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Effect of Carbon Dioxide and Sodium Chloride on Oxidative Stability of Frozen Mechanically Deboned Poultry Meat
Research Note Effect of Carbon Dioxide and Sodium Chloride on Oxidative Stability of Frozen Mechanically Deboned Poultry Meat A. e. Noble Department of Food Science University of Guelph Guelph, Ontario Present address: Department of Viticulture and Enology University of California, Davis, CA 95616
Introduction Raw poultry meat, pork and beef have all been demonstrated to be subject to lipid oxidation during refrigerator or freezer storage (Watts and Peng, 1947; Keller and Kinsella, 1973; Witte et al., 1970; Keskinel et al., 1964). The use of mechanically deboned poultry meat (MDPM) in frankfurter formulations has resulted in several investigations of the stability of MDPM in frozen and refrigerator storage (Maxon and Marion, 1970; Dimick et al., 1972; Froning et al., 1971; MacNeil et al., 1973). . Oxygen availability, degree of unsaturation of fatty aCIds, state and amount of heme and non-heme iron (Greene, 1971; Liu and Watts, 1970; Tappe!, 1962), the time meat is held prior to refrigeration (MacNeil et al., 1973), and the use of salt (Love and Pearson, 1971) have been demonstrated to accelerate lipid oxidation in meat systems. Changes in the pH of the meat, however, have been shown to have variable effects on the rate oflipid oxidation. Oxidation of unsaturated fatty acids in model systems, catalyzed by heme and non-heme iron, was not affected by pH changes in the range 5.5 to 8.0 (Wills, 1965). In contrast, Liu (1970) reported the oxidation of linoleic and linolenic acids catalyzed by metmyoglobin increased as the pH was raised from 6.2 to 7.8 in raw refrigerated pork and beef (Witte et al., 1970; Keskinel et al., 1964). In raw frozen pork (Watts and Peng, 1947), decreasing the pH with the addition of acid resulted in increased rates of lipid oxidation. In this experiment, the effect of the addition of solid ~arbon dioxid~, which ~auses a temporary pH drop when it IS added to ChIll the chIcken meat, has been investigated in salted and unsalted mechanically deboned chicken meat.
Materials and Methods . MDPM which was 23% ± 2 fat was produced from chIcken necks and backs in a commercial.plant in Ontario, Canada. Meat temperature prior to deboning was held at or below l~°c;. Immediately after deboning, which produced no nse In meat temperature, the meat was divided into 40 lb lots and treated as described below. Sample A was the Control. Sample B had 1% (w/w) food grade sodium chloride added and mixed in manually. Samples C and D were stirred while a fine spray of carbon dioxide "snow" was introduced into the meat until the meat became rigid and difficult to manipulate. One percent salt (w/w) was added to D prior to the addition of carbon 105
dioxide. The samples were then packaged in two lb aliquots in polyethylene bags closed with a wire twist and held at -23 ± 3°C until removed for analyses. The experiment was repeated in three identical trials initiated in successive months. The pH of each of the treatments was taken within one hour of preparation at 100e. The pH was also determined (at 20°C) for all samples after freezer storage intervals of 24 hours, one week and six weeks. To determine the extent of oxidation with time for each treatment, fat oxidation determinations were made on each of the three trials for each sample at one day after s~mple preparation, and after storage at -23°C for one, SIX and 12 weeks. The samples were allowed to warm to room temperature (27°C). The fat was separated and clarifi~d. by c.ent~fuging the meat for 20 min at 2000 rpm. LIPId OXIdatIOn expressed as the Peroxide Number or Value. (PV) ~as me~sured by the Official Method of the Amencan 011 ChemIsts' SOCIety (1971). For all titrations, 0.001 N sodium thiosulfate was used for greater sensitivity at the lower levels of oxidation encountered. The PV tests were made in triplicate on each sample. For sensory evaluation, the MDPM was shaped into small balls and heated in an oven at 150°C for 25 min on glass trays. The samples were presented in triangle tests in which treatment used as the odd sample was chosen randomly. The meat was served in paper cups coded with random numbers. Fifteen panelists who were members of the department sensory evaluation panel and familiar with the testing procedures, but not with MDPM, evaluated the treatments in two sets per session in individual booths which were illuminated with red lights. For each trial, differences between the meats with and without carbon dioxide addition were evaluated for both the salted and unsalted samples after storage for 6 and for 12 weeks. MDPM whIch had been held for 12 weeks in frozen storage was compared with that which had been frozen one week (for treatments A and B only).
Results and Discussion With the addition of solid carbon dioxide to chill the mechanically deboned poultry meat, the pH dropped approximately 0.5 pH unit initially, but, within 24 hours, rose to the pH of the untreated samples (Table 1). In Table 2 the peroxide values for all samples are J. Insl. Can. Sci. TechnoL Aliment. VoL 9, No.2. 1976
Table I. pH of mechanically deboned poultry meat.
-Treatment
AControl............ B 1% NaCI...........
C CO,.................. D CO, + 1% NaCI...............
Initial
24 hrs
I wk
6.5 6.3 6.0 5.8
6.5 6.4 6.5 6.4
6.5 6.5 6.5 6.5
Table 2. Effect of sodium chloride, carbon dioxide, storage time and trial on oxidative stability of MDPM stored at -23 ±3°C as measured by peroxide value.'
Although minor oxidation occurred in all samples, no significant differences in peroxide values among treatments were demonstrated. Further, since the "time x treatment" interaction was not significant, it may be concluded that the addition of sodium chloride and/or carbon dioxide had no effect on the oxidation rate of MDPM during frozen storage. Although the oxidation levels of the three trials were shown to differ (P < 0.05), neither the "trial x treatment" nor the "trial X time" interaction was significant, showing that the samples in each trial oxidized in a similar way. As shown by the sensory evaluation results in Table 4, Table 4. Effect of time, carbon dioxide and sodium chloride on flavor of mechanically deboned poultry meat.
Treatment A B C D
ControL.................... 1% NaCI ..................... CO,............................. CO, + 1% NaCl ........
Trial Number Trial I ...................... Trial 2 ...................... Trial 3 ......................
0 1.48 1.43 1.39 1.39 0
2.80 2.22 2.37 2.42
3.70 3.50 3.43 4.09
Storage Time (weeks)' I 6
1.47 1.45 1.35 0
Average of All Trials and Treatments ........
Storage Time (weeks)b 6 ·1
1.91 2.90 2.55
4.17 3.85 3.03
Storage Time (weeks)d I 6
1.42
2.45
3.68
12 1.93 2.68 1.78 2.69 12 2.66 2.62 1.53 12
2.71
2.55
2.11
'Peroxide value = milliequivalents iodine formed per kg of fat. bEach value is mean of 3 trials. 'Each value is mean of 4 treatments. dEach value is mean of 12 samples; Least Significant Difference (LSD) (P< 0.00 I) is 1.03. eEach value is mean of 16 samples; LSD (0.05) = 0.48.
listed. Although these low numbers reflect very low concentrations of hydroperoxides, the primary products of lipid autoxidation, the low levels of oxidation which occurred did significantly change with time (P < 0.001) as seen in the analysis of variance (Table 3). No cause for the significantly higher peroxide values for the 6 week samples is proposed. Table 3. Analysis of variance of peroxide values.
Source Storage Time (A) Trial (B) AxB Treatment (C) AxC BxC Error *p< 0.05 ***p< 0.001 NS No significant difference Can. lnst. Food Sci. Technol. J. Vol. 9. No.2, 1976
. .. .. .. .. . .
df. 3 2 6 3 9 6 18
MS 10.420*** 1.503* 0.849 NS 0.334 NS 0.271 NS 0.377 NS 0.417
Samples Compared Six week storage Aavs C, Bb vs Dd
Twelve week storage AvsC
. .
..
2.27
Trial Numbere 2 3 Average of all Trials and Treatments ........
Triangle Test Results
BvsD
One week vs twelve week storage A B
.
. .
Trial
Correct identifications of odd sample (n = 15)
Significance
I 2 3 I 2 3
5 7 7 6 8 6
NS NS NS NS NS NS
I 2 3 I 2 3
8 5 6 7 6 5
NS NS NS NS NS NS
I 2 3
7 6 8 5 7 6
NS NS NS NS NS NS
I
2 3
a = Treatment A, Control MDPM b = Treatment B, 1% (w/w) NaCl added c = Treatment C, CO, added d = Treatment D, CO, and 1% (w/w) NaCl added NS = No significant difference
after 6 and 12 weeks of frozen storage, no differences were detected between treatments with and without the addition of carbon dioxide in both the salted and unsalted MDPM. No significant sensory differences were detected between the control (A) samples held for 12 weeks versus those of one week frozen storage. Similarly, no differences were observed in the salted (B) MDPM when the 1 and 12 week samples were compared. Because of the nature of the chain reaction mechanism by which lipid oxidation occurs, no sensory comparisons of the six week storage with the week old samples were made, since no oxidative changes were detected after 12 weeks ofstora~e. (Due to the lack of differences demonstrated in the testmg between the samples with and without the addition of carbon dioxide, neither the 6 nor 12 week C and D samples were compared with their one week storage counterparts.)
106
Summary In all samples, extremely low levels of oxidation were detected by peroxide value determinations. No differences between the I and 12 week samples were detected by sensory evaluation for either the control samples (A) or for the salted samples (B). The use of carbon dioxide did not affect the oxidation rate in either the salted or unsalted mechanically deboned poultry !peat during the 12 week storage at -23 ± 3°C as determined by chemical and sensory evaluations.
Acknowledgement The author thanks Christopher Gaul and Kathey Cunningham for their technical assistance.
References American Oil Chemists' Society. 1971. Ollicial and tentative methods. (Method Cd.8-53) 3rd ed. AOCS. Champaign. Iltinois. Dimick. P. S.• MacNeif. J. H., and Grunden. L. P. 1972. Poultry product quality. Carbonyl composition and organoleptic evaluation of mechanically deboned poultry meat. J. Food Sci. 37: 544.
107
Froning. G. W., Arnold, R. G., Mandigo, R. W., Neth, C E. and Hartung, T. E. 1971. Quatity and st~rage stability of frankfurters containing 15% mechanically deboned turkey meat. J. FOOd SCI. 36: 974. Greene, B. E. 197 I. Oxidations involving the heme complex in raw meat. J. Am. Oil Chern. Soc 48: 637. . Keller, J. D. and Kinsella, J. E. 1973. Phospholipid changes and lipid oxidation during COOking and frozen storage of raw ground beef. J. Food Sci. 38: 1200. Keskinel. A., Ayres, J. C. and Snyder, H. E. 1964. Determination of oxidative changes in raw meats by the 2-Thiobarbituric acid method. Food Technol. 18: 223. Liu, H. 1970. Catalysts of tipid peroxidation in meats. 2. Linoleate oxidation catalyzed by tissue homogenates. J. Food Sci. 35: 593. Liu, H. and Watts, B. M. 1970. Catalysts of tipid peroxidation in meats. 3. Catalysts of oxidative rancidity in meats. J. Food Sci. 35: 596. Love, J. D. and Pearson, A. M. 1971. Lipid oxidation in meat and meat products - a review. J. Am. Oil Chern. Soc. 48: 547. MacNeil, J. H., Dimick, P. S. and Mast, M. G. 1973. Use of chemical compounds and a rosemary spice extract in quatity maintenance of deboned poultry meal. J. Food Sci. 38: 1080. Maxon, S. T. and Marion, W. W. 1970. Lipids of mechanically boned turkey. Poultry Sci. 49: 1412. Tappel, A. L. 1%2. Hematin compounds and tipoxidase as biocatalysts. In "Lipids and Their Oxi. dation." p. 122. Schultz, H. H., Day, E. A., and Sinnhuber, R. 0., eds. The Avi Pubtishing Co., Westport, Conn. Watts, B. M. and Peng, D. 1947. Rancidity development in raw versus precooked frozen pork sausage. J. Home Ec. 39: 88. Wills, E. D. 1965. Mechanisms oftipid peroxide formation in tissues. Role of metals and haematin proteins in the catalysis of the oxidation of unsaturated fatty acids. Biochem. Biophys. Acta. 98: 238. Witte, V. C, Krause, G. F. and Bailey, M. F. 1970. A new extraction method for determining 2. thiobarbituric acid values of pork and beef during storage. J. Food Sci. 35: 582. Received Oct. 15, 1974
J. Inst. Can. Sci. Technol. Aliment. Vol. 9, No.2, 1976
Introduction Raw poultry meat, pork and beef have all been demonstrated to be subject to lipid oxidation during refrigerator or freezer storage (Watts and Peng, 1947; Keller and Kinsella, 1973; Witte et al., 1970; Keskinel et al., 1964). The use of mechanically deboned poultry meat (MDPM) in frankfurter formulations has resulted in several investigations of the stability of MDPM in frozen and refrigerator storage (Maxon and Marion, 1970; Dimick et al., 1972; Froning et al., 1971; MacNeil et al., 1973). . Oxygen availability, degree of unsaturation of fatty aCIds, state and amount of heme and non-heme iron (Greene, 1971; Liu and Watts, 1970; Tappe!, 1962), the time meat is held prior to refrigeration (MacNeil et al., 1973), and the use of salt (Love and Pearson, 1971) have been demonstrated to accelerate lipid oxidation in meat systems. Changes in the pH of the meat, however, have been shown to have variable effects on the rate oflipid oxidation. Oxidation of unsaturated fatty acids in model systems, catalyzed by heme and non-heme iron, was not affected by pH changes in the range 5.5 to 8.0 (Wills, 1965). In contrast, Liu (1970) reported the oxidation of linoleic and linolenic acids catalyzed by metmyoglobin increased as the pH was raised from 6.2 to 7.8 in raw refrigerated pork and beef (Witte et al., 1970; Keskinel et al., 1964). In raw frozen pork (Watts and Peng, 1947), decreasing the pH with the addition of acid resulted in increased rates of lipid oxidation. In this experiment, the effect of the addition of solid ~arbon dioxid~, which ~auses a temporary pH drop when it IS added to ChIll the chIcken meat, has been investigated in salted and unsalted mechanically deboned chicken meat.
Materials and Methods . MDPM which was 23% ± 2 fat was produced from chIcken necks and backs in a commercial.plant in Ontario, Canada. Meat temperature prior to deboning was held at or below l~°c;. Immediately after deboning, which produced no nse In meat temperature, the meat was divided into 40 lb lots and treated as described below. Sample A was the Control. Sample B had 1% (w/w) food grade sodium chloride added and mixed in manually. Samples C and D were stirred while a fine spray of carbon dioxide "snow" was introduced into the meat until the meat became rigid and difficult to manipulate. One percent salt (w/w) was added to D prior to the addition of carbon 105
dioxide. The samples were then packaged in two lb aliquots in polyethylene bags closed with a wire twist and held at -23 ± 3°C until removed for analyses. The experiment was repeated in three identical trials initiated in successive months. The pH of each of the treatments was taken within one hour of preparation at 100e. The pH was also determined (at 20°C) for all samples after freezer storage intervals of 24 hours, one week and six weeks. To determine the extent of oxidation with time for each treatment, fat oxidation determinations were made on each of the three trials for each sample at one day after s~mple preparation, and after storage at -23°C for one, SIX and 12 weeks. The samples were allowed to warm to room temperature (27°C). The fat was separated and clarifi~d. by c.ent~fuging the meat for 20 min at 2000 rpm. LIPId OXIdatIOn expressed as the Peroxide Number or Value. (PV) ~as me~sured by the Official Method of the Amencan 011 ChemIsts' SOCIety (1971). For all titrations, 0.001 N sodium thiosulfate was used for greater sensitivity at the lower levels of oxidation encountered. The PV tests were made in triplicate on each sample. For sensory evaluation, the MDPM was shaped into small balls and heated in an oven at 150°C for 25 min on glass trays. The samples were presented in triangle tests in which treatment used as the odd sample was chosen randomly. The meat was served in paper cups coded with random numbers. Fifteen panelists who were members of the department sensory evaluation panel and familiar with the testing procedures, but not with MDPM, evaluated the treatments in two sets per session in individual booths which were illuminated with red lights. For each trial, differences between the meats with and without carbon dioxide addition were evaluated for both the salted and unsalted samples after storage for 6 and for 12 weeks. MDPM whIch had been held for 12 weeks in frozen storage was compared with that which had been frozen one week (for treatments A and B only).
Results and Discussion With the addition of solid carbon dioxide to chill the mechanically deboned poultry meat, the pH dropped approximately 0.5 pH unit initially, but, within 24 hours, rose to the pH of the untreated samples (Table 1). In Table 2 the peroxide values for all samples are J. Insl. Can. Sci. TechnoL Aliment. VoL 9, No.2. 1976
Table I. pH of mechanically deboned poultry meat.
-Treatment
AControl............ B 1% NaCI...........
C CO,.................. D CO, + 1% NaCI...............
Initial
24 hrs
I wk
6.5 6.3 6.0 5.8
6.5 6.4 6.5 6.4
6.5 6.5 6.5 6.5
Table 2. Effect of sodium chloride, carbon dioxide, storage time and trial on oxidative stability of MDPM stored at -23 ±3°C as measured by peroxide value.'
Although minor oxidation occurred in all samples, no significant differences in peroxide values among treatments were demonstrated. Further, since the "time x treatment" interaction was not significant, it may be concluded that the addition of sodium chloride and/or carbon dioxide had no effect on the oxidation rate of MDPM during frozen storage. Although the oxidation levels of the three trials were shown to differ (P < 0.05), neither the "trial x treatment" nor the "trial X time" interaction was significant, showing that the samples in each trial oxidized in a similar way. As shown by the sensory evaluation results in Table 4, Table 4. Effect of time, carbon dioxide and sodium chloride on flavor of mechanically deboned poultry meat.
Treatment A B C D
ControL.................... 1% NaCI ..................... CO,............................. CO, + 1% NaCl ........
Trial Number Trial I ...................... Trial 2 ...................... Trial 3 ......................
0 1.48 1.43 1.39 1.39 0
2.80 2.22 2.37 2.42
3.70 3.50 3.43 4.09
Storage Time (weeks)' I 6
1.47 1.45 1.35 0
Average of All Trials and Treatments ........
Storage Time (weeks)b 6 ·1
1.91 2.90 2.55
4.17 3.85 3.03
Storage Time (weeks)d I 6
1.42
2.45
3.68
12 1.93 2.68 1.78 2.69 12 2.66 2.62 1.53 12
2.71
2.55
2.11
'Peroxide value = milliequivalents iodine formed per kg of fat. bEach value is mean of 3 trials. 'Each value is mean of 4 treatments. dEach value is mean of 12 samples; Least Significant Difference (LSD) (P< 0.00 I) is 1.03. eEach value is mean of 16 samples; LSD (0.05) = 0.48.
listed. Although these low numbers reflect very low concentrations of hydroperoxides, the primary products of lipid autoxidation, the low levels of oxidation which occurred did significantly change with time (P < 0.001) as seen in the analysis of variance (Table 3). No cause for the significantly higher peroxide values for the 6 week samples is proposed. Table 3. Analysis of variance of peroxide values.
Source Storage Time (A) Trial (B) AxB Treatment (C) AxC BxC Error *p< 0.05 ***p< 0.001 NS No significant difference Can. lnst. Food Sci. Technol. J. Vol. 9. No.2, 1976
. .. .. .. .. . .
df. 3 2 6 3 9 6 18
MS 10.420*** 1.503* 0.849 NS 0.334 NS 0.271 NS 0.377 NS 0.417
Samples Compared Six week storage Aavs C, Bb vs Dd
Twelve week storage AvsC
. .
..
2.27
Trial Numbere 2 3 Average of all Trials and Treatments ........
Triangle Test Results
BvsD
One week vs twelve week storage A B
.
. .
Trial
Correct identifications of odd sample (n = 15)
Significance
I 2 3 I 2 3
5 7 7 6 8 6
NS NS NS NS NS NS
I 2 3 I 2 3
8 5 6 7 6 5
NS NS NS NS NS NS
I 2 3
7 6 8 5 7 6
NS NS NS NS NS NS
I
2 3
a = Treatment A, Control MDPM b = Treatment B, 1% (w/w) NaCl added c = Treatment C, CO, added d = Treatment D, CO, and 1% (w/w) NaCl added NS = No significant difference
after 6 and 12 weeks of frozen storage, no differences were detected between treatments with and without the addition of carbon dioxide in both the salted and unsalted MDPM. No significant sensory differences were detected between the control (A) samples held for 12 weeks versus those of one week frozen storage. Similarly, no differences were observed in the salted (B) MDPM when the 1 and 12 week samples were compared. Because of the nature of the chain reaction mechanism by which lipid oxidation occurs, no sensory comparisons of the six week storage with the week old samples were made, since no oxidative changes were detected after 12 weeks ofstora~e. (Due to the lack of differences demonstrated in the testmg between the samples with and without the addition of carbon dioxide, neither the 6 nor 12 week C and D samples were compared with their one week storage counterparts.)
106
Summary In all samples, extremely low levels of oxidation were detected by peroxide value determinations. No differences between the I and 12 week samples were detected by sensory evaluation for either the control samples (A) or for the salted samples (B). The use of carbon dioxide did not affect the oxidation rate in either the salted or unsalted mechanically deboned poultry !peat during the 12 week storage at -23 ± 3°C as determined by chemical and sensory evaluations.
Acknowledgement The author thanks Christopher Gaul and Kathey Cunningham for their technical assistance.
References American Oil Chemists' Society. 1971. Ollicial and tentative methods. (Method Cd.8-53) 3rd ed. AOCS. Champaign. Iltinois. Dimick. P. S.• MacNeif. J. H., and Grunden. L. P. 1972. Poultry product quality. Carbonyl composition and organoleptic evaluation of mechanically deboned poultry meat. J. Food Sci. 37: 544.
107
Froning. G. W., Arnold, R. G., Mandigo, R. W., Neth, C E. and Hartung, T. E. 1971. Quatity and st~rage stability of frankfurters containing 15% mechanically deboned turkey meat. J. FOOd SCI. 36: 974. Greene, B. E. 197 I. Oxidations involving the heme complex in raw meat. J. Am. Oil Chern. Soc 48: 637. . Keller, J. D. and Kinsella, J. E. 1973. Phospholipid changes and lipid oxidation during COOking and frozen storage of raw ground beef. J. Food Sci. 38: 1200. Keskinel. A., Ayres, J. C. and Snyder, H. E. 1964. Determination of oxidative changes in raw meats by the 2-Thiobarbituric acid method. Food Technol. 18: 223. Liu, H. 1970. Catalysts of tipid peroxidation in meats. 2. Linoleate oxidation catalyzed by tissue homogenates. J. Food Sci. 35: 593. Liu, H. and Watts, B. M. 1970. Catalysts of tipid peroxidation in meats. 3. Catalysts of oxidative rancidity in meats. J. Food Sci. 35: 596. Love, J. D. and Pearson, A. M. 1971. Lipid oxidation in meat and meat products - a review. J. Am. Oil Chern. Soc. 48: 547. MacNeil, J. H., Dimick, P. S. and Mast, M. G. 1973. Use of chemical compounds and a rosemary spice extract in quatity maintenance of deboned poultry meal. J. Food Sci. 38: 1080. Maxon, S. T. and Marion, W. W. 1970. Lipids of mechanically boned turkey. Poultry Sci. 49: 1412. Tappel, A. L. 1%2. Hematin compounds and tipoxidase as biocatalysts. In "Lipids and Their Oxi. dation." p. 122. Schultz, H. H., Day, E. A., and Sinnhuber, R. 0., eds. The Avi Pubtishing Co., Westport, Conn. Watts, B. M. and Peng, D. 1947. Rancidity development in raw versus precooked frozen pork sausage. J. Home Ec. 39: 88. Wills, E. D. 1965. Mechanisms oftipid peroxide formation in tissues. Role of metals and haematin proteins in the catalysis of the oxidation of unsaturated fatty acids. Biochem. Biophys. Acta. 98: 238. Witte, V. C, Krause, G. F. and Bailey, M. F. 1970. A new extraction method for determining 2. thiobarbituric acid values of pork and beef during storage. J. Food Sci. 35: 582. Received Oct. 15, 1974
J. Inst. Can. Sci. Technol. Aliment. Vol. 9, No.2, 1976