Sun-dried milk
Sun-dried milk Jane MacAskill 16.11.97
Sun-dried milk Ezzeddine Boutrif 18.11.97
Sun-dried milk -Reply Janak Upadhyay 18.11.97
sun-drying and contamination of milk Mike Golden 18.11.97
FW: Sun-dried milk J C Lambert 20.11.97


Date: Tue, 11 Nov 1997 23:06:56 +0300

Subject: Sun-dried milk


I have recently received the following request for information from Somalia and would be grateful for any information on this subject but particularly details of the drying process.

"In times of plenty in some locations in Turkana, Northern Kenya, milk is sun-dried and stored for consumption later in the year". Are there any details of milk being sun-dried in other countries. If so how is this done? Details of methods used including type of milk (camel, cow, sheep or goat) used, processing method, time frame, level of technology used, storage time and how it is consumed would be appreciated.

Additional details of the sun-drying process used in Turkana would also be appreciated.

All replies gratefully received.



Jane MacAskill

Date: Tue, 18 Nov 1997 09:34:00 +0100

From: "Egal, Florence (ESNP)"

Subject: FW: Sun-dried milk


To Jane MacAskill, with best regards!


Florence Egal, Nutrition Programmes Service, FAO


From: Boutrif, Ezzeddine (ESNS), FAO


However, although I have never heard of sun-dried milk, my first reaction to this type of process, from the hygienic point of view, would be skeptical if not completely negative. Milk, unlike fruits and vegetables, is a very sensitive food which deteriorates rapidly and gets easily contaminated with all sorts of micro-organisms which could cause serious health problems to the consumer. The only possibility that I can see for this type of conservation to be applied is on fermented milk or cheese. Natural fermentation reduces the pH which acts to protect the milk product during its sun drying. But even this technique could lead to health problems. To my view it should be discouraged.


Date: Tue, 18 Nov 1997 10:19:21 +0100

From: Janak Upadhyay <>

Subject: Sun-dried milk -Reply


Considering that any protein rich products with high moisture is susceptible to microbial attack, it would be extremely hard to dry milk in the ambient temperature of Somalia. Perhaps, if any one is doing, it must be the combination of other preservation technics. For example, Lactic fermentation followed by drying, make into cottage cheese and dry etc. But to dry directly would not be advisable unless you utilize sophisticated equipment as spray drier, freeze drier etc.



Janak Upadhyay, Food & statistical Unit, UNHCR, Geneva

Date: Tue, 18 Nov 1997 11:17:52 +0000

From: Michael Golden <>

Subject: sun-drying and contamination of milk


Another problem with sun drying will be the destruction of light sensitive vitamins in the milk. Andrew Tomkins recently spoke about the practice of exposure of red palm oil to sun-light to reduce the red color and staining - it then contains almost no carotene and will no longer protect from vitamin A deficiency.

The comments about bacterial contamination of milk are also germane - as these societies have established traditions of yoghurt production, perhaps the milk is fermented before drying?

However, there is another low-cost technology for milk preservation that few seem to be aware of: the addition of modest amounts of thiocyanate and peroxide to the milk. Leif Hambraeus recently brought this to my attention and I understand that it is being used in parts of China at the moment.

The levels of thiocyanate added are not sufficient to interfere with thyroid function (although it would be wise to have some iodate there as well). For those who are concerned about bacterial contamination of milk this might be worth exploring. I do not know if the necessary enzymes are preserved in DSM but if they are such methods would allow therapeutic milk to be safely made up and kept for overnight feeding.

Relevant references are:

Reiter B, Pickering A, Oram JD, Pope GS. Peroxidase-thiocyanate inhibition of streptococci in raw milk. J Gen Microbiol 1963; 33: 12

Bjoerck L. Antibacterial effect of the lactoperoxidase system on psychotrophic bacteria in milk. J Dairy Res 1978; 45: 109-118.

Bjoerck L, Claesson O, Schulthess W. The lactoperoxidase/thiocyanate/hydrogen peroxide system as a temporary preservative for raw milk in developing countries. Milchwissenschaft 1979; 34: 726-729.

Bjoerck L, Claesson O. Correlation between concentration of hypothiocyanate and antibacterial effect of the lactoperoxidase system against Escherichia coli. J Dairy Sci 1980; 63: 919-922.

Harnulv B, Kandasamy C. Increasing the keeping quality of milk by activation of its lactoperoxidase system: results from Sri Lanka. Milchwissenschaft 1982; 37: 454-457.

Dahlberg P, Bergmark A, Bjorck L, Bruce A, Hambraeus L, Claesson O. Intake of thiocyanate by way of milk and its possible effect on thyroid function. Am J Clin Nutr 1984; 39: 416-420.

Best wishes,


Prof. Michael H.N.Golden

Date: Thu, 20 Nov 1997 10:54:00 +0100

From: "Egal, Florence (ESNP)"

Subject: FW: Sun-dried milk


A little exercise on your French...


From: Lambert, JeanClaude (AGAP)

J'ai photocopie de la revue mondiale de zootechnie (No 79) un article que j'ai fait sur "l'amelioration de la technologie du fromage TCHOUKOU au Niger". C'est une technologie pour le sechage au soleil d'un fromage traditionnel.



Production animale, FAO