Purity criteria

The vertex of a separation region points out the better operating conditions, since it is the point where the purity criteria are fulfilled with a higher feed flow rate (and so lower eluent flow rate). Hence, in the operating conditions specified by the vertex point, both solvent consumption and adsorbent productivity are optimized. Comparing the vertex points obtained for the two values of mass transfer coefficient, we conclude that the mass transfer resistance influences the better SMB operating conditions. Moreover, this influence is emphasized when a higher purity requirement is desired [28]. 

There are a whole variety of types of fuel cell, named after the electrolyte used, each operating at a preferred temperature range with its own feedstock purity criteria (Table 6.3). 

Food coloring is restricted by law to prevent misuse that may lead to deception of consumers related to reduced value or usability. For this purpose, the European Union implemented food colorant guidelines in 1994 based on the understanding that food coloration presents a technological need. While European Parliament and Council Directive 94/36/EC lists colors and their uses in food, the European Commission Directive 95/45/EC contains specific purity criteria for colors in foodstuffs, e.g., a maximal lead content of 20 ppm. " ... 

Cochineal, carminic acid, and carmines are approved as food colorants in the EU under code E 120, and their purity criteria are regulated.The amount of E 120 permitted in food ranges from 50 to 500 mg/kg. Carminic acid and carmine are considered very good food colorants due to their high stability and tinctorial properties. Solutions of carminic acid are yellow to orange, while carmines show various stable brilliant red hues. - ... 

According to EU purity criteria, color intensity is defined as the absorbance of a 0.1% (w/v) solution of caramel color solids in water in a 1 cm cell at 610 nm. The color intensity must be 0.01 to 0.12 for class I (E 150a), 0.05 to 0.13 for class II (E 150b), 0.08 to 0.36 for class III (E 150c), and 0.10 to 0.60 for class IV (E 150d). Ammonia caramels show the highest tinctorial power and are most commonly used as food colorants. Class I has the weakest coloring properties and is mostly used as flavor. 

Commission directive 95/45/EC of 26 July 1995, layiug dowu specific purity criteria concerning colours for use in foodstuffs, Ojf. J. Eur. Communities, L226, 22.09,1995. 

Sodium copper chlorophyllin, approved by the FDA as a color additive in citrus-based dry beverage mixes, should have a ratio of absorbance (SoretQ band) not less than 3.4 and not more than 3.9. In Europe, purity criteria of the food additives E141[i] and E141[ii], which are copper complexes of chlorophyll and chlorophyllin, respectively, are set out in the EC color specifications that include identification and spectrophotometric assay tests. ... 

In the EU, the use of color additives in food was settled by two directives 94/36/EC, which establishes the list of permitted colors, and 95/45/EC, which deals with purity criteria for colors. Directive 94/36/EC also contains five annexes ... 

Commission Directive 95/45/EC, July 26, 1995, laying down specific purity criteria concerning colors for use in foodstuffs. Off. J. Eur. Commun., L226, 22.09.1995. U.S. Food Drug Administration, Summary of color additives listed for use in the United States in food, drugs, cosmetics and medical devices, Washington, D.C., 1999. JECFA, online edition. Combined compendium of food additive specifications, http //WWW. fao. org. 

In the case of an excipient that contains a mixture of constituents, qualitative and quantitative details of the composition should be provided (other than for flavoring or aromatic products, which must state the information only qualitatively provided there is a suitable method for ensuring consistency of composition and of the presence of the main ingredients and any carriers, with relevant references to purity criteria such as those established by the World Health Organization Food and Agriculture Organization). 

Fig. 9-14. Influence of the mass transfer resistance on the separation region yin-yn plot for a 99 % purity criteria.

Regarding colorants no uniform EU regulation exists so far concerning the coloration of food packing. The European Resolution AP (89)1 [10] aims at an harmonized EU regulation. The required purity criteria for colorants to be used for the coloration of food packing materials made from plastics are ... 

Lebensmittel- und Bedarfsgegenstandegesetz der Bundesrepublik Deutschland (1974), 30 (Purity Criteria), 31 (Migration). 

Commission Working Document SANCO/1796/2000 amending purity criteria Directives for colours, miscellaneous food additives and sweeteners (i.e. evaluation of additives and flavourings from GM sources)... 

Commission Directive 95/45/EC laying down specific purity criteria for colours... 

The Council and the Commission must adopt positive fists of additives, authorised to the exclusion of all others, fists of foods in which the additives may be used with conditions of use, and rules on carrier solvents. The Standing Committee on Foodstuffs must approve adoption of purity criteria for listed additives and, if necessary, methods of analysis to verily these purity criteria, sampling procedures and methods of analysis for food additives in food. The directive includes provisions that a member state may temporarily suspend or restrict application of an authorisation if it has detailed grounds for considering that the use of the additive in food, although permitted, endangers health. The... 

As required by Directive 89/107/EEC, criteria of purity have been drawn up for all the listed food additives (with a couple of exceptions). Purity criteria for all the permitted sweeteners have been prescribed in Directive 95/31/EC,6 as amended, and criteria for all the permitted colours are contained in Directive 95/ 45/EC,7 as amended. Directives that prescribe purity criteria for all the additives authorised under Directive 95/2/EC have been drawn up in stages. Directive 96/ 77/EC8 containing purity criteria for antioxidants and preservatives is amended by Directives 98/86/EC which lays down purity criteria for emulsifiers, stabilisers and thickeners and 2000/63/EC which contains purity criteria for most additives numbered E 500 and above, and for certain other additives not covered in the earlier directives. Purity criteria for most of the few remaining permitted miscellaneous additives are contained in Directive 2001/30/EC however, purity criteria for E 1201 polyvinylpyrrolidone and E 1202 polyvinylpolypyrrolidone are still being considered by the Scientific Committee on Food. Some methods of analysis for verifying prescribed purity criteria have been developed at EU level these are contained in Directive 81/712/EEC.9... 

Commission Directive 96/77/EC of 2 December 1996 laying down specific purity criteria on food additives other than colours and sweeteners Official Journal of the European Communities (L339) of 30 December 1996, pp. 1-69), as amended by Directives 98/86/EC of 11 November... 

Only sweeteners conforming to certain purity criteria are permitted for use in foods. Such purity specifications are normally based on the specifications of the substance used in safety evaluations as byproducts and impurities may affect the toxicological profile of a substance. 

Purity criteria are published by JECFA as well as by national authorities. The JECFA specifications33 may be endorsed by the Codex Alimentarius as advisory specifications which means that they are equivalent to a Codex Alimentarius standard. In the EU a directive laying down special criteria of purity for sweeteners for use in foodstuffs with subsequent amendments sets the purity standards,31 while in the USA criteria may be listed in conjunction with the approval. Normally a monograph of the Food Chemicals Codex34 is considered the applicable basis for assessment of purity. 

Commission Directive No. 95/31/EC laying down special purity criteria concerning sweeteners for use in foodstuffs, Official Journal of the European Communities 1995 L178 1-19 with subsequent amendments. 

In the latter Directive, except for antioxidants and preservatives, individual uses are not listed in either the basic Directive or in the Directives on purity criteria (specifications). In the EU, the functional use of the main additives permitted for use in processed foods are described in Directive 89/107/EC. There are 23 listed which are shown in Table 11.1. In this chapter we are concerned with 17 categories listed in the Directive 95/2/EC on food additives other than colours and sweeteners (these are indicated by an asterisk in Table 11.1). 

Directive = The number of the relevant EU Directive on purity criteria (specification) for the additive listed. 

Purity Criteria. Purity of lignin peroxidase was analyzed with analytical anion exchange chromatography using detection at 405 nm. About 4 U of lignin peroxidase was applied to a Pharmacia Mono Q column (HR 5/5,0.25 x 5.0 cm) and eluted with linear sodium acetate, pH 6.0, gradient (0.01 to 0.55 M, 1 ml/min, 14 min). 

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