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Iron Discoloration of Egg Shells1
266
RESEARCH NOTES
sequence, determinations can be made very quickly. The device as shown in Figure 2 is simple to make, the components can be had for less than $10.00, and, when used as shown, it has many advantages over other methods. ACKNOWLEDGMENTS
REFERENCES
lowered to touch the albumen the circuit is complete and the buzzer operates. The dial and measuring rod which have previously been "zeroed" with the table is then read, the indicator rod retracted and moved to another egg. When eggs are broken and laid out in a row in proper
Haugh, R. R., 1937. The Haugh unit for measuring egg quality. U. S. Egg Poultry Mag. 43: 552. Heiman, V., and J. S. Carver, 1936. The albumen index as a physical measurement of observed egg quality. Poultry Sci. 15: 144-153. Wilgus, Jr., H. S., and A. Van Wagenen. 1935. The height of the firm albumen as a measure of its condition. Poultry Sci. 15: 319-321.
IRON DISCOLORATION OF EGG SHELLS 1 A. E. ARMAS2 AND F. R. TARVER, JR. 3 University of Florida, Gainesville, Florida (Received for publication August 26, 1963)
Economic losses due to soiled eggs have been reduced through the use of improved methods of cleaning egg shells. Funk (1948) and Winter el al. (1958) reported wet cleaning methods were more desirable than dry ones. However, certain minerals present in water used for washing eggs can hasten the deterioration 1
Florida Agri. Exp. Sta., Journal Series No. 1718. 2 Graduate student from Maracay, Venezuela where he is an agronomist, Agricultural Experiment Station, Ministry of Agriculture. 3 Department of Poultry Science. Present address: Department of Food Science, University of North Carolina at Raleigh, Raleigh, North Carolina.
of egg quality. Iron has been reported to hasten bacterial spoilage in experimentally inoculated eggs and eggs washed under actual farm conditions (Garibaldi and Bayne, 1960,1962a,b). Since iron imparts a brownish color to laundered goods and affects the taste of beverages it is considered an objectionable constituent in water supplies (Riddick el al., 1958). It would be reasonable to expect that iron present in egg wash water could stain the shell of eggs. The research reported herein was to determine the effects of various concentrations of iron (FeSO.r 7H 2 0) present in water on staining of the egg shell.
Downloaded from http://ps.oxfordjournals.org/ by guest on April 14, 2015
FIG. 2. Components of electric buzzer box showing simple installations.
The authors are grateful to A. F. Meyer, School of Agriculture, for photographs taken, and J. D. White, School of Technology, for technical assistance in electrical work.
267
RESEARCH NOTES TABLE 1.—Iron discoloration of egg shells after washing for 3 to 4 minutes in heated and non-heated iron solutions a1L
Rd 1 P.P.M.ofiron (FeS0 4 -7H 2 0) Unwashed (control) 0.00 0.01 0.1 1.0 5.0 10.0 1
120°F. wash water
70°F. wash water
120°F. wash water
70°F. wash water
120°F. wash water
- 3 , .6
83.3 81.8 83.1 49.4 44.0 38.5 39.7
b!
82.3 82.1 68.7 59.2 47.4 48.5
+1.6 -3.4 -3.8 -9.8 -5.8 +8.5 +8.2
-3.2 -3.8 +0.5 +2.7 + 13.6 + 12.7
70°F. wash water
+ 1.4 +3.6 +30.9 +32.9 +31.4 +31.4
+ 1.4 +4.9 +23.9 +28.6 +31.9 +31.9
EXPERIMENTAL
White shell egg produced by a commercial strain of egg production pullets were gathered and held over night at room temperature. The following morning, 12 groups of 3 eggs each were wrapped in a double thickness of cheesecloth. This aided in keeping the eggs suspended while submerged in the wash water during the 3 to 4 minute wash period. The wash water was composed of 800 ml. of singularly distilled tap water in 1,000 ml. glass beakers with sufficient iron (Fe S0 4 • 7H20) added in each of two beakers to provide concentrations of 0.00, 0.01, 0.1, 1.0, 5.0 and 10.0 p.p.m. During the wash period, one-half of the beakers containing the 6 iron solutions were non-heated (70°F.) and the remaining half were heated and maintained at 120°F. All solutions were agitated by a magnetic stirrer during the time of washing. The length of wash period and the temperature of the heated iron solution simulated submerged egg washing methods with the exception that a detergent and/or sanitizer was not added to the various solutions. Nonwashed eggs were used as controls. Variations of egg shell discoloration were measured with the aid of the Hunter color and color-difference meter.4 Re-
corded values include Rd (the degree of change from gray-—0 to white—100); a (degree change in red, with high values showing intense red) and b (degree change in yellow with high values showing intense yellow). RESULTS AND DISCUSSION
Shells of eggs were intensely stained after the 3 to 4 minute wash period in water containing 0.1, 1.0, 5.0 and 10.0 p.p.m. of iron (Table 1). Waters containing 0.00 and 0.01 p.p.m. of iron were similar as indicated by Rd, a and b measurements of the shells, thus indicating the absence of staining. Shells of eggs washed in iron solutions maintained at 120°F. had more intense staining than shells washed in non-heated (70°F.) iron solutions. Upon removing the eggs from the various iron solutions, the shells possessed a greenish-blue hue, but after drying, a uniform rust color developed over the surface of the shells. The color varied directly with the concentration of iron in the wash water. When Rd values for the non-heated iron solutions of 0.1, 1.0 and 10.0 p.p.m. 4 The color plate used in this study to standardize the Hunter color difference meter had the following serial number C-Ly-844-57 with instrument settings of Rd=61.3, a = - 1 . 8 and b = +22.6.
Downloaded from http://ps.oxfordjournals.org/ by guest on April 14, 2015
Rd = Degree change from gray to white with higher values representing white. a = Degree of red with highest values representing intense red. b = Degree of yellow with highest values representing intense yellow.
268
RESEARCH NOTES
were plotted on a semilogarithmic scale a straight line was obtained. A similar line was obtained from egg shells washed in heated iron solutions of 0.01, 0.1, 1.0 and lO.Op.p.m.
Dennison, Head, Food Technology Department, for his assistance during this study.
SUMMARY
Garibaldi, J. A., and H. G. Bayne, 1960. The effect of iron on the Pseudomonas spoilage of experimentally infected shell eggs. Poultry Sci. 39: 1517-1520. Garibaldi, J. A., and H. G. Bayne, 1962a. Iron and the bacterial spoilage of shell eggs. J. Food Sci. 27: 57-59. Garibaldi, J. A., and H. G. Bayne, 1962b. The effect of iron on the Pseudomonas spoilage of farm washed eggs. Poultry Sci. 41: 850-853. Riddick, T. M., N. Lindsay and A. Tomassi, 1958. Iron and manganese in water supplies. J. Am. Water Works Assoc. 50: 688-696.
ACKNOWLEDGMENTS
The authors wish to thank Dr. R. A.
ARGININE REQUIREMENT AND THE ARGININE CONTENT OF CASEIN H. FISHER AND P. GRIMINGER Department of Animal Science, Rutgers University, New Brunswick,
NJ.
(Received for publication October 1, 1963)
Much has been written concerning the high arginine requirement of chicks fed diets based on casein as the source of protein. The peculiar amino acid balance of casein, as suggested by studies from this laboratory (Fisher, Shapiro and Griminger, 1960), may in part explain this phenomenon. We now wish to draw attention to a recently published article on seasonal variations in the arginine content of casein, which might provide another missing link in explaining the high arginine requirement of chicks on casein diets. According to Kiermeier and Kirchmeier (1963) the amino acid content of milk casein changes considerably with the season. The authors found, for example, a large increase in essential amino acids between July and November, and a corresponding decrease in
nonessential amino acids. Specifically, the value for arginine ranged from 3.5 to 4.8% of the protein during the year. This could mean a difference in excess of 30% between the arginine content of casein-based diets, using a high- and a low-argininecasein sample. The arginine value for casein, as given by Block and Weiss (1956), is 4.2, or midway between the extreme values recorded by the German workers. It is not improbable that the relatively large differences reported in the above mentioned article are differences in the various casein components rather than differences in the structure of any single protein. With easier access to amino acid analyzers it is to be hoped that researchers will carry out more analyses of casein samples used in studies of arginine requirement and metabolism.
Downloaded from http://ps.oxfordjournals.org/ by guest on April 14, 2015
Egg shells were stained when washed for 3 to 4 minutes in water containing various concentrations of iron (FeS04-7H 2 0). The stains intensified as the concentrations of iron increased from 0.01 to 10.0 p.p.m. Heating the iron solution to 120°F. produced staining more intensified than the non-heated iron solutions.
REFERENCES
RESEARCH NOTES
sequence, determinations can be made very quickly. The device as shown in Figure 2 is simple to make, the components can be had for less than $10.00, and, when used as shown, it has many advantages over other methods. ACKNOWLEDGMENTS
REFERENCES
lowered to touch the albumen the circuit is complete and the buzzer operates. The dial and measuring rod which have previously been "zeroed" with the table is then read, the indicator rod retracted and moved to another egg. When eggs are broken and laid out in a row in proper
Haugh, R. R., 1937. The Haugh unit for measuring egg quality. U. S. Egg Poultry Mag. 43: 552. Heiman, V., and J. S. Carver, 1936. The albumen index as a physical measurement of observed egg quality. Poultry Sci. 15: 144-153. Wilgus, Jr., H. S., and A. Van Wagenen. 1935. The height of the firm albumen as a measure of its condition. Poultry Sci. 15: 319-321.
IRON DISCOLORATION OF EGG SHELLS 1 A. E. ARMAS2 AND F. R. TARVER, JR. 3 University of Florida, Gainesville, Florida (Received for publication August 26, 1963)
Economic losses due to soiled eggs have been reduced through the use of improved methods of cleaning egg shells. Funk (1948) and Winter el al. (1958) reported wet cleaning methods were more desirable than dry ones. However, certain minerals present in water used for washing eggs can hasten the deterioration 1
Florida Agri. Exp. Sta., Journal Series No. 1718. 2 Graduate student from Maracay, Venezuela where he is an agronomist, Agricultural Experiment Station, Ministry of Agriculture. 3 Department of Poultry Science. Present address: Department of Food Science, University of North Carolina at Raleigh, Raleigh, North Carolina.
of egg quality. Iron has been reported to hasten bacterial spoilage in experimentally inoculated eggs and eggs washed under actual farm conditions (Garibaldi and Bayne, 1960,1962a,b). Since iron imparts a brownish color to laundered goods and affects the taste of beverages it is considered an objectionable constituent in water supplies (Riddick el al., 1958). It would be reasonable to expect that iron present in egg wash water could stain the shell of eggs. The research reported herein was to determine the effects of various concentrations of iron (FeSO.r 7H 2 0) present in water on staining of the egg shell.
Downloaded from http://ps.oxfordjournals.org/ by guest on April 14, 2015
FIG. 2. Components of electric buzzer box showing simple installations.
The authors are grateful to A. F. Meyer, School of Agriculture, for photographs taken, and J. D. White, School of Technology, for technical assistance in electrical work.
267
RESEARCH NOTES TABLE 1.—Iron discoloration of egg shells after washing for 3 to 4 minutes in heated and non-heated iron solutions a1L
Rd 1 P.P.M.ofiron (FeS0 4 -7H 2 0) Unwashed (control) 0.00 0.01 0.1 1.0 5.0 10.0 1
120°F. wash water
70°F. wash water
120°F. wash water
70°F. wash water
120°F. wash water
- 3 , .6
83.3 81.8 83.1 49.4 44.0 38.5 39.7
b!
82.3 82.1 68.7 59.2 47.4 48.5
+1.6 -3.4 -3.8 -9.8 -5.8 +8.5 +8.2
-3.2 -3.8 +0.5 +2.7 + 13.6 + 12.7
70°F. wash water
+ 1.4 +3.6 +30.9 +32.9 +31.4 +31.4
+ 1.4 +4.9 +23.9 +28.6 +31.9 +31.9
EXPERIMENTAL
White shell egg produced by a commercial strain of egg production pullets were gathered and held over night at room temperature. The following morning, 12 groups of 3 eggs each were wrapped in a double thickness of cheesecloth. This aided in keeping the eggs suspended while submerged in the wash water during the 3 to 4 minute wash period. The wash water was composed of 800 ml. of singularly distilled tap water in 1,000 ml. glass beakers with sufficient iron (Fe S0 4 • 7H20) added in each of two beakers to provide concentrations of 0.00, 0.01, 0.1, 1.0, 5.0 and 10.0 p.p.m. During the wash period, one-half of the beakers containing the 6 iron solutions were non-heated (70°F.) and the remaining half were heated and maintained at 120°F. All solutions were agitated by a magnetic stirrer during the time of washing. The length of wash period and the temperature of the heated iron solution simulated submerged egg washing methods with the exception that a detergent and/or sanitizer was not added to the various solutions. Nonwashed eggs were used as controls. Variations of egg shell discoloration were measured with the aid of the Hunter color and color-difference meter.4 Re-
corded values include Rd (the degree of change from gray-—0 to white—100); a (degree change in red, with high values showing intense red) and b (degree change in yellow with high values showing intense yellow). RESULTS AND DISCUSSION
Shells of eggs were intensely stained after the 3 to 4 minute wash period in water containing 0.1, 1.0, 5.0 and 10.0 p.p.m. of iron (Table 1). Waters containing 0.00 and 0.01 p.p.m. of iron were similar as indicated by Rd, a and b measurements of the shells, thus indicating the absence of staining. Shells of eggs washed in iron solutions maintained at 120°F. had more intense staining than shells washed in non-heated (70°F.) iron solutions. Upon removing the eggs from the various iron solutions, the shells possessed a greenish-blue hue, but after drying, a uniform rust color developed over the surface of the shells. The color varied directly with the concentration of iron in the wash water. When Rd values for the non-heated iron solutions of 0.1, 1.0 and 10.0 p.p.m. 4 The color plate used in this study to standardize the Hunter color difference meter had the following serial number C-Ly-844-57 with instrument settings of Rd=61.3, a = - 1 . 8 and b = +22.6.
Downloaded from http://ps.oxfordjournals.org/ by guest on April 14, 2015
Rd = Degree change from gray to white with higher values representing white. a = Degree of red with highest values representing intense red. b = Degree of yellow with highest values representing intense yellow.
268
RESEARCH NOTES
were plotted on a semilogarithmic scale a straight line was obtained. A similar line was obtained from egg shells washed in heated iron solutions of 0.01, 0.1, 1.0 and lO.Op.p.m.
Dennison, Head, Food Technology Department, for his assistance during this study.
SUMMARY
Garibaldi, J. A., and H. G. Bayne, 1960. The effect of iron on the Pseudomonas spoilage of experimentally infected shell eggs. Poultry Sci. 39: 1517-1520. Garibaldi, J. A., and H. G. Bayne, 1962a. Iron and the bacterial spoilage of shell eggs. J. Food Sci. 27: 57-59. Garibaldi, J. A., and H. G. Bayne, 1962b. The effect of iron on the Pseudomonas spoilage of farm washed eggs. Poultry Sci. 41: 850-853. Riddick, T. M., N. Lindsay and A. Tomassi, 1958. Iron and manganese in water supplies. J. Am. Water Works Assoc. 50: 688-696.
ACKNOWLEDGMENTS
The authors wish to thank Dr. R. A.
ARGININE REQUIREMENT AND THE ARGININE CONTENT OF CASEIN H. FISHER AND P. GRIMINGER Department of Animal Science, Rutgers University, New Brunswick,
NJ.
(Received for publication October 1, 1963)
Much has been written concerning the high arginine requirement of chicks fed diets based on casein as the source of protein. The peculiar amino acid balance of casein, as suggested by studies from this laboratory (Fisher, Shapiro and Griminger, 1960), may in part explain this phenomenon. We now wish to draw attention to a recently published article on seasonal variations in the arginine content of casein, which might provide another missing link in explaining the high arginine requirement of chicks on casein diets. According to Kiermeier and Kirchmeier (1963) the amino acid content of milk casein changes considerably with the season. The authors found, for example, a large increase in essential amino acids between July and November, and a corresponding decrease in
nonessential amino acids. Specifically, the value for arginine ranged from 3.5 to 4.8% of the protein during the year. This could mean a difference in excess of 30% between the arginine content of casein-based diets, using a high- and a low-argininecasein sample. The arginine value for casein, as given by Block and Weiss (1956), is 4.2, or midway between the extreme values recorded by the German workers. It is not improbable that the relatively large differences reported in the above mentioned article are differences in the various casein components rather than differences in the structure of any single protein. With easier access to amino acid analyzers it is to be hoped that researchers will carry out more analyses of casein samples used in studies of arginine requirement and metabolism.
Downloaded from http://ps.oxfordjournals.org/ by guest on April 14, 2015
Egg shells were stained when washed for 3 to 4 minutes in water containing various concentrations of iron (FeS04-7H 2 0). The stains intensified as the concentrations of iron increased from 0.01 to 10.0 p.p.m. Heating the iron solution to 120°F. produced staining more intensified than the non-heated iron solutions.
REFERENCES