Freshly Cooked and Reheated Turkey Breast Muscle

Freshly Cooked and Reheated Turkey Breast Muscle 1. C O O K I N G L O S S E S A N D S E N S O R Y E V A L U A T I O N O F M U S C L E AND EXPRESSED JUICE PAMELA G. JOHNSON AND J A N E A . BOWERS

Department of Foods and Nutrition, Kansas State University, Manhattan, Kansas 66506 (Received for publication May 22, 1973)

POULTRY SCIENCE 53: 343-348,

INTRODUCTION EHEATED meats, including turkey, have been described as having "warmedover," "stale," and "rancid" flavors (Tims and Watts, 1958; Cipra and Bowers, 1971). Off-flavors develop quickly in cooked, stored meats. Harris and Lindsay (1972) found that panelists were able to detect off-flavors in fried chicken reheated after only 2 hr. of refrigerated storage. Oxidation of tissue lipids has been established as one source of offflavor development in reheated meats; however, the mechanism by which warmedover flavors develop is not understood. Younathan and Watts (1960) suggested that the autoxidation of tissue lipids was heme catalyzed. Sato and Hegarty (1971), however, found that heme iron had little effect on the development of warmed-over flavor in ground beef as indicated by TBA values and

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Contribution No. 293, Department of Foods and Nutrition, Kansas Agricultural Experiment Station, Manhattan, Kansas 66506

1974

odor evaluations; Liu and Watts (1970) found evidence that both heme and non-heme iron were functioning as catalysts of lipid oxidation in cooked meats. Water activity has been described as the freedom of absorbed water molecules to be involved in chemical reactions. The effect of absorbed water can be expressed as vapor pressure or a related term such as relative humidity (Quinn, 1967). Using both model systems and intermediate moisture foods, Labuza (1971) indicated that there is an optimum water activity at which each food system should be stored. Storage above or below that level may result in increased susceptibility to oxidative deterioration. Oxidative changes in meat may be associated with changes in water activity during cooking and/or storage, which could explain why cooked meats deteriorate more rapidly with storage than do raw meats. Phosphate salts, used to maintain freshly cooked flavor in poultry meats (Schlamb, 1970), are thought to act as chelating agents

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ABSTRACT Water or a phosphate salt solution was added to turkey breast muscle. Muscles—untreated, phosphate-treated, and water-treated—were frozen either raw or partially cooked and stored 5 wk. For freshly cooked and reheated muscle, percentage cooking losses were determined, and panelists evaluated the intensity of aroma and flavor components of muscle and aroma components of juice expressed from that muscle. The relationship between juiciness and the perception of flavor components was investigated. Phosphate-treated samples had lower percentage cooking loss than did the other samples. Freshly cooked muscles, as a whole, had less cooking loss than reheated muscles, as would be expected. In general, flavor and aroma components were affected similarly by additive treatment. Phosphate-treated samples had more intense meaty-brothy but less intense stale, rancid, and acid aromas and flavors than did reheated water- or untreated samples. Adding water had little effect on flavor and aroma components of either freshly cooked or reheated turkey muscle. Aroma components of expressed juice were similar to, but less intense than, those of muscle. Tenderness was not affected by additive or heating treatment; however, juiciness was affected. The phosphate-treated muscle scored more juicy than other muscles, also frequently was described as having "soapy" flavor.

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MATERIALS AND METHODS Breast portions from 30 U.S. Grade A torn turkeys (24-26 lb.) from one lot were purchased from a local plant. Pectoralis major (PM) muscles with skin were excised. Six treatments—phosphate-treated, freshly cooked; water-treated, freshly cooked; untreated, freshly cooked; phosphate-treated, reheated; water-treated, reheated; and untreated, reheated—were assigned to experimental units (PM muscles) according to an incomplete block design described by Cochran and Cox (1957, p. 471). One turkey represented a block and each treatment appeared with every other treatment twice. For phosphate-treatment, a 5% solution of

Kena (a commercial polyphosphate salt) was injected (10% by weight). Injected muscles were refrigerated 2 hr. before precooking or freezing. For reheated samples, PM muscles were roasted in Pyrex baking dishes to an internal temperature of 71° C. in a rotary hearth gas oven at 350° F. and then cooled 30 min. at room temperature. The cooked and raw muscles were placed in polyethylene bags, frozen in an upright household-type freezer at -13° C , and held frozen for 5 wk. Before evaluation, muscles were thawed 24 hr. at 6° C. Cooked muscles were reheated in oven-proof film (3M Scotchpak) to an internal temperature of 55° C. to complete cooking; and raw muscles were cooked to an internal temperature of 80° C. Total cooking losses were determined on the basis of drained weight—the weight of the muscle 2 hr. after treatment solution was injected. Center 1/4-inch slices from each PM muscle were presented randomly to a 7member laboratory panel for evaluation of aroma and flavor components, tenderness, and juiciness. After a rest period, 3 panel members evaluated aroma components of juice expressed from muscle. Juice was obtained using a Carver Laboratory Press at a pressure of 3,750 p.s.i. for 5 min. Samples were maintained at 60° C. in a water bath and presented randomly to the panel members. Intensity of aroma and flavor components of muscle and of juice was scored on a 5 point scale (0, absent to 4, strong). Tenderness and juiciness were evaluated on a 6-point scale (6, very tender or juicy to 1, very tough or dry). Adjusted treatment means were determined and analysis of variance was run on data for each measurement. When F-values were significant, least significant differences (LSD) were calculated. Simple linear correlation coefficients were calculated for pooled data to determine the relationship among selected aroma and flavor components.

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for free radicals that initiate lipid oxidation. Mahon (1962) reported that panelists evaluating aroma and flavor preferred phosphatetreated, reheated chicken to untreated samples. Smith (1971), who prepared turkey roulades from ground turkey muscle and skin wrapped in breast fillets, reported that reheated samples containing polyphosphate salts received lower off-flavor and higher flavor desirability scores than did reheated samples containing no additive. By increasing pH, phosphate salts increase water holding capacity of muscle, resulting in a more juicy product (Morse, 1955). Considering factors that may be related to development of off-flavors in cooked, stored turkey, we studied the effect of added phosphate or water on the flavor and juiciness characteristics of freshly cooked and reheated turkey breast muscle. The effect of treatment on various determinations of moisture was measured, and the relationship between those moisture values and sensory impressions of juiciness was investigated. Effect of treatment on cooking losses and sensory characteristics of muscle and expressed juice are reported here; findings on chemical and physical characteristics of muscle will be reported subsequently.

2.9 0.6 0.6 0.3 0.1 0.1 2.7 0.6 0.2 0.2 0.3 0.1 0.2 0.2 3.1 0.5 0.1 0.3 0.4 0.2 5.0 4.0

2.5 0.8 0.3 0.1 0.1 0.1 2.5 0.5 0.2 0.2 0.1 0.1 0.1 0.1 2.1 1.1 0.4 0.1 0.1 0.5 4.4 3.6

27.6 2.3 1.0 0.5 0.3 0.2 0.1 2.7 0.5 0.2 0.2 0.3 0.1 0.0 0.1 2.0 1.0 0.3 0.2 0.2 0.5 4.7 3.7

2.9 0.6 0.2 0.1 0.1 0.2 2.9 0.2 0.2 0.1 0.0 0.1 0.4 0.1 2.5 0.7 0.1 0.2 0.3 0.4 5.2 4.6

Phosphate 31.2

Untreated 18.8

Water

Freshly cooked 20.7

Phosphate 3

W

Re

2 **, 3

'Intensity scores: 0, absent to 4, strong. Tenderness and juiciness: 6, very tender or juicy to 1, ve significant at 1% level; *, significant at 5% level; ns, non significant. Percentage drained weight.

Cooking loss 3 Aroma of muscle: Meaty-brothy Stale Rancid Acid Sulfur Ammonia Flavor of muscle: Meaty-brothy Stale Rancid Acid Sulfur Sweet Salty Bitter Aroma of juice: Meaty-brothy Stale Rancid Acid Sulfur Ammonia Tenderness Juiciness

Components

TABLE 1.—Adjusted means of cooking losses and sensory scores' for turkey m

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P. G. JOHNSON AND J. A. BOWERS

RESULTS AND DISCUSSION

Aroma and Flavor of Muscle. In general, flavor and aroma components of muscle were affected similarly by treatment (Table 1). Phosphate-treated samples had more intense meaty-brothy flavor and aroma than did samples of the other treatments. Water- and untreated samples developed stale and rancid flavor and aromas, and the meaty-brothy component became less intense with storage a n d / o r reheating. Other workers have reported similar development of off-flavors and aromas in cooked, stored meats (Tims and Watts, 1958; Cipra and Bowers, 1970). Heating treatment appeared to have less effect on phosphate-treated samples than on other samples. Those results agree with the work of other researchers who have reported that adding polyphosphate salts reduces offTABLE 2.-

Aroma of Expressed Juice. Meaty-brothy and stale aromas were affected significantly by treatment (Table 1). Phosphate-treated samples had higher scores for meaty-brothy and lower scores for stale aromas than did water- or untreated samples. Ammonia, acid,

-Correlation coefficients among scores for selected flavor and aroma components of turkey breast muscle. Flavor components Component

Meaty-brothy Stale Rancid Acid

"Significant at 1% level *Significant at 5% level

Stale

Rancid

Acid

-0.08

-0.15 0.38**

-0.04 0.28 0.34*

Aroma components Sulfur

Stale

-0.01 -0.50** 0.47** 0.31* -0.02

Rancid

Acid

-0.57** 0.30*

-0.10 0.16 0.33*

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Cooking Losses. Total cooking losses were affected (P < 0.01) by additive and heating treatments (Table 1). Within each heating treatment, the water-treated sample had the greatest percentage cooking loss; phosphateand untreated samples had similar percentages cooking loss indicating that the added water was retained only when phosphate salts were present. Using various phosphate salts, Tims and Watts (1958), found that for several ground meats, adding phosphate salts decreased cooking loss. In our study, freshly cooked treatments had lower percentages cooking loss than reheated treatments, as was expected.

flavor development and maintains freshly cooked flavor in poultry meat (Tims and Watts, 1958; Schlamb, 1970; Smith, 1971). Correlation coefficients for selected flavor and aroma components are presented in Table 2. As might be expected, an inverse relationship was noted among meaty-brothy and stale and rancid aromas. Stale and acid flavor and aroma components increased with increasing intensity of rancid aroma (P < 0.05) and flavor (P < 0.01). Other investigators have indicated that loss of freshly cooked aroma in stored poultry is accompanied by increased staleness and rancidity (Cipra and Bowers, 1970). Sulfur flavor was correlated positively to stale (P < 0.01) and rancid (P < 0.05) flavor components indicating that the sulfur may not be related to the development of offflavors. Cipra and Bowers (1970) reported a similar correlation between rancid aroma and sulfur flavor (P < 0.05) and between stale and sulfur flavor and aroma (P < 0.01) for freshly braised and braised, reheated turkey. Although a sulfur-containing fraction has been identified in cooked chicken volatiles by several workers, that fraction has not been related to off-flavor development (Bouthilet, 1951; Minor et al., 1965; Mecchi et al., 1964).

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COOKED AND REHEATED TURKEY BREAST

Juiciness and Tenderness. Within each heating treatment, the phosphate-treated sample was significantly (P < 0.01) more juicy than the other treatments. Several workers have reported that adding phosphate salts increased juiciness (May et al, 1963; Schlamb, 1970). The water- and untreated samples received similar scores for juiciness. The water-treated samples might have been expected to be more juicy; however, an average of only 34% of the injected water was retained by the muscle 2 hr. after injection, as compared with 79% of injected phosphate solution retained. Freshly cooked, phosphate-treated turkey was significantly more juicy than the reheated treatments. Frozen storage and/or reheating, however, did not affect the juiciness scores for water- or untreated samples. Reheated samples might have been expected to be less juicy because they were exposed to oven temperatures twice. Tenderness was not affected by treatment; however, panelists tended to score phosphate-treated samples as being more tender.

TABLE 3.—Correlation coefficients among meaty-brothy components, juiciness, tenderness, and cooking losses Y

Factors Meaty-brothy flavor Meaty-brothy aroma of muscles Meaty-brothy aroma of juice Tenderness Cooking loss **, Significance at 1% level *, Significance at 5% level

Tenderness 0.73**

Juiciness 0.70**

0.25 0.41* 1.00** 0.52**

0.30* 0.35* 0.78** 0.33*

May et al. (1963) reported increased tenderness of meat with added phosphate salts; however, Smith (1971) found the addition of polyphosphate salts to turkey roulades did not affect their tenderness. A positive correlation (P < 0.01) was noted between juiciness and the intensity of meatybrothy flavor and aroma perceived by panelists (Table 3). Cipra and Bowers (1970) found a similar relationship in dark muscle of turkey. In this study juiciness and tenderness were correlated positively as might be expected from work by other investigators (Cover et al., 1962; Gaddis et al., 1956; and Ritchey, 1965). REFERENCES Bouthilet, R. J., 1951. Chicken flavor: The source of the meat flavor component. Food Res. 16: 201204. Cipra, J. S., and J. A. Bowers, 1970. Precooked turkey. Flavor and certain chemical changes caused by refrigeration and reheating. Food Technol. 85-87. Cipra, J. S., and J. A. Bowers, 1971. Flavor of microwave- and conventionally reheated turkey. Poultry Sci. 50: 703-706. Cochran, W. G., and G-. M. Cox, 1957. Design of Experiments, John Wiley and Sons, Inc., New York, 2nd ed. p. 471. Cover, S., R. L. Hostetler and S. J. Ritchey, 1962. Tenderness of beef. IV. Relations of shear force and fiber extensibility to juiciness and six components of tenderness. J. Food Sci. 27: 527-536. Gaddis, A. M., O. G. Hankins and R. L. Hiner, 1950. Relationship between the amount and composition of press fluids, palatability, and other factors of meat. Food Technol. 4: 498-503.

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sulfur, and rancid aroma components were not affected by treatment. Juice expressed from phosphate-treated, reheated muscle had more intense meatybrothy aroma but similar intensity of stale aroma when compared with phosphate-treated, freshly cooked muscle. Juice from waterand untreated samples had similar intensity of rrieaty-brothy aroma for both heating treatments. Water- and untreated samples developed more intense stale aromas during storage and/or reheating than did phosphatetreated samples. More differences attributable to additive treatment were apparent in aroma of muscle than in aroma of expressed juice; however, the intensity of most aroma components was similar for muscle and expressed juice. Ammonia aroma was more intense in expressed juice than in muscle.

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meats. Food Eng. 27: 84-86. Quinn, F. C , 1967. The quality of water the "other" raw material. Paper Trade J. 151(36): 40-44. Ritchey, S. J., 1965. The relationship of total, bound, and free water, and fat content to subjective scores for eating quality in two beef muscles. J. Food Sci. 30: 375-381. Sato, K., and C. R. Hegarty, 1971. Warmed-over flavor in cooked meats. J. Food Sci. 36: 1098-1102. Schlamb, K. F., 1970. Food grade phosphates can improve new poultry products, pp. 27-40. Proc. 7th Annual Poultry and Egg Conf. Ithaca, New York. Smith, M. L., 1971. Effects of polyphosphate salt on eating and microbial quality of precooked and freshly cooked turkey roulades stored 4 and 8 weeks. M.S. thesis, Kansas State University, Manhattan. Tims, M. J., and B. M. Watts, 1958. Protection of cooked meats with phosphates. Food Technol. 12: 240-243. Younathan, M. T. and B. M. Watts, 1960. Oxidation of tissue lipids in cooked pork. Food Res. 25: 538-543.

NEWS AND NOTES (Continued from page 310) that produce yeast and other fermented products. This material is divided into three categories: dried grain with solubles, dried grains only, and the solubles. At the Arkansas Experiment Station, Drs. P. W. Waldroup, T. Nelson and L. Barton will be comparing distillers dried grain with solubles and dried grain alone against soybean and corn meal in standard diets. About 1,000 breeder hens and 3,000 broiler chickens will be involved in the year-long study.

grade may appear only on shipping containers, not on individual birds. Consumer grades for turkeys, which are based on the appearance of the bird as well as its meat yield and quality, remain unchanged. The new processing grade for turkeys was established, officials said, to avert needless discounting of prices to farmers for birds sold for manufacturing use. About 50 percent of all turkeys produced in the U.S. go into such usage. Grade standards for ducks were changed to permit ducks with wings clipped off at the second joint to U.S.D.A. NOTES qualify for U.S.D.A. Grade A. Meat yield will not Revised grade standards announced by the U.S. be appreciably affected by clipping the wings since Department of Agriculture (U.S.D.A.) will provide there is very little edible meat on the lower portion a new processing grade for turkeys used to make rolls, of waterfowl wings. Grade standards for geese already roasts, pot pies, and similar products. Another change permit clipped wings in U.S.D.A. Grade A. Officials modifies slightly the grade standards for ducks. explain that clipping both wings when one is accidentally damaged in processing permits the marketing of The revisions are identical to those proposed by a more attractive retail product. the U.S.D.A. on July 6. Most comments on the proposal favored their adoption. Copies of the revised standards may be obtained Turkeys to be used for processing may now receive from the Poultry Division, Agricultural Marketing a U.S.D.A. Grade A-For Further Processing rating Service, U.S. Department of Agriculture, Washington, on the basis of meat yield and quality without regard D.C. 20250. to the attractiveness of the bird for table use. This An updating of U.S. grade standards for shell eggs (Continued on page 383)

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Harris, N. D., and R. C. Lindsay, 1972. Flavor changes in reheated chicken. J. Food Sci. 37: 19-22. Labuza, T. P., 1971. Kinetics of lipic oxidation in foods. Critical Rev. in Food Technol. 2: 380-389. Liu, H. P., and B. M. Watts, 1970. Catalysts of lipid peroxidation in meats. III. Catalysts of oxidative rancidity in meats. J. Food Sci. 35: 596-598. Mahon, J. H., 1962. Phosphates improve poultry. Food Eng. 34: 108, 113. May, K. N., R. L. Helmer and R. L. Saffle, 1963. Effect of polyphosphate treatment on carcassweight changes and organoleptic quality of cut-up chicken. Poultry Sci. 42: 24-32. Mecchi, E. P., E. L. Pippen and H. Lineweaver, 1964. Origin of hydrogen sulfide in heated chicken muscle. J. Food Sci. 29: 393-399. Minor, L. J., A. M. Pearson, L. E. Dawson and B. S. Schweigert, 1965. Chicken flavor: The identification of some chemical components and the importance of sulfur compounds in the cooked volatile fraction. J. Food Sci. 30: 686-696. Morse, R. N., 1955. How phosphates can benefit