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Effect of Freezing Temperature on Bone Darkening in Cooked Broilers1
EFFECT OF FREEZING TEMPERATURE ON BONE DARKENING IN COOKED BROILERS' F . E . CUNNINGHAM
Dairy and Poultry Science Department, Kansas State University, Manhattan, Kansas 66506 (Received for publication July 23, 1973)
ABSTRACT To help clarify the role of freezer temperature on acceptability of fryers, I tray-wrapped fresh breast and drumsticks in polyethylene and froze them at 8° F. (-13.3° C.) in a household freezer, -20° F. (-28.9° C.) in a blast freezer overnight, or at -197° F. (-127° C.) in a liquid-nitrogen freezer for 10 minutes. Once frozen, the pieces were stored in a household freezer at 8° F. for 8 weeks before testing. After deep-fat frying, the meat was removed and bones examined for degree of darkening. Fresh, unfrozen pieces were used as controls. Bone darkening was severe in meat frozen at 8° F. or -20° F. but nearly absent in meat frozen at -197° F. POULTRY SCIENCE 53: 425-427, 1974
INTRODUCTION
ESPITE consumer resistance, marketing fryer parts as frozen tray-packs seems to be increasing. Many factors, both real and imaginary, contribute to buyers' resistance; bone darkening may be a factor. Considerable information is still needed on what constitutes acceptable frozen broilers. Koonz and Ramsbottom (1947) reported that rate of freezing had no marked influence in preventing bone darkening. Woodroof and Shelor (1948) found that chilling before freezing did not prevent darkening, but storage at temperatures below -15°F. (-26° C.) lowered or prevented it entirely. Brant and Stewart (1950) found that darkening could be somewhat reduced by a combination of freezing and storage at -30° F. (-34.4° C.) and immediate cooking after thawing. However, aside from that combination, freezing rate, temperature or length of storage, or temperature fluctuations during storage had no practical influence on degree of darkening. Sauter et al. (1961) found that bone darkening was not observed in fresh controls, but was found in all frozen broilers. Length of
D
1. Contribution No. 874, Department of Dairy and Poultry Sciences, Kansas Agricultural Experiment Station, Manhattan, Kansas 66506.
frozen storage had no effect on the degree of bone darkening observed. Spencer et al. (1961) reported that bone darkening was never noted in unfrozen controls, but was evident in all frozen birds. Length of frozen storage or method of cooking seemed not to affect darkening. Heaton et al. (1969) found that thighs wrapped in Nylon pouches and frozen by LNP (-150° F., 5 min.) had (a) high scores on initial color and appearance, (b) low drips, and (c) low shear-press values. Thighs frozen in direct contact with vapor from liquid nitrogen at -320° F. in 2-1/2 min. had much less bone and meat darkening. The influence of freezing temperature on degree of bone darkening in fryer parts is reported here.
MATERIALS AND METHODS Fresh fryer parts were purchased from a local retail market immediately after receipt from a wholesaler. Drumsticks and breasts were individually wrapped in polyethylene and frozen at 8° F. (-13.3° C), in a blast freezer at -20° F. (-28.9° C.) overnight, or in a liquid nitrogen freezer at -197° F. (-127° C.) for 10 minutes. After freezing, the pieces were put into polyethylene bags and stored at 8° F. (-13.3° C.) for 8 weeks
425
426
RESEARCH NOTES
CORACOID
lb Fresh
Frozen
at
Control -I97c
-20°
FIG. 1. The influence of freezing temperature on darkening of coracoids removed from fried broiler breasts.
before testing. The meat was defrosted as needed overnight in a refrigerator. Light and dark meat samples were evaluated separately. Thawed breasts and drumsticks were dipped into a milk and egg wash, dredged in a dry, commercial batter mix and cooked in a deepfat fryer at 350° F. (176.7° C.) to an internal temperature of at least 185° F. (85° C ) . The fried pieces were placed on absorbent paper to eliminate excess cooking oil. When cool, the meat was removed and the bones examined for darkening. Photographs were made the same day the pieces were cooked.
RESULTS AND DISCUSSION The coracoid from the breast and the tibia from the drumstick were used to estimate degree of bone darkening due to freezing
deep-fat
(Figs. 1 and 2). There was essentially no darkening of fresh (unfrozen), deep-fat fried bones and essentially none of bones from meat frozen at -197°. Bones from meat frozen at either 8° or -20° darkened severely, which agrees with Heaton et al. (1969) that bone darkening can be controlled by proper, rapid freezing.
REFERENCES Brant, A. W.,andG. F. Stewart, 1950. Bone darkening in frozen poultry. Food Technol. 4: 168-174. Heaton, E. K., K. C. Li and J. E. Marion, 1969. Freezing chicken thighs by liquid nitrogen and sharp freezing process. Food Technol. 23: 241-243. Koonz, C. H., and J. M. Ramsbottom, 1947. Influence of freezing on color of bones and adjacent tissue. Food Research, 12: 393-395. Sauter, E. A., J. V. Spencer and W. J. Stadelman, 1961. Effect of freezing, thawing and storing broilers on spoilage, flavor and bone darkening. Poultry Sci. 40:918-920.
RESEARCH NOTES
427
TIBIA
FIG. 2. The influence of freezing temperature on darkening of tibias removed from deep-fat fried fryer drumsticks.
Spencer, J. V., E. A. Sauter and W. J. Stadelman, 1961. Effect of freezing, thawing and storing broilers on spoilage, flavor and bone darkening. Poultry Sci. 40: 918-920.
Woodroof, J. G., and E. Shelor, 1948. Prevention of bone darkening in frozen-packed chicken. Food Inds. 20: 48-52.
AUGUST 5-8. 63RD ANNUAL MEETING OF THE POULTRY SCIENCE ASSOCIATION, INC., WEST VIRGINIA STATE UNIVERSITY, MORGANTOWN. WEST VIRGINIA AUGUST 11-16. CONGRESS, WORLD'S POULTRY SCIENCE ASSOCIATION, NEW ORLEANS, LOUISIANA, U.S.A. AUGUST 19-23.
THE IV INTERNATIONAL SYMPOSIUM ON RUMINANT PHYSIOLOGY, SYDNEY, AUSTRALIA
SEPTEMBER 22-27.
IVTH INTERNATIONAL CONGRESS OF FOOD SCIENCE AND TECHNOLOGY, MADRID, SPAIN
Dairy and Poultry Science Department, Kansas State University, Manhattan, Kansas 66506 (Received for publication July 23, 1973)
ABSTRACT To help clarify the role of freezer temperature on acceptability of fryers, I tray-wrapped fresh breast and drumsticks in polyethylene and froze them at 8° F. (-13.3° C.) in a household freezer, -20° F. (-28.9° C.) in a blast freezer overnight, or at -197° F. (-127° C.) in a liquid-nitrogen freezer for 10 minutes. Once frozen, the pieces were stored in a household freezer at 8° F. for 8 weeks before testing. After deep-fat frying, the meat was removed and bones examined for degree of darkening. Fresh, unfrozen pieces were used as controls. Bone darkening was severe in meat frozen at 8° F. or -20° F. but nearly absent in meat frozen at -197° F. POULTRY SCIENCE 53: 425-427, 1974
INTRODUCTION
ESPITE consumer resistance, marketing fryer parts as frozen tray-packs seems to be increasing. Many factors, both real and imaginary, contribute to buyers' resistance; bone darkening may be a factor. Considerable information is still needed on what constitutes acceptable frozen broilers. Koonz and Ramsbottom (1947) reported that rate of freezing had no marked influence in preventing bone darkening. Woodroof and Shelor (1948) found that chilling before freezing did not prevent darkening, but storage at temperatures below -15°F. (-26° C.) lowered or prevented it entirely. Brant and Stewart (1950) found that darkening could be somewhat reduced by a combination of freezing and storage at -30° F. (-34.4° C.) and immediate cooking after thawing. However, aside from that combination, freezing rate, temperature or length of storage, or temperature fluctuations during storage had no practical influence on degree of darkening. Sauter et al. (1961) found that bone darkening was not observed in fresh controls, but was found in all frozen broilers. Length of
D
1. Contribution No. 874, Department of Dairy and Poultry Sciences, Kansas Agricultural Experiment Station, Manhattan, Kansas 66506.
frozen storage had no effect on the degree of bone darkening observed. Spencer et al. (1961) reported that bone darkening was never noted in unfrozen controls, but was evident in all frozen birds. Length of frozen storage or method of cooking seemed not to affect darkening. Heaton et al. (1969) found that thighs wrapped in Nylon pouches and frozen by LNP (-150° F., 5 min.) had (a) high scores on initial color and appearance, (b) low drips, and (c) low shear-press values. Thighs frozen in direct contact with vapor from liquid nitrogen at -320° F. in 2-1/2 min. had much less bone and meat darkening. The influence of freezing temperature on degree of bone darkening in fryer parts is reported here.
MATERIALS AND METHODS Fresh fryer parts were purchased from a local retail market immediately after receipt from a wholesaler. Drumsticks and breasts were individually wrapped in polyethylene and frozen at 8° F. (-13.3° C), in a blast freezer at -20° F. (-28.9° C.) overnight, or in a liquid nitrogen freezer at -197° F. (-127° C.) for 10 minutes. After freezing, the pieces were put into polyethylene bags and stored at 8° F. (-13.3° C.) for 8 weeks
425
426
RESEARCH NOTES
CORACOID
lb Fresh
Frozen
at
Control -I97c
-20°
FIG. 1. The influence of freezing temperature on darkening of coracoids removed from fried broiler breasts.
before testing. The meat was defrosted as needed overnight in a refrigerator. Light and dark meat samples were evaluated separately. Thawed breasts and drumsticks were dipped into a milk and egg wash, dredged in a dry, commercial batter mix and cooked in a deepfat fryer at 350° F. (176.7° C.) to an internal temperature of at least 185° F. (85° C ) . The fried pieces were placed on absorbent paper to eliminate excess cooking oil. When cool, the meat was removed and the bones examined for darkening. Photographs were made the same day the pieces were cooked.
RESULTS AND DISCUSSION The coracoid from the breast and the tibia from the drumstick were used to estimate degree of bone darkening due to freezing
deep-fat
(Figs. 1 and 2). There was essentially no darkening of fresh (unfrozen), deep-fat fried bones and essentially none of bones from meat frozen at -197°. Bones from meat frozen at either 8° or -20° darkened severely, which agrees with Heaton et al. (1969) that bone darkening can be controlled by proper, rapid freezing.
REFERENCES Brant, A. W.,andG. F. Stewart, 1950. Bone darkening in frozen poultry. Food Technol. 4: 168-174. Heaton, E. K., K. C. Li and J. E. Marion, 1969. Freezing chicken thighs by liquid nitrogen and sharp freezing process. Food Technol. 23: 241-243. Koonz, C. H., and J. M. Ramsbottom, 1947. Influence of freezing on color of bones and adjacent tissue. Food Research, 12: 393-395. Sauter, E. A., J. V. Spencer and W. J. Stadelman, 1961. Effect of freezing, thawing and storing broilers on spoilage, flavor and bone darkening. Poultry Sci. 40:918-920.
RESEARCH NOTES
427
TIBIA
FIG. 2. The influence of freezing temperature on darkening of tibias removed from deep-fat fried fryer drumsticks.
Spencer, J. V., E. A. Sauter and W. J. Stadelman, 1961. Effect of freezing, thawing and storing broilers on spoilage, flavor and bone darkening. Poultry Sci. 40: 918-920.
Woodroof, J. G., and E. Shelor, 1948. Prevention of bone darkening in frozen-packed chicken. Food Inds. 20: 48-52.
AUGUST 5-8. 63RD ANNUAL MEETING OF THE POULTRY SCIENCE ASSOCIATION, INC., WEST VIRGINIA STATE UNIVERSITY, MORGANTOWN. WEST VIRGINIA AUGUST 11-16. CONGRESS, WORLD'S POULTRY SCIENCE ASSOCIATION, NEW ORLEANS, LOUISIANA, U.S.A. AUGUST 19-23.
THE IV INTERNATIONAL SYMPOSIUM ON RUMINANT PHYSIOLOGY, SYDNEY, AUSTRALIA
SEPTEMBER 22-27.
IVTH INTERNATIONAL CONGRESS OF FOOD SCIENCE AND TECHNOLOGY, MADRID, SPAIN