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milk, respectively (Paape et al. 2007). Higher SCC is associated with impaired processability of milk (Raynal-Ljutovac et al. 2005; Skeie 2014) and may lead to undesirable effects on the health of the consumer, due to the toxins produced by
pathogenic bacteria, as a result of udder infection (Skeie 2014). To commercialise
goat milk, it is important to set the acceptable level of SSC, and it should be included
in the routine recording of the milk quality as a measure for reducing the increase in
bacteria load in milk and to improve the welfare of milk-producing animals. One of
the means for reducing SCC is to control the most contagious diseases in dairy
goats, including caprine arthritis encephalitis virus (CAEV), caseous lymphadenitis
(CLA) and Johne’s disease (Skeie 2014). Elevated SCC has been associated with
these diseases (Sanchez et al. 2001).
Milk lipids are the main contributors to flavour in goat milk and milk products
(Chilliard et al. 2003). Lipids are enclosed within milk fat globule (MFG) in the
form of triglycerides. The MFG is surrounded by the milk fat globule membrane
(MFGM), which prevents lipolysis of milk fat by endogenous lipoprotein lipase
(LPL). When MFGM is disrupted by either agitation or temperature fluctuations,
the triglycerides are exposed to LPL and hydrolysed to release free fatty acids
(FFA). The LPL activity is controlled by both environmental and genetic factors
(Chilliard et al. 2003). Higher content of FFA was linked to the tart or rancid flavour
of the milk (Eknæs and Skeie 2006) and impaired rennet coagulation properties
(Skeie 2014). The negative effects of high contents of FFA on the flavour of the milk
and on cheesemaking properties were a serious issue for the NL goat milk. The
Norwegian dairy company (TINE SA) has therefore introduced results from the
analysis of FFA as one of the parameters in the payment system for the goat milk.
Efforts made by the NL goat industry on feeding and selective breeding have led to
an improvement in flavour and cheesemaking properties of milk from these animals
in recent years (Skeie 2014). A well-established milk quality control is needed during the commercialisation of goat milk from the smallholder dairy goat farmer in
rural areas. Training program on the hygiene of milk production, milk handling and
dairy recording of milk quality should be established together with a well- established
disease control and treatment program. The joint collaboration with dairy processing companies would be the possible means to enforce quality standards of goat
milk from rural areas of Tanzania and Malawi.
2.2 Chemical Composition of Goat Milk
Milk components occur in three phases. One phase is the true solution of lactose,
organic and inorganic salts, vitamins and small molecules in water. Proteins are dispersed in an aqueous phase of the milk at a molecular level (whey proteins,
α-lactalbumin, β-lactoglobulin, serum albumin, etc.) and larger colloidal particles
(casein micelles) with a diameter of 50–600 nm. The last phase is the milk lipids,
which occur in the emulsified state as fat globules with a diameter of 0.1–20 μm (Fox
et al. 2015). Both nutritional and technological properties of milk are determined by
Goat Milk Quality and Possible Dairy Products from Rural Households of Tanzania…
milk, respectively (Paape et al. 2007). Higher SCC is associated with impaired processability of milk (Raynal-Ljutovac et al. 2005; Skeie 2014) and may lead to undesirable effects on the health of the consumer, due to the toxins produced by
pathogenic bacteria, as a result of udder infection (Skeie 2014). To commercialise
goat milk, it is important to set the acceptable level of SSC, and it should be included
in the routine recording of the milk quality as a measure for reducing the increase in
bacteria load in milk and to improve the welfare of milk-producing animals. One of
the means for reducing SCC is to control the most contagious diseases in dairy
goats, including caprine arthritis encephalitis virus (CAEV), caseous lymphadenitis
(CLA) and Johne’s disease (Skeie 2014). Elevated SCC has been associated with
these diseases (Sanchez et al. 2001).
Milk lipids are the main contributors to flavour in goat milk and milk products
(Chilliard et al. 2003). Lipids are enclosed within milk fat globule (MFG) in the
form of triglycerides. The MFG is surrounded by the milk fat globule membrane
(MFGM), which prevents lipolysis of milk fat by endogenous lipoprotein lipase
(LPL). When MFGM is disrupted by either agitation or temperature fluctuations,
the triglycerides are exposed to LPL and hydrolysed to release free fatty acids
(FFA). The LPL activity is controlled by both environmental and genetic factors
(Chilliard et al. 2003). Higher content of FFA was linked to the tart or rancid flavour
of the milk (Eknæs and Skeie 2006) and impaired rennet coagulation properties
(Skeie 2014). The negative effects of high contents of FFA on the flavour of the milk
and on cheesemaking properties were a serious issue for the NL goat milk. The
Norwegian dairy company (TINE SA) has therefore introduced results from the
analysis of FFA as one of the parameters in the payment system for the goat milk.
Efforts made by the NL goat industry on feeding and selective breeding have led to
an improvement in flavour and cheesemaking properties of milk from these animals
in recent years (Skeie 2014). A well-established milk quality control is needed during the commercialisation of goat milk from the smallholder dairy goat farmer in
rural areas. Training program on the hygiene of milk production, milk handling and
dairy recording of milk quality should be established together with a well- established
disease control and treatment program. The joint collaboration with dairy processing companies would be the possible means to enforce quality standards of goat
milk from rural areas of Tanzania and Malawi.
2.2 Chemical Composition of Goat Milk
Milk components occur in three phases. One phase is the true solution of lactose,
organic and inorganic salts, vitamins and small molecules in water. Proteins are dispersed in an aqueous phase of the milk at a molecular level (whey proteins,
α-lactalbumin, β-lactoglobulin, serum albumin, etc.) and larger colloidal particles
(casein micelles) with a diameter of 50–600 nm. The last phase is the milk lipids,
which occur in the emulsified state as fat globules with a diameter of 0.1–20 μm (Fox
et al. 2015). Both nutritional and technological properties of milk are determined by
Goat Milk Quality and Possible Dairy Products from Rural Households of Tanzania…