Compression of Freeze-Dried Beef to Form Bars: Plasticizing with Water Transferred as a Vapor.

摘要

The plasticizing of freeze-dried beef by water addition and the compression of the beef to form rehydratable bars have been accomplished using two different sets of equipment. Water addition has been accomplished by transfer of water vapor to the meat in an evacuated system. The water added should be about 12% of the weight of the dry meat. It can be transferred in a period of 3 to 5 hours. Fat weakens the bars and when high-fat beef is used it may be desirable to use a binder to give the bars sufficient mechanical strength. A forming pressure of 3000 psi is suitable for some lots of beef. High forming pressures should be avoided since they generally give bars that reconstitute (rehydrate) poorly. Basic information is given on adsorption and desorption, on the temperatures reached as these processes occur rapidly, and on the vapor pressure and heat of vaporization of the ice and associated volatile constituents of freeze-dried raw beef. (Author)