NEW FREEZING PROCESS

New Zealand Herald, Volume LXVIII, Issue 21029, 13 November 1931, Page 12

NEW FREEZING PROCESS

EFFORTS OF MEAT BOARD. OBJECTIVES OF RESEARCH. EXHAUSTIVE INVESTIGATIONS. Nothing is known in Auckland of Dr.. iW. A. Bowie's process of meat freezing, under which a trial shipment of mutton, lamb and beef is being taken from Gisborne by the Tort Hunter, but the fact that the Meat Producers' Board is concerned in the experiment will stimulate general interest in it. Practically from its inception the Meat Board has been most active in investigating freezing, storage- and transport conditions with a view to improving the appearance of meat, and hence the market. Experiments in New Zealand freezing works were followed by the calling of a conference of refrigerating engineers and these are now held annually. The most important step was the detailed., scientific survey of freezing conditions carried out by arrangement with the British Food Investigation Board. Toward the end of 1929 Dr. Ezer Griffiths, of the National Physical Laboratory, Teddington, and Dr. J. R. \ ickery, of the Low Temperature Research Station, Cambridge, came to New Zealand, and starting their investigations in the abattoirs, continued them through the voyage to England. Their chief aims were the preservation of the ''bloom" of lamb carcases and the maintenance, of weight. The Meaning of " Bloom." By "bloom" is meant- a freshly-killed appearance. It. is the fine sheen on the outer membrane, most readily seen on the shoulders. With it goes a healthy pink colour in the patches of externa] muscle on either side of the spine. When "bloom" is lacking the muscle is liable to have a yellowish tinge. The scientists made careful observations from thi? time the lambs were killed until they reached the English shops, gathering data respecting temperature, humidity and movement of the air at all stages. Continuous observations wgre made of the loss in weight. It is estimated that if a saving of 1 per cent, could be made in the loss of weight during the freezing process it would mean £IOO.OOO -to New Zealand in an average season. Their work was linked with fundamental studies proceeding at the Cambridge Research. Station. It was most important because science required more knowledge about the effect of temperatures and humidity upon frozen meat. While the biological behaviour of fruit under cold storage conditions is well understood, the complexity of meat makes its problem much more difficult. The structure of muscle, the changes it undergoes after death, the meaning of rigor mortis, the chemistry of fat, and the effect of enzymes, bacteria and moulds on fat. rancidity-are among the problems involved. Report Under Consideration.

The report of the travelling scientists is now in the hands of the Meat Board and is being studied by every refrigerating engineer. It is regarded bv the board as the most comprehensive survey thathas yet been made of the frozen meat industry. Every link from the entry of lambs into the slaughterhouse until they were delivered at the retail shops in England was closely analysed. It shows that although there is no need for radical alterations of technique there appears to he room for improvement at each stage of the- chain of treatment. It is impossiblevto say at the moment whether' Dr. Bowie's process, which is now bfeing tested with the co-operation of the board, is related to the investigations described. The last report of the board ■ stated that it- had been closely ■watching "recent developments in rapid freezing of meat and the introduction of quickly-frozen meat in carton packages. It had also conducted experiments in regard to quick-freezing of whole carcases of lamb at low temperatures and tests had been made -in the direction of improving the "bloom" of lambs, particularly in regard to the effect of an improved cover. Quick-freezing Probable. It may be safe to assume that quickfreezing is a feature of the Fort Hunter experiment. Last year a new freezing process was announced in England, the inventor claiming that it reduced freezing time by 50 per cent., reduced shrinkage and maintained "bloom" after defreezing, ■which is further evidence of the amount of scientific attention that is being accorded the subject that is so important to New Zealand.

Some curiosity will be aroused by the fact that the Port Hunter shipment is to include the beei: of three bullocks. So far serious freezing difficulties handicap the beef export trade. While mutton and lamb are frozen, thawed and cooked ■without any loss of quality, beef suffers. When thawed beef leases some of its nutritive juices through "drip." The reason is that because of its bulk beef freezes more slowly than mutton or lamb and time is given for cell moisture to be drawn out of its compartments, which results in comparatively large ice crystals forming in the intercellular spaces. These crystals push the meat cells apart and the tissue becomes broken up and stringy. On thawing the water is not reabsorbed but runs away in "drip." This is the reason why it is much preferable to transport beef in chilled state only, but owing to the time it takes to transport beef from Australia or New Zealand to England there is always the risk of chilled beef producing moulds and bacteria. This problem is being attacked by the Cambridge research station. In the meantime, Argentine chilled beef has a great advantage through shorter distance. A report on the condition of the parcel of beef frozen under Dr. Bowie's process when it reaches England will he. a waited with great interest, although the. preservation of the "bloom" of lambs is doubtless the main object.