Plastic Packaging of Eggs

156

J. V. SHUTZE, W. E. MATSON AND J. MCGINNIS

tardation of sexual maturity. Otherwise, some pullets will be stimulated into production at too early an age. REFERENCES Bowman, J. C , and R. H. Jones, 1961. Lighting techniques for the domestic fowl. 2. Experiment 1959-60. British Poultry Sci. 2: 91-106. Dobie, J. B., J. S. Carver and J. Roberts, 1946. Poultry lighting for egg production. Washington Exp. Sta. Bull. No. 471. Duncan, D. B., 1955. Multiple range and multiple " F " tests. Biom. 11: 1-42. Farner, D. S., 1961. Comparative Physiology: Photoperiodicity. Annual Rev. Physiol. 23: 71-96. Fox, S., 1961. Personal communication, University of Reading, England. King, D. F., 1961. Effect of decreasing and constant lighting treatments on growing pullets. Poultry Sci. 40: 479-484. Lanson, R. K., and P. D. Sturkie, 1961. The influence of light and darkness upon the reproductive

performance of the fowl. 1. Effect of continuous, intermittent, and flashing light on egg production, feed consumption, and body weight. Poultry Sci. 40: 1751-1756. Lowe, R. W., and B. W. Heywang, 1961. Effect of additional light during growing period on egg production of October hatched White Leghorn pullets. Poultry Sci. 40: 177-180. McClary, C. F., 1960a. Step down step up lighting plan. Pacific Poultryman, Feb., 14-15. McClary, C. F., 1960b. Genetic behavior and photoperiodism in laying hens. Poultry Sci. 39: 1273. Morris, T. R., and S. Fox, 1960. The use of lights to delay sexual maturity in pullets. British Poultry Sci. 1: 25-36. Shutze, J. V., W. E. Matson and J. McGinnis, 1961. Influence of different photoperiods during brooding and rearing on subsequent productive characteristics in chickens. Poultry Sci. 40: 1604-1611. Snedecor, G. W., 1948. Statistical Methods. Iowa State college Press, Ames, Iowa, p. 222. Wilson, W. O., 1961. Personal communication. Univ. of California, Davis.

Plastic Packaging of Eggs 2. COOKING QUALITIES OF OIL-DIPPED AND CRYOVAC-PACKAGED EGGS1 PATRICIA W. MYERS, 2 GEORGE T. DAVIS AND GLADYS HARTLEY ROEHM School of Home Economics and Department of Animal Science and Range Management, Montana State College, Bozeman, Montana (Received for publication July 10, 1962)

have been made concerning STUDIES the quality of shell eggs as influenced by different methods of packaging. Davis and Beeckler (1962) compared eggs packaged in polyethylene, Cryovac, a variety of cellophane wraps, and eggs dipped in oil. The plastic films effectively prevented much loss of carbon dioxide and water and maintained low albumen pH and high Haugh unit values. The authors reported that an average pH of 8.6 was needed be1 Journal Series No. 585, Montana Agricultural Experiment Station. 2 Present address: Dept. of Foods & Nutrition, School of Home Economics, Purdue University, Lafayette, Ind.

fore hard-cooked eggs wrapped in polyethylene could be peeled without damage. Egg quality has a direct relation to the volume, tenderness, acceptability, and texture of angel food cakes, whole-egg sponge cakes, and whole-egg butter-type cakes, as reported by Hollinger et al. (1956) and Pyke and Johnson (1940, 1941). Egg quality was determined by height of firm albumen, length of storage, and yolk index. Eggs of high quality produced angel food cakes with greater volume than eggs of low quality. Hunt and St. John (1931) reported that thin egg whites whipped to a greater volume than thick egg whites at room temperature. Cakes prepared with

157

EGG COOKING QUALITIES TABLE 1.—Mean physical and chemical changes of fresh, oiled, and Cryovac•gs stored 4, 6 and 8 weeks Methods of preservation

Weeks of storage

Mean Mean Mean Mean initial weight final weight weight loss albumen height (gm.) (gm.) (gm.)

Mean pH

Mean Haugh unit

Cryovac

4 6 8

58.374 57.826 58.257

57.889 57.235 57.613

0.485 0.591 0.644

6.45 5.77 5.46

7.93 7.87 7.88

80.28 75.75 73.49

Oiling

4 6 8

58.278 58.459 57.844

58.008 57.973 57.233

0.270 0.486 0.611

6.40 5.85 5.66

7.64 8.10 8.17

80.24 75.60 75. CO

Fresh

0

—

60.854

—

7.59

7.72

86.58

thin egg whites were usually larger in volume. Hollinger et al. (1956) found that offflavors of eggs were more noticeable in soft-cooked eggs and custards than in cakes. The investigators reported that high-quality eggs were more acceptable as poached and soft-cooked eggs than were low-quality eggs. The objective of this experiment was to evaluate similarities and differences in the chemical, physical, and cooking qualities of Cryovac-packaged and oil-dipped eggs stored four, six, and eight weeks as compared to fresh laid eggs. PROCEDURE

Over 900 eggs from a single strain of White Leghorn hens were used in this study to determine the differences and similarities between eggs packaged in Cryovac (a vinylidene-type copolymer) and eggs dipped in oil. Fresh eggs from the White Leghorn hens were used as the control. Eggs from the Montana State College Poultry Farm were gathered and immediately washed in a basket in a sanitizing detergent with 200 parts of Roccal (trade name for benzalkonium chloride) at 100°F. for three minutes. The eggs were dried for one hour at room temperature in an airblown drier. They were then candled, randomized, weighed to the nearest one-thou-

sandth gram, and packaged. One dozen eggs was dipped in a lightweight mineral oil at room temperature and placed in a carton. One dozen eggs was also placed in a carton and then sealed in Cryovac. Both packages were stored in a refrigerator at 50°F. for four, six, and eight weeks. Fresh eggs were gathered daily and not held over 12 hours before being used in the laboratory. They were not washed. Packaging eggs began December 15, 1960 and continued through January 10, 1961. Chemical and physical tests. Eggs were tested in a room that maintained a temperature of 20°C. to 25°C. Two eggs from each carton were weighed to the nearest one-thousandth gram to determine the loss in weight during storage. Albumen height, Haugh unit values, and pH of the albumen were also measured. TABLE 2.—Mean specific volumes of soft meringues; fresh, oiled, and Cryovac-packaged eggs Weeks of storage

Mean specific volume

Cryovac bags

4 6 8

ml. 3.582 4.080 4.249

Oiling

4 6 8

3.466 3.918 3.820

Fresh

0

3.796 4.142 4.459

Method of preservation

158

P. W. MYERS, G. T: DAVIS AND G. H. ROEHM

TABLE 3.—Mean scores for texture, color, and flavor of I custards; fresh, oiled, and Cryovac-packaged eggs Method of Preservation

Weeks of Texture Storage

Mean Scores Color

Flavor

Total

Cryovac

4 6 8

8.25 8.60 9.50

8.70 8.80 9.35

7.75 8.40 8.65

24.70 25.80 27.50

Oiling

4 6 8

8.45 8.80 9.60

8.30 8.50 9.15

7.75 8.00 8.55

24.50 25.40 27.30

Fresh

0

8.20 8.60 9.50

8.70 8.70 8.95

8.20 7.60 8.40

25.10 24.90 26.85

Formulas and tests for egg products. Leavening and baking values of the eggs were determined by whole-egg sponge cakes; foaming ability of the albumen by solf meringues; acceptability for flavor, color and texture by poached eggs, hardcooked eggs, French omelets, and baked custards. The sponge cakes were also scored by a taste panel for color, flavor, and texture. The seven members of the organoleptic panel were students and staff members in the School of Home Economics at Montana State College. Scoring was from 10 to 1 on all products: 10 to 9 as excellent, 8 to 6 as good, 5 to 4 as fair, and 3 to 1 as poor. The same utensils were used to prepare the various products, and methods were standarized as much as possible. The laboratory temperature ranged from 20°C. to

22°C. The mixing order was varied in the two replications; I.e., Cryovac eggs first and fresh eggs third, oiled eggs first and Cryovac eggs third. 1. Soft meringues. A standard recipe minus the flavoring from Experimental Cookery (Lowe, 1955) was used. Egg whites were allowed to reach room temperature before they were whipped. Each meringue was weighed to the nearest one-half gram and the volume measured in milliliters. A specific volume (milliliters/grams) for each meringue was thus obtained. 2. Baked custards. A receipe for baked custards from Experimental Cookery (Lowe, 1955) was used; reconstituted dry skim milk was the liquid. Each custard mix was divided into two 120-gram portions and baked at 330°F. for about one hour. Baking dishes were placed in approximately the same position in the oven each time. 3. Poached eggs. One pint tap water and 1.5 gms. salt were brought to a boil. The eggs were broken into a sauce dish and slipped into the boiling water. They cooked for five minutes over very low heat. 4. Hard-cooked eggs. Eggs were gently added to one quart boiling tap water and cooked for 20 minutes over very low heat. The eggs were cooled quickly and allowed to become cool before being tasted. 5. French omlet. Egg magma (144

TABLE 4.—Mean scores for texture, color and flavor of poached eggs; fresh, oiled, and Cryovac-packaged eggs Weeks of storage

Texture

Color

Flavor

Total

Texture

Color

Flavor

Total

Cryovac

4 6 8

7.85 7.70 7.40

9.15 8.80 9.10

8.35 7.10 8.00

25.35 23.60 24.50

8.50 8.30 7.80

9.25 8.90 9.10

8.60 7.40 8.40

26.35 24.60 25.30

Oiling

4 6 8

8.55 7.80 7.60

8.30 8.50 9.10

8.85 7.60 7.40

25.70 23.40 24.10

8.65 7.80 7.40

9.50 8.40 8.90

8.45 7.70 7.40

26.60 23.90 23.70

Fresh

0

8.30 7.10 7.00

9.25 9.00 9.10

8.25 7.30 6.60

25.80 23.40 22.70

8.45 8.10 8.00

9.20 9.20 9.00

8.45 7.60 7.00

26.10 24.90 24.00

Method of Preservation

Mean scores:for egg whites

Mean scores for egg yolks

159

EGG COOKING QUALITIES TABLE 5.—Mean scores for texture, color and flavor of hard-cooked eggs; fresh, oiled, and Cryovac-packaged eggs Methods of preservation

Mean scores for egg yolks

Mean scores for egg whites

Weeks of storage

Texture

Color

Flavor

Total

Texture

Color

Flavor

Total

Cryovac

4 6 8

7.40 6.45 7.20

9.30 8.35 8.90

7.60 6.85 7.00

24.30 21.65 23.10

7.80 6.85 7.90

7.10 7.85 8.20

8.45 6.85 7.90

23.55 21.55 24.00

Oiling

4 6 8

6.90 7.05 7.10

8.65 8.30 9.10

7.10 6.55 6.10

22.65 21.90 22.30

7.85 7.30 7.70

7.90 7.55 8.30

7.80 7.50 7.60

23.55 22.35 23.60

Fresh

0

6.55 6.40 6.10

8.95 8.05 8.70

6.90 6.60 6.80

22.40 21.05 21.60

8.00 6.35 7.20

7.65 7.45 8.00

8.15 6.25 7.30

23.80 20.05 22.50

the volume measured by seed displacement, as described by Piatt and Kratz (1933).

grams), 45.75 grams reconstituted dry skim milk and salt (1.5 gms.) were mixed and cooked in a skillet containing 6 gms. of margarine. 6. Whole-egg sponge cakes. A recipe developed at the Colorado Agricultural Experiment Station (Anonymous, 1954) for a 5,000 foot altitude whole egg sponge cake was adapted and the following ingredients used: 97.2 gms. granulated sugar, 74.5 gms. sifted cake flour, 0.8 gms. cream of tartar, 1.3 gms. salt, 1.8 gms. vanilla, 11.3 gms. tap water, 54 gms. egg yolk and 90 gms. egg white. All ingredients were at room temperature before being combined. Sixty-eight gms. of batter was weighed into each of three identical experimental cake pans and baked at 330°F. until they responded to the finger test for doneness. One cake from each lot was allowed to become stale and

The mean initial weight, final weight, weight loss, albumen pH, and Haugh unit values for Cryovac-packaged, oiled, and fresh eggs appear in Table 1. Cryovac and oiled eggs had similar pH and Haugh unit values at four weeks storage. After the four weeks, the oiled eggs increased in alkalinity slightly more than the Cryovac-packaged eggs. The mean specific volumes for the soft meringues made from the three types of stored eggs are shown in Table 2. The differences in specific volumes between methods of packaging and lengths of storage were not significant. Tables 3, 4, 5, 6, and 7 give the texture,

TABLE 6.—Mean scores for texture, flavor, and color of French omelets; fresh, oiled, and Cryovac-packaged eggs

TABLE 7.—Mean scores for texture, color, and flavor for whole-egg sponge cakes; fresh, oiled, and Cryovac-packaged eggs

Method Weeks of of Texture Preservation Storage

M e a n Scores Color

Flavor

Total

Cryovac

4 6 8

8.65 8.05 8.65

8.05 6.75 8.80

7.80 6.85 7.10

24.50 21.65 24.55

Oiling

4 6 8

8.00 7.60 8.65

8.20 7.90 8.90

8.45 7.00 7.15

24.65 22.50 24.70

Fresh

0

8.05 7.80 9.0

8.75 7.80 8.90

8.05 7.60 7.55

24.85 23.20 25.45

RESULTS

Method Weeks of of Preservation Storage

Mean Scores Texture

Total Color

Flavor

Cryovac

4 6 8

7.40 7.60 7.35

8.10 8.10 7.65

7.55 8.15 7.35

23.05 23.85 22.35

Oiling

4 6 8

7.50 7.10 6.30

9.25 8.50 7.85

8.05 7.00 6.70

24.80 22.60 20.85

Fresh

0

7.00 7.30 5.80

8.60 8.15 7.70

7.40 7.65 6.40

23.00 22.10 19.90

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P. W. MYERS, G. T. DAVIS AND G. H.

TABLE 8.—Mean volume of whole-egg sponge cakes; fresh, oiled, and Cryovac-packaged eggs Method of preservation

Weeks of storage

Mean volume

Cryovac bags

4 6 8

ml. 260 215 255

Oiling

4 6 8

265 250 252.5

Fresh

0

265 240 262.5

ROEHM

weeks were compared with fresh eggs. No significant differences were observed in texture, color, and flavor of baked custards, poached eggs, hard-cooked eggs, French omelets, and whole-egg sponge cakes prepared from the stored eggs and fresh eggs. Significant differences in specific volumes of soft meringues and volume of sponge cakes were not found. Thus, Cryovac and oiled eggs stored for four, six, and eight weeks were equal in cooking quality to fresh eggs for the foods prepared. REFERENCES

color, and flavor mean scores for the baked custards, poached eggs, hard-cooked eggs, omelets, and whole-egg sponge cakes as rated by the organoleptic panel. Mean flavor scores for baked custards show that the rating for both the Cryovac-packaged and oiled eggs increased as storage time increased. There were no significant differences in texture, color, and flavor of egg products prepared from fresh, oiled, and Cryovac-wrapped eggs. The mean volumes of the whole-egg sponge cakes are shown in Table 8. Again, there were no significant differences in the volume of sponge cakes prepared with fresh, oiled, and Cryovac-packaged eggs. SUMMARY

The chemical, physical, and cooking qualities of Cryovac-wrapped, and oiltreated eggs stored for four, six, and eight

Anonymous, 1954. Mile-high cakes. Colorado Agr. Exp. Sta. Bui. 404A. Davis, G. T., and A. F. Beeckler, 1962. Plastic packaging of eggs. 1. Methods of packaging. Poultry Sci. 4 1 : 391-397. Hollinger, M. E., R. Jordan, B. A. McLaren and W. J. Stadelman, 1956. Cooking quality and flavor of eggs. U.S. Dept. of Agr. Info. Bui. No. 164. Hunt, L. W., and J. L. St. John, 1931. Angel food cake from the thick and thin portions of egg white. J. Home Ec. 23: 1151-1156. Lowe, B., 1955. Experimental Cookery. John Wiley and Sons, Inc., New York. Piatt, W., and P. D. Kratz, 1933. Measuring and recording some characteristics of test sponge cakes. Cereal Chem. 10: 73-89. Pyke, W. E., and G. Johnson, 1940. Preparing and baking yellow sponge cake at different altitudes. Colorado Agr. Exp. Sta. Bui. No. 27. Pyke, W. E., and G. Johnson, 1941. Relationships between certain physical measurements upon fresh and stored eggs and their behavior in the preparation and baking of cake. Poultry Sci. 20: 125-138.

NEWS AND NOTES (Continued from page 94) The Second Section is subdivided into : (a) Neuroendocrine Factors and Reproduction, (b) Behaviour of Sperm in the Female Genital Tract and Insemination, (c) Longevity and Reproductive Power, and (d) Lactation and Reproduction. The following Symposia are planned: (a) Abnormalities of Meiosis and Lethality of Gametes, (b) Gametogenesis in Interspecific Hybrids and Fer-

tility, and (c) Substances having a Hormonal Effect Contained in Natural Foodstuffs and Fertility. The Third Section is subdivided into: (a) Dilution and Storage of Semen, (b) Standardization of Methods for the Collection and Evaluation of Data to A. I. Centers, (c) Artificial Insemination of Cattle, (d) Artificial Insemination of Pigs, (e) Artificial Insemination of Horses, (f) Artificial (Continued on page 185)