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59-421: Caramel color is one of the oldest and most used food colorings for enhancing naturally occurring colors, correcting natural variations in color, and replacing color that is lost to light degradation during food processing and storage. The use of caramel color as a food additive in the brewing industry in the 19th century is the first recorded instance of it being manufactured and used on a wide scale. Caramel color

118-432: A colloid such as milk, the colloidal particles are globules of fat, rather than individual fat molecules. Because colloid is multiple phases, it has very different properties compared to fully mixed, continuous solution. The following forces play an important role in the interaction of colloid particles: The Earth’s gravitational field acts upon colloidal particles. Therefore, if the colloidal particles are denser than

177-478: A colloid. The scattered light will form an interference pattern, and the fluctuation in light intensity in this pattern is caused by the Brownian motion of the particles. If the apparent size of the particles increases due to them clumping together via aggregation, it will result in slower Brownian motion. This technique can confirm that aggregation has occurred if the apparent particle size is determined to be beyond

236-459: A conclusion that caramel colors are not carcinogenic. While the US FDA, Canadian Health Products and Food Branch and European Food Safety Authority (EFSA) have found caramel color safe for use in food and beverages, California has listed 4-Methylimidazole (4-MeI), a compound formed in the manufacture of Class III and IV caramel colors, in the state's Proposition 65 , thus legally including it in

295-539: A diameter of approximately 1 nanometre to 1 micrometre . Some colloids are translucent because of the Tyndall effect , which is the scattering of light by particles in the colloid. Other colloids may be opaque or have a slight color. Colloidal suspensions are the subject of interface and colloid science . This field of study began in 1845 by Francesco Selmi , who called them pseudosolutions, and expanded by Michael Faraday and Thomas Graham , who coined

354-714: A dilute solution. When reacted with sulfites, caramel color may retain traces of sulfite after processing. However, in finished food products, labeling is usually required only for sulfite levels above 10 ppm . In 2010, the International Programme on Chemical Safety (IPCS) concluded that commercially produced caramel color has the same toxicological properties as caramel produced by cooking or heating sucrose , except for those prepared using ammonium (Class III and IV). The IPCS has concluded that caramel color does not exhibit carcinogenicity or mutagenicity , based on its studies. Additional long-term studies support

413-890: A dispersed phase in this size range may be called colloidal aerosols , colloidal emulsions , colloidal suspensions , colloidal foams , colloidal dispersions , or hydrosols . Hydrocolloids describe certain chemicals (mostly polysaccharides and proteins ) that are colloidally dispersible in water . Thus becoming effectively "soluble" they change the rheology of water by raising the viscosity and/or inducing gelation. They may provide other interactive effects with other chemicals, in some cases synergistic, in others antagonistic. Using these attributes hydrocolloids are very useful chemicals since in many areas of technology from foods through pharmaceuticals , personal care and industrial applications, they can provide stabilization, destabilization and separation, gelation, flow control, crystallization control and numerous other effects. Apart from uses of

472-399: A food has a standard of identity, caramel color may be safely used in foods generally at levels consistent with " good manufacturing practice " (GMP). Caramel color has excellent microbiological stability. Since it is manufactured under very high temperature, high acidity, high pressure, and high specific gravity , it is essentially sterile, as it will not support microbial growth unless in

531-462: A natural diffraction grating for visible light waves , particularly when the interstitial spacing is of the same order of magnitude as the incident lightwave. Thus, it has been known for many years that, due to repulsive Coulombic interactions, electrically charged macromolecules in an aqueous environment can exhibit long-range crystal -like correlations with interparticle separation distances, often being considerably greater than

590-504: A negative charges depending upon the reactants used in their manufacture. Problems such as precipitation , flocculation , or migration can be eliminated with the use of a properly charged caramel color for the intended application. Internationally, the United Nation's Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives ( JECFA ) recognizes four classes of caramel color, differing by

649-438: A perturbation. Aggregation causes sedimentation or creaming, therefore the colloid is unstable: if either of these processes occur the colloid will no longer be a suspension. Electrostatic stabilization and steric stabilization are the two main mechanisms for stabilization against aggregation. A combination of the two mechanisms is also possible (electrosteric stabilization). A method called gel network stabilization represents

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708-533: A reactive metabolite. Secondly, carcinogenic doses of 4-MeI exceed estimates of exposure from the consumption of caramel coloring by several thousand-fold. Caramel coloring may be derived from a variety of source products that are themselves common allergens , namely starch hydrolysates (from wheat), malt syrup (in general derived from barley), or lactose (from milk ). As such, persons with known sensitivities or allergies to food products are advised to avoid foods including generic caramel coloring or first determine

767-500: A result of the relatively simple methods that have evolved in the last 20 years for preparing synthetic monodisperse colloids (both polymer and mineral) and, through various mechanisms, implementing and preserving their long-range order formation. Colloidal phase separation is an important organising principle for compartmentalisation of both the cytoplasm and nucleus of cells into biomolecular condensates —similar in importance to compartmentalisation via lipid bilayer membranes ,

826-877: A type of liquid crystal . The term biomolecular condensate has been used to refer to clusters of macromolecules that arise via liquid-liquid or liquid-solid phase separation within cells. Macromolecular crowding strongly enhances colloidal phase separation and formation of biomolecular condensates . Colloidal particles can also serve as transport vector of diverse contaminants in the surface water (sea water, lakes, rivers, fresh water bodies) and in underground water circulating in fissured rocks (e.g. limestone , sandstone , granite ). Radionuclides and heavy metals easily sorb onto colloids suspended in water. Various types of colloids are recognised: inorganic colloids (e.g. clay particles, silicates, iron oxy-hydroxides ), organic colloids ( humic and fulvic substances). When heavy metals or radionuclides form their own pure colloids,

885-488: A wavelength of 610 nanometers (or 560 nm for tinctorial power). In this case, A stands for absorbance and TS stands for total solids . The color tone of the caramel color is also important. This is defined by the Linner Hue Index , which is the measure of the color hue or red characteristics of the caramel color. It is a function of the absorbance of light of wavelengths 510 and 610 nm. In general,

944-481: Is defined by particles remaining suspended in solution and depends on the interaction forces between the particles. These include electrostatic interactions and van der Waals forces , because they both contribute to the overall free energy of the system. A colloid is stable if the interaction energy due to attractive forces between the colloidal particles is less than kT , where k is the Boltzmann constant and T

1003-489: Is directly proportional to the average particle size and volume fraction of the dispersed phase. Therefore, local changes in concentration caused by sedimentation or creaming, and clumping together of particles caused by aggregation, are detected and monitored. These phenomena are associated with unstable colloids. Dynamic light scattering can be used to detect the size of a colloidal particle by measuring how fast they diffuse. This method involves directing laser light towards

1062-544: Is found in many commercially made foods and beverages, including batters , beer , brown bread, buns, chocolate, cookies, cough drops, spirits and liquor such as brandy , rum , and whisky , chocolate-flavored confectionery and coatings, custards , decorations, fillings and toppings, potato chips , dessert mixes, doughnuts, fish and shellfish spreads, frozen desserts, fruit preserves , glucose tablets, gravy, ice cream , pickles , sauces and dressings, soft drinks (especially colas ), sweets, vinegar , and more. Caramel color

1121-648: Is the absolute temperature . If this is the case, then the colloidal particles will repel or only weakly attract each other, and the substance will remain a suspension. If the interaction energy is greater than kT, the attractive forces will prevail, and the colloidal particles will begin to clump together. This process is referred to generally as aggregation , but is also referred to as flocculation , coagulation or precipitation . While these terms are often used interchangeably, for some definitions they have slightly different meanings. For example, coagulation can be used to describe irreversible, permanent aggregation where

1180-542: Is the alteration of materials by light. Commonly, the term is used loosely to refer to the combined action of sunlight and air , which cause oxidation and hydrolysis . Often photodegradation is intentionally avoided, since it destroys paintings and other artifacts. It is, however, partly responsible for remineralization of biomass and is used intentionally in some disinfection technologies. Photodegradation does not apply to how materials may be aged or degraded via infrared light or heat, but does include degradation in all of

1239-421: Is the sedimentation or creaming velocity. The mass of the colloidal particle is found using: where and ρ 1 − ρ 2 {\displaystyle \rho _{1}-\rho _{2}} is the difference in mass density between the colloidal particle and the suspension medium. By rearranging, the sedimentation or creaming velocity is: There is an upper size-limit for

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1298-956: Is used to control colloid suspensions. A colloidal crystal is a highly ordered array of particles that can be formed over a very long range (typically on the order of a few millimeters to one centimeter) and that appear analogous to their atomic or molecular counterparts. One of the finest natural examples of this ordering phenomenon can be found in precious opal , in which brilliant regions of pure spectral color result from close-packed domains of amorphous colloidal spheres of silicon dioxide (or silica , SiO 2 ). These spherical particles precipitate in highly siliceous pools in Australia and elsewhere, and form these highly ordered arrays after years of sedimentation and compression under hydrostatic and gravitational forces. The periodic arrays of submicrometre spherical particles provide similar arrays of interstitial voids , which act as

1357-548: Is widely approved for use in food globally but application and use level restrictions vary by country. Caramel color is manufactured by heating carbohydrates, either alone or in the presence of acids, alkalis, and/or salts. Caramel color is produced from commercially available nutritive sweeteners consisting of fructose , dextrose (glucose), invert sugar , sucrose , malt syrup , molasses , starch hydrolysates , and fractions thereof. The acids that may be used are sulfuric , sulfurous , phosphoric , acetic , and citric acids;

1416-679: The ultraviolet light wavebands. The protection of food from photodegradation is very important. Some nutrients, for example, are affected by degradation when exposed to sunlight. In the case of beer , UV radiation causes a process that entails the degradation of hop bitter compounds to 3-methyl-2-buten-1-thiol and therefore changes the taste. As amber-colored glass has the ability to absorb UV radiation, beer bottles are often made from such glass to prevent this process. Paints, inks, and dyes that are organic are more susceptible to photodegradation than those that are not. Ceramics are almost universally colored with non-organic origin materials so as to allow

1475-457: The alkalis are ammonium , sodium , potassium , and calcium hydroxides; and the salts are ammonium , sodium , and potassium carbonate , bicarbonate , phosphate (including mono- and dibasic), sulfate , and bisulfite . Antifoaming agents , such as polyglycerol esters of fatty acids, may be used as processing aids during manufacture. Its color ranges from pale yellow to amber to dark brown. Caramel color molecules carry either positive or

1534-453: The atmosphere, the organic compounds are degraded by hydroxyl radicals , which are produced from water and ozone. Photochemical reactions are initiated by the absorption of a photon, typically in the wavelength range 290–700 nm (at the surface of the Earth). The energy of an absorbed photon is transferred to electrons in the molecule and briefly changes their configuration (i.e., promotes

1593-417: The case of non-ionic surfactants or more generally interactions forces inside the system. Storing a dispersion at high temperatures enables to simulate real life conditions for a product (e.g. tube of sunscreen cream in a car in the summer), but also to accelerate destabilisation processes up to 200 times. Mechanical acceleration including vibration, centrifugation and agitation are sometimes used. They subject

1652-630: The category of chemicals "known to the state to cause cancer or reproductive toxicity". According to the Food Chemicals Codex , 4-MeI in caramel color is allowed up to 250 ppm on a color-adjusted basis, which means 250 ppm maximum for every 0.100 color absorbance of a 0.10% solution at 610 nm. The exposure to 4-MeI at levels present in Class III and IV caramel colors are not expected to be of concern for two reasons. Firstly, 4-MeI does not appear to be genotoxic or metabolized to

1711-418: The centres of attack. Ultraviolet rays interact with these bonds to form free radicals , which then react further with oxygen in the atmosphere, producing carbonyl groups in the main chain. The exposed surfaces of products may then discolour and crack, and in extreme cases, complete product disintegration can occur. In fibre products like rope used in outdoor applications, product life will be low because

1770-446: The chemical conditions of the soil sample, i.e. soil pH . Colloid solutions used in intravenous therapy belong to a major group of volume expanders , and can be used for intravenous fluid replacement . Colloids preserve a high colloid osmotic pressure in the blood, and therefore, they should theoretically preferentially increase the intravascular volume , whereas other types of volume expanders called crystalloids also increase

1829-626: The control of rheology and the physical modification of form and texture. Some hydrocolloids like starch and casein are useful foods as well as rheology modifiers, others have limited nutritive value, usually providing a source of fiber. The term hydrocolloids also refers to a type of dressing designed to lock moisture in the skin and help the natural healing process of skin to reduce scarring, itching and soreness. Hydrocolloids contain some type of gel-forming agent, such as sodium carboxymethylcellulose (NaCMC) and gelatin. They are normally combined with some type of sealant, i.e. polyurethane to 'stick' to

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1888-413: The diameter of colloidal particles because particles larger than 1 μm tend to sediment, and thus the substance would no longer be considered a colloidal suspension. The colloidal particles are said to be in sedimentation equilibrium if the rate of sedimentation is equal to the rate of movement from Brownian motion. There are two principal ways to prepare colloids: The stability of a colloidal system

1947-586: The flavoring components in bottled beverages. Internationally, JECFA has set the Acceptable Daily Intake (ADI) of Class I caramel color as "not specified"; that of Class II as 0–160 mg/kg body weight; and that of Class III and IV as 0–200 mg/kg body weight. The United States Food and Drug Administration (FDA) classifies and regulates caramel color in Title 21 CFR § 73.85 as an approved color additive exempt from certification. Unless

2006-400: The forces holding the particles together are stronger than any external forces caused by stirring or mixing. Flocculation can be used to describe reversible aggregation involving weaker attractive forces, and the aggregate is usually called a floc . The term precipitation is normally reserved for describing a phase change from a colloid dispersion to a solid (precipitate) when it is subjected to

2065-513: The forces that govern the structure and behavior of matter, such as excluded volume interactions or electrostatic forces, govern the structure and behavior of colloidal suspensions. For example, the same techniques used to model ideal gases can be applied to model the behavior of a hard sphere colloidal suspension. Phase transitions in colloidal suspensions can be studied in real time using optical techniques, and are analogous to phase transitions in liquids. In many interesting cases optical fluidity

2124-630: The higher the Tinctorial Power, K 0.56 , the lower the Hue Index and the lower the red tones. Various other indices are in use around the world and there are conversion factors between them. Caramel color is a colloid . Though the primary function of caramel color is for coloration, it also serves additional functions. In soft drinks, it can function as an emulsifier to help inhibit the formation of certain types of " floc " and its light protective quality can aid in preventing oxidation of

2183-444: The individual particle diameter. In all of these cases in nature, the same brilliant iridescence (or play of colors) can be attributed to the diffraction and constructive interference of visible lightwaves that satisfy Bragg’s law , in a matter analogous to the scattering of X-rays in crystalline solids. The large number of experiments exploring the physics and chemistry of these so-called "colloidal crystals" has emerged as

2242-455: The material to resist photodegradation even under the most relentless conditions, maintaining its color. The photodegradation of pesticides is of great interest because of the scale of agriculture and the intensive use of chemicals. Pesticides are however selected in part not to photodegrade readily in sunlight in order to allow them to exert their biocidal activity. Thus, more modalities are implemented to enhance their photodegradation, including

2301-486: The medium of suspension, they will sediment (fall to the bottom), or if they are less dense, they will cream (float to the top). Larger particles also have a greater tendency to sediment because they have smaller Brownian motion to counteract this movement. The sedimentation or creaming velocity is found by equating the Stokes drag force with the gravitational force : where and v {\displaystyle v}

2360-527: The molecule from a ground state to an excited state ). The excited state represents what is essentially a new molecule. Often excited state molecules are not kinetically stable in the presence of O 2 or H 2 O and can spontaneously decompose ( oxidize or hydrolyze ). Sometimes molecules decompose to produce high energy, unstable fragments that can react with other molecules around them. The two processes are collectively referred to as direct photolysis or indirect photolysis , and both mechanisms contribute to

2419-484: The outer fibres will be attacked first, and will easily be damaged by abrasion for example. Discolouration of the rope may also occur, thus giving an early warning of the problem. Polymers which possess UV-absorbing groups such as aromatic rings may also be sensitive to UV degradation. Aramid fibres like Kevlar , for example, are highly UV-sensitive and must be protected from the deleterious effects of sunlight. Many organic chemicals are thermodynamically unstable in

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2478-463: The particles must be dispersed in a liquid , while others extend the definition to include substances like aerosols and gels . The term colloidal suspension refers unambiguously to the overall mixture (although a narrower sense of the word suspension is distinguished from colloids by larger particle size). A colloid has a dispersed phase (the suspended particles) and a continuous phase (the medium of suspension). The dispersed phase particles have

2537-429: The photon and convert it to heat. Typical UV-absorbers are hydroxy-substituted benzophenones , related to the chemicals used in sunscreen . Restoration of yellowed plastic of old toys is nicknamed retrobright . Colloid A colloid is a mixture in which one substance consisting of microscopically dispersed insoluble particles is suspended throughout another substance. Some definitions specify that

2596-431: The presence of oxygen; however, their rate of spontaneous oxidation is slow at room temperature. In the language of physical chemistry, such reactions are kinetically limited. This kinetic stability allows the accumulation of complex environmental structures in the environment. Upon the absorption of light, triplet oxygen converts to singlet oxygen , a highly reactive form of the gas, which effects spin-allowed oxidations. In

2655-532: The primary packaging material the photodegradation of pharmaceuticals has to be prevented. For this, amber glasses like Fiolax amber and Corning 51-L are commonly used to protect the pharmaceutical from UV radiations. Iodine (in the form of Lugol's solution ) and colloidal silver are universally used in packaging that lets through very little UV light so as to avoid degradation. Common synthetic polymers that can be attacked include polypropylene and LDPE , where tertiary carbon bonds in their chain structures are

2714-673: The principal way to produce colloids stable to both aggregation and sedimentation. The method consists in adding to the colloidal suspension a polymer able to form a gel network. Particle settling is hindered by the stiffness of the polymeric matrix where particles are trapped, and the long polymeric chains can provide a steric or electrosteric stabilization to dispersed particles. Examples of such substances are xanthan and guar gum . Destabilization can be accomplished by different methods: Unstable colloidal suspensions of low-volume fraction form clustered liquid suspensions, wherein individual clusters of particles sediment if they are more dense than

2773-416: The process of ultrafiltration occurring in dense clay membrane. The question is less clear for small organic colloids often mixed in porewater with truly dissolved organic molecules. In soil science , the colloidal fraction in soils consists of tiny clay and humus particles that are less than 1μm in diameter and carry either positive and/or negative electrostatic charges that vary depending on

2832-536: The product to different forces that pushes the particles / droplets against one another, hence helping in the film drainage. Some emulsions would never coalesce in normal gravity, while they do under artificial gravity. Segregation of different populations of particles have been highlighted when using centrifugation and vibration. In physics , colloids are an interesting model system for atoms . Micrometre-scale colloidal particles are large enough to be observed by optical techniques such as confocal microscopy . Many of

2891-422: The reactants used in their manufacture, each with its own INS and E number , listed in the table below. Each class consists of a variety of caramels with their own unique properties that make it suitable for use in specific foods and/or beverages. Color intensity (or, tinctorial power) is defined as the absorbance of a 1 mg/mL (0.1% weight/volume) solution in water, measured using a 1 cm light path at

2950-460: The removal of pollutants. The United States federal standard for testing plastic for photodegradation is 40 CFR Ch. I (7–1–03 Edition) PART 238. Photodegradation of plastics and other materials can be inhibited with polymer stabilizers , which are widely used. These additives include antioxidants , which interrupt degradation processes. Typical antioxidants are derivatives of aniline . Another type of additive are UV-absorbers. These agents capture

3009-470: The skin. A colloid has a dispersed phase and a continuous phase, whereas in a solution , the solute and solvent constitute only one phase. A solute in a solution are individual molecules or ions , whereas colloidal particles are bigger. For example, in a solution of salt in water, the sodium chloride (NaCl) crystal dissolves, and the Na and Cl ions are surrounded by water molecules.  However, in

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3068-471: The soluble forms some of the hydrocolloids have additional useful functionality in a dry form if after solubilization they have the water removed - as in the formation of films for breath strips or sausage casings or indeed, wound dressing fibers, some being more compatible with skin than others. There are many different types of hydrocolloids each with differences in structure function and utility that generally are best suited to particular application areas in

3127-435: The source for the caramel coloring before consuming the food. Caramel color produced from corn or cane-based materials would be unlikely to contain gluten due to the lack of gliadin in the carbohydrates. North American and European manufacturers mostly use glucose derived from corn or wheat to produce caramel color, which is highly processed and is generally considered gluten-free . Light degradation Photodegradation

3186-401: The suspension medium, or cream if they are less dense. However, colloidal suspensions of higher-volume fraction form colloidal gels with viscoelastic properties. Viscoelastic colloidal gels, such as bentonite and toothpaste , flow like liquids under shear, but maintain their shape when shear is removed. It is for this reason that toothpaste can be squeezed from a toothpaste tube, but stays on

3245-401: The term colloid in 1861. Colloid : Short synonym for colloidal system. Colloidal : State of subdivision such that the molecules or polymolecular particles dispersed in a medium have at least one dimension between approximately 1 nm and 1 μm, or that in a system discontinuities are found at distances of that order. Colloids can be classified as follows: Homogeneous mixtures with

3304-480: The term " eigencolloid " is used to designate pure phases, i.e., pure Tc(OH) 4 , U(OH) 4 , or Am(OH) 3 . Colloids have been suspected for the long-range transport of plutonium on the Nevada Nuclear Test Site . They have been the subject of detailed studies for many years. However, the mobility of inorganic colloids is very low in compacted bentonites and in deep clay formations because of

3363-436: The toothbrush after it is applied. The most widely used technique to monitor the dispersion state of a product, and to identify and quantify destabilization phenomena, is multiple light scattering coupled with vertical scanning. This method, known as turbidimetry , is based on measuring the fraction of light that, after being sent through the sample, it backscattered by the colloidal particles. The backscattering intensity

3422-559: The typical size range for colloidal particles. The kinetic process of destabilisation can be rather long (up to several months or years for some products). Thus, it is often required for the formulator to use further accelerating methods to reach reasonable development time for new product design. Thermal methods are the most commonly used and consist of increasing temperature to accelerate destabilisation (below critical temperatures of phase inversion or chemical degradation). Temperature affects not only viscosity, but also interfacial tension in

3481-427: The use of photosensitizers, photocatalysts (e.g., titanium dioxide ), and the addition of reagents such as hydrogen peroxide that would generate hydroxyl radicals that would attack the pesticides. The photodegradation of pharmaceuticals is of interest because they are found in many water supplies. They have deleterious effects on aquatic organisms including toxicity, endocrine disruption, genetic damage. But also in

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