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Научни трудове на Съюза на учените в България-Пловдив. Серия В. Техника и технологии, т. XV, ISSN 1311 -9419 (Print), ISSN 2534-9384 (On- line), 2017. Scientific Works of the Union of Scientists in Bulgaria-Plovdiv, series C. Technics and Technologies, Vol. XV., ISSN 1311 -9419 (Print), ISSN 2534-9384 (On- line), 2017.
CHANGES IN THE QUALITY CHARACTERISTICS OF EGGS
DURING STORAGE
Katerina Petrovska1, Elena Joshevska,nTatijana Kalevska2 1 Faculty ofBiote chnical Sci ences,University St.IOiment Ohridski,
Bitola, R. Macedonia 2 Facultyof Technology and Technicalsci ences, University 0t. Klimene Odnideki, Bllola, R.MacedoniT
Fbslticl: Shu main purpose rf this research was examination rf the caiogui that rccut (o the quil(lB characteristics rf eggs frr crosumptiro, during storage in different croditiros (rrrm temperature and refrigerator) frrm laying tr the 40la day rf storage. Fs t material frr research were used eggs frrm twr hybrid lines OIF Vrrwo and DeKilb. F trtTl 112 eggs frrm cTtegrrB L (63 -73 g) were used frr the indestigitirn. Half rf the eggs (frrm brth hybrid lines) ire kept it rrrm temperature (13 tr 22°t) and half (o the refrigeratrr (0-4°t). Weight lrss, air cell size and yrlT crlrr were kucykdud it 0, 10, 21 and 40 days rf strrage. She egg weight lrss (o eggs strred it 4 °n significantly (P<0.01) lrwer thin the eggs strred it 22 °C Changes in the crlrr rf egg yrlT were mrre prrnrunced in eggs strred it rrrm temperature.
Key wrrds: eggs, hybrid lines, quality characteristics, strrage
Ontrrductirn
The poultry industry, which is mainly focused on egg production, shows constant development in the last twenty years, and the private individual farms which increase their activity in this sector are the greatest contributors. The egg and broilers production in small family agricultural economies has long tradition and representation in the Republic of Macedonia and it is also a part of the rural heritage. In egg production part, the main goal is keeping the current situation of total self-sufficiency on the domestic market with domestic production through keeping and advancing of the domestic consumption. According to data from the Statistical Office from 2015, the total number of laying hens is 1.352.564 and the average egg production by laying hen is 150. In total production, 109.977 is from individual producers and 93.406 is a part of egg production in the business sector. Global production and egg consumption, as well as their effects on human's health is result of their easy availability and accessibility, high-quality proteins, vitamins and minerals, which are necessary for healthy and quality life Zaheer, (2000). Eggs are available for everyone through the year, easy for cooking and also tasty and useful. Eggs are perfect food for balanced and healthy diet.
Material and metards
Eggs from two hybrid lines: (Isa Brown which lay brown eggs) and De Kalb which lay white eggs), grown in modern private poultry farm, were taken as research material in this researches.
According to quality, they belong to A "fresh eggs" class intended for consumption. Eggs from L category with weight 63 - 73 g or in total 112 eggs from both hybrid lines were taken from each hybrid line for foreseen research. Half of the eggs (from both hybrid lines) are stored at room temperature (13 - 22°C), and half of them in refrigerator (0 - 4°C).
Examinations of physical characteristic of eggs for consumption from both hybrid lines are conducted in Meat and Meat Products Control and Quality Laboratory at the Faculty of Biotechnical Sciences -Bitola. For the necessary examinations, seven eggs from each hybrid line were taken immediately after laying, then on 10th day, 21st and 40th day. In the last group eggs from both lines, after 40 days, on each 10 days the mass change of eggs and the height of air chamber were followed individually. Egg mass was measured every day with digital beam scale. The height of air cell size was determined with candling. After each measurement, mean value was calculated. Yolk color was determinate with DSM Fan Yolk scale. The data obtained was analyzed by using the statistical program (Ms.Excel), so as to compare the treatments and to make analysis of variance.
Results and discussion
From the results presented in (Table 1), it could be determined that the mean values of egg mass on laying day of white and brown eggs stored at room temperature (16°C) are: 58±0.93; 59.14±1.02.
Table 1. Changes in egg mass
Storage condition Hybrid lines Parameter Day of storage
DeKalb 0 10 21 40
x 58.00±0.93 57.71±0.52 55.28±1.13 52.14±0.96
min 55.00 56.00 53.00 52.00
(16°C) max 62.00 60.00 59.00 58.00
Sd 2.44 1.38 2.98 2.54
Cv 4.22 2.35 5.39 4.70
ISA x 59.14±1.02 57.71±0.75 54.42±0.68 51.42±1.18
Brown min 55.00 55.00 53.00 46.00
max 62.00 61.00 57.00 56.00
Sd 2.67 1.97 1.81 3.15
Cv 4.51 3.42 3.33 6.13
DeKalb x / 58.85±0.74 56.71±0.89 53.43±1.16
min / 57.00 54.00 49.18
(4°C) max / 62.00 61.00 57.34
Sd / 1.95 2.36 3.06
Cv / 3.31 4.02 5.74
ISA x / 58.85±0.51 56.28±1.11 53.16±1.06
Brown min / 57.00 54.00 50.93
max / 61.00 62.00 58.54
Sd / 1.34 2.92 2.80
Cv / 2.28 5.02 5.28
On the 10th day of storage, a decrease in the average mass from 57.71±0.52 of white eggs and 57.71±0.75 of brown eggs has been noticed. On 21st day, bigger decrease in the weight of eggs from
both hybrid lines, such as: 55.28±1.13; 54.42±0.68. On the 40th day of storage of the egg at room temperature, white eggs mass is 52.14±0.96, and brown eggs mass is 51.42±1.18.
The obtained results for eggs stored in refrigerator (4°), starting from the 10th until the 40th day also show decrease in the weight of the egg mass. The difference in the decrease of values from the 10th until the 40th day of egg storage in refrigerator is 5.42 of white eggs and 5.69 of brown eggs. Our results are similar to the results of (Akyurek and Okur, 2009) and Chonkas et al., (2014).
From the results in (Figure 1), it could be stated that on the initial day, at room temperature, the air cell size has smallest value 5.8±0.38 of white eggs and 6.4±0.51 of brown eggs. Gradually, as time passes by, the mean values of air cell size, starting from 10th day, 21th, until 40th day of eggs storage from both hybrid lines increase, which indicates drastic changes regarding the values.
40 ~i-
35--
30 -J___
DeKalb (16 T) IS ABrown (16 T) DeKalb (4 T) IS ABrown (4 T)
0 \-'-T-T-T-,
0 10 21 40
Storage period
Figure 1. Dynamics of changes of air cell size during storage period
In comparison with other author for air cell size in the same or similar conditions, our results are similar to the results of Chonkas et al.,(2014); (Vasilev and Kitanovski, 2005), Kralik et al., (2014). Results of the yolk color during storage period of the eggs from both hybrid lines are presented in (Table 2).
Egg yolk pigmentation is a practical subject for the egg production industry, which requires the production of eggs with an appropriate pigmentation level and homogeneous distribution of color to satisfy food industry demands, (Sachchidananda et al.,2008).
From the results of Table 2 can be determined that color of the yolk is changing during storage period. According to the indicators of the DSM Yolk Fan ranges from 13 to 15 at the ISA Brown and DeKalb. Changes in the color of egg yolk were more pronounced in eggs stored at room temperature.
Storage condition Hybrid lines Parameter Day of storage
DeKalb 0 10 21 40
x 13±0.00 14.20±0.01 14.60±0.00 14.20±0.00
min 12.00 13.00 14.00 14.00
(16°C) max 14.00 15.00 15.00 15.00
Sd 0.71 1.09 0.54 2.54
Cv 5.44 7.71 3.75 4.70
ISA x 15.00±0.00 14.60±0.00 14.60±0.00 14.20±0.00
Brown min 15.00 14.00 14.00 13.00
max 15.00 15.00 15.00 15.00
Sd / 0.54 0.54 0.83
Cv / 3.75 3.75 5.89
DeKalb x / 13.00±0.00 14.20±0.00 14.60±0.00
min / 13.00 15.00 14.00
(4°C) max / 13.00 15.00 15.00
Sd / / 1.05 0.54
Cv / / 7.71 3.75
ISA x / 15.00±0.00 14.60±0.00 14.40±0.00
Brown min / 15.00 14.00 13.00
max / 15.00 15.00 15.00
Sd / / 0.54 0.89
Cv / / 3.75 6.21
Conclusion
From the study, it was observed that egg weight, height and width, air cell size indices decreased with increase in storage period. The regression relations given for the external evaluation parameters can be used for estimating optimum period for loss in egg qualities and for planning storage facilities. It can be concluded that the quality of an egg is affected by the method and length of storage and also a hybrid line.
References
Akyurek, H., Okur A.A. (2009). Effect of Storage Time, Temperature and Hen Age on Egg Quality in Free-Range Layer Hens. Journal of Animal and Veterinary Advances, 8, 1953-1958 Kralik, Z., Kralik, G., Grcevic, M., Galovic D. (2014). Effect of storage period on the quality of table eggs. Acta Agraria Kaposvariensis Vol 18 Supplement 1, 200-206.
Sachchidananda, D. C., M. H. Begum, C. D. Shubash, M. H. Rashid, and J. M. Ferdaus. (2008). Evaluation of marigold flower and orange skin as sources of xanthophylls pigment for the improvement of egg yolk color. Poult. Sci. 45:265-272
Vasilev, K., Kitanovski, D., (2005). Eggs storage. In: Technology of poultry meat and eggs, Vol. I, eds. University St. Kliment Ohridski, Faculty of Biotechnical sciences, Bitola, 257-280. Zaheer K (2000). An Updated Review on Chicken Eggs: Production, Consumption, Management Aspects and Nutritional Benefits to Human Health. Food and Nutrition Sciences, 6: 1208-1220 Conkas J., Mihalac J. (2014). Promjene fizikalnih svojstava jaja u razlicitim uvjetima skladistenja. Societas biologorum croatica, 1, 6-19.
