Milk is an important source of all basic
nutrients required foraals including human beings. Milk from various
mammals such as cow, buffalo, goat, sheep, camel is uses for different
nutritional purposes e.g. feeding to young ones and preparation of some
nutritional products such as milk cream, butter, yoghurt, ghee,sour milk
( Webb et al.,1994; Hassan, 2005). Nutritionally enriched milk and its
products with enhanced biological potential and without health risks are
generally demanded (Khan and Zeb, 2007; Baloch et al., 2006; Rahman et
al., 2006). The major chemical components of milk include water, fats,
proteins, carbohydrate, minerals, organic acids, enzymes and vitamins.
In order to assess the quality of milk, milk samples including infant
formulas, milk powder, milk fromarkets, raw milk (unprocessed human milk
and animal milk) from various countries such as Canada, Lithuania,
Italy, USA, UK, and Nigeria have been extensively studied.
The content of 38 micro and trace
elements in raw milk of cows in the Silesian region, Poland were studied
by Dorzanski et al.(2005). They found that the location if cows has a
significant impacts on the contents ofany micro and trace elements in
milk. In another study, infant formula samples sold in Nigeria, UK, USA
were analyzed for various essential elements ( Can, Co Cu Cr, Fe, Mg, Mn
Mo, Na and Zn) and non essential elements (Ag, Al,As, Ba, Be, CD, Hg,
Ni, Pb, Sb, Sn, Sr, Ti, Tl, U and V) (Ikem et al., 2002). They found
that soy based powder infant formulas generally had higher element
levels than milk based powder formulas. Some brands also had low
nutritional contents when compared with the recommended dietary
allowances (RDAs) and dietary reference intakes (DRIs) for use in North
America.
Commercial production of dried milk
dates back to 1832 and was pioneered by Russian chemist M. Dirchoff
(Hunzike, 1920). Since then the powdered milk has been produced using
different techniques. The production method and stages employed makes
the whole milk susceptible to contamination and /or having the required
essential element. Most of the powdered milk available in the market is
produced from Cow's milk. However, the breed of cow and its environment,
method of manufacture and storage, all combined, affect the quality and
quantity of essential and trace elements present (Salah et al., 2013). A
review on the sources and defuency diseases of mineral nutrients in
human health and nutrition can be found in Gupta and Gupta (2014).
Powdered milk is widely consumed in Nigeria. In fact most of tea served
during breakfast in Nigeria consists of powdered milk.
1.2 Problem Statement
Milk is frequently used in the
manufacture of infant formulas recipes for bakes products, beverages and
confectionary. However, storage conditions and high temperature can
degrade the nutritive value of milk powder. Hence, there is need to
periodically assess the milk quality for both food safety and
nutritional considerations.
1.3 Objectives of the Study
The major objective of the study is to
assess the quality of various milk samples available in Nigeria which is
to be achieved through the following specific objectives:
(i) Assessment of the physical characteristics of the milk.
(ii) The chemical analysis of the various milk samples and
(iii) The bacteriological examination of the milk samples.
1.4 Research Questions
1. What are the various milk samples available in Nigeria?
2. Do the various milk samples conform with the standard provides by regulatory authorities?
3. Why the need to assess the quality of milk available in Nigeria?
1.5 Significance of the study
This research is a prelinary study to
ascertain the physiochemical characteristics and nutritional quality of
the various milk samples available in Nigeria market. The findings of
this research will help to know if the milk brands are within the
recommended nutritional levels. The findings may also be helpful for the
concerned goverental parties to monitor the quality of the milk
products in the market in Nigeria.
1.6 Scope of the study
The research focuses on the quality assessment of various milk samples available in Nigeria.
Refrences
Baloch MS, Awan IU, Hassan G. Growth and
yield of rice as affected by planting dates and seedlings per hill
under high temperature of Dear Ismail Khan, Pakistan J Zhejiang Univ.
Sci B. 2006; 7(7): 572-579
Dobrzanski Z, Kolarz R, Gorecka H,
Chojnacka K, Bartkowiak A. The content of micro elements and trace
elements in raw milk feo. Cows in the Silesian region. Polish J Environ
Stud, 2005, 14(5): 685-689.
Gupta, U.C and Gupta, S.C 2014. Sources
and defiency diseases of mimaral nutrients in human health and
nutrition. A review. Pedosphere 24(1): 13-58.
Hassan SS. Quality Assurance of various Dairy Products Pakistan: Department of Chemistry, University of Peshawar; 2005.
Hunziker O.F. 1920. Condensed milk and
milk powder Prepared for the use of milk condenseries, dairy students
and pure food departments. 3rd end. LaGrange II. P. 277.
Khan I, Zeb A. Nutritional composition of Pakistani wheat varieties J. Zhejiamg Univ. Sci.B. 2007; 8(8): 555-559.
Rahman S, Khalid N, Zaidi JH, Aad S,
Iqbal MZ, Non occupational lead exposure and hypertension in Pakistani
adults. J zhejiang Univ. Sci. B, 2006; 7(9): 732-737.
Salah, F.A.A.E, Esmat, I.A. and
Mohammed, A.B. 2018. Heavy metals residues and trace elements in milk
powder marketed in Dakahlia Governorate. International Food Research
Journal 20(4): 1807-1812.
Webb BH, Johnson AH, Alford JA. Fundamental of Dairy Chemistry 2nd End. Westport. CT: AVI Publishing Co; 1974. Chapter I.