**5. Critical control points in the milk chain**

As with hygiene and food safety, the issue of quality has been growing prominently in recent years and the optimum approach to these two areas is remarkably similar. Providing quality assured products to the consumer has traditionally relied on quality control of finished products, that is, a set of procedures to test and analyze the product to ensure it conforms to the required specification. This approach has drawbacks that include incidents of food poisoning in spite of quality control procedures, less effective as microorganisms are not evenly distributed in products, and high cost of rejected products as the quality control is based solely on finished product testing. This is one reason why, developments in quality management have focused on the prevention of defects in the first place (through effective design and hazard elimination) rather than trying to measure defects once the product has been manufactured. Applying this approach to hygiene has led to the development of preventive

Microbial Properties of Ethiopian Marketed Milk and Milk Products and

**Butter**

Container, wash water, ingredients added

**Nitir kibe** 

Container, storage temperatur,

**Butter** 

Container, wash water, personnel, environment, keeping temperature

at cooperative centers in different parts of Ethiopia

**Cream** 

processing in the central Ethiopian highlands

Separator, wash water, personnel, environment

Churn (container), personnel, wash water, environment

**Fresh whole milk**

**Ergo**

Associated Critical Points of Contamination: An Epidemiological Perspective 315

**Arera**

Cow, milker, wash water, utensils used for milking and filtering the milk, environment

Churning (container), added warm water

> Low cooking temperature, utensils used for draining the whey or ladling out the Ayib, filtration

**Ayib Aguat** 

**Skim milk** 

**Arera (Defatted sour milk)** 

> **Aguat (Whey)**

filtration

Low cooking temperature, utensils used for draining the whey or ladling out the Ayib,

Container, wash water, personnel, environment

Cow, milker, wash water, utensils used for milking, filtering, storage and transportation, environment

Container, storage temperature, personnel

Fig. 7. Flow scheme of critical points of microbial contamination during traditional milk

**Fresh whole milk** 

**Ayib (Ethiopian cottage cheese)** 

Container, storage temperature, personnel, environment

Fig. 8. Flow scheme of critical points of microbial contamination of milk and milk products

Quality Assurance (QA) systems. Hazard Analysis and Critical Control Point (HACCP) in particular is employed in the identification of stages in the food chain where spoilage as well as pathogenic microorganisms can enter, survive and proliferate in the food and managing these as the key control strategy rather than relying on testing end products (IDF, 1994).

In the Ethiopian smallholder context, six Critical Control Points (CCPs) where milk and milk products can be contaminated can be identified (Fig. 7). These include:


CCPs at dairy cooperatives are summarized in Fig. 8:


The aforementioned critical points of contaminations can be considered for making improvement interventions.

Quality Assurance (QA) systems. Hazard Analysis and Critical Control Point (HACCP) in particular is employed in the identification of stages in the food chain where spoilage as well as pathogenic microorganisms can enter, survive and proliferate in the food and managing these as the key control strategy rather than relying on testing end products (IDF, 1994).

In the Ethiopian smallholder context, six Critical Control Points (CCPs) where milk and milk

i. *During milk production*: During milking, contamination can come from the cow, the milker, utensils used for milking, storage and filtering the milk, and the barn or the

ii. *During fermentation*: Milk containers used for fermentation, wash water of poor quality used, ingredients added with the intention of improving the flavor of the final product

iii. *During churning (butter-making)*: Churns and warm water added to facilitate the churning process (speed-up butter recovery) can be possible sources of contamination. iv. *During Ayib-making*: Low cooking temperatures that may not be enough to kill spoilage as well as pathogenic microorganisms can be considered as an important point for the poor quality of the final product. Other potential sources of microbial contamination include: materials used for *Ayib*-making, other utensils such as that used for draining

v. *Packaging/storage of butter and Nitir Kibe/ghee*: Potential sources of contamination here include: product container/packaging, high keeping temperature, and poor personal

vi. *Packaging/storage of Ayib*: Potential sources of contamination here are similar with that

i. *The milk/reception*: The raw material milk can be contaminated via the cow; the milker; the barn; utensils used for milking, filtering, storage (at farm and cooperative center)

ii. *During cream separation*: Contamination at this point can come from the separator, wash

iii. *During fermentation of skim milk*: Containers used for fermentation, poor quality wash water, personnel and the environment represent potential sources of contamination. iv. *During churning (butter-making)*: Contamination at this point can come from the churn

v. *During Ayib-making*: Low cooking temperatures that may not be enough to kill spoilage as well as pathogenic microorganisms can be considered as an important point for the poor quality of the final product. Other potential sources of contamination include: materials used for *Ayib*-making, other utensils such as that used for draining the whey

vi. *Packaging/storage of butter*: Potential sources of contamination here include: product container/packaging, high keeping temperature, poor personal hygiene of people

vii. *Packaging/storage of Ayib*: Potential sources of contamination here are similar with that

The aforementioned critical points of contaminations can be considered for making

products can be contaminated can be identified (Fig. 7). These include:

can represent potential sources of contamination.

the whey or ladling out the *Ayib*, and filtration.

hygiene of people handling the product.

CCPs at dairy cooperatives are summarized in Fig. 8:

(container), personnel, wash water, and environment.

water, personnel, and environment.

or ladling out the *Ayib*, and filtration.

handling the product, and environment.

milking environment.

under v above.

and transport.

under vi above.

improvement interventions.

Fig. 7. Flow scheme of critical points of microbial contamination during traditional milk processing in the central Ethiopian highlands

Fig. 8. Flow scheme of critical points of microbial contamination of milk and milk products at cooperative centers in different parts of Ethiopia

Microbial Properties of Ethiopian Marketed Milk and Milk Products and

Raw cow's milk intended

Raw cow's milk intended for direct human consumption

Cheese made from raw and

Soft cheese made from heat treated milk

Powdered milk and milk based products

Source: Council Directives 92/46 EEC (1992)

force by the European Commission

for processing

thermized milk

Associated Critical Points of Contamination: An Epidemiological Perspective 317

**Milk product Microorganism Maximum limit (cfu/ml or g)** 

Pasteurized drinking milk Pathogenic microorganisms Absent in 25g

Fresh cheese *L. monocytogenes* Absent in 25g

Butter *L. monocytogenes* Absent in 25g

Frozen milk based products *L. monocytogenes* Absent in 1g

Liquid milk based products *L. monocytogenes* Absent in 1g

Table 7. Microbiological safety limits for selected milk products in community legislation in

consumed raw, a more stringent standard is generally required because consumers of raw milk are at a greater risk for contracting a milk-borne illness such as salmonellosis. In some countries, standards adopted may depend on whether milk is refrigerated or merely water-cooled. For example, in North America, SPC values of <106 ml-1 or equivalent are

UHT milk and sterilized milk Total bacteria 100

Total bacteria 105 *Staphylococcus aureus* 2 x 103

Coliforms 5 Total bacteria 5 x 105

*Salmonella* Absent in 25g *S. aureus* 5 x 102 Total bacteria 5 x 104

*Salmonella* Absent in 1g *S. aureus* 104 *E. coli* 105

*L. monocytogenes* Absent in 25g *Salmonella* Absent in 1g *S. aureus* 103 *E. coli* 103 Coliforms 105

*Salmonella* Absent in 1g *S. aureus* 100

*Salmonella* Absent in 1g Coliforms 10

*L. monocytogenes* Absent in 1g *Salmonella* Absent in 1g *S. aureus* 100 Coliforms 10

*Salmonella* Absent in 1g *S. aureus* 100 Coliforms 100 Total bacteria 105

*Salmonella* Absent in 1g Coliforms 5

*Listeria monocytogenes* Absent in 1g hard cheese or in

25g other cheese varieties
