orgaholeptic tests developed for measuriig ... - meat …

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O R G A H O L E P T I C TESTS D E V E L O P E D FOR M E A S U R I I G T H E P A L A T A B l L l T Y O F NEAT

B E L L E LOWE I O W A S T A T E COLLEGE

No one rea l izes be t te r than the author, t ha t an adequate presentation of scoring cannot be presented i n 20 minutes. several others a re omitted, cussed rul ly . promote discussion from t h i s group.

For each point t ha t i s mentioned, I n addition, the points presented cannot be dis-

It i s hoped, however, that the material t h a t i s presented w i l l

The Necessity f o r Organoleptic Scores

Objective t e s t s a r e excellent i n f i e lds o f research i n whioh perform- ance can be determined by objective t e s t s . There a re no objective t e s t s for evaluating cer ta in factors upon which acceptabili ty depends i n ra t ing the var i - a t ions between samples o f meat o r other foods. I n addition, it seems unlikely that usable, val id objective tests fo r evauat ing character is t ics such a8 odor and taste of meat w i l l be developed within a short time. Hence, it seems wise t o use a l l objective t e s t s t ha t give u s e m information i n evaluating scoring data and t o spend time in elucidation of the complicating factors i n organolep- t i c scoring. and the development of score cards. Food technologists, however, rea l ize there i s s t i l l much t o do along these l i nes . ized i n order t o be t te r compare r e su l t s from different laboratories.

Much thought has been put upon the selection of scoring panels

I n addition t e s t s need t o be standard-

One of the major d i f f i cu l t i e s in organoleptic t e s t s i s the separation of the pa la tab i l i ty factors . they s t a r t scoring. f a i r l y evaluate the flavor of a product i f the texture i s unacceptable or vice versa. a r e four t a s t e perceptions, b i t t e r , sour, salt, and sweet. that a l l four tabtee a re intimately connected and tha t the presence of any one taste a f f ec t s and m y modify the other three t a s t e s (Moncrieff, 1946. p. 12 ) .

Students constantly comment on t h i s point when It ta,kes mental discipl ine and t ra in ing t o separate and

Even one pa la tab i l i ty factor, tha t of t a s t e , may be complicated. There We a re fur ther to ld

Crocker i n a study published i n 1948 s t a t e s t h a t raw beef when cold The taste is ' sweetish, sa l ty , and generally bloodlike has only a weak odor.

When the beef i s warmed, considerable odor develops. l i k e a mixture of amines, including piperdine. cating the presence of sulfur compounds. s i s ten t , and chiefly sweet and sa l ty . Crocker found most of the meat flavor came from the meat f ibe r , an optimum i n 3 t o 3.5 hours of boiling, then with longer cooking the flavor decreased. Crocker concluded tha t cooked-beef f lavor i s quite complicated chemically, and consists more of odor than taste. several kinds including a low simple form, one of t h e piperdine type, and possible indole were present. vo la t i l e acids. The only elements of t rue t a s t e noted were sweetness and sal t iness , no doubt owing t o blood salts. t r a c t s as w e l l a8 in cooked fiber. Many of these consti tuents a re associated i n our minds &from our chemistry days as unpleasant odors. Yet the s m a l l con- centrations present and the combination bring about the fragrant, appetizing

It i s alkal ine and me118 It i s also somewhat eggy, indi-

The t a s t e i s mild, pleasant, per-

With longer cooking the flavor increased, reaching

Hydrogen sulfide, amines of

The vegetable type odors imply the presence of

Astringency was noted i n beef ex-

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odor of cooked meat, surface of the meat during Prying, roasting, etc. differed from beef i n cer ta in flavor character is t ics .

None of Crocker's work included flavor developed on the Lamb, pork, and chicken all

Enough of Crocker'a r e su l t s have been included t o indicate that scoring meat flavor i s not a simple process, and that the flavor i s developed t o an optimum during cooking, then decrease8 with longer cooking. Crocker (1948) found that the flavor was increased by cooking, it follows that the character is t ic f lavor of meat is a breakdown product by cooking or i s re- leased from meat upon cooking. 1949) indicates the flavoring property i n chicken meat i s a weak acid produced by cooking.

Since

Work at the university of California (Bouthilet,

The Score Card

The score card should be prepared with care and above everything should be simple. A very complicated score card only frustrates the scorer and a l l too often ends with no s ignif icant variations having been found. of factors t o be scored should be kept as smll as possible i n re la t ion t o the information sought i n the study. may be aroma, flavor i n i t s wider sense, tenderness, and juiciness. Flavor of fat and texture may be added, although some cuts of cer ta in meats such as veal have l i t t l e f a t for acoring.

The number

If four pa la tab i l i ty factors a re used, they

I f flavor i s t o be divided in to in tens i ty and des i rab i l i ty , then t h i s i s d i f f i c u l t scoring and a t l e a s t two or three pa la tab i l i ty factors should be eliminated (such a s texture and tenderness or juiciness) t o give the scorer time t o concentrate on the points being scored.

I t is unfortunate from some standpoints t h a t numerical ra t ings must be assigned to pala tab i l i ty factors for acceptabili ty i s not basical ly a math- ematical f'unction. A score of 4 does not imply that the sample i s twice as palatable a8 one with a score of 2, nor that it i s two-thirds as acceptable as a sample with a score of 6. means of evaluating the results' s t a t i s t i c a l l y and f o r making comparisons with other laboratories.

But, numerical ra t ings a re pract ical ly our only

Nothing i s gained by using a scoring system that has a range of num- bers beyond the number of gradations of quali ty that can be recognized, On the other hand using a range of numbers smaller than the range of qua l i t i es t ha t can be recognized is a lao disadvantageous. use only the numerical ra t ings between the top and bottom scores a range of 0 t o 5 w i t h 1 point variation i s less than the gradations of quali ty factors t h a t can be recognized,

Since there i s a tendency to

A range of qua l i t i es l e easier t o remember i f descriptive terms are assigned t o each numerical ra t ing. used, 10 might be assigned the word perfect for a description, 9 excellent, 8 very good, 7 high average, 5 average, 4 low average, 3 f a i r , 2 poor, 1 very poor, and 0 unacceptable, negative rat ings, t ha t can be recognized, but tenderness, i f based upon the number of chews t o masticate a standard s ize sample t o a determined end point, has a wide range of tenderness variations.

For example, i f scores of 0 t o 10 a r e

Varying degrees of inedib i l i ty can be assigned Some pa la t ab i l i t y factors have a limited range of qua l i t i es

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The Scoring Panel

Variation i n organoleptic scoring i s admitted. Even a person who i s ordinar i ly an almost perfect scorer may be thrown off base when he has a head cold. scores for a panel. Probably four scorers i s the minimum number. However, a s t i l l smaller panel composed of members who have high sens i t i v i ty and a b i l i t y t o d i f f e ren t i a t e perceptions may be preferable t o a la rge group w i t h less sens i t iv i ty . One of the basic tene ts of the s t a t i s t i c a l treatment of the scoring data i s that a la rger number of individuals a r e needed fo r the panel when t h e var ia t ion i n scoring i s great. A l a rger number of scorers will a l s o tend t o rule out the experimental e r ror of da i ly individual var ia t ion because of physical o r mental conditions.

Hence, no hard and fast rule can be made concerning t h e numbers o f

A scorer should have a high degree of in tegr i ty , be able t o concen- t ra te and develop an objective and sc i en t i f i c a t t i t ude towards scoring meat or other foods, and above a l l be wi l l ing t o spend t i m e and e f f o r t needed for a falr evaluation of the problem.

If the members of the panel are t o be selected on t h e i r sens i t iv i ty of organoleptic ratings, the concenms a t present seems t o favor using the food t o be scored as a basis of selection instead o f d i lu t e salt solutions, sugar solution, e tc . I n panel t a s t ing it is the a b i l i t y of the scorer t o detect a flavor i n a mixture of flavors tha t i s important.

Probably the most common tes t used a t present f o r t he selection of a scoring panel i n t he t r iangular one. samples of meat. s ize . The scorer i s t o l d tha t two samples are duplicates and asked t o pick out t he duplicates. It i s advantageous t o ask upon what character is t ica , such as aroma, t a s t e , a f t e r taste, texture, tenderness, and/or juiciness the decision i s made, of using a l l pa l a t ab i l i t y factors . prospective scorer can be cal led t o his at tent ion in the preliminary t ra ining. I n the t r iangular t es t a person has t o pick the duplicates 5 times out of 7 fo r the results t o be s ignif icant . t he samples and who cannot duplicate their judgments i n picking duplicate samples should not be placed on t h e scoring panel.

Prospective scorers are given three The samples a re cut from a par t icu lar muscle, a l l t he same

Some persons w i l l t r y t o make the select ion on taste alone instead This lack of observation on the pa r t of the

Persons who cannot detect differences i n

Members of a panel should be given preliminary t ra in ing i n a6 wide var ia t ion i n qua l i t i e s of meat as possible. be greater than w i l l be m e t i n the study.

This var ia t ion should preferably

Preparation of and Scoring of the Sample

The sample should be presented t o the scorer i n an a t t r a c t i v e manner. A l l samples are coded, but coding does not mean t h a t the sample should be placed over a l a rge red o r black pencilled number or presented i n such a manner t h a t the scorer i s adversely affected. t o the appearance of the sample.

The scorer 's f irst reaction i s usually

Each scorer is given a sample, a8 nearly as possible, from the same anatomical location of each cut. This i s important for d i f fe ren t p a r t s of t he cu t may vary i n composition of f ibe r and connective t i s sue . center s l i c e has not been subjected t o heat during cooking as long as a s l i c e close t o the ex ter ior of t h e cut, par t icu lar ly i n meat cooked rare o r medium done.

I n addition, a

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The temperature of t he neat sample should be about the same for each Odor i s more intense when the meat scoring, or the scorer may be handicapped.

temperature i s high. (b i t te r , sour, salt, and meet ) (Moncrieff, 1946, Chapter 5) i s doubled on rais- ing the temperature from 10' t o 20%. from 2OoC t o 3@C, then falls off a s the temperature i s raised from 30' t o 40' C. I n h i s summary Moncrieff (p 125) give8 the optimum temperature for taste different ia t ion a8 200 to 4OoC.

In addition, the a b i l i t y t o d i f fe ren t ia te the four tastes

Acuteness of taste then i s f a i r l y steady

Sl ices of meat a re cut acros8 the f iber and should be of uniform thickness. i t s r e l a t ive tenderness, the meat should be s l iced on 8 s l i c ing machine. gives sections of the f ibe r s and connective tissue with as nearly uniform length as possible.

Preferably, from the standpoint of chewing the sample t o determine This

Samples should be large enough for the scorer t o have more than one Crocker thinks it i s preferable to w a i t long enough between bites for taste.

the sa l iva to c lear the mouth rather than eat other food or drink water o r beverage between samples. It should a l s o be indicated t h a t i f another food o r a drink is used between samples, it should also be used before s t a t i n g t o score the first sample.

Moncrieff (1946) s t a t e s that the sweet t a s t e is most eas i ly perceived a t the t i p of the tongue, the b i t t e r a t the back, the sour a t the edge, and the salt a t both the t i p and edge, t r ibu t ion of the t a s t e buds. I n 80me areas two or a l l of the t a s t e s can be distinguished and there is an area a l i t t l e l ee s than the size of a dime back of the tongue t i p i n which no taste i s perceived. Other areas i n which t a s t e buds a re located i n addition t o the dorsal par t of the tongue, a r e the sof t palate, the ep ig lo t t i s , and the beginning of the esophagus.

Crocker (1945) gives a somewhat d i f fe ren t dis-

It i a not necessary for us t o decide whether Moncrieff o r Crocker i s r ight . It i s indicated though that i n the preliminary t ra in ing the pros- pective scorer should not swallow the sample too hast i ly , but should develop a def in i te procedure of ro l l i ng the sample over the tongue between chews. addition, t o the t a s t e buds being located i n different areas, some t a s t e perceptions a re ident i f ied more slowly than others. The four t a s t e s i n order of ease of detection a re b i t t e r , sour, salt, and sweet, It is the combined result of a l l of these t a s t e and odor perceptions t h a t determine the re la t ive pa l a t ab i l i t y of two or more samples of meat. A good scorer develops a pro- cedure t o obtain as much information a b u t each sample as possible,

I n

The scorer should not be interrupted during scoring. be done i n a place f r ee of odors of other materials and foods.

Scoring should

Each ecorer, after the preliminary training, works independently.

There i s no def in i te ru le i n deciding upon the number of samples that can be ecored a t one t i m e . The senses of t a s t e and smell fatigue easi ly , hence the number should not be large. The number of samples that can be scored a t one t i m e i s a l so re la ted t o the number of pa la tab i l i ty factors t o be scored. If the score card i s complicated two samples &re suf f ic ien t for scoring. only pa r t of the pa l a t ab i l i t y factors are t o be rated, then four o r more samples may be scored a t one t i m e .

I f

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Subjective and Objective Tests

Subjective tenderness and juiciness of t he meat ra t ings may be com- pared with objective shear force (pounde or ounces t o shear a cylinder of a de f in i t e s ize) and press f luid. by the Carver prees of the Minnesota pressometer. t h e number of chews t o masticate a standard s i z e sample t o a predetermined end point gives a very easy way of evaluating comparative tenderness i n d i f - ferent samples. Do not be surprised i f objective tests and subjective tests do not always agree. For example, there are some meats, which with the first b i t e l o se a great deal of juice. After a f e w chews, t h e meat may become dry i n the mouth, The sample may be ra ted dry on an organoleptic rating, yet give a high percentage of press f lu id .

The amount of press f l u i d can be determined We have found t h a t counting

They may be measuring d i f fe ren t things.

Evaluation of Tests

Usually the study i s not complete unti l the scoring data have been analyzed by some standard s t a t i s t i c a l methods t o t e s t the significance of t he data.

L i te ra ture Cited

Bouthilet , R . J . , 1949. A note on the flavor constituent of poultry meat, Food Tech, 3: 118

Crocker, E.C., 1945. Flavor, McGraw-Hill Book Company, Inc. 172 pp.

Crocker, E.C., 1948. Flavor of meat, Food Research 13: 179-183

Moncrieff, R.W., 1946. The chemical senses, John Wiley and Sons, Inc., 424 pp.

CHAIRMAN BUTLER: Thank you, Miss Lowe.

The discussion w i l l be directed by V . K. Johnson of Illinois.

PROF, JOHNSON: A r e there any questions t h a t you would l i k e t o d i r ec t t o Miss Lowe?

PROF. WANDERSTOCK: Miss Lowe, do you think t h a t it i s advisable, i n s e t t i ng up a pa la t ab i l i t y panel f o r a meat study, t o have your committee get together and have a trial run?

MISS LOWE: Oh, yes, that i s a preliminary t ra in ing , par t icu lar ly i f they have not been judging, o r i f you have been judging for t h i r t y years, like I have, and you had a vacation during the summer, you need t o refresh before you go in .

PROF. JOHNSON: Anybody else?

PROF, KLINE: Miss Lowe, would you use the pa l a t ab i l i t y committee a f t e r they have eaten, o r just before they have eaten, o r does tha t seem t o make much difference?

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MISS LOWE: Most of ours we use a t the time that it i s very easy; usually about eleven o'clock, because the meat w i l l come out about that time. I rather gather, i f I remember Moncrieffrightly, tha t that i s a pret ty good t i m e t o score,

I n the af'ternoon, we usually score at about four o'clock. some t h a t advocate ea r l i e r than that. t e s t , a f t e r we s ta r ted our co-operative meat proJects in 1926, that they sug- gested scoring a t 9:30 a.m. but I think it has not been borne out altogether that t h a t i s the best t i m e t o do it.

There m e I remember in our first pa la tab i l i ty

PROF. JOHNSON: Any other questione?

If not, I w i l l turn the meeting back t o Chairman Butler.

CHAIRMAN BVILER: Thank you, M r . Johnson,

Prof. Bratzler has been s t a l l i ng me off about two days on some ques- t ions I have been asking about tenderness of meat, and we w i l l now have a dis- cussion by him on "Determining the Tenderness of Meat by the Use of the Warner- Bratzler Method".

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