Mineral-protein composites

Figure 13.2 A model of biocomposites, (a) Schematic diagram of staggered mineral crystals embedded in a protein matrix (b) Simplified model showing the load-carrying structure of the mineral-protein composites. Most of the load is carried by the mineral platelets, whereas the protein transfers load via the high-shear zones between mineral platelets. Reprinted from Ref. [38].

Honey composition varies, depending on floral origin, the climate, environmental and seasonal conditions, as well as agricultural practices (Al-Mamary et al., 2002 Anklam, 1998 Arraez-Roman et al., 2006 Azeredo et al., 2003 Baltrusaityte et al., 2007 Kii iik et al., 2007). Honey contains about 200 different substances (Al-Mamary et al., 2002 Arraez-Roman et al., 2006 Kiigiik et al., 2007), carbohydrates being the main constituents, followed by the minerals, proteins, vitamins, lipids, organic acids, amino acids (Finola et al., 2007), phenolic compounds (flavonoids and phenolic acids), and other phytochemicals (Bertoncelj et al., 2007). 

Milk consists of 85—89% water and 11—15% total soflds (Table 1) the latter comprises soflds-not-fat (SNF) and fat. Milk having a higher fat content also has higher SNF, with an increase of 0.4% SNF for each 1% fat increase. The principal components of SNF are protein, lactose, and minerals (ash). The fat content and other constituents of the milk vary with the animal species, and the composition of milk varies with feed, stage of lactation, health of the animal, location of withdrawal from the udder, and seasonal and environmental conditions. The nonfat soflds, fat soflds, and moisture relationships are well estabhshed and can be used as a basis for detecting adulteration with water (qv). Physical properties of milk are given in Table 2. 

Proteins and Meals. Nutritional properties of the oilseed protein meals and their derived products are deterrnined by the amino acid compositions, content of biologically active proteins, and various nonprotein constituents found in the defatted meals. Phytic acid (3), present as salts in all four meals, is beheved to interfere with dietary absorption of minerals such as 2inc, calcium, and iron (67) (see Food toxicants, naturally occurring Mineral nutrients). ... 

Nutritional Requirements. The nutrient requirements of mammalian cells are many, varied, and complex. In addition to typical metaboHc requirements such as sugars, amino acids (qv), vitamins (qv), and minerals, cells also need growth factors and other proteins. Some of the proteins are not consumed, but play a catalytic role in the cell growth process. Historically, fetal calf semm of 1—20 vol % of the medium has been used as a rich source of all these complex protein requirements. However, the composition of semm varies from lot to lot, introducing significant variabiUty in manufacture of products from the mammalian cells. 

The use of foods by organisms is termed nutrition. The ability of an organism to use a particular food material depends upon its chemical composition and upon the metabolic pathways available to the organism. In addition to essential fiber, food includes the macronutrients—protein, carbohydrate, and lipid—and the micronutrients—including vitamins and minerals. 

Seven diets were constructed from purified natural ingredients obtained from either C3 (beet sugar, rice starch, cottonseed oil, wood cellulose, Australian Cohuna brand casein, soy protein or wheat gluten for protein) or C4 foodwebs (cane sugar, corn starch, com oil, processed corn bran for fiber, Kenya casein for protein) supplemented with appropriate amounts of vitamins and minerals (Ambrose and Norr 1993 Table 3a). The amino acid compositions of wheat gluten and soy protein differ significantly from that of casein (Ambrose and Norr 1993). 

Finally, the versatility of the technique and its use as a chemical imaging technique allow retrieval of the structural composition of a sample, in order to understand its complete recipe [Mazel et al. 2008]. The composition of a sample from the Dogon statuette 71.1935.105.169 has been studied. Proteins, polysaccharides, lipids and minerals have been found. The distribution of these different chemicals shows that the patina sample can be divided into four different layers (Figure 15.14). Layers 1 and 3 are mainly composed of proteins whereas layer 2 consists of lipids and polysaccharides. Minerals can be found at the interface of layers 1 and 2, and 2 and 3. Finally, layer 4 is the more complex because it contains all the types of compounds. One can suppose that it is in fact composed of different layers that do not appear clearly on the cross-section. 

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