177 e

REVIEW O F TECHNOLOGY OF NEAT FREEZING

W. L a SULZBACHER

In a weak moment I agreed t o begin t h i s thing w i t h a discussion or review of the technology of meat freezing and then when I sat down t o think t h i s problem Gver I decided there really was not a great deal I could say about it e

You have a l l heard the story about the explorers who are supposed t o have found the Siberians eating frozen mastadon encased i n a glacier. And from what I know of the people who are sent t o Siberia, it may be t h i s i s a l l the meat they have t o eat, but I doubt t h i s i s a significant comment on the freezing technology of meat. mastadons tha t were several decades o r times ten t o the th i rd old.

I really don't think anyone ate any

However, this s tory does i l l u s t r a t e the f ac t that meat freezing i s not a development en t i re ly of the modern technologist, but an old product. The Eskimos freeze meat, of course, and the people i n northern China have known that frozen game and frozen birds could be eaten. So it was perfectly natural that with the development of a r t i f i c i a l refrigeration, t h a t when freezing was applied you might say i n ear ly times t o meat, it could be kept. And during the 1930's I can w e l l remember tha t people bought ice cream cabi- nets and put meat i n them. And when the locker plant industry began t o spring up In the United States, the lockers were Just naturally used as repositories for frozen meat. And t h i s has continued t o the present time

Presents, I think, the principal paradox i n meat technology.

That is tha t this i s a very well recognized, very standard form of meat preservation w n g those people who freeze meat f o r themselves, among householders o r persons who rent locker plants or persons who deal w i t h locker plant owners.

But among our large, commercial meat packers meat freezing is s t i l l relegated t o what is referred t o as 8 young line. buy a few frozen pa t t i e s and a few chip steaks, but by and large you don't buy on the general commercial market any frozen meat cuts of any quality.

That is, we can

Now there are some notable exceptions t o this. There are some businesses that specialize i n freezing meat and there have been a few ef- forts by large packers t o get into the Frozen meat field. One of those tha t w e par t icular ly remember of a couple o r three years ago turned out t o be rather disastrous.

So you wonder, how i s t h i s ? How can it be almost everybody knows from his own personal experience t h a t he can freeze meat a t home and it is a very excellent product but $mu can't go t o the store and buy it? Meat experts have been saying fo r the las t ten years, a t leas t t o my personal knowledge, t h a t within the next three years o r within the next f ive years, X per cent of the meat sold i n the United States w i l l be

frozen. And they have gone on t o make estimates of w h a t savings t h i s w i l l make i n the r e t a i l cost of meat. I have heard well documented estimates of t h i s sor t and they sounded very reasonable.

It w i l l be ceiitrally boned, packed and frozen.

Now I first heard them ten years ago and they said it was sure t o happen within the next f ive years. nothing has happened.

Now it i s ten years and j u s t about

So there are various problems that ex is t even though I am

But I would l i k e t o emphasize those problems that I am aware of possibly unaware of them al l , and I suppose you fellows are i n the same boat. and then throughout the discussion by our panel t h i s morning you w i l l hear a l i t t l e more of these problems.

The principal problem i n preserving frozen meat i s the problem of oxidative rancidity, enzymatic ac t iv i ty is slow, with one exception that I w i l l mention i n a few minutes. The growth of micro-organism i s not a serious matter. i f the temperature is maintained there should be no growth of micro- organisms a t a l l and if the meat i s very well protected from air there w i l l be no rancidity.

A t the temperatures at which frozen meat i s held,

In fact,

nis i s the main crux of the thing, it must be protected, and t o have it protected y-ou have t o have absolutely an oxygen impervious package material and a package tha t contains no oxygen i n it. attained in any commercial packages I have seen. The obvious method is t o use a vacuum sealed can. I don't knm that it has ever been done com- mercially.

This has not been

We have done it i n Beltsvil le. Dick Heiner was putting vacuum meat i n cans when I came t o Beltsville i n 1945 and I know he had been doing it f o r some time before that. Other people have done it experimentally and I think the results are uniformly good.

O f course, t in cans a re expensive. But if we can afford t i n cans f o r frozen c i t ru s Juices, It is hard t o understand w h y we can't afford them fo r meat. as much marketing research people as those people engaged i n pract ical marketing, t ha t when they have a good thing tha t makes money f o r them, they don't l ike t o penalize it any mre than they absolutely have to .

But it seems the thinking of marketing people, and I don't mean

This has been a factor a lso i n the development of new packages. One of the great aims of the technologist would be t o devise an automatic scheme by which meat cuts would oome off the cutt ing l i ne and go through EL machine that would package them i n a good package and go into the freezer. O r it might be frozen first and then packaged, whichever the par t icular kind of mechanism demanded.

Well, the Dow Company and a few others, I think notably Dow, have come forth with materials that could be used fo r t h i s purpose.

We have experimented with it a t Beltsvil le. Professor Bratzler has experimented with it. It is a plastic material with which the meat may

179.

be covered and one wotild hope tha t a machine could be developed 80 it could be coated by mchiiie. pal objections t o it has been the expense.

However, it i s rather expensive and one of the princi-

There happens i n t h i s case t o be further objection t o t h i s material because of i t s composition. t ing something which w i l l adhere t igh t ly t o the meat which w i l l not leave oxygen between the packaging material and the meat and w i l l exclude the ef- forts of any oxygen fromthe air. This is the primary technological objec- t ive, an obJective we are not particularly close t o reaching a t the moment unless we would go t o t i n cans or aluminum cans or some type of metallic f i3m.

But the greatest problem i s the problem of get-

The problem i s largely compromised wi th in the locker plant and

I think you home. We use f lexible films because we want t o see through them. These f lexible films have an unlimited capacity t o exclude oxygen. fellows know t h i s story as w e l l as I do and I won't dwell on it any further.

Now assuming we could develop t h i s perfect package o r tha t we knew of some anti-oxidents which could help us with a perfect package, and a t the moment we don't, we would s t i l l have a sort of three-fold problem tha t our panel i s going t o deal with t h i s morning. We would have the problem of what would happen t o bacteria which happened, as they always w i l l happen, t o be on the meat a t the time we freeze it, when the meat i s thawed and cooked and generally handled in comerce. these micro-organisms tha t might f ind the i r way into t h i s package. we speak of pathogenic micro-organisms it w i l l include a l l the organisms of public health significance even though they m y not be from the medical sense pathogists. And we would want t o know.haw, we control people who are responsible for safeguarding the consumer, t o deal with these matters.

We would want t o knm what happens t o And when

O f course, we want t o know how the consumer i s going t o accept t h i s a l l to begin w i t h . consumer*s standpoint by turnin8 to the largest single consumer we have, which is the Army, or the Armed Forces. about the Army's a t t i tude towards prefabricated frozen meats.

And so, we we going t o discuss it first from the

And Al Savich is going t o t e l l us

Then we had scheduled a discussion by Roman Kulwich of the U. S. Department of Agriculture, but Roman consented t o having himself promoted from discussion leader t o projector operator. the s l ides by A l Savich.

So he is gotng t o project So a t th i s point we w i l l not have any discussion,

And then Dr. Allen KitcheU. of the low temperature research sta- t ion i n Cambridge, which i s one of the few groups in the world that has paid close attention t o the growth and development of micro-organisms at low temperatures, is going t o t e l l us about the micro-biological aspects of meat freezing,

And Dr. Davis Mossel of the Centra?. In s t i t u t e f o r Nutrition Re- search i n the Netherlands is very fortunately with us today and he is a man who probably knows as much 8s anyone i n the world about the public health significance of micro-organisms that might be found i n food.

We arc fo r tma te because the National Academy of Sciences held a meeting last week on t h i s vzry subject. bacteria i n foods and meats, the control of them. And we asked Dr. mssel if he would come t o t h i s country and discuss it at the National Academy, so I kidnapped him and brought him, I will admit with his consent, t o Chicago and we have him here t o answer our discussion.

That i s the significance of

And f inal ly , Dr. P. J. Brandly, who is Biological Control off icer f o r the Meat Inspection, who w i l l t e l l us w h a t the Inspection Services methods of dealing with these problems are l ike ly t o be.

So we begin w i t h our mutual f r iend f'rom the Quartermaster Corps, Al Savich, who will t e l l us about the Army's New b o k at Pre-Fabricated Frozen Meats, Al.

MR. SAVICH: Thank you, B i l l , snd members of the Conference:

Yesterday you heard about the problems related t o producing beef type carcasses and some of the problems that the packer is having in evalu- a t ing the meat type carcass. mention what the mil i tary as a consumer wants.

What I would l i ke t o do t h i s morning i s

# # # # # # # # i f #