F. B'. THOWAS NORTH CAROLINA STATE UNIVERSITY

Transcription

1 CLTRRENTAND PROPOSRDCATFISH PROCESSING AND MARKETING" F. B'. THOWAS NORTH CAROLINA STATE UNIVERSITY In t h e last decade, we have s e e n t h e development o f a new farm e n t e r p r i s e r i s e from d i t c h bank f i s h e r y i n t o a complicated, y e t young, p o t e n t i a l f i s h e r y, In t h e f i r s t t e n t o eleven years of e x i s t e n c e as a farm e n t e r p r i s e, much has been l e a r n e d about c a t f i s h farming. The developnents by approximately s i x t e e n processors, though n o t a b l e, l e a v e much room f o r i n n o v a t i o n, development and a p p l i e d and b a s i c r e s e a r c h from both t h e equipment and t h e product p o i n t s o f view, With t h i s ground work s t a t e m e n t, w e would l i k e t o follow up w i t h a more d e t a i l e d d e s c r i p t i o n o f t h e processing a c t i v i t i e s o f today and make some proposals f o r t h e f u t u r e, Let's examine a f a i r l y t y p i c a l c a t f i s h processing o p e r a t i o n. ( C h a r t I ). As t h e c a t f i s h a r r i v e at t h e processing p l a n t by l i v e haul t r a n s p o r t a t i o n, t h e y may e i t h e r be s t o r e d i n holding t a n k s o r t h e y may be handled d i r e c t l y i n t h e p r o c e s s i n g l i n e a t t h e o p t i o n o f t h e p r o c e s s o r, The unloading o p e r a t i o n, as conducted i n some processing p l a n t s, proceeds i n t h e following way. The l i v e haul t r u c k backs over a p i t c o n t a i n i n g a p e r f o r a t e d s t e e l basket i n t o which t h e i s h are dumped and as t h e c a t f i s h a r e dumped i n t o t h i s basket, t h e water is allowed t o d r a i n away. Ekch i n d i v i d u a l b a s k e t o f c a t f i s h is t h e n removed from t h i s well, brought t o t h e r e c e i v i n g end of t h e processing p l a n t conveyor where t h e y are weighed, stunned w i t h a n e l e c t r i c a l charge, moved onto a conveyor and I n t o t h e processing p l a n t, On t h e i n s i d e o f t h e processing p l a n t, t h e y may be hand skinned as we have seen i n o u r flow chart No, 1. Persons on both s i d e s o f a moving b e l t with a s t a t i o n a r y meat hook, hang t h e f i s h, make a quick c i r c l i n g motion around t h e head area, apply a pair of p l i e r s and immediately remove t h e e n t i r e o u t e r s k i n o f t h e f i s h. This is done v e r y d e f t l y by s k i l l e d workers, The skinned c a t f i s h i s placed back on t h e conveyor and moved t o t h e n e x t o p e r a t i o n where t h e head is remwed immediately behind t h e c o l l a r bone by a conventional meat saw, A conveyor a g a i n moves t h e c a t f i s h t o t h e e v i s c e r a t i n g o p e r a t i o n i n which t h e entrails are removed, then t o a wash tank. After a thorongh c l e a n s i n g, t h e c a t f i s h i s moved OR a conveyor once a g a i n where free running water is allowed t o d r a i n anay as i t approaches t h e packaging s t a t i o n. A t t.he packaginq s t a t i o n t h e small c a t f i s h, which weigh approximately t h r e e - f o u r t h s of a pound t o a pound and o n e - q u a r t e r, are i n d i v i d u a l l y wrapped in c e l l o p h a n e or a cellophanel i k e material with t h e proper p r i n t i n g on t h e wrapper. The packages are placed on f r e e z e r r a c k s r e a d y for f r e e z i n g. C a t f i s h processing, * Presented a t t h e 24th Annual Reciprocal Meat Conference of t h e American Meat Science Association, 1971.

2 204

3 stated simply, is a 1, 2, 3 type of operation: hand removal of all the skin, deheading, gutting, washing and packaging. Herein lies one of the first challenges of trying to do a better job and mechanize the entire operation, 205 One processor uses equipment which gives the catfish a hot water treatment and removes the skin with a mechanical skinning device. As we have learned through the developnent of fishery products, notably the blue crab, much time is consumed picking the meat f'rom this very delicious crustacean, In the case of scallops, considerable ingenuity and capital is necessary to eviscerate the product mechanically, It is evident today in this very young industry that the innovating type of person has a great deal to contribute to achieve a higher degree of mechanizatlon while maintaining the best standards of quality and sanitation that we know, After the catfish has been through the processing plant, ne are confronted nith a market situation. The fish may be sold f'resh, processed, and iced to restaurants where the product will be used immediately or the fish may be frozen for use at a later time by either a restaurant or consumer. The so-called "catfish kitchen" in the Delta region and other parts of the country where catfish are a delicacy, are prime outlets, If we scan a map of the Delta region, we find a concentration of the catfish industry in that section of the United States and most catfish are sold and consumed within the immediate area, When we confine our problem to catfish that are reared in the further reaches of our country where catfish is not a noted delicacy, we find something must be done with our market form, market structure and marketing expertise in order to develop an industry that will compete with other protein sources, The average retail outlet uses catfish weighing three-fourths of a pound to a pound and a quarter, The Larger size, above a pound and a quarter are frozen then cut with a band-saw, steaked and packaged in such a manner that they can be sold as small portims. The immediate need is to apply some "thinking power" and come up with ideas, We have the opportunity to move into the chain store marketing program, As an example, the Blue Channel Corporation of Port Royal, South Carolina, has recently introduced a new canned fishery product into the market, The back panel reads as follows: Contents: fish stock, eesh water catfish, potatoes, etc. If we were to look at the front panel of this label, it would say "Catfish Stew." These people are innovative, they are promotionally conscious and they are trying to satisfy a new market area, This is just one example. What else can we do? Since frying is the conventional way of preparing catfish, we need to experiment with entirely new methods of preparation, One suggestion is to use a deboning machine for removal of the flesh and skin, thus producing a minced product which can be used for new market forms such as patties or bologna-type products, This method has been used in our laboratories in Raleigh, at North Carolina State University, Department of Fbod Science. The deboning machine used in this particular work removed the flesh by a

4 206 squeezing/tearing a c t i o n, A wide f l e x i b l e b e l t moves a g a i n s t t h e o u t s i d e o f a r o t a t i n g, p e r f o r a t e d metal drum. The b e l t and drum move a t d i f f e r e n t speeds i n t h e same d i r e c t i o n. Flesh i s separated from s k i n and bones by a s h e a r i n g a c t i o n due t o a d i f f e r e n c e i n speed between drum and b e l t. C a t f i s h, o t h e r f i s h species, o r p o u l t r y products can be f e d i n t o t h e upper r i g h t o f t h i s machine, The s k i n and bone materials are discharged out t h e l e f t at t h e bottom of t h i s machine, The f l e s h, s t r i p p e d from t h e bone, comes o u t a p e r f o r a t e d c y l i n d e r in t h e c e n t e r o f t h e machine, Since f l e s h is s o f t e r and i s l e s s cohesive t h a n s k i n s o r bones, t h e pressure developed between drum and b e l t d r i v e s it through p e r f o r a t i o n s o f t h e drum, It has a c o n s i s t e n c y of c o a r s e ground hamburger, The emulsifying c a p a c i t y, ( E ) i. e. t h e c a p a c i t y o f meat p r o t e i n s t o f u n c t i o n as e m u l s i f i e r s I n sausage-type emulsions, i s a basis f o r comparing t h e p r o t e i n s o f f i s h, beef and pork, The M: f o r sea bass and c a t f i s h a r e shown i n t a b l e 1. A comparison of t h e EC f o r beef and pork are presented i n t a b l e 2.1 The d a t a i n d i c a t e t h a t t h e p r o t e i n s from c a t f i s h o f f e r e x c e l l e n t binding p r o p e r t i e s f o r u s e i n comminuted t y p e s of products o r o t h e r forms o f p a t t i e s o r c a k e s, Another e s s e n t i a l i n working with new product developnent is t o have some idea o f t h e approximate composition of t h e material with which you are working;. This is i n d i c a t e d i n t a b l e 3 and we would l i k e t o i l l u s t r a t e some of t h e f i n d i n g s t h a t are shown f r a n t h e moisture, f a t, a s h and p r o t e i n a n a l y s i s o f c a t f i s h f 1 e s h. l The averages i n d i c a t e t h a t ne have approximately 75% m o i s t u r e, about 4.2% f a t, a l i t t l e over 1%a s h and n e a r l y 20% p r o t e i n i n c a t f i s h flesh. A s we are well aware i n working with o t h e r p r o t e i n s o u r c e s, we are d e a l i n g many times with a carcass and a l l o f t h i s is n o t u s a b l e material f o r t h e primary product. Attempts have been made t o i n d i c a t e t h e percentages of c a t f i s h that are a v a i l a b l e i n d i f f e r e n t forms and u s e s, table 4. W e have compared hand d r e s s i n g where t h e c a t f i s h has been c o n v e n t i o n a l l y e understand that some handled and end up w i t h a 50% y i e l d. W p r o c e s s o r s achieve a l i t t l e b e t t e r percentage than t h i s, about 55%. When t h e f i s h is skinned and boned by hand, we f i n d a l o s s o f a t h i r d o f t h e material i n t h e head and g u t s. With removal of t h e s k i n, a n a d d i t i o n a l 10%is l o s t. In t h e removal o f t h e bones and carcass, 16%i s l o s t, The bone and s k i n t o g e t h e r w i l l y i e l d about 26.4% and a f i n a l y i e l d o f meat o f about 39,8%. W e can improve t h e average somewhat by doing t h i s mechanically, as was I l l u s t r a t e d with * Webb, N. R., F. J. Ivey, H. B. Craig, V. A. Jones, and R. J. Monroe, The measurement o f emulsifying c a p a c i t y by e l e c t r i c a l r e s i s t a n c e. Vol, 35, J o u r n a l of Faod Science.

5 2 07 TABLE 1, COMPARISON OF EMULSIFYING CAPACITY ENWPOINT RACTS. OF FRESH AND FROZEN SEA BllSS AND FRESH CATFISH MUSCLE: TISSUE T o t a l extract (slurry) Visual Resistance Sea Bass Fresh X C.V.% n Frozen -x c.v *% n Catfish Fresh X c.v.% n * 145.lf i:i % e Of4,O 2.1% ~ ki Of Centrifuged extract (supernatant ) Visual Resistance " The mean (E) values and s t a n d a r d errors are expressed as m l of o i l p e r 20 g sample of muscle extract (slurry o r s u p e r n a t a n t ). I n i t i a l o p t i c a l d e n s i t i e s were averaged and o n l y one visual r e a d i n g was determined.

6 208 TABLE 2. COMPARISON OF EMULSIFYING CAPACITY END-POINT CRITERU MIR EXTRACTS OF F R E S H AND FROZEN BEEF AND PORK MUSCLE TISSUE^ T o t a l extract (nlurry) Visual Pork 7 Fresh Frozen j? 132.6?1.1 n 33 c.v.$ 4.8 Beef Fresh 136.W 7.6.a , ,o * x c.v.% n I _ Resistance Centrifuged extract (supernatant ) Visual Resistance. x n 18 c.v.% Pfn, The mean (?) v a l u e s and s t a n d a r d errors are expressed as m l of o i l p e r 20 g sample of muscle extract ( s l u r r y o r s u p e r n a t a n t ).

7 TABLE 3. Sample number Average APPROXIMATE PERCENT COMPOSITION OF CATFISH MUSCLE TISSUE Percent of fat Percent o f ash w Percent o f moisture I Perc ent of protein TABLE 4, COMPARISON OF YIELD BY DIFFERENT METHODS OF PREPARING CATFISH FLESH Hand dressed (Headed-gutted-skinned) % head and guts removed 4 skin removed % bone removed % bone and s k i n removed % yield Skinned & deboned Hand Mechanical ,

8 21 0 t h e deboner, and a r e able t o i n c r e a s e t h e y i e l d t o almost 43%. C a t f i s h y i e l d is n o t q u i t e as h i g h as w e have found w i t h o t h e r f i s h. Many f i s h s p e c i e s can be deboned w i t h y i e l d s i n d i c a t i n g about a 2% i n c r e a s e over hand f i l e t i n g. The r e s u l t i n g waste must be removed t o l a n d f i l l, disposed o f by o t h e r s a n i t a r y means, o r can be u t i l i z e d t o y i e l d f i s h meal, depending upon l o c a t i o n and t h e r e l a t i v e economics of s c a l e of operation. It was mentioned e a r l i e r t h a t t h e e n t i r e area o f c a t f i s h processing and marketing i s one which need c o n s i d e r a b l e i n n o v a t i o n, I would l i k e t o p r e s e n t a n idea t h a t may be somewhat o f a n innovation. Those of us who have been engaged with t h e processing i n d u s t r i e s a r e well aware of t h i s high c o s t o f a f i x e d p l a n t, i t s investments and a l l of t h e a t t e n d a n t f a c i l i t i e s and r a m i f i c a t i o n s t h a t are involved. ( f i g u r e 1). With a f l e d g l i n g i n d u s t r y, w e f e e l t h e r e should be c o n s i d e r a t i o n o f a mobile processing p l a n t t h a t could be moved onto t h e farm pond area. The c a t f i s h can t h e n be processed i n u n i t s o f approximately 1,000 pounds p e r day o r larger and moved o u t a t t h e completion o f t h e h a r v e s t, t h u s a v o i d i n g t h e high c o s t o f f i x e d b u i l d i n g s and expensive t r a n s p o r t a t i o n equipment from pond t o processing p l a n t, This p a r t i c u l a r schematic is only one i d e a t o i l l u s t r a t e something t h a t can p o s s i b l y be achieved i n t h e n e a r f u t u r e. The e n t i r e mobile processing p l a n t has been programmed e do not propose t o a t e n f t n i d e, 38 f t long tractor t r a i l e r, W t h a t we have answered a l l t h e problems i n t h i s particular s i t u a t i o n by b r i n g i n g t h e processing p l a n t t o t h e product, This i s quite a marked c o n t r a s t t o o u r t r a d i t i o n a l way o f t h i n k i n g, but we do f e e l t h a t with t h e many a l t e r n a t i v e s we have d i s c u s s e d w i t h i n o u r o m team and with some members o f OUT i n d u s t r y, t h e r e are p o s s i b l e s o l u t i o n s within t h e framework o f t h i s concept. By b r i n g i n g t h e processing u n i t t o t h e farm pond w e can a c h i e v e greater s a v i n g s and c o s t i n i t i a l l y p l u s achieve a greater m o b i l i t y and m a i n t a i n t h e q u a l i t y and freshness of t h e product. This e n t i r e concept is m t e d on t h e fact t h a t w e would have a c e n t r a l c o o l i n g, refrigera t i n g, freezing and packafl;inp; system. As t h e product l e a v e s t h i s t y p e o f an o p e r a t i o n, in o u r concept, it would be a c h i l l e d or i c e d product, n o t i n i t s f i n a l market form, W e have worked t o a reasonable d e g r e e through some of t h e parameters o f t h e problem and w e a r e o f f e r i n g t h i s as a suggestion t o be considered i n t h e marketing and merchandizing o f c a t f i s h, To t h o s e of us engaged i n t h e meat processing i n d u s t r i e s, we c e r t a i n l y have been w e l l aware o f t h e i n s p e c t i o n programs t h a t have been t h r u s t upon us i n r e c e n t y e a r s. I m u s t, i n a l l f a i r n e s s, s a y something about i n s p e c t i o n. I n c o n t r a s t t o t h e USDA I n s p e c t i o n, we do have a f i s h e r i e s i n s p e c t i o n program a d m i n i s t e r e d by t h e Department of Commerce. The impartial o f f i c i a l i n s p e c t i o n s e r v i c e f o r f i s h e r y products is v o l u n t a r y and is o f f e r e d on a service f r e e basis, "Federal government i n s p e c t o r s check p r o d u c t s f o r q u a l i t y, q u a n t i t y, c o n d i t i o n, packaging, and o t h e r f a c t o r s t h a t affect product acceptab i l i t y. Within t h i s scope t h e r e are two major t y p e s o f i n s p e c t i o n service a v a i l a b l e and each has s e v e r a l advantages f o r t h e mass f e e d i n g buyer,

9 FIG.1. A SUGGESTED PLAN FOR A MOBILE PROCESSING FACILITY c--

10 212 Continuous--During continuous i n s p e c t i o n, one o r more i n s p e c t o r s are a s s i g n e d t o a processing p i a n t a t a l l times when i t is o p e r a t i n g, This service is made a v a i l a b l e o n l y i f a p l a n t meets r i g i d s a n i t a r y requirements f o r f a c i l i t i e s, equipnent, and product. Continuous i n s p e c t i o n assures t h e purchaser t h a t t h e products may b e a r approved i n s p e c t i o n marks and/or grade d e s i g n a t i o n such as U.S. Grade "A" o r "B", These grades i n d i c a t e t h e following. Grade "A" means t o p or best q u a l i t y. A l l a r e uniform i n s i z e, p r a c t i c a l l y f r e e from blemishes and defects, i n e x c e l l e n t c o n d i t i o n, and possess a good f l a v o r and odor i n t h e cooked s t a t e, Grade "B" means good q u a l i t y. Products may not be as uniform i n s l z e o r as free from blemishes o r d e f e c t s as i n Grade "A". This is a g e n e r a l commercial grade and is q u i t e s u i t a b l e f o r most purposes, Q u a l i t y Grade s+.andards a r e s u b s t a n t i a l l y above any minimum r e q u i r e ments f o r s a f e t y and e d i b i l i t y designed f o r consumer p r o t e c t i o n. After i n s p e c t i o n,a c e r t. i f i c a t e is i s s u e d s t a t i n g t h e q u a l i t y, q u a n t i t y, c o n d i t i o n, and o t h e r p e r t i n e n t f i n d i n g s t h a t a f f e c t m a r k e t a b i l i t y o f t h e product. ht--you may r e q u e s t i n s p e c t i o n on s p e c i f i c l o t s o f f i s h or f i s h e r y products i n which you have a f i n a n c i a l i n t e r e s t. The l o t s may be o f any s i z e and may be l o c a t e d i n p l a c e s such as processing p l m t s, warehoiises, cold-storage p l a n t s, or t e r m i n a l markets. Products a r e examined from a r e p r e s e n t a t i v e number o f samples, deoendins upon l o t s i z e, t o determine grade, q u a l i t y and c o n d i t i o n, c o I l d i t l. c n d y, o r compliance with o t h e r f a c t o r s r e q u e s t e d by t h e a p p l i c a n t. The r e s u l t s are r e p o r t e d on a n o f f i c i a l c e r t i f i c a t e, Lot i n s p e c t i o n f o r c o n d i t i o n only can be u t i l i z e d p r i o r t o d e l i v e r y t o assure that p r e v i o u s l y i n s p e c t e d products are s t i l l i n t h e o r i g i n a l c o n d i t i o n. Such c e r t i f i c a t i o n i s used t o assure that t h e products have been p r o p e r l y handled i n t r a n s i t o r c o l d storage':z Having d i s c u s s e d v o l u n t a r y i n s p e c t i o n, ne n o t e t h a t f o r t h e f o u r t h c o n s e c u t i v e y e a r, t h e r e axe s e v e r a l b i l l s b e f o r e Congress t o c o n s i d e r a "Mandatory" f i s h e r i e s i n s p e c t i o n program similar t o meat and p o u l t r y, To s a y how and a t what time and i n w h a t form t h e mandatory i n s p e c t i o n programs w i l l be t h r u s t upon t h e i n d u s t r y, we do not know. Honever, it behooves a l l o f u s t o prepare o u r s e l v e s f o r t h a t day, Anon, "How t o Eye and Buy Seafood", National Marketing S e r v i c e Office, National Marine F i s h e r i e s S f l i c e, 100 East Ohio S t r e e t, Chicago, Ill., U,S, Government P r i n t i n g Office :

11 213 I could not conclude my comments without t e l l i n g you a l i t t l e more about t h e s o u r c e of t h e d a t a - a n d work that has been p r e s e n t e d i n t h i s paper. I would l i k e t o i n d i c a t e t h a t t h e emulsifying c a p a c i t y work, t h e proximate composition work and a l o t of product formulation, development and u t i l i z a t i o n o f c a t f i s h was -performed by f o u r s e n i o r s t u d e n t s under Dr. N. B. Webb's guidance, These gentlemen a r e M r. G. JiLngerfelt, Mr, M, B d u o, Mr. C. Houpt, and Mr, S, Thomas. It happened t o be my f o r t u n a t e p o s i t i o n, i n working with Dr. Webb, t o have served i n a n a d v i s o r y c a p a c i t y t o t h e s e young e f e e l t h a t t h e y have made a n o t a b l e c o n t r i b u t i o n t o gentlemen, W t h e i r education, t o t h e department, and we hope, t o t h e c a t f i s h industry. N. E., 'rlebb: Thank you, D r. Thomas. I t h i n k we have time f o r about two o r t h r e e q u e s t i o n s i f you've g o t something on y o u r mind, 9 i g h t now w e ' l l move on t o t h e q u e s t i o n p e r i o d, UWIDENTIFIXC SPEAKdR : N. i3. WEBB: The q u e s t i o n i s what percentage o f c a t f i s h a r e skinned by hand v e r s u s mechanically? The answer t o t h e q u e s t i o n is that approximately three processes a r e now employed mechanically. I may comment here, and t h e s p e a k e r s c e r t a i n l y i f t h e y wish; but t h i s i n d u s t r y as we have been s t u d y i n g i t with v a r i o u s people i s one i n which t h e processing is a real problem because of volume, There is i n s u f f i c i e n t volume t o c a r r y t h e processing i n d u s t r y i n most areas, I n o t h e r words, t h e production is n o t up t o where r e t a i l c a n c a r r y them o u t. M. MARTINI Another problem is t h a t t h e processors have not been able t o g e t c a t f i s h t h e e n t i r e y e a r, It's d u r i n g t h e summer inonths t h a t f i s h are n e a r l y a l l s o l d f o r r e c r e a t i o n. These l i v e h a u l e r s out-bid t h e processing p l a n t s, Most processing p l a n t s can only pay no more t h a n 306 a l b. Live h a u l e r s w i l l b i d a b o u t 40@ and get t h e f i s h, This i s one of t h e problems, None of t h e processors, almost none, have been a b l e t o make a p r o f i t because t h e y c a n only o p e r a t e about s i x o r seven months a y e a r. R. L. H r n R I C K S O N, OKLAHOMA STATEr 14. B. Not recorded. W U B : The q u e s t i o n i s can you commercially s k i n c a t f i s h by chemical means, M. MARTIN: Research has been done a l o n g t h i s l i n e u s i n g sodium hydroxide f o r s k i n n i n g c a t f i s h but I don't t h i n k anyone commercially h a s s t a r t e d using t h i s process y e t, C, E, ALLdNz Not recorded.

12 214 N. B. WEBB: Question-Is handling c a t f i s h? t h e r e any stress problems due t o M. IUIABTIN: This is a r e a l i n t e r e s t i n g q u e s t i o n because c a t f i s h a r e r e a l l y s u b j e c t t o stress a l o t and t h e y o f t e n break out e have s h i p p i n g f e v e r j u s t with a disease as a r e s u l t of stress. W Often c a t f i s h w i l l be stressed by l i k e t h e cattleman might have. low oxygen i n hot summer temperatures. Maybe t h e temperature is 105 and t h e oxygen g e t s low i n t h e pond and t h e farmer s a y s, "Whee, I got through without l o s i n g a f i s h. I ' m i n good shape." About 10 days l a t e r o r 2 weeks later t h e y ' l l break out with a disease and t h i s is a r e a l problem f o r us, LJNIDI~NTIFIEDSPEAKHI : N. 8. WEBB: 'The q u e s t i o n is--are c a t f i s h tough? M. MARTIN: Well, t h e f i s h a r e raised e i t h e r one y e a r o r two y e a r s. If i n one y e a r a t o u r l a t i t u d e t h e y are about a pound and a t t h e end of two y e a r s t h e y are 2 1/2 t o 3 pounds i n average weight. The two-year-old c a t f i s h are much h a r d e r t o s k i n by hand t h a n oneyear-old c a t f i s h, They probably are a l i t t l e tougher but toughness i s n ' t a problem w i t h t h e product, The only problem with 2roduct q u a l i t y is t h a t o c c a s i o n a l l y t h e pond used i n pond c u l t u r e w i l l have a musty f l a v o r, This w i l l u s u a l l y cause about t h e same problem as w i t h t h e c i t y water r e s e r v o i r. N. B. 'dt3bb: I b e l i e v e our time is up and I would l i k e t o t a k e t h i s o p p o r t u n i t y t o thank M r. Martin and Dr. Thomas.