Milk from Camels., Goats and Sheep: A Review

By Connie Landis

Oregon State University, Corvallis, Oregon 97331


Abstract The use of camel, goat and sheep milk in gaining in acceptance and importance worldwide. Research has fostered this development by studying the animals and their milk, This review was prepared to bring together a variety of information on the subject to compare the milks and milk products of camels, goats and sheep and their importance today. Specific comparisons are made on chemical composition, amino acid composition, and vitamin and mineral composition.

 

1. INTRODUCTION

 

Camels, goats and sheep are three of the oldest domesticated animals. Their uses are many including transportation, as a food, and fiber for clothing. However, these animals are also significant milk producers whose milk and milk products are an important component of the human diet in many parts of the world.' In a time when there are issues of cow milk adulteration and scares of milk-bom pathogens such as Listeria, it becomes necessary to evaluate the alternatives to cow's milk. This paper was undertaken to compare the milks and milk products of other Old World domesticated ruminants, mainly camels, goats, and sheep.

 

II. BACKGROUND

 

A.Camel Background

Camels have long been used as pack

animals and it is currently estimated that there are 17 million camels on earth today.' Camels are an important part of the life of desert dwellers providing a source of income and transportation, while at the same time giving them a source of protein and energy through food products. Unique to camels is the ability to thrive under extreme weather conditions and still produce milk of high nutritional value.

B.Goat Background

Goat husbandry has been around since the first domestication of animals.' Goats have been used as pack animals, as foragers, and for their hair and milk. Goat milk currently plays an important nutritional role in many parts of the world, accounting for approximately 30% of the total milk production in Saudi Arabia in 1981.1

C.Sheep Background

The milking of sheep for dairy production has been practiced for thousands of years in the Mediterranean countries and is 6 becoming increasingly popular worldwide. Sheep are raised primarily for their meat and wool, although their milk products are gaining in acceptance and economical importance.

Ill. COMPOSITION AND

CHARACTERISTICS

A.Chemical Composition

The chemical compositions of camel, goat and sheep milks are given in Table 1. The distribution of energy between fat, lactose and protein differs considerably between the three kinds of milk. As you will note, sheep's milk is considerably higher than both camel and goat milk in fat and protein, but nearly the same in lactose.

Lipids in milk fat serve as an energy source, act as a solvent for the fat-soluble vitamins and supply essential fatty acids. In milks of all species studied, tn'acylglycerols are by far the major lipid class of milk fat. The ruminant herbivores have branched-chain fatty acids in all their phospholipids;

they have only a small proportion of fatty acids with more than two double bonds.' Fat globule size distribution of camel milk is similar to that in cow's milk, while goat's milk averages a smaller fat globule size distribution. However, both display a very slow creaming rate.

Table 1. Chemical Composition of Camel, Goat and Sheep Milk.

Component

Camel

Goat

Sheep

Fat %

3.24

3.21

7.52

Protein (Nx6.38)%

3.35

2.87

5.85

Lactose %

4.52

4.10

4.86

Ash %

0.80

0.79

0.92

Total Solids %

11.91

11.05

18.63

Energy (kcal/liter)

670

622

1080

 

B.Amino Acid Composition

The amino acid compositions of camel, goat and sheep milks are given in Table 2. The three milks differ in proportions (see Table 1) and kind of proteins, but the overall amino acid composition of the mixture of proteins is similar in all three. All three have a satisfactory balance of essential amino acids equaling or exceeding the FAO-WHO requirements for each amino acid.

The vitamin and mineral compositions of camel, goat and sheep milks are given in Table 3. The most important contributions of milk to human nutrition are in the calcium and phosphate that it supplies.(9) The concentration ranges of certain health-related elements in milk and milk products are closely dependent upon animal species.(11) sheep's milk appears to have the highest amounts of these calcium and phosphate, with goat's milk at second and camel milk providing the least of the three.

Comprehensive information on vitamin C content was unavailable. however, camel milk was shown by Farah et al.(2) to contain over three times as much vitamin C as cow's milk.

the clotting properties of milk are affected by its composition, microbiological quality, somatic cell count and by the processing itself. High protein, fat and total solids concentrations in the milk are associated with high yields in the resulting dairy products, such as yogurt and cheese. As a consequence, the milk of sheep has a higher yield (quantity of product produced per batch) of dairy products than the milk of camels and goats because it has higher concentrations of protein, fat and total solids.(6)

IV. Milk and Milk Product Consumption.

A. Food Products

Most camel milk is consumed fresh or when just soured. it is difficult to convert camel milk into butter.(12) Ice cream of acceptable quality has been successfully produced from camel milk, although this practice is not widespread as of yet.(13)

Goat's milk lends itself to use in the same types of products that are considered for cow's milk, and perhaps surpasses the cow's milk in some categories. Major amounts of goat's milk are processed annually into dried milk, evaporated milk, cheese and yogurt as well as being sold as bottled whole milk. The use of goat's milk in the production of cheese has become very widespread in France. this use is largely based on the capacity of goat milk curd to be frozen and produce a product not only equal but often considered better in flavor than one in which freezing did not take place. This process is normally accomplished without using salt and the curd can be held for up to six months at 5F.(4) Goat's milk is whiter than cow's milk because it contains no carotene which causes fat to have various degrees of yellow coloring; thus butter made from the cream of goat's milk is white.(8)

Sheep milk is rarely consumed in its liquid form, but is often processed into cheese, butter, and some yogurt.(6) It can be consumed in liquid form by mixing it at a ratio of 60 parts of milk to 40 parts of water, where it resembles the taste and mouthfeel of cow milk. Most of the sheep milk produced throughout the world is transformed into cheese such as feta. Some sheep milk yogurt is produced in Greece. Therefore when the quality of sheep's milk is referred to, the emphasis is placed on the capability of the milk to be transformed into high quality food products.(6)

B. Inedible Products

In addition to cheese production, sheep's milk is currently used to produce milk skin bars (as a cleanser and moisturizer). Sheep's milk has the natural ability to moisturize and nourish the skin and is safe on even the most delicate skin.(14).

V. Product Importance Today

A. Rising Trend in America

The use of camel milk in the United States is rare. However, the use of goat and sheep milk is on the rise. This may be due, in part, to the number of small herds maintained by individuals either as a source of income or avocation. The milk produced by such enterprise is typically sold as whole milk or processed into cheese, yogurt, evaporated milk, or dried milk products.(4) This has been facilitated by the introduction of milking machines made especially for these smaller animals. This industry has prompted interest and research within Agricultural Departments and other research organizations, that has helped to further the information on the subject.(6) all in all, the milking of goats and sheep and the use of their milk and milk products, is on the rise in America.

B. Sensory Analysis

Several factors affect milk and milk product flavor, and most consumers base the quality of these products on flavor. They want milk that tastes good. The flavors most often found in milk are feed and weed, oxidized, rancid, salty, and mediciny. The farm manager has the greatest control of these off flavors by controlling feed and milking conditions and maintaining animal health. The processors must then employ safe handling procedures and protect products from post-process contamination.(8)

Camel milk is generally opaque-white. It has a sweet taste, but sometimes can also be salty. The type of feed and the availability of drinking water cause the changes in taste.(7)

Goat milk products were rated by a sensory panel of six individuals. All products evaluated were an opaque-white. The plain goat milk yogurt moderate to poor acceptance on its own, but would be used in recipes or with added flavoring, such as berries. The goat cheese Chavrie was noted as being similar to cream cheese and applicable for the same uses, but most participants would not choose it if given a choice. The goat's milk feta received moderate to poor scores, and was noted as having a flavor that was too strong for the participant's taste.

Some sheep milk products were also evaluated by the same six member sensory panel. These products showed more variance in appearance and color. Sheep milk Myzithra had a strong odor and taste that did not suit the majority of the participants. However, it is comparable to other italian cheese and may find uses in ethnic dishes. The sheep milk feta received moderate scores and would be used by participants, especially if flavors, such as herbs, were added. It was noted as having a salty taste, which is commonly dairy product defect.

C. Nutritional Contribution Around the World

Camel, goat, and sheep milk products play important roles in various parts of the world.(3) These milks and their milk products are an important nutritional contribution around the world. This contribution is most prominent in areas where protein sources are not readily available.

What has been seen in the early analyses are that enterprise from these three milks is capable of producing products that equal or in many cases surpass their common dairy counterpart. In addition, these animals appear to thrive around the world in many areas where dairy cattle cannot, providing an excellent component of the food supply to the people in those areas. However, a major difficulty faced by the industry has been the lack of definite compositional profiles for these milks, without which it is difficult to compare their milk and milk products. The bottom line: more research and development in this area is a necessity.,<p> This paper has critically reviewed milks from Old World domestic ruminants (except cattle, on which extensive research has already been done) and their importance. Their history, composition and characteristics, and products and uses each contribute to the overall value these contributions provide to the 20th century world. An understanding of these factors and their importance is essential as we move on into the 21st century and continue to fight food born pathogens, poor nutrition, and world hunger.

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Updated: Wednesday, May 23, 2012.