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The Effect of Freezing and Reheating on Shear Press Values of Precooked Chicken1
281
RESEARCH NOTES REFERENCES
Cook, R. M., 1966. Use of CM to study utilization of substrate in ruminants. J. Dairy Sci. 49: 1018-1023. Kleiber, M., and M. Edick, 1952. A respiration apparatus for C" studies with cows. J. An. Sci. 11: 61-71. Kleiber, M., A. H. Smith, A. L. Black, M. A. Brown, B. M. Tolbert, 1952. Acetate as a precursor of milk constituents in the intact dairy cow. J. Biol. Chem. 197: 371-379. Robertson, J. S., 1957. Theory and use of tracers in determining transfer rates in biological systems. Physiol. Rev. 37: 133-154.
THE EFFECT OF FREEZING AND REHEATING ON SHEAR PRESS VALUES OF PRECOOKED CHICKEN 1 J. N. BUTTS AND F. E. CUNNINGHAM Dairy and Poultry Science Department, Kansas State University, Manhattan, Kansas 66502 (Received for publication October 30, 1970)
INTRODUCTION Precooked frozen meat is increasing in popularity because of greater convenience. However, Watts et al. (1948), West et al. (1959), and Mitchell (1963) have reported that precooking reduces palatability of frozen meat. Mickelberry and Stadelman (1960, 1962) compared the following cooking methods: micro-wave, deep-fat fry, deepfat fry and micro-wave, rotary-reel oven, and steam and deep-fat fry. They found that cooking chicken before freezing made it significantly less tender. Deep-fat fried birds were less tender than birds cooked by other methods. Stadelman and Wise (1961) reported shear values of breast meat increased (indicating less tenderness) by cooking before freezing. Miller and May (1965) reported 1 Contribution No. 798, Department of Dairy and Poultry Sciences, Kansas Agricultural Experiment Station, Manhattan, Kansas 66502
that rate of freezing (0°, —30° and — 90°F.) did not significantly influence tenderness. They also reported that cooking chicken breasts before freezing and storing resulted in greater shear-press values than when the breasts were cooked after frozen storage. The present study was to evaluate methods of freezing and reheating on tenderness of broilers as indicated by shear-press values. METHODS AND MATERIALS Broilers (2 to 2^2 pounds) of unknown history were purchased from a commercial processing plant. They came packed in ice, were held overnight in a cooler, then deepfat fried after being cut into individual parts. A batter was applied by first dipping the pieces in a milk-and-egg solution, then coating with a commercial, dry batter mix. The pieces were fried at 300°F. in a thermostatically controlled commercial-size
Downloaded from http://ps.oxfordjournals.org/ at Uniwersytet Warszawski Biblioteka Uniwersytecka on April 16, 2015
have been used. There are several important advantages derived from vessel catheterization in experiments involving rapidly metabolized substrates. The isotope may be given as a pulse label single injection or as a continuous infusion. In addition, it is easier to quantitate the amount of isotope injected and there is no delay in isotope absorption due to local sequestration or pocket formation. Finally, serial blood samples may be taken to assess entry rates or transfer quotients (Kleiber et al., 1952).
282
RESEARCH NOTES
TABLE 1.—Mean shear press values for methods of freezing Freezing method Liquid nitrogen freezer Blast freezer Household freezer Pounds of force/gm. of meat.
Mean value 1 4.089 5.033 6.182
TABLE 2.—Analysis of variance for shear-press data on precooked frozen light and dark meat of broilers Source of variation
Degrees of freedom
Reps. Reheating method Freezing method Meat (light and dark) Reheating X freezing ReheatingX meat Freezing X meat ReheatingX freezingX meat Residual
1 2 2 1 4 2 2 4 64
Mean squares 349.7 1013.9 2371.2** 37.0 821.9 135.1 3.4 216.9 370.0 -
** P<0.01 RESULTS AND DISCUSSION Sh
ear press values (pounas oi iorce per gm. of meat) indicated that the method of freezing cooked chicken influenced tenderness. Shear-press values among meats frozen in the liquid nitrogen freezer, blast freezer or household freezer differed significantly (P<0.01). That frozen in the liquid nitrogen freezer was the tenderest, in the blast freezer intermediate, in the household freezer least tender. The means of the freezing methods are given in Table 1 and the analysis of variance of the shear-press data is shown in Table 2. Shear-press values for light and dark meat did not differ significantly. Relatively large differences in shear-press values for meat reheated by the different methods were not statistically significant. SUMMARY
Light and dark portions of deep-fat fried broilers were frozen by three methods: a liquid nitrogen freezer, a blast freezer, or a household freezer. After six months storage in a household freezer, the pieces were reheated by three methods: a micro-wave oven, a deep-fat frier, or a household oven. Shear strengths of the samples were determined using an Allo-Kramer shear press. Method of freezing, but not method of reheating, significantly altered the shearpress values of the meat. Meat frozen in
Downloaded from http://ps.oxfordjournals.org/ at Uniwersytet Warszawski Biblioteka Uniwersytecka on April 16, 2015
deep-fat frier, then placed on paper towels to drain and cool. Cooked pieces were placed in polyethylene bags, evacuated with a Cryovac machine, and frozen as described by Berry and Cunningham (1970) by three methods: 1. Household freezer at — 10°C. 2. Blast freezer at — 30°C. overnight. 3. Liquid nitrogen freezer at — 50 °C. for 45 minutes. After freezing, all meat was held in a household freezer at — 10°C. for 6 months. Breasts and thighs were prepared for shear-press evaluation by three reheating methods (all reheated from the frozen state): 1. Micro-wave oven (2 min. for 2 pieces of meat). 2. Deep-fat fry (300°F. for 7 min.). 3. Household oven (425°F. for 30 min.). Meat reheated in the household oven was covered with aluminum foil for 20 min., then the foil was opened for the final 10 min. All breading and skin was removed from the reheated pieces to provide a uniform sample. The pieces were deboned and cut into cubes. Ten gram portions of meat were used for each shear-press measurement on an Allo-Kramer shear press with an electronic recorder. The press was set on 100 with a 3,000 pound ring and a 15-second down stroke. Shear press values were obtained on duplicate samples from each piece of meat. Two pieces were measured for each of the 18 different combinations of freezing, reheating and light vs. dark meat for a total of 72 measurements.
RESEARCH NOTES
the liquid nitrogen freezer was tenderest; in the blast freezer, intermediate; in the household freezer, least tender.
age time and temperature and freeze drying. Food Technol. 19: 1171-1174. Mitchell, J. D., 1963. Problems relating to uniform meat tenderness in a commercial operation. Proc. Meat Tenderness Symposium, Campbell Soup Co., Camden, N.J., p. 243. Stadelman, W. J., and R. G. Wise, 1961. Tenderness of poultry meat. I. Effect of anesthesia, cooking and irradiation. Food Technol. 15: 292-294. Watts, B. M., D. Peng and E. A. Kline, 1948. Precooking pork for freezing storage. J. Home Econ. 40: 579-583. West, L. C , M. C. Titus and F. O. VanDuyne, 1959. Effect of freezing storage and variations in preparation on bacterial count, palatability, and thiamine content of ham loaf, Italian rice, and chicken. Food Technol. 13: 323-327.
THE EFFECT OF EARLY GROWTH RETARDATION OF COTURNIX (JAPANESE QUAIL) ON THEIR SUBSEQUENT SEXUAL MATURITY KIYO MORSE AND PRAN VOHRA Department of Avian Sciences, University of California, Davis, California 95616 (Received for publication October 13, 1970)
Early growth of chickens has been arrested at a physiological age of about 10 days over a period of six months either by severely restricting the intake of a well-balanced diet (McCance, 1960) or by decreasing food intake via tryptophan deficiency (Gordon, 1965) as in the corn-dextrose diet of McRoberts (1965). The subsequent sexual maturity of these birds when fed well-balanced diets was delayed by the approximate length of time that they were kept on the early growth restricting regimens. Similar observations have been made for the Coturnix (Japanese quail) and are reported here. A preliminary study indicated that heavy mortality was observed if an attempt was made to restrict the growth of day-old quail. For this reason, chicks from mixed sources were hatched and, initially, fed a
commercial turkey poult starter. At six days of age, the quail chicks were weighed, wing-banded, and divided into 5 treatment groups with 2 replicates per group and 11 chicks per replicate so that a total of 110 chicks were treated. Control group A remained on poult starter (about 28% protein) throughout the entire experiment while at 6 days of age the other 4 groups were placed on a protein deficient diet (9% protein) containing 85.58% ground corn, 2.00% dried whey, 3.00% alfalfa meal, 5.50% CaHPGv2H 2 0, and the other necessary minerals and vitamins. Groups B to E were re-fed the poult starter in consecutive weeks beginning at 13 days of age (Table 1). Quail were weighed weekly and sexed at about 5-7 weeks of age as the females were placed in individual laying cages and males were culled. Survival was noted, and the
Downloaded from http://ps.oxfordjournals.org/ at Uniwersytet Warszawski Biblioteka Uniwersytecka on April 16, 2015
REFERENCES Berry, J. G., and F. E. Cunningham, 1970. Factors affecting the flavor and composition of frozen fried chicken. Poultry Sci. 49: 1436-1442. Mickelberry, W. C , and W. J. Stadelman, 1960. The effect of method of cookery on tenderness of pre-cooked frozen chicken meat. Poultry Sci. 39: 1275-1276. Mickelberry, W. C , and W. J. Stadelman, 1962. Effect of cooking method on shear press values and weight changes of frozen chicken meat. Food Technol. 16: 94-97. Miller, W. D., and K. N. May, 1965. Tenderness of chicken as affected by rate of freezing, stor-
283
RESEARCH NOTES REFERENCES
Cook, R. M., 1966. Use of CM to study utilization of substrate in ruminants. J. Dairy Sci. 49: 1018-1023. Kleiber, M., and M. Edick, 1952. A respiration apparatus for C" studies with cows. J. An. Sci. 11: 61-71. Kleiber, M., A. H. Smith, A. L. Black, M. A. Brown, B. M. Tolbert, 1952. Acetate as a precursor of milk constituents in the intact dairy cow. J. Biol. Chem. 197: 371-379. Robertson, J. S., 1957. Theory and use of tracers in determining transfer rates in biological systems. Physiol. Rev. 37: 133-154.
THE EFFECT OF FREEZING AND REHEATING ON SHEAR PRESS VALUES OF PRECOOKED CHICKEN 1 J. N. BUTTS AND F. E. CUNNINGHAM Dairy and Poultry Science Department, Kansas State University, Manhattan, Kansas 66502 (Received for publication October 30, 1970)
INTRODUCTION Precooked frozen meat is increasing in popularity because of greater convenience. However, Watts et al. (1948), West et al. (1959), and Mitchell (1963) have reported that precooking reduces palatability of frozen meat. Mickelberry and Stadelman (1960, 1962) compared the following cooking methods: micro-wave, deep-fat fry, deepfat fry and micro-wave, rotary-reel oven, and steam and deep-fat fry. They found that cooking chicken before freezing made it significantly less tender. Deep-fat fried birds were less tender than birds cooked by other methods. Stadelman and Wise (1961) reported shear values of breast meat increased (indicating less tenderness) by cooking before freezing. Miller and May (1965) reported 1 Contribution No. 798, Department of Dairy and Poultry Sciences, Kansas Agricultural Experiment Station, Manhattan, Kansas 66502
that rate of freezing (0°, —30° and — 90°F.) did not significantly influence tenderness. They also reported that cooking chicken breasts before freezing and storing resulted in greater shear-press values than when the breasts were cooked after frozen storage. The present study was to evaluate methods of freezing and reheating on tenderness of broilers as indicated by shear-press values. METHODS AND MATERIALS Broilers (2 to 2^2 pounds) of unknown history were purchased from a commercial processing plant. They came packed in ice, were held overnight in a cooler, then deepfat fried after being cut into individual parts. A batter was applied by first dipping the pieces in a milk-and-egg solution, then coating with a commercial, dry batter mix. The pieces were fried at 300°F. in a thermostatically controlled commercial-size
Downloaded from http://ps.oxfordjournals.org/ at Uniwersytet Warszawski Biblioteka Uniwersytecka on April 16, 2015
have been used. There are several important advantages derived from vessel catheterization in experiments involving rapidly metabolized substrates. The isotope may be given as a pulse label single injection or as a continuous infusion. In addition, it is easier to quantitate the amount of isotope injected and there is no delay in isotope absorption due to local sequestration or pocket formation. Finally, serial blood samples may be taken to assess entry rates or transfer quotients (Kleiber et al., 1952).
282
RESEARCH NOTES
TABLE 1.—Mean shear press values for methods of freezing Freezing method Liquid nitrogen freezer Blast freezer Household freezer Pounds of force/gm. of meat.
Mean value 1 4.089 5.033 6.182
TABLE 2.—Analysis of variance for shear-press data on precooked frozen light and dark meat of broilers Source of variation
Degrees of freedom
Reps. Reheating method Freezing method Meat (light and dark) Reheating X freezing ReheatingX meat Freezing X meat ReheatingX freezingX meat Residual
1 2 2 1 4 2 2 4 64
Mean squares 349.7 1013.9 2371.2** 37.0 821.9 135.1 3.4 216.9 370.0 -
** P<0.01 RESULTS AND DISCUSSION Sh
ear press values (pounas oi iorce per gm. of meat) indicated that the method of freezing cooked chicken influenced tenderness. Shear-press values among meats frozen in the liquid nitrogen freezer, blast freezer or household freezer differed significantly (P<0.01). That frozen in the liquid nitrogen freezer was the tenderest, in the blast freezer intermediate, in the household freezer least tender. The means of the freezing methods are given in Table 1 and the analysis of variance of the shear-press data is shown in Table 2. Shear-press values for light and dark meat did not differ significantly. Relatively large differences in shear-press values for meat reheated by the different methods were not statistically significant. SUMMARY
Light and dark portions of deep-fat fried broilers were frozen by three methods: a liquid nitrogen freezer, a blast freezer, or a household freezer. After six months storage in a household freezer, the pieces were reheated by three methods: a micro-wave oven, a deep-fat frier, or a household oven. Shear strengths of the samples were determined using an Allo-Kramer shear press. Method of freezing, but not method of reheating, significantly altered the shearpress values of the meat. Meat frozen in
Downloaded from http://ps.oxfordjournals.org/ at Uniwersytet Warszawski Biblioteka Uniwersytecka on April 16, 2015
deep-fat frier, then placed on paper towels to drain and cool. Cooked pieces were placed in polyethylene bags, evacuated with a Cryovac machine, and frozen as described by Berry and Cunningham (1970) by three methods: 1. Household freezer at — 10°C. 2. Blast freezer at — 30°C. overnight. 3. Liquid nitrogen freezer at — 50 °C. for 45 minutes. After freezing, all meat was held in a household freezer at — 10°C. for 6 months. Breasts and thighs were prepared for shear-press evaluation by three reheating methods (all reheated from the frozen state): 1. Micro-wave oven (2 min. for 2 pieces of meat). 2. Deep-fat fry (300°F. for 7 min.). 3. Household oven (425°F. for 30 min.). Meat reheated in the household oven was covered with aluminum foil for 20 min., then the foil was opened for the final 10 min. All breading and skin was removed from the reheated pieces to provide a uniform sample. The pieces were deboned and cut into cubes. Ten gram portions of meat were used for each shear-press measurement on an Allo-Kramer shear press with an electronic recorder. The press was set on 100 with a 3,000 pound ring and a 15-second down stroke. Shear press values were obtained on duplicate samples from each piece of meat. Two pieces were measured for each of the 18 different combinations of freezing, reheating and light vs. dark meat for a total of 72 measurements.
RESEARCH NOTES
the liquid nitrogen freezer was tenderest; in the blast freezer, intermediate; in the household freezer, least tender.
age time and temperature and freeze drying. Food Technol. 19: 1171-1174. Mitchell, J. D., 1963. Problems relating to uniform meat tenderness in a commercial operation. Proc. Meat Tenderness Symposium, Campbell Soup Co., Camden, N.J., p. 243. Stadelman, W. J., and R. G. Wise, 1961. Tenderness of poultry meat. I. Effect of anesthesia, cooking and irradiation. Food Technol. 15: 292-294. Watts, B. M., D. Peng and E. A. Kline, 1948. Precooking pork for freezing storage. J. Home Econ. 40: 579-583. West, L. C , M. C. Titus and F. O. VanDuyne, 1959. Effect of freezing storage and variations in preparation on bacterial count, palatability, and thiamine content of ham loaf, Italian rice, and chicken. Food Technol. 13: 323-327.
THE EFFECT OF EARLY GROWTH RETARDATION OF COTURNIX (JAPANESE QUAIL) ON THEIR SUBSEQUENT SEXUAL MATURITY KIYO MORSE AND PRAN VOHRA Department of Avian Sciences, University of California, Davis, California 95616 (Received for publication October 13, 1970)
Early growth of chickens has been arrested at a physiological age of about 10 days over a period of six months either by severely restricting the intake of a well-balanced diet (McCance, 1960) or by decreasing food intake via tryptophan deficiency (Gordon, 1965) as in the corn-dextrose diet of McRoberts (1965). The subsequent sexual maturity of these birds when fed well-balanced diets was delayed by the approximate length of time that they were kept on the early growth restricting regimens. Similar observations have been made for the Coturnix (Japanese quail) and are reported here. A preliminary study indicated that heavy mortality was observed if an attempt was made to restrict the growth of day-old quail. For this reason, chicks from mixed sources were hatched and, initially, fed a
commercial turkey poult starter. At six days of age, the quail chicks were weighed, wing-banded, and divided into 5 treatment groups with 2 replicates per group and 11 chicks per replicate so that a total of 110 chicks were treated. Control group A remained on poult starter (about 28% protein) throughout the entire experiment while at 6 days of age the other 4 groups were placed on a protein deficient diet (9% protein) containing 85.58% ground corn, 2.00% dried whey, 3.00% alfalfa meal, 5.50% CaHPGv2H 2 0, and the other necessary minerals and vitamins. Groups B to E were re-fed the poult starter in consecutive weeks beginning at 13 days of age (Table 1). Quail were weighed weekly and sexed at about 5-7 weeks of age as the females were placed in individual laying cages and males were culled. Survival was noted, and the
Downloaded from http://ps.oxfordjournals.org/ at Uniwersytet Warszawski Biblioteka Uniwersytecka on April 16, 2015
REFERENCES Berry, J. G., and F. E. Cunningham, 1970. Factors affecting the flavor and composition of frozen fried chicken. Poultry Sci. 49: 1436-1442. Mickelberry, W. C , and W. J. Stadelman, 1960. The effect of method of cookery on tenderness of pre-cooked frozen chicken meat. Poultry Sci. 39: 1275-1276. Mickelberry, W. C , and W. J. Stadelman, 1962. Effect of cooking method on shear press values and weight changes of frozen chicken meat. Food Technol. 16: 94-97. Miller, W. D., and K. N. May, 1965. Tenderness of chicken as affected by rate of freezing, stor-
283