in productivity of the massaging, increased cooking yield, increased slicing yield, highly improved meat texture and greater intermuscular binding in the cooked meat products treated with this technology