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This chapter explains how theories of gelatin and osmazome were eventually replaced by a more modern approach to the diet. It illustrates this change by comparing two very similar products that emerged over the space of just a decade: a substance called Osmazome Food, which was promoted by Alexis Soyer, and one known as Extractum Carnis, or “extract of meat,” which was promoted by the founder of modern biochemistry, Justus Liebig. These two products were essentially the same, but were marketed in radically different ways: the former framed by classical dietetics; the latter by modern nutritional science. The chapter shows how classical dietetic tradition, which had spread throughout Europe in the Renaissance, died away with modern biochemistry, and Liebig's science shifted attention inside the body. This had four main implications which profoundly changed how food was judged, how nutritional authority was conducted, how food was removed from its social context, and how food became a tool of progress.

Gelatine is a well-known structural protein widely used in the daily life, as well as in the scientific and technological areas for the preparation of a great variety of composite materials. But in spite of its abundance and common use, gelatine presents itself as a complex biopolymer with a mixed character between a protein, since it is derived from collagen, and a synthetic linear polymer with random spatial arrangement above certain temperature. For numerous applications, mainly in biomedicine, the biocompatible and biodegradable properties of gelatine are crucial, and usually the reinforcement of biopolymer matrix by assembling to inorganic or hybrid nanoparticles is also required to improve its mechanical stability. Alternative treatments such as chemical crosslinking may also contribute to reduce water swelling and enhance the mechanical properties as well as thermal stability. The incorporation of inorganic solids into the proteinous matrix allows tailoring both the mechanical and functional properties of the resulting gelatine-based composites. Many strategies may be followed to tune the functional properties: selection of inorganic solids offering the desired functionalities, grafting of suitable functional groups to the gelatine hybrids, or combination of additional polymers or fillers in ternary composites. In this way, advanced functional materials of increasing complexity are developed from the basis of a very common biopolymer, opening the way for a wide range of applications of the gelatine-based nanocomposites.

This chapter answers questions regarding the ingredients of vaccines. The CDC estimates that every year, about 200 people suffer severe allergic reactions to substances in vaccines. These substances include egg proteins, antibiotics, yeast proteins, and gelatin. the preservative in vaccines that has caused the most concern among parents of young children is thimerosal because it contains mercury. Although large quantities of mercury might be harmful to the nervous system, small quantities are not. Likewise, studies show that aluminum vaccines do not increase the amount of aluminum in the blood. Other studies have shown that the body eliminates aluminum quickly; in fact, about half of it is completely eliminated in one day. Some viral vaccines are also made using animal cells. One animal product in vaccines that is present in fairly large quantities is gelatin, which comes from the skin or hooves of pigs.

This chapter describes the processes of gelation and spherification. Gelation involves the use of a gelling agent to solidify food by trapping molecules in time and space. Gelatin is the oldest of gelling agents and is a key ingredient in Jell-O that causes the liquid blend to solidify upon cooling. A variety of relatively new gelling agents have allowed culinary practitioners to create new textural experiences previously unknown in the context of the kitchen. In 1998, El Bulli, the world-renowned restaurant in Spain, introduced agar-agar, a natural seaweed extract that serves as the vegetarian counterpart to gelatin. It is a very common ingredient in Asian cuisine, where it is used as a gelling agent in the preparation of jellies, puddings, and custards. Agar-agar gels can resist melting to 140°F (60°C) and show less slippery and less brittle mouthfeel than gelatin-based gels. Another revolution is the spherification technique. In its simplest form, spherification is a culinary technique in which a gel forms around a liquid center, like caviar. From a culinary standpoint, the advent of this technique represented a major step forward because it allowed the creation of two simultaneous textures: a liquid interior and a solid exterior—the most famous examples being apple caviar and pea ravioli.

Opening with the significance of making Jell-O at him in the author’s 1960s kosher household, shows how dispute of Jell-O, and the gelatin it contained, narrowed definition of what could be accepted as kosher among the Orthodox, generated a deep disagreement between Orthodox and Conservative Jews – and generated a conundrum that the non-Jewish food industry followed the stricter Orthodox standard.

The stability of Ag nanoparticles is described in this chapter by taking into account the following two conflicting facts. On the one hand, Ag nanoparticles are not regarded to be stable enough for use in plasmonics, although they exhibit a stronger plasmonic effect than Au nanoparticles that are representative of plasmonic elements. On the other hand, Ag nanoparticles have aquired an extremely long lifetime in air, being surrounded by gelatin in photographic materials. Analytical studies of gelatin and synthetic polymers have revealed that gelatin has the significant ability to protect Ag nanoparticles from degradation by controlling their Fermi level with respect to that of gelatin phase around them in air. This result led to the idea of protecting metal nanoparticles from degradation by polymers with widely controllable properties.

What materials can be used to make optical elements – that are transparent and mostly homogeneous -- but which are also edible? Think of this as an exercise in optical engineering with a very odd requirement. Optical designers are often bound by restrictions that require their materials to be transparent in certain regions of the spectrum, or are vacuum-qualified for use in space, or which must function at extreme ntemperatures. This is just a very different requirement. If it seems too outrageous, consider that there can be practical reasons for this requirement. Several edible optical devices have, in fact, already been designed and constructed.

The term “gel” has been used in a wide variety of contexts, and there have been difficulties in reaching an all-inclusive, workable definition for it. Perhaps the simplest way to proceed is to list some of its most important characteristics: It is a solidlike material that when deformed responds in the manner of a typical elastic body, but generally with a very small modulus. If it does show plastic flow, then this occurs above a threshold value of the stress, with full recoverability below this limit. It typically consists of two or more components: one a liquid in substantial quantity, and the other generally a polymeric network. One of the most direct ways of obtaining a gel is to place a network into a solvent known to be capable of dissolving the network chains in the absence of cross-links. In fact, a unique property of a highly extensible elastomer (resulting from a low degree of cross-linking) is its ability to swell greatly when exposed to a good solvent. A gel with less than 10-6 mol cm-3 of cross-links, for example, may increase its volume more than thousandfold when immersed in a suitable solvent. The extent to which such a network will swell depends specifically not only on the degree of cross-linking, but also on the interactions between the chains and the solvent. While the degree of cross-linking is established during the preparation of a network, the extent of the interaction of chains and solvent may be modified as desired, and therefore the degree of swelling may be controlled. A gel can be made to swell or shrink continuously by changing the quality of the solvent with which it is in contact. Alternatively, it may go through critical conditions and, in fact, can exhibit phase transitions, depending on the type of the polymer-solvent interaction and the extent of cross-linking. The discrete shrinkage of the gel, by changing the polymer-solvent interaction parameter, is a volume phase transition similar to the gas-liquid transition of a condensing gas. The possibility of such phase transitions was, notably, first discussed by Dusek and collaborators many years ago. Their treatment was confined to nonionic networks.

The kidneys are of fundamental importance in the regu­lation of fluid and electrolytes, maintaining permissive extracellular fluid composition (salts and water), pH, and volume, while also mediating the removal of waste prod­ucts. Based on the anatomy of the nephron, three main processes occur in order to deliver this balance: glom­erular filtration, tubular secretion, and tubular resorption. Drugs can act at different sites within this system, so that functional equilibrium can be restored in various disease states (e.g. hypertension, heart failure, liver failure, neph­rotic syndrome). CKD is a long- term condition that lasts more than 3 months and affects the function of both kidneys. It results from any pathology that reduces renal functional capacity and produces a decrease in GFR to less than 60 mL/ min/ 1.73 m². Prevalence within the UK is high, particularly in the elderly and affects 6– 8% of the population. The most common cause of CKD is idiopathic (unknown, usually with small kidneys), then diabetes mellitus. In both, glom­erular damage and mesangial injury (causing metabolic and haemodynamic effects) occur. Mild- moderate essen­tial hypertension does not cause CKD. Knowledge of the functional anatomy of the proximal tubule and loop of Henle is essential in understanding therapeutic targets and treatment of pathologies, as each region and transporter system has a key role. In brief, the journey of solutes from the blood to the production of urine occurs at five main anatomical sites— the glom­erulus, the proximal tubule, the loop of Henle, the distal tubule (proximal part and distal part), and the collecting ducts (Figures 5.1 and 5.2). The glomerulus is a network of capillaries (like a ball of string), which merge with the nephron via Bowman’s cap­sule. It is the first site of filtration and the place where solutes, toxins, and small proteins are removed from the wider circulatory system, after delivery by the renal ar­teries (via an afferent arteriole). Blood and larger proteins remain in the arteriole and leave via an efferent branch, while the filtrate enters the proximal convoluted tubule. The afferent:efferent system ensures that a constant filtration pressure is maintained irrespective of variations in arterial pressure. The capillary bed is very large, so that permeability and filtration rates are high. A normal glomerular filtration rate (GFR) i.e. 90– 120 mL/ min/ 1.73 m², depends on hydrostatic pressure, the colloid osmotic pressure and hydraulic per¬meability.