Conclusions. DR. BROkJN: Thank you, Tom. It's always a pleasure to be Deibel's paper. This will give me a chance to talk to you for a few

Transcription

1 168. The fat was decidedly yellow and rancid smelling - especially on the controls. Mold gmwth was abundant and was present in fairly large amounts even on the shank portion. Penicillium expansum and Penicillium viridicatum again were the predominant fungi with Aspergillus ruber and Aspergillus repens also appearing as a result of the considerably lower water activity. No bacteria were found on the surface of the hams while only a few Bacillus, Micrococcus and yeasts were found on the interior. This would indicate that the salt concentration and. decreased water activity were inhibitory to a great extent. Conclusions On the basis of these findings, it may be concluded that fungi do play a role in the preservation of aged sausages and hams. Their contribution to retention of moisture and color has been noted for both types of meat. The use of molds is intentional for many European gourmand sausages but is incidental for most country cured hams. Salami overgrovrn by molds develop an attractive greyish white felt-like surface that protects the meat from spoilage fungi and serves as a fairly impermeable coating to moisture vapor and oxygen transmission. As a consequence, these sausages retain more moisture, develop more intense color, have reduced estraneous microbial growth and can be preserved for longer tines without development of rancidity. Hams cure satisfactorily without any mold activity but when these meats remain in storage for 6-9 months and lose 25-30$ of their original weight, growth of Penicillia and Aspergilli appear as a result of the reduced water activity. The fat of these hams is less yellow and rancid than that of meat free of mold growth. DR. BLUMER: Our next speaker is Director of Research of John Morrell and Company. So, he will make a few remarks concerning the paper which was presented by Dr. Deibel. Dr. Brown. DR. BROkJN: Thank you, Tom. It's always a pleasure to be back and meet with you. I was very much interested in hearing Dr. Deibel's paper. This will give me a chance to talk to you for a few minutes about some specific things that we do to control the microbial content of finished products. I won't talk about the animal we slaughter ourselves, because we have rather good control from the live animal all the way through to the finished product. But we buy a lot of meats from outside; we call these extra-purchase meats. We have our own intercompany specification for these inccming neats. Now we found out long ago that you can't give numbers to your supervisory and operating people to use. So, you don't report results to them on these meats as so many per gram. You simply send them a report after the meat has been properly sampled and the analysis has been made. You say that it is very good, good, questionable, or excessive. We

2 169. think that anything up to ten thousand should be classified a real good product. Ten thousand to a hundred thousand is good; questionable is one hundred thousand to one million. If it's over one million, it's excessive, and we want to have something to say about where the product is finally used. Another area that we're quite concerned about is the bacteriological condition of food contact areas, Any place where the meat touches a piece of equipment, we're concerned about. We do quite a lot of work with swabs. We take a swab of a square inch area. We find that, if we use the same method of reporting here, this also is effective. If we find less than six microorganisms per square inch, we consider this real good. Six to fifteen we consider good. Fifteen to seventy-five is fair. Seventy-five to three hundred is poor. And more than three hundred is excessive, and we need to do some clean-up work. These values are, of course, relative, and they, I'm sure, would not be the same ones that our good friends from Swift and the rest of the meat industry would use, but I'm sure they'd have a similar system. We work on packaging material; we've established standards for items like cartons, paper, pan liners, can liners, labels, various plastic bags, all the films, office labels, inserts, overwraps, tags and string. You may not think that string is a hazard; but we've had some pretty high counts on string used on manufacturing meat, Pails, lids for casing ends, etc. We're also concerned with ingredients. We've established standards for items like mustard, olives, pimento, pickles, gelatin?, soy flour, binders, salt, sugar, dried milk, sauces, starch and, of course, water. Pepper is another one that we get into trouble on quite frequently. I've clipped out an article in the May issue of Applied Microbiology. They've just completed analysis of thirty samples. On eleven samples they made a total count, and they averaged million per gramwith a range of 8,300,000 to 704,000,000 organisms per gram. So, that gives you an example of the kind of counts you can run into. We're always concerned with personnel. We've used plastic gloves quite successfully. To extend storage life, we've tested plastic aprons and we like them pretty well. We use germicidal soaps, of course, and we do a lot of checking on the air movement through the plant. We check especially for mold spores in smoked meat areas. We have training sessions set up for supervisory personnel. We put out reminder bulletins to the various departments, especially in the springtime, because they get a little careless about leaving the meat out in warm areas. So, it is necessary to stimulate them in the springtime. And we try to make everybody conscious of the fact that we must have low temperatures and we must have fast handling. I think this supplements Eob's statements a bit. I think, Tom, if we have time for a question or two, we'll do that now. DR. BLUMER: I believe on the microphone situation, we'd be better off to cover each panelist at this time, and then have questions fromthe floor. Our next panelist is Dr. R. B. Tompkin, Bruce Tompkin, chief microbiologist for Swift and Company. I met him for the first time yesterday evening, and I said, lrbruce, you're not very old." He said, "Well, I grew real fast and got a lot of breaks." So, Bruce, Dr. Tornpkin will speak of the second paper or Dr. Riemann's paper. Dr. Tompkin.

3 170. DR. TOMPKIN: Thank you, Tom. I have t h e following comments t o make on D r. Riemann's paper. I t h i n k t h a t f o r l a c k of time t h e o v e r a l l emphasis of t h e paper d e a l t p r i m a r i l y w i t h avoiding public h e a l t h problems. He only b r i e f l y mentioned t h a t t h e b a s i c p r i n c i p l e s could apply t o any microbial species. Perhaps it should be emphasized f u r t h e r t h a t s i m i l a r t e s t s can and should be made which w i l l p r e d i c t t h e acceptable s h e l f l i f e of new products and products produced under new processes or put up i n new packaging concepts. It i s not impossible f o r a new concept t o f a i l i n t h e l a t e developmental s t a g e s a f t e r u n r e a l i s t i c preliminary t e s t s. S p e c i f i c a l l y, t h i s might occur when t h e normal b a c t e r i a l l e v e l of meat produced a t t h e p l a n t l e v e l might be higher t h a n t h a t f o r meat produced under a c c e p t i o n a l conditions i n t h e l a b o r a t o r y. A s a r e s u l t it lowers s h e l f l i f e of a product more t h a n might be expected. This a l s o t i e s i n w i t h D r. Riemann's point t h a t inoculated packs must simulate t h e a c t u a l processing c o n d i t i o n, pack work f o r food-poisoning organisms and s h e l f - l i f e t e s t s Icoculated f o r normal spoilage organisms should be i n t e g r a t e d w i t h t h e developmental program f o r new products. I b e l i e v e t h i s b a c t e r i o l o g i c a l work should be done a s l a t e a s p o s s i b l e i n t h e developmental program. I n v a r i a b l y t h e r e w i l l be changes i n e i t h e r t h e formulation of t h e product or i n t h e packaging concept which could e v e n t u a l l y r a i s e a b i g question mark on t h e t e s t s t h a t were developed up t o t h a t time. My next c o m e n t concerns t h e p a s t more t h a n t h e f u t u r e. A s information becomes a v a i l a b l e, we should review a l r e a d y e x i s t i n g products. What had been accepted i n t h e p a s t might not be acceptable..at present. Times change. For example, t h e o l d process of producing head cheese by cooking t h e i n g r e d i e n t s, f i l l i n g i n t o a pork stomach o r beef bung, and t h e n giving a mild heat t o cook t h e casing has been shown t o be p o t e n t i a l l y hazardous from t h e standpoint of Salmonella i n f e c t i o n s, Now t h i s i s p r i m a r i l y j u s t a matter of s a n i t a t i o n i n t h e operation. A s i m i l a r process i s c u r r e n t l y being used i n some segments of t h e i n d u s t r y f o r producing cooked turkey r o l l s. Thus, t o me t h i s means t h a t we have t o look backward a s w e l l a s forward i f we a r e t o make t h e n o s t of our r e s e a r c h e f f o r t s. One o t h e r p o i n t, while we must be f o r e v e r conscious of t h e hazard of botulism i n our canned foods, it should be pointed out t h a t one of t h e major problems f a c i n g t h e canning i n d u s t r y i s t h a t of highly h e a t - r e s i s t a n t thermophilic anaerobic spore formers. Many of t h e s e spore formers a r e more h e a t - r e s i s t a n t t h a n c l o s t r i d i u m botulinum. And f o r t h i s reason a l o n e t h e thermo-process f a r exceeds t h e minimum b o t u l i n a l cook f o r a l a r g e number of food products. And ph's above approximately 3 a r e o f t e n considered f o r c l o s t e r i d i u m botulinum; b u t I wonder j u s t how many products would survive on t h e shelves w i t h such a process. And I r a i s e t h e question i s a ph of 6 s o comlon. -- F i n a l l y, I ' d l i k e t o point out t h a t it vas apparent from Dr. Riemann's paper t h a t whenever we 8re i n doubt about t h e s a f e t y of a new product o r process, we should always conduct an inoculated-pack t e s t. Tom. DR. BLUMER: Thank you, Bruce. Now very few people know t h e He's t h e next p a n e l i s t, Nr. W. L. Sulzbacher, A. R. S., U.S.D.A. Chief of t h e Meats Laboratory t h e r e, and B i l l has a chief also unique p o s i t i o n -- He's a p a r t of t h e p r o j e c t of which Dr. Ayres spoke, So, I hope we can g e t him shut o f f i n time. B i l l MR. SULZEACHER: Thank you, Tom..It 's nice t o know t h a t I 'm not t o o w e l l known, because I have some f e a r s about t h a t. He s a i d I was t h e c h i e f. We have one i r r e v e r e n t employee whose name I won't t e l l you,

4 171. but who calls the "chief meathead." (Laugh). I haven't had much of a part to play in the project that Dr. Ayres described, except that we went to him a few years ago. We were interested in someone doing some research on fungi and meat, and we knew that John had some experience as a mycologist, and we asked him if he'd be interested in working on this kind of a project. He admitted that he would be and so, that's about my part of it. The man who really supervises it from our standpoint in that the supervision is extremely meager is John Allford who is in charge of our microbiology group whom I think you also know. But I was quite pleased; I must say, by the way, that Dr. Apes presented this very complicated subject. And I can assure you that he didn't tell you the whole story either, because there's a lot to some of the other chemical data that is also very interesting. We should have had the whole time for this, but we just didn't have enough time. I would like to emphasize two things that John covered in his paper. One is the rather interesting activity of microorganisms in changing the characteristics of fat. And these are things that we are just beginning to become aware of. We have a fellow in our laboratory who's working, not quite along these lines, but he's come up with information that's complementary to what John's people have found out. This chap that I'm referring to is Dr. Smith in our group, and he has shown recently that various microorganisms change the carbonyls found in oxidized fat in various ways. In some groups, for instance, we'll knock out all the saturated aldehydes. In other organisms we'll knock out the two-four dieneals. In cther organisms we'll knock out 2-enols. And then in some organisms we'll knock out all the carbonyls. But regardless of these things which have an interest to bacteriologists, there remains the clear implication that microorganisms growing on food products that are kept for long periods of time such as these sausages, and hams, will alter the kinds of flavors which you would get from the oxidation that ordinarily would occur in this period of time. Some years ago at Beltsville when we were experimenting with cured hams, we observed that if we aged these hams at forty degrees Fahrenheit, they were quite unpalatable and had a very, very, poor sort of a flavor. But if we aged them at seventy degrees, the flavor was highly acceptable. It now appears that what's happened is that the molds and possibly some other microorganisms grown at the higher temperature have altered the kinds of flavors that are produced by the oxidizing fat. Another point that I wanted to make was that this sort of work that JohnAyres has reported here points out a new area of research for some of the rest of us that might be interested in new kinds of products. You know that the meat curer today wants to get high flavor and maybe unusual flavors; but he has to do it in a minimum period of time. Not very many meat processors are so geared that they can spend months and even years in producing a, product for sale. Now I know that, Tom, there are those fellows down in North Carolina and in other places. But most of the country is not that leisurely anymore, and we want to get these kinds of products in weeks rather than months. DR. BLUMER: You're misinformed. (Laugh). MR. SULZBACKER: So, I believe that more investigations of the fungal enzymes, and how they can be used in meat processing, may bring us a whole new family of meat products and certainly new flavors that can be

5 172. incorporated into rreats. This is just a sort of challenging idea that occurs to me, and I thought maybe some of you might want to do a little work on microbialbiochemistry along with meats and might like to pick this up. I'd just like to say one more thing. I have a friend who's from Virginia. A few years ago I was in his cellar for some reason or another. And there hanging in his coalbin were some rather odd-looking things. I a.sked him a question about that. He told me that those were four hams produced on his place down in Virginia, and he was saving them for their fiftieth wedding anniversary. DR. BLUMER: No comment. (Laugh). Now we would like to have audience participation and questions. IbTR. BEERY: (Penn. State). This is directed to Dr. Ayres. Do the microbial changes take place in the center of the hams as well as on the outside? DR. AYRES: No, +re found very little microbial change in the center, except where you had bad cracks in the ham. Then you would have migration of the molds to the center. We've shown no association between the yeast and the flavor of the aged ham. &E. SWIFT: What is water activity? You were talking about some growth was different than another on account of the water activity. DR. AYRES: As the ham gets older, I'd say it loses twentyfive to thirty per cent of its original weight. And because you have a higher salt content, you have less water per gram of ham. You have necessarily more salty material and less water, and where you encounter some of these molds such as Aspergillus Ruber, this organism will grow down to a water activity of Does this hel?? You contrast this with what you find with Staphalococcus aureus. It won't grow below 0.9. And if you take Salmonella. it won't grow below And if you take Pseudorronas, they won't grow below Therefore, you have to have a wet surface for Penicillia to produce colonies and, therefore, slime. And if you have a slightly salted product, you won't have much trouble with Salmonella. If you have a heavily salted product, you won't have too much trouble with Staph. But you will have to leach the salt back out to eat it. DR. HEIJRICKSON: In rela.tion to the topic of control of microbial flora in raw material, when a company poceeds to establish a new plant, how do you proceed to survey the micro-flora that would be present in the air in that area to determine the extent of contamination that you might expect? br. SULZEACKER: I think this is going to depend upon, at least to some extent, what products are involved, and, secondly, if you want to get a rough idea as to the extent of airborn contamination, you could use the exposure-plate techcique. If you wanted to become more refined, you could go on to some of these forced-air or slit-samplers and actually definitively determine the number of bacteria or spores that are in a given air volume. I think that, generally speaking, for most sausage operations and things of this nature, air contamination is not a major consideration in reference to sanitation of the line itself. Although at times it can be a problem with spore -formers. Have I answered your question?

6 173. DR. HENRICKSON: Yes, I was j u s t wondering. t h e analyses of v a r i o u s s t r a t a of t h e a i r? Do you t a k e MR. SULZBACHER: Generally, what you're concerned w i t h i s t h e s u r f a c e a r e a t h a t y o u ' r e working with--the s u r f a c e a r e a t h a t t h e product i s going through. And you can make your exposure p l a t e s f o r your a i r samplings a t t h a t l e v e l. I f e e l t h a t w i t h forced a i r t h e r e i s a f i l t e r a s s o c i a t e d w i t h your a i r system. Generally, t h i s i s a good place t o sample, and t h i s w i l l d i c t a t e t h e n e c e s s i t y f o r change or frequency of change of t h e f i l t e r. I t h i n k t h e milk people a r e extremely concerned w i t h a i r - b o r n contamination and t h e d r i e d milk operations a r e now. They a r e becoming a c u t e l y aware of a i r - b o r n contamination and environmental contamination i n general, and a i r f i l t r a t i o n seems t o be a c a z d i n a l c o n s i d e r a t i o n i n t h i s type of p l a n t. -- i f you're t a l k i n g UNIDEhTIFIED VOICE: One more comment about a smoked-meat p l a n t, you've got t o be concerned about moldspore contamination. This i s t h e r e a l problem. I t h i n k D r. Deibel answered haw t o determine t h e numbers, b u t i f you're t a l k i n g about smoked meat, mold spores w i l l be your p r i n c i p a l problem. UNIDENTIFIED VOICE: Bob has broken down t h e problem i n t o two types. The one i s t h e milk-drying p l a n t, where you're a c t u a l l y u s i n g a l a r g e volume of a i r t o d r y t h e product. I n t h e meat-packing p l a n t t h i s i s done i n c e r t a i n instances, b u t I f e e l, personally, t h a t t h e problem i n t h e meat-packing i n d u s t r y l i e s more w i t h what i s i n a p e r s o n ' s hands and what i s on t h e equipment used and t h e c o n d i t i o n of t h e raw m a t e r i a l i s question. These a r e t h e a r e a s i n which we should put t h e g r e a t e s t emphasis f o r t h e m a j o r i t y of t h e products and processes i n t h e meat p l a n t s. MR. HOKE: I ' d l i k e t o d i r e c t a q u e s t i o n t o D r. Brown. You mentioned t h a t on your imported meats or t h e purchased meats t h a t you b r i n g i n t o your p l a n t, t h a t you sample t h e s e. I assume t h a t most of t h e s e a r e carcasses. What p a r t of t h e carcass do you t a k e your sample from? DR. BROWN: Well a c t u a l l y, OUT b i g g e s t percentage of products a r e not c a r c a s s e s ; t h e y ' r e i n d i v i d u a l c u t s. A l o t of them i r r e g u l a r trimmings and a l l kinds a r e r a w m a t e r i a l s f o r sausage Pork m a t e r i a l s a r e used for sausage, W e a l s o buy primal of beef. c u t s. We use a l o t of hams. We've developed v a r i o u s techniques for sampling, depending upon t h e product. We've even devised some techniques f o r sampling f r o z e n products and I would be g l a d t o d i s c u s s w i t h you a f t e r t h e meeting. B u t you almost have t o d e f i n e your product b e f o r e you d e f i n e your sampling technique. -- DR. ALSMEYER: I ' d l i k e t o d i r e c t a question t o Dr. Brown. How do you b e s t reduce t h e microbial contamination i n packaging m a t e r i a l s and black pepper. I t h i n k you mentioned r a t h e r high counts. Do you use d r y heat o r how do you do t h i s? supplier. DR. BROWN: Well, we g e n e r a l l y t r y t o leave t h i s up t o t h e I n t h e case of b l a c k pepper, we buy s t e r i l i z e d s p i c e s t h a t

7 174. have either been through ethylene or propylene oxide sterilization. And we have a pretty good supply of' these, In the case of packaging materials you've got to work with the suppliers. We don't run into too much problem on plastic films. We do run into problems with strings and stockinettes and with this kind of product occasionally. UNIDEhTIFIED VOICE: products can be sterilized? Bill, can you specify that these DR. BRGWN: Yes. The black pepper that we used in a lot of contract.work. It states that we will use spices of good bacteriological quality, and in case we get into limitations on what we can use, we buy sterilized spices. They cost a little more, but you can see from these counts that I quoted earlier, that black pepper can contribute to the total microorganisms in your products. MR. BRATZLER: Dr. Ayres, in the health aspects, a consumer calls in and says that there is mold on this product (we'll say dried sausage or even commercial hams of today) and she's worried whether it's fit to eat. What do you from your experience tell the consumer? What should she do with the product? DR. AYRES: Well, I used to speak rather glibly about this. I put my tongue in my cheek now, and I'd try to avoid saying anything, because (laugh) this mycotoxin problem has everyone worried. What is the government spending on the program now? This is, per year on the Nycotoxin Program? UNIDEJ!iTIFIED VOICE: Nearly two million. DR. AYRES: I think many people are worried about what food products may have mycotoxins, and I would say to be safe, don't touch it. But we know that most of this refers to symptoms they have found under rather strange exotic conditions. It does not refer to a real food product. The probability is that most of the molds are entirely harmless, and I certainly hope so as far as blue cheese is concerned. DR. BLWER: I have one question, I would like to direct this question to Dr. Riemann. What percentage of our color problems is due to microorganisms in our packaged meats? DR. RIEmNN: Well, I don't think I'm the right one to answer this question. It probably ought to be directed to Dr. Tompkin. Are you talking about fresh meat or processed meat? I don't think I can give you any figures or any numbers. Maybe Dr. Brown or Dr. Tompkin or Dr. Sulzbacher can give you a better answer. UNIDENTIFIED VOICE: Your question, I'd like to repeat it to make sure it comes out right. VJhat percentage of the problems of color are associated with bacterial growth? Is that right? Well, all I can say is that frequently, I don't know what percentage this is, wherever we do have off-color, we have a high bacterial count. It's more or less directly associated. They're hand in hand. Whether or not the bacteria cause the color changes, per se, some work needs to be done on that.

8 175. UNIDENTIFIED VOICE: I'll make one comment here. I think you have to divide your question into cured color and fresh color. If you're talking about the cured color of a vacuum-packaged product, I would guess that your bacterial growth has very little effect on whether or not this vacuum-packed product holds its color in the retail display case. On the other hand I would have to agree that on fresh meat your bacterial growth will have a marked effect on the colored product. DR. BLUMER: I wish to thank the speakers and the panel for appearing on our program. If you'll turn to page thirteen, you'll note the Microbiological Committee, who helped formulate the program, and R. B. Sleeth is coordinator of this particular section. Lunch is in the Omaha Room here at the Center, If there are no announcements, we're adjourned until after lunch. ###########