Non-fat dry milk is
whole milk from which moisture and cream have been removed. This product still
contains the other nutrients like minerals, vitamins, natural sugar and high
quality protein; milk fat is content left ranges from 0.6 - 1.25% of total
product weight (1, 3). The reduced
moisture content (2.0 – 4.5 % of total product weight) or low water activity in
dried milk will prevent microbial growth and spoilage (1, 3). Exposure of the
product to moisture will cause caking, undesirable changes in flavor and
increased microbial growth which may result in food borne illnesses (1). Non-fat dry milk is also canned
under nitrogen and carbon dioxide to exclude oxygen thus preventing microbial
growth, browning and change of flavor due to oxidation of dried milk (1, 2). Additionally, milk proteins
lactoferrin and lactoperoxidase have known anti-microbial properties.
Storage temperature for
dry milk depends on the time the product is to be stored. Products that are to
be shelved for 3, 24 and 48 months should be shelved at 90o, 70o
and 50oF respectively to prevent microbial growth (1).
The dry milk product should also be stored in an air tight container and
a cool dry dark place with less than 65% relative humidity. Exposure to light
will accelerate undesirable chemical changes (1).
References
1.
Charlotte, P. B. 1992. Utah State
University Cooperative Extension: Storage of dry milk products. Document no.
FN177. Available at: http://extension.usu.edu/files/publications/publication/FN_177.pdf.
Last accessed on 27/1/2012
2.
Henrik, S., B. R. Nielsen, and L. H.
Skibsted. 1997. Effect of heat treatment, water activity and storage
temperature on the oxidative stability of whole milk powder. Int. Diary J. 7:331-339
3.
United States Diary Export Council. Nonfat
dry milk and skimmed milk powder. Document no. 82271. Available at: http://www.usdec.org/Products/content.cfm?ItemNumber=82654&navItemNumber=82271.
Last accessed on 28/1/2012
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