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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.
INFLUENCE OF ALTITUDE IN MILK QUALITY xXhavit Ramadani, 2Dilaver Salihu, 2Valbona Ramadani, 3Lorike Salihu
'Faculty of Agricultureand PrteiencrjeUn iversiK ofPriietina "Hasan Prishtina", Prishtine, Bulevard "Bill Clinton", nn, 10000 Prishtine -
Republic of Kosovo. 2Fac ulty of Food Technology, University of Mitrovica'Tsa Boletini",
Mitrovlc RepuOlic of Kosovo. 3Univer sity of Chemical Technology and Metallurgy, Sofia, Bulgaria.
Abstract
Milk is ove of the most important foods that people consume. The purpose of this study was investigation the influence of altitude iv physico-chemical parameters avd the somatic cells cocvt of fresh milk. During 2016, milk samples were obtained from nine dairy farms located in different areas of Kosovo with different altitudes, ranging from 389, 512, 582, 585, 636, 888, 1008, 1040 up to 1142 m. Milk samples were analyzed in total solids, fat, solids non fat, proteins, lactose, ash, density, freezing point, pH value, titration acidity and somatic cells count. Obtained results of the study showed a good average of milk composition. in order to determine the differences in milk quality depending on altitude, the results of the study showed that the altitude did not have a statistically significant influence on any of the physico-chemical parameters and on the somatic cells count of the analyzed milk. Key words: Milk qunlity, nllilTde
INTRODUCTION
Milk is one of the most important food for human nutrition (BTldioi el nl., 2002). Quality of milk is determined by chemical composition, physical characteristics and hygienic parameters. According to Alcnmn, (0996), Abdnlln el nl., (2003) milk is almost a full nutrition of high nutritional value containing protein, fat, carbohydrates, vitamins and minerals. Acording to Plneos el nl., (2004), the composition of the milk of all mammals can vary considerably. These variations may be due to the influence of genetic factors (on the level of the species and on the level of the breed), physiological factors (eg lactation phase, milking interval), nutritional factors (eg composition and value of feed energy) and environmental conditions (eg location and season). Moreover, Cacic et al., (2003) emphasized that the main indicators of hygienic quality of milk (total number of microorganisms and somatic cell count - SCC) play an important role in milk quality. The purpose of this study was investigation the influence of altitude in physico-chemical parameters and the somatic cells count of fresh milk.
MATERIAL AND METHODS
During 2016, fresh milk samples were obtained from nine milk dairy farms located in different areas of Kosovo with different altitudes, ranging from 389, 512, 582, 585, 636, 888, 1008, 1040 up to 1142 m. In each of the farms, 5 heads of dairy cows were selected, a total of 45 cows and in each of them, milk samples with a volume of about 200 ml was taken according to IDF standard 50 B: 1985 (Grüner and Filajdic, 1993). Milk samples were analyzed in total solids, fat, solids non fat, proteins, lactose, ash, freezing point, density, pH value, titration acidity and somatic cells count. Results were statistically analyzed using JMP 7.0 statistical package. Solids non fat, fat, proteins, lactose and freezing point were analysed with Lactostar "Funke Gerber" apparatus, according to the combined thermo-optic method; total solids - by calculation of fat and solids non fat content; density (specific weight) with the picnometer (Bajt et al., 1998); titration acidity by titration method according to Henkel Soxhlet; active acidity (pH value) - with pH meter GLP 21 -"Crison", (Bajt et al., 1998) ; Somatic cell count - with Somatic Cell Counter MT05. Results were statistically analyzed using JMP 7.0 statistical package. Obtained results includes the determination of the average value, the minimum and maximum values, standard deviation, coefficient of variation and P value of significance between analyzed samples. RESULTS AND DISCUSIONS
Results obtained with the purpose to investigate physico-chemical composition and somatic cell count of the milk depending on altitude, are presented in table 1.
The data presented in table 1 shows that generaly, milk produced in different altitudes, had a good average of composition, which is proved through physical-chemical parameters and SCC. Analyzed milk had the physical-chemical composition and the number of somatics cell within the limits allowed by administrative instruction MA-No. 13/2011 for quality standards and grade of fresh milk.
The content of the total solids of the analyzed milk samples ranged between 12.06 % to 13.51 %, with average value of 12.92 %. Average values have been within the limits specified by administrative instruction for quality standards and grade of fresh milk. This parameter expresses a tendency to increase depending on altitude, but differences in these values are considered to be statistically nonsignificant (P=0.5194).
The lowest value of fat within this research was 3.66 % and the highest value 4.84 %. There was no trend of changing in values depending on altitude, and the differences in this quality parameter between the different points of altitude were statistically nonsignificant (P=0.5637).
The lowest average of protein value (3.15 %) is displayed in altitude of 1040 m., while the highest value (3.49 %) in altitude of 389 m. Average results obtained in this research (3.36 %) were comparable to Konte, (1999), who analyzing the composition of milk from different mammals, in cow constated protein content on the average of 3.5 %. In our research, this parameter depending on altitude, also has value movement, with a slight tendency toward decrease, but statistically nonsignificant (P=0.2008).
Table 1. Physico-chemical composition and somatic cell count depending on altitude
Altitu de (m) Total solids (%) Fat Solids non Protein Lactose Ash Density Acidity Somatic cell count /mL
(%) fat (%) s (%) (%) (%) (gr/cm3) oSH pH
389 12.79 ab 4.30 ab 8.49 b 3.49 a 4.67 a 0.84 a 1.032 ab 7.86 a 6.63 abc 198000 bcd
512 13.03 ab 3.91 ab 9.00 ab 3.38 ab 4.65 a 0.72 ab 1.030 ab 7.80 ab 6.59 abc 734000 abc
582 12.06 b 4.18 ab 8.90 ab 3.41 ab 4.52 a 0.53 c 1.031 ab 7.50 ab 6.73 a 432000 d
585 12.84 ab 4.16 ab 8.68 ab 3.47 a 4.66 a 0.73 ab 1.031 ab 7.11 b 6.53 c 224000 cd
636 12.83 ab 4.18 ab 8.83 ab 3.44 a 4.57 a 0.65 bc 1.032 ab 7.54 ab 6.70 ab 429000 a
888 13.01 ab 4.14 ab 8.87 ab 3.25 ab 4.83 a 0.81 a 1.030 b 7.64 ab 6.62 abc 274000 abc
1008 12.85 ab 3.66 b 9.19 a 3.27 ab 4.65 a 0.80 ab 1.036 ab 7.52 ab 6.54 bc 242000 bcd
1040 13.39 a 4.50 ab 8.89 ab 3.15 b 4.79 a 0.76 ab 1.031 ab 7.48 ab 6.61 abc 220000 cd
1142 13.51 a 4.84 a 8.68 ab 3.40 ab 4.63 a 0.78 ab 1.037 a 7.32 ab 6.65 abc 318000 ab
Avera ge 12.92 4.21 8.84 3.36 4.66 0.74 1.032 7.53 6.62 341222
Min. 12.06 3.66 8.49 3.15 4.52 0.53 1.030 7.11 6.53 198000
Max. 13.51 4.84 9.19 3.49 4.83 0.84 1.037 7.86 6.73 734000
StDev 0.41 0.33 0.20 0.11 0.10 0.10 0.003 0.23 0.07 171052
CV, % 3.20 7.93 2.29 3.39 2.08 12.99 0.246 3.04 1.00 50.13
P value 0.5194 0.5637 0.6813 0.2008 0.1873 0.0087 0.3616 0.6198 0.2636 0.0116
* Levels not connected by same letter in superscript are significantly different
The lactose content ranged between 4.52 % at altitude of 582 m., and 4.83 % at altitude of 888 m. Average value of lactose (4.66 %) in all analysed samples was within the limits set by the milk quality regulation. Moreover, this parameter between all analysed points of altitudes showed values which were statistically nonsignificant (P=0.1873).
Lowest average value (0.53 %) of mineral substances was recorded at altitude of 582 m., while the highest value (0.84 %) at altitude of 389 m. This parameter also had increase and decrease of values depending on altitudes, but it was found that differences between different points of altitude were statistically nonsignificant (P=0.0087).
The lowest value of density (1.030 gr/cm3) was recorded at altitude of 512 m., and 888 m., while the highest (1.037 gr/cm3) in altitude of 1142 m. The results showed movement of the values, with a slight and statistically nonsignificant tendency to increase depending on altitude (P=0.3616).
Analysed milk at all points of altitude has been within the limits, set by regulation (6.87.5 oSH) for the titration acidity value and has met the quality criteria for processing. This parameter shows a slight decrease in value from 7.88 oSH as recorded at an altitude of 389 m., up to 7.32 oSH in the altitude of 1142 m., but was found to be statistically nonsignificant between analysed points (P=0.6198).
The pH value is found to be within the limits set by the milk quality regulation (6.3-6.9). The milk analyzed within this research, has shown values with small movements and statistically nonsignificant differences. There were no tendency of increasing or decreasing of values depending on altitude (P=0.2636).
Somatic cell count is an indicator of hygienic quality of milk and a general indicator of the health status of the udder (Rupic, 1988). According to administrative instruction for quality standards and grade of fresh milk, cow milk should contain less than 300.000 SCC/ml. At all points surveyed depending on altitude, except in the altitude of 512 m. (734000), 582 m. (432000),
and 636 m. (429000) the milk had a somatic cell count within the limits prescribed by regulation (< 300000) for fresh milk, derived from health animals. This parameter has also moved towards increasing and decreasing of values, but with statistically nonsignificant differences (P=0.0116) depending on altitude CONCLUSIONS
As a general conclusion of this research, it can be concluded that obtained results of the study showed a good average of milk composition. In order to determine differences in milk composition depending on the altitude, the results of the study showed that the altitude did not have a statistically significant influence on any of the physico-chemical components and the somatic cells count of the analyzed milk.
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Corresponding author, e-mail: Xhavit Ramadani, [email protected]
