**3.2 Milk processing**

Although various traditional milk processing and storage equipment are used in different parts of Ethiopia, clay pot is the most commonly available and used. Though not regularly practiced, 74.4% of the producers process milk in to different products. Butter, *Ergo* and *Ayib* are the major fermented milk products, while clay pot is the most commonly used equipment under smallholder condition. Flow diagram of smallholder milk processing is presented in Fig. 3 and Fig. 4 depicts utilization of milk and milk products under smallholder condition. In Ethiopia, heating milk to sterilization temperature of above 100oC for 15 to 40 minutes followed by cooling and inoculation with known bacteria culture (starter) to achieve a controlled fermentation (O'Connor, 1994) is not practiced by smallholders.

Fig. 3. Flow diagram of smallholder milk processing in the highlands of Ethiopia

Fermented milk is reported to have a storage stability of 15 to 20 days at a temperature of about 16 to 18oC (O'Connor, 1994). About 48% of the interviewees use clay pot for milk souring and/or churning for butter-making. In smallholder butter-making, microbial contamination can come from unclean surfaces, the butter maker and wash water. Packaging materials such as cups and leaves can also represent important sources of

Although various traditional milk processing and storage equipment are used in different parts of Ethiopia, clay pot is the most commonly available and used. Though not regularly practiced, 74.4% of the producers process milk in to different products. Butter, *Ergo* and *Ayib* are the major fermented milk products, while clay pot is the most commonly used equipment under smallholder condition. Flow diagram of smallholder milk processing is presented in Fig. 3 and Fig. 4 depicts utilization of milk and milk products under smallholder condition. In Ethiopia, heating milk to sterilization temperature of above 100oC for 15 to 40 minutes followed by cooling and inoculation with known bacteria culture (starter) to achieve a controlled fermentation (O'Connor, 1994) is not practiced by

**Fresh whole milk** 

**Ergo**  (naturally fermented milk)

Fig. 3. Flow diagram of smallholder milk processing in the highlands of Ethiopia

Fermented milk is reported to have a storage stability of 15 to 20 days at a temperature of about 16 to 18oC (O'Connor, 1994). About 48% of the interviewees use clay pot for milk souring and/or churning for butter-making. In smallholder butter-making, microbial contamination can come from unclean surfaces, the butter maker and wash water. Packaging materials such as cups and leaves can also represent important sources of

**Ayib**  (Ethiopian cottage cheese)

**Arera**  (defatted sour milk)

Churning

**Aguat**  (whey)

Cooking (50-70°C, 50-70 mins)

Fermentation: 2-3 days Ambient temperature: <20 - >30°C pH: 6.7 – 4.3

**Butter** 

**Nitir kibe**  (Ghee)

**3.2 Milk processing** 

smallholders.

Cooking (<100°C, 50-60 mins) contamination. Although washing and smoking the churn reduce bacterial numbers, traditional equipments are often porous and difficult to clean, therefore can serve as a reservoir for many organisms (O'Connor, 1994). Over 61% of the respondents in the study areas reported to use clay pot as a churn and for storage. *Ayib* is made by heating *Arera* or sour skim milk in a clay pot or another material on a low fire to about 40-50oC (FAO, 1990; O'Connor, 1993). In the current study, over 59% of the respondents reported to use clay pot for *Ayib*-making and storage.

1Naturally fermented cow's milk, 2Defatted sour milk, 3Ghee, 4Ethiopian cottage cheese, 5whey

Fig. 4. Flow scheme of smallholder utilization of milk and milk products

Milk cooperatives sell fresh whole milk directly without further processing as well as process into more shelf stable products whenever there is no market for fresh whole milk. Unlike smallholder producers, cooperatives use hand operated cream separator and therefore, milk makes the basis of processing in cooperative settings (Fig. 5). Although, smallholder and cooperative milk processing differs, both produce similar major marketable products: butter and Ayib. Cooperatives also use manual churn for buttermaking.

Microbial Properties of Ethiopian Marketed Milk and Milk Products and

**3.4 Marketing of milk and milk products** 

cannot be detected by such tests.

**3.5 Major milk quality related constraints** 

subsequent handling.

group discussions

areas.

Associated Critical Points of Contamination: An Epidemiological Perspective 305

There are basically two marketing systems in the central highlands of Ethiopia: formal and informal. In the formal system milk is collected at cooperative or private milk collection centers and transported to processing plants. In this system, there are somehow milk quality tests (alcohol and clot-on-boiling tests and density) up on delivery, and therefore the quality of milk is fairly secured. Producers supplying milk in this system pay a due emphasis in the production, storage and transportation of milk if their milk has to be accepted. In the informal system producers supply their surplus production to their neighbors and/or in local markets, either as liquid milk or in the form of butter and/or *Ayib* (O'Connor, 1992). In this system, the quality of milk and milk products is very poor mainly due to the prevailing situation where producers have limited knowledge of dairy product handling coupled with the inadequacy of dairy infrastructure such as electricity and clean water in the production

In Ethiopia, there is no an operational hygienic regulation set for smallholder marketed dairy products. This indicates that the health of the dairy consuming community is not secured. This particularly holds true for *Ayib,* which is consumed with *Enjera* without farther treatment (Duteurtre, 1998). On open markets buyers of milk products practice organoleptic tests. The transaction of *Ayib* is particularly subject to such tests and it is uncommon that a buyer of *Ayib* is not tongue-testing the *Ayib* before buying it. This type of test is only partly associated with the effects of putrefactive microorganisms that can be detected by a simple tongue test. The presence of pathogenic microorganisms, however,

There are reports that depict experiences of certain cooperatives around the Selale area (about 14%) (Yilma, 1999) that had a rewarding mechanism through better payment for good quality milk supplied. Such an approach encourages cooperative member and nonmember farmers to be concerned about sanitary conditions during milk production and

Milk quality related constraints ranked during group discussions with dairy cooperatives are presented in Table 2. The major milk quality related constrains include: limited

**Constraints Rank**  Limited awareness on hygienic handling 1st Shortage of capital 1st Lack of clean water 3rd Poor type of barn 3rd Hygiene of the milker 5th Lack of transport facilities 6th Mastitis (udder health problem) 7th Inappropriate materials used for milk production and handling 8th Table 2. Major milk quality related problems ranked using pair-wise comparison during

Fig. 5. Flow diagram of milk processing in cooperative centers in the highlands of Ethiopia
