Today's advanced technical knowledge gives us a measure of control

Transcription

1 97 F A C T O R S A F F E C T I N G S T A B I L I T Y OF NEAT PlGNENtS OEORQE E BRISSEY There a r e undodbtedly many motivating f a c t o r s which a f f e c t the homemakers' r e t a i l meat purchase Chiefly among these, however, are her experiences with her p a r t i c u l a r s t o r e and b r a d s, Price too has a way of making i t s e l f f e l t But, when she i s "coming down t o the wire" i n making her ultimate selection, there is nothing so important a s appearance And of the f a c t o i s t h a t go i n t o t h i s a t t r i b u t e, none is g r e a t e r than color Today's advanced technical knowledge gives us a measure of control e can therefore c a p i t a l i z e on t h e tremendous s a l e s poof t h i s aspect W t e n t i a l created by t h e display appeal of f r e s h and cured meats through proper development of meat's bright fresh color, t h e control of t h i s a t t r a c t i v e color and t h e proper display illumination of t h e meat cuts Freshly cut beef has a purple-red color t h a t has l i t t l e display appeal i n t h e r e t a i l case Good meat market practice allows exposure of t h e cut meat surface t o the a i r (oxygen) t o develop the desired bright red color This allows the niyoglobin t o be converted t o oxy-myoglobin and i s accomplished i n a matter of minutes A s i m i l a r condition is found i n lamb, but i s not as pronounced a s i n beef In pork and veal an a t t r a c t i v e color i s present when t h e neat i s cut The b r i g h t color of f r e s h meat w i l l remain as long as s u f f i c i e n t oxygen i s available and no discoloration f a c t o r s Prolonged exposure impose dark red, gray, gray-brown, o r gray-green colors t o oxygen several hours o r days, w i l l bring t h i s about, a s w i l l surface drying and b a c t e r i a l contamination t o be subsequently discussed - Occasionally a dark-cutting beef carcass i s found A s the name implies, t h i s beef, when cut, is dull, dark-red o r b l a c k - r e d i n color and prolonged exposure t o a i r does not brighten i t s color, The incidence of dark-cutters may increase if animals a r e subjected t o severe changes i n handling p r i o r t o slaughter A s a matter of f a c t, t h e condition may be brought about p r a c t i c a l l y a t w i l l through preslaughter treatment, In t e s t s a t t h e University of Missouri, dark-cutters were produced by simulating severe s t r e s s conditions through the i n j e c t i o n of Adrenalin i n t o the l i v e animal once each day on two days p r i o r t o slaughter A s of this date, however, the meat industry does not h o w how t o e n t i r e l y eliminate dark-cutters It is important t o note that the eating q u a l i t y of such beef i s not impaired Occasionally, two-tone meat carcasses occur i n beef, lamb o r pork In such meat one m s c l e may be bright and another muscle f r o m the same carcass may be dark red i n color O f course, there i s the n o m 1 difference i n non-working nuscles A s pigmentation between the so-called working versus with dark-cutting beef, there i s no solution t o t h i s problem a t t h e moment O f increasing inportance t o t h e swine industry is t h e growing incidence of pale, watery pork Workers a t the University of Wisconsin and others have done much t o elucidate the incidence of t h i s condition and t o determine the environmental f a c t o r s which cause it t o occur The condition i s manifested i n a low, ultimate ph, with some muscles being exceptionally pale t o almost

2 98 translucent i n appearance, a varying two-tone condition with a flabby, exudative surface Among the Immediate f a c t o r s responsible for i t s appearance a r e feeding, a c t i v i t y, temperature and r a t e of carcass c h i l l There is evidence that t h e basic cause, however, resides i n genetic fwtors which have been bred in during the great emphasis on the development of t h e meat-type hog This author's experience of 1 2 t o 15 years ago was t h a t the ph of pork muscle t i s s u e would vary in the range of 55 t o 65 with the In recent time, we have observed a ph as low as average being 60 t o with the general range running from 50 o r 5 1 t o 65 with the average I n one s e r i e s of studies a t tlisconsin, t h i s pale, a t about 56 t o 58 watery pork was shown t o avemge about 305 a t one p a r t i c u l a r packing plant with an occasional incidence as high as 70$ i n the case of the heavier (18-20 l b ) weight range of hams I n order t o maintain the desired color of meat, it is necessary t o recognize what conditions protect t h i s color,what conditions cause discoloration, and what kind and amount of l i g h t provides the b e s t color rendit i o n i n the display came S l x general areas a f f e c t i n g t h e protection and proper illumination of meat will be discussed: 1 Sanitation 2 TmpemtUre 3 D r y m 4 Packaging 5 Freezing 6 Lighting The e f f e c t s of these f a c t o r s are usually more pronounced and occur more rapidly on aged meat o r meat that has been inproperly handled than on freshly dressed o r processed meats The e f f e c t of poor housekeeping leadt o poor s a n i t a t i o n is marked Pronounced surface discoloration can occur in l e s s than one hour i f t h e meat surface i s brushed with a heavy b a c t e r i a l inoculation Such a cond i t i o n can happen with direct contact with an aged piece of meat, uncleaned blocks o r c u t t i n g boards, and dirty equipment Any practice which increases the surface b a c t e r i a l load on meat cuts w i l l promote surface discoloration In t h i s connection, however, it f a i n t e r e s t i n g t o note the i n h i b i t i n g e f f e c t of phosphate curing i n delaying the onset of greenish b a c t e r i a l discoloration i n ham Paired hams were cured with and without phosphate, processed, a s e p t i c a l l y sampled, gmund, -placed i n s t e r i l e petri dishes, and s t e r i l i z e d with ethylene oxide gas The samples were then inoculated with cultures of known "greening" organism and incubated at 100' F The non-phosphated ham turned green i n l e s s than f o u r hours while i t s paired phosphated mate rem i n e d normal in appearance f o r a t l e a s t double that time Poor colors of cut meat surfaces a r e d i r e c t l y correlated with surface meat spoilage It is therefore n a t u r a l and expected t h a t the rate of discoloration of meat cuts in the display case is increased with increased storage temperature Meat cuts displayed a t F w i l l, i n general, discolor in one day, whue cuts displayed a t F may maintain excellent color f o r periods of up t o three o r four days In general, the n o m 1 spoilage bacteria on cut meat surfaces, a t these r e l a t i v e temperatures, w i l l multiply t e n times more rapidly with each f i v e degree increase in temperature

3 99 Improper s a n i t a t i o n and poor temperatures can combine t o bring on discolorat i o n and spoilage within a matter of a few hours An unattractive b r i c k red color r e s u l t s a s cut meat surfaces l o s e surface moisture and dry Low humidities, excessive a i r movement and nonmoistureproof p a c a g i n g material promote surface drying Surface drying does not e n t i r e l y i n h i b i t surface b a c t e r i a l growt'n Thus, protection against drying may s e t up a moist surface condition that requires optimum s a n i t a t i o n measures and temperatures if' more than one day's display case l i f e i s desired Since packaging materials a r e available which w i l l give any degree of oxygen and moisture permeability, it i s possi5le t o maintain good color wlth proper p a c b g i r g materials o r t o promote discoloration through the use of improper packcging materials o r materials improperly applied It i s well known t h a t freah m e a t packnging films w i l l maintain t h e bloom of t h e meat f o r several days i f proper care is taken t o maid against other discoloration factors When a non-moistureproof film i s used, a dried surface and hard b r i c k red c o l o r develops i n a very short time With f r e s h meat the use of a vacuw package and an oxygen impermeable film will always produce a d u l l purple-red color It i s generally accepted that t h t s d u l l purple-red color does not have the appeal of the b r i g h t red color maintained with proper fresh meat packaging film, However, a vacuum package does provide a longer display case l i f e This resuit6, because of the f a c t that t h e vacuum package, and t h e oxygen impermeable f i l m provide a nearly oxygen f r e e package which i s not conducive t o t h e growth of the normal 8,poFtage bacteria found on meat Tbere is a growing u t i l i z a t i o n of vacuum packages on fresh ground meat The consumer has found that when the meat i s removed from the package, t h e c h a r a c t e r i s t i c b r i g h t red color i s quickly formed Freezing and storage temperatures of frozen meat have a marked influence on color A quickly frozen cut of meat has a b r i g h t red color A slowly frozen cut is dark red i n color Quick freezing produces small i c e c r y s t a l s and when the meat is thawed the d r i p loss i s less than i n the slowly frozen out where l a r g e r i c e c r y s t a l s have been formed i n t h e meat Frozen meat when stored a t r e l a t i v e l y high temperatures - 10 F t o 2 5 ' F, w i l l d i s c o l o r even though it was o r i g i n a l l y quick frozen and did o r i g i n a l l y have a b r i g h t red color The rate of discoloration can be vcly rapid, a matter of j u s t a few weeks a t temperatures around 25OF bbch of the discoloration of f r e s h frozen meats i n f r e e z e r display cases is due t o t h e f a c t that the frozen meat cuts are not held a t temperatures of 0%' o r lower The position of the meat cuts i n the case can a f f e c t t h e color of t h e packaged meat i t e m Very often t h e package is placed too high i n the case and does not have the advantage of t h e proper f r e e z e r temperature I n addition, the f l u c t u a t i o n of temperatures due t o defrost cycles and surface warming due t o radiant heat f r o m high i n t e n s i t y l i g h t contribute t o more rapid discoloration i n t h e display case than is found i n a closed freezer

4 100 Everyone has noted the frost that accumulates i n a package when the packaging f i l m is not i n close contact with the meat surface Wherever such f r o s t a m e a r s and whenever a non-moisture-proof packaging film i s used freezer burn w i l l devehp Freezer burn detracts from the appearance of the meat and if' it continues t o develop under prolonged storage, w i l l cause a decrease i n the juiciness of the meat and rasry lead t o undesirable flavor of the meat when cooked The e f f e c t of good and poor illumination is most s t a r t l i n g The i n t e n s i t y of l i g h t i t s e l f is most hnportant Case and store lighting has been constantly increased Stores toda3 have as much as 200 foot candles of light, sometimes over 100 foot candles of light a t the l e v e l of the meats i n the display case Waf displays that had 30 foot candles of l i g h t a t the product now have foot candles o r m o ~ The b r i l l i a n c e of the display i s greatly enhanced by increased l i g h t intensity There is som question concerning possible undesirable e f f e c t s of high intensity l i g h t levels It may be t h a t radiant heat from such intense l i g h t actually causes an increased temperature on the surface of the meat Such an increase in temperature could, of course, promote the r a t e of b a c t e r i a l growth and a s a r e s u l t promote discoloration lhcandescent l i g h t ing has been developed using special f i x t u r e s t o provide high l e v e l l i g h t i n t e n s i t y without excessive heat and is o r soon w i l l be conmtercially available, In addition, if there is any u l t r a v i o l e t radiation a t the high int e n s i t y l i g h t levels, discoloration will be increased because u l t r a v i o l e t l i g h t will discolor f r e s h meat cuts, Under r e l a t i v e l y normal l i g h t i n g i n t e n s i t i e s of 50 foot candles or under f r e s h meat does not aiscolor i n a matter of one o r two days display case l i f e Irkether t o use incandescent l i g h t s, fluorescent lighting, o r a combination of these two is 8 matter of opinion Everyone l i k e s t h e color rendition secured with incandescent lighting bhny believe t h a t proper fluorescent tubing produces an excellent display e f f e c t Improper fluorescent tubing, however, can produce a very unsatisfactory display Color enrichment possible with special colored l i g h t s i s a very questionable practice As long as the meat remains under these lights the qpearance i s outstanding If t h e shopper notices the neat package a f t e r she leaves t h e display and finds the color undesirable, she may drop the package most any place i n the store Discoloration I s the most important problem connected with the marketing of cured, smlced, and Table-Ready Meats This does n o t mean t h a t t h e factors of sanitation, temperature, drying, packaging, freezing, and lighting which were discussed i n the relationship to f r e s h meats should not be given equal consideration i n the handling of cured, smoked, and Table-Ready Meats In general, however, any cured meat item Will discolor aa t h e r e s u l t of display under l i g h t s before any of the above mentioned f a c t o r s become effective Discoloration in these proce66ed meat items occurs when the cured meat pigment i n the processed product combines with the oxygen of the air t o produce brown, grey brown and grey green discolorations Vacuum packaging, of course, admirably takes care of t h i s As opposed t o fresh meats, the cured meats r e t a i n t h e f r desired pirilrish-red color in the aksence of oxygen This chemi c a l reaction of the cured meat pigment and oxygen is accelerated when the product

5 101 i s displayed under l i g h t and the r a t e of change o r reaction i s correlated with the i n t e n s i t y of the l i g h t Intense l i g h t can stimulate t h i s oxidative process so that the bloom of f r e s h l y s l i c e d product can be l o s t within a period of one hour o r even less On the other hand i f the i n t e n s i t y of the l i g h t i s maintained a t under 30 foot candles, b r i g h t color can be retained f o r a t l e a s t one-half day i n non-vacuum packaged product Fluorescent l i g h t s do not discolor cured meats more rapidly tlm incandescent l i g h t i n g A s long a s the l i g h t i n t e n s i t y i s t h e same t h e meat discoloration problem will be j u s t a s severe regardless of t h e source of l i g h t I n a previous discussion c h a r a c t e r i s t i c s and properties of meat pigments were presented In the present paper an attempt was made t o show t h e p r a c t i c a l implications of these c h a r a c t e r i s t i c s and properties by discussing t h e e f f e c t s of common, simple f a c t o r s such as oxygen, temperature, bacteria and l i g h t on the s t a b i l i t y and appearance of meat pigments MR SAFFLE: Thank you very much, George i7e have ample time f o r a discussion, i f anybody has a question they would l i k e t o a s k e i t h e r one of the previous three speakers? -- In the l a s t year George, I'd l i k e t o ask one myself o r two we have seen a great d e a l more emphasis put onto vacuum packaging, p a r t i c u l a r l y of ground meat, and using something where we do not see through the film From an i n d u s t r i a l standpoint do you think t h i s will become more important and a major way of s e l l i n g ground meat o r not? MR BRISSEY: Yes, I think t h i s movement i s d e f i n i t e l y i n t h i s d i r e c t i o n t o pre-package ground meats a t the packer l e v e l f o r d i s t r i b u t i o n t o the r e t a i l trade The f a c t that t'ne pigment changes s o rapidly upon exposure t o oxygen o r t o t h e a i r so t h a t the homemaker, i f she does see through the package and sees the brown surface on the package, t h e minute she cuts it she g e t s the desired b r i g h t red color MEt ZAFFZE: I might mention one thing of interest,we have one chain s t o r e i n Georgia who came out w i t h what they c a l l a p r e s t i g e steak, and it i s a high-quality steak cut extra t h i c k, and they wrap it i n a vacuum package and it has t h e purple color of myoglobin, and a c t u a l l y they use t h i s a s a s a l e s point and, if anything, it has gone over b e t t e r than if it had the red color A s you go down the showcase you immediately see t h i s purple color and it stops you f o r a moment and you end up reading t h e i r l i t t l e advertisement above it, and they do put out a top-notch product and i n this p a r t i c u l a r case they have taken something which we said they couldn't do and W e it i n t o a s e l l i n g point Are there any other questions anybody might l i k e t o ask?

6 102 ME? VERN CARILL (Ohio State) : Is there any evidence that a product which has been vacuum packaged w i l l have a shorter shelf l i f e than one that i s open? MR BRISSEY: The question is, is there any evidence t o indicate t h a t a vacuum-psc3taged product wiu have a s h o r t e r shelf l i f e than one that is open? I can't think of anything with respect t o freshness, however, because of t h e metabolic processes going on i n the vacuum package ip you have had some of these peroxides that Dr Fox mentioned in curing these items which have been vacuum-packaged I have seen these cured meats t u r n green within t e n minutes a f t e r opening t h e vacuum package when they were a perfectly bright red color as l o n g a s the vacuum package w8s present, and the discolorat i o n would take place very, very rapidly once it is removed MR,%ETLE: A r e there any other questions? If not, Jim, we w i l l gut you back on time schedule, and even gained some, which I guess is unusual CHAIKMAN KEMP: Thank YOU, Bob A t t h i s time we wiu have the report of t h e W e r a h i p Committee, and George Wellington, we w i l l t u r n the program over t o you m GEORGE WEUIIVmN (Cornell) : Thank you, Jim report I s very b r i e f, and I think it w i l l consist f o r the mst part in passing out the Directories Mtny of you have received a copy of the Directory which has been available f o r the past few days; I know there are many here who did not receive it so I w i l l Just pause a minute while it it3 passed out The M e r s h f p Committee consists of Adams, Bratzler, Bray, assigned the Committee he gave us Cahill and a y s e l f, and a8 Chainnan these r e s p o n s i b i l i t i e s : First, t o publish the Directory, and t h i s we t r i e d t o do knowing that there would be some incmpletions Gle did the b e s t we could with it We laow that there are 8ome errors i n it, an6 we a r e sorry where it is incomplete We have tried t o make it accurate t o the extent that it agree with the yellow sheet which hat3 been submitted I hope that it is correct to that extent I think you w i l l pmbably be interested i n knowing that we took bids on the cost t o p r i n t 1,000 copies We had bids ranging from about $90000 up t o about $1,45000 Actually we gave the job t o the lowest bidder Due t o the selection of the cover material there was a l i t t l e more cost t o t h e p r i n t e r than we had anticipated The final b i l l was about $95000, eo these copies cost about 9S# each I think when and if it i s done again we probably could do a b e t t e r Job by getting, more complete