Definition of an additive

Additives may be classified into nine categories according to function acidification, antimicrobial, antioxidant, clarification, deacidification, fermentation, preservation, stabilisation and sweetening (Tables 9.1-9.3). 

This chapter is also restricted to those additives deemed contentious by certain health departments and/or the public. These are sulphur dioxide (SO2), sorbate, dimethyldicarbonate (DMDC), ascorbic acid, erythorbic acid, and nisin. These additives are either antimicrobial and/or antioxidant in action, and probably represent the two most problematic areas in winemaking and brewing. In addition, as the use of sulphur dioxide in winemaking is under review and is the most contentious of the additives, a greater proportion of this chapter is devoted to minimising and/or optimising its usage. 

Acidification Tartaric acid Citric acid Lactic acid Malic acid 700 

Deacidification Calcium carbonate Calcium phosphate Potassium bicarbonate Potassium carbonate Potassium tartrate Sodium bicarbonate Sodium carbonate 5000 

Fermentation Ammonium sulphate Bacteria (MLF starter culture) 300 

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However, this Formal Graph can be simplified by removing the poles in the chemical reaction energy variety and by connecting directly the physical chemical poles to the multipole, as shown in Graph 12.9. Such a simplification corresponds to the definition of an additive equivalence, which extends the notion of equivalence by allowing several contributions to a more complex Formal Object. 

It is useful at this point to consider the definition of an additive as given by the EC (European Commission) an additive is a substance, which is incorporated into plastics to achieve a technical effect in the finished product, and is intended to be an essential part of the finished product. Since the very early stages of the development of the polymer industry, it was realized that useful materials could only be obtained if certain additives were incorporated into the polymer matrix, in a process normally known as compounding. Additives confer on plastics significant extensions of properties in one or more directions, such as general durability, stiffness and strength, impact resistance, thermal resistance, resistance to flexure and wear, acoustic isolation, etc [86]. 

Consider, for example, the data in Table 4.1 for the mass of a penny. Reporting only the mean is insufficient because it fails to indicate the uncertainty in measuring a penny s mass. Including the standard deviation, or other measure of spread, provides the necessary information about the uncertainty in measuring mass. Nevertheless, the central tendency and spread together do not provide a definitive statement about a penny s true mass. If you are not convinced that this is true, ask yourself how obtaining the mass of an additional penny will change the mean and standard deviation. 

Thickness. The traditional definition of thermal conductivity as an intrinsic property of a material where conduction is the only mode of heat transmission is not appHcable to low density materials. Although radiation between parallel surfaces is independent of distance, the measurement of X where radiation is significant requires the introduction of an additional variable, thickness. The thickness effect is observed in materials of low density at ambient temperatures and in materials of higher density at elevated temperatures. It depends on the radiation permeance of the materials, which in turn is influenced by the absorption coefficient and the density. For a cellular plastic material having a density on the order of 10 kg/m, the difference between a 25 and 100 mm thick specimen ranges from 12—15%. This reduces to less than 4% for a density of 48 kg/m. References 23—27 discuss the issue of thickness in more detail. 

Exceptions to the simple definition of an essential oil are, for example, gadic oil, onion oil, mustard oil, or sweet birch oils, each of which requires enzymatic release of the volatile components before steam distillation. In addition, the physical process of expression, appHed mostly to citms fmits such as orange, lemon, and lime, yields oils that contain from 2—15% nonvolatile material. Some flowers or resinoids obtained by solvent extraction often contain only a small portion of volatile oil, but nevertheless are called essential oils. Several oils are dry-distiUed and also contain a limited amount of volatiles nonetheless they also are labeled essential oils, eg, labdanum oil and balsam oil Pern. The yield of essential oils from plants varies widely. Eor example, nutmegs yield 10—12 wt % of oil, whereas onions yield less than 0.1% after enzymatic development. 

In contrast, the AIM theory provides a clear definition of an atom in a molecule as a space-filling object, from which all its properties can be obtained. The properties of these atoms are additive to give the corresponding molecular property. 

Crystals Obtained by Acid Addition. Figure 4 shows the effect of initial solution composition on the impurity content of crystals obtained by acid addition. Clearly, this corresponds to the definition of an ideal system as presented above. These data show the order followed in impurity incorporation in the L-Ile crystals is L-Val > L-Leu > L-a-ABA, although there is only one data point on a-amino butyric acid. Also, the value of purification factors for all impurities is less than one. This means that purification by crystallization was indeed occurring. 

The use of microcapsules in food is generally that of an additive. By regulatory definition, a food additive is any substance which becomes added to food either intentionally or unintentionally other than food itself. This includes both compounds added directly and those that are added indirectly such as migrating from packaging materials. We will limit our discussion here to direct, intentional additives. This means, for example, that the Vitamin C in orange juice is not an additive but the Vitamin C added to orange juice is. 

Exceptions to the simple definition of an essential oil are, for example, garlic oil, onion oil, mustard oil, or sweet birch oils, each of which requires enzymatic release of the volatile components before steam distillation. In addition, rhe physical process of expression, applied mostly to citrus fruits such as orange, lemon, and lime, yields oils that contain from 2-15% nonvolatile material. 

The mechanism of the Chichibabin amination of pyridine has been discussed in terms of an addition-elimination mechanism via a covalent a-adduct.38 39 The possible formation of 2,3-didehydropyridine (2,3-pyridyne) as intermediate in the Chichibabin amination has been advocated, but this is now definitely rejected.38 39 In this section we discuss the Chichibabin amination of the parent naphthyridines and their derivatives and the products that are obtained in these aminations. The formation of their precursors (the covalent n-adducts) has already been discussed in Section II,A and II,B. 

Emulsions are colloidal dispersions of liquid droplets in another liquid phase, sometimes stabilized by surface active agents. Emulsions thus consist of a discontinuous phase, dispersed in a continuous phase. The most common types of emulsions are water-in-oil (W/O) in which oil is the continuous phase, and oil-in-water (OAV) in which water forms the continuous phase. However, this traditional definition of an emulsion is too narrow to include most food emulsions. For example, in foods the dispersed phase may be partially solidified, as in dairy products or the continuous phase may contain crystalline material, as in ice cream. It may also be a gel, as in several desserts. In addition to this, air bubbles may have been incorporated to produce the desired texture. 

The concise scientific definition of an aerosol refers specifically to a colloidal state of material suspended in a gas. However, the term has acquired an additional meaning in common household usage. In the commercial packaging field, the term aerosol now is synonymous with pressurized products that are released in a dispersed form from a can or a bottle. The discharge ranges from coarse fogs and mists to finely divided liquid or powder dispersions. 

The factors 2 and 4 in the denominators are due to the definition of the field amplitudes (Eq.(14) and Eq.(15)). In order to prevent these factors some authors drop the factor 1/2 in the definitions of the amplitudes. The disadvantage of this convention is the unusual convergence behaviour of the electric field as the frequency to approaches zero. This different field definition of course additionally complicates the comparison of different hyperpolarizability values. The factors in the numerator arise from the different possibilities to permute the input frequencies. As an example, in self-phase modulation the three input electric fields each provide a factor 1/2 which, with the factor 1/2 from the polarization, results in a denominator of 4. The negative frequency for SPM allows three permutations yielding finally a prefactor of 3/4. 

Toxicology is the science of poisons but what is a poison The word poison conjures up many different ideas in people s minds and is often associated with the word chemical . Consulting various dictionaries, I found several definitions which were basically similar A substance that when introduced into or absorbed by Hving organisms causes death or injury—especially one that kills by rapid action even in small quantities . Another definition had an additional concept Any substance which taken into or formed in the body which destroys life or impairs health . Both definitions tell us that a poison is a substance that is hazardous to life, possibly lethaUy so. The first indicates that a poison is also likely to be potent and the second that it might be naturally produced. 

Solubilization can be defined as the preparation of a thermodynamically stable isotropic solution of a substance normally insoluble or very slightly soluble in a given solvent by the introduction of an additional amphiphilic component or components. The amphiphilic components (surfactants) must be introduced at a concentration at or above their critical micelle concentrations. Simple micellar systems (and reverse micellar) as well as liquid crystalline phases and vesicles referred to above are all capable of solubilization. In liquid crystalline phases and vesicles, a ternary system is formed on incorporation of the solubilizate and thus these anisotropic systems are not strictly in accordance with the definition given above. 

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