Constituents of food additives

Another important aspect of the safety assessment is the evaluation of constituents of food additives, which include impurities and byproducts, as well as the low molecular weight oligomeric fraction of polymeric substances. For example, the safety evaluation for every FCN encompasses all components that would be expected to migrate to food, including the FCS, the food additive, and constituents of the food additive. This assessment is complex and the lack of proper evaluation and supporting documentation on all substances is the most common deficiency. 

Carcinogenicity risk assessment for constituents of food additives... 

Structure activity relationship (SAR) analysis in the safety assessment of constituents of food additives... 

The work will review the literature on the reactions of food additive and food constituents and with other additives in foods. The literature data will be used as a training tool and it is intended that this research will help inform and guide the setting of priorities on which additives may merit experimental attention in the future. 

Special attention was paid to the potential influence on phenylketonurics (PKU), as aspartame contains phenylalanine. As persons suffering from PKU should avoid uncontrolled intake of phenylalanine-containing food constituents or food additives, most countries require a warning on aspartame-sweetened products unless the aspartame level brought about by constituents of these products will exceed the aspartame levels.1314 Evaluations of aspartame were carried out by JECFA, and an ADI of 0-40mg/kg of body weight was allocated.15 The SCF allocated the same level,10 whereas the FDA published a value of 50 mg/kg.16... 

The influence of diet on drug metabolism, disposition, and toxicity consists of many constituent factors. Food additives and naturally occurring contaminants in food may influence the activities of various enzymes by induction or inhibition. However, these factors are discussed in a later section Enzyme induction and Inhibition. The factors with which this section will be concerned are the nutritional aspects of diet. 

Until very recently the risks associated with different types of chemicals such as food additives, pesticides, environmental contaminants and natural constituents of food were assessed and managed separately. However, a particular substance might fall into two or more of these categories and so the opportunity for simultaneous exposure might be overlooked. Furthermore, exposure to a chemical could occur through diet, drinking water, air pollution or dermal absorption. Aggregate exposure assessment aims to take all of the possible sources and routes of exposure into account in a realistic manner and thereby obtain a better overall estimate of risk. Initiatives have been set up in both the... 

At present there is insufficient reliable scientific data on the adverse effects of food additives in humans but there is much public concern and many anecdotal reports of problems relating to food additives, particularly allergic reactions. The extent of intolerance to food additives in the population at large is, however, only around 3 in 10,000 or, to be more precise, 0.026 per cent). Most of the data available refers to patients who have symptoms such as skin rashes (urticaria). Some of the studies carried out have, however, highlighted certain effects and the same food additives appear to feature in the reports tartrazine and benzoic acid are the most common offenders, especially in relation to h5q>eractivity in children. There may also be cross-reactivity, where an additive causes an effect in a person who has been sensitized by another additive. This can occur between additives and naturally occurring food constituents, for... 

Potential concerns for a constituent of an additive raised by a qualitative SAR analysis may be addressable by a more in-depth, quantitative SAR (QS AR) analysis. The approach to QSAR used in the food contact notification program is to identify the most appropriate specific structural analogs from the pool of chemicals for which adequate carcinogenicity data are available. If, in the expert judgment of FDA reviewers, the analogs can reasonably be considered to be as toxic or more toxic than the compound of concern, these analogs can be used to develop a quantitative estimate of its upper bound LCR. 

Capable of transferring constituents of the additive into food substances. 

Organic acids are typical products of microbial metabolism. All organic acids occur naturally in a variety of vegetable and animal substrates and can, therefore, be either naturally present as constituents of foods as a result of normal biochemical metabolic processes, direct addition as acid-ulants, hydrolysis, or bacterial growth, or can later be added directly or indirectly to the products (Gomis, 1992). 

The other primary statutory provisions that the FDA relies upon in determining the safety of food and food constituents are sections 201 (s) and 409, the food additive provisions of the FD C Act. The definition of food additive appears in section 201 (s) of the FD C Act and includes both artificial and natural substances. The definition provides that ... 

Commonly used drugs, dietary constituents and food additives may be electroactive and consequently are potential sources of interference when biological samples are analysed. Quinine may originate from tonic water, for example, caffeine from coffee and cafifeinated soft drinks and some proprietary stimulants, nicotine and cotinine from tobacco smoke, chloroquine and related compounds from malaria prophylaxis, and pholcodine and other opiate analogues from cold cures. Many such compounds and their metabolites will show an EC response at carbon electrodes under appropriate conditions and can be sources of confusion if unrecognised. 

Inhibitors are found among food constituents. Proteins which specifically inhibit the activity of certain peptidases (cf. 16.2.3), amylases or 3-fructofuranosidase are examples. Furthermore, food contains substances which nonselectively inhibit a wide spectrum of enzymes. Phenolic constituents of food (cf. 18.1.2.5) and mustard oil (cf. 17.1.2.6.5) belong to this group. In addition, food might be contaminated with pesticides, heavy metal ions and other chemicals from a polluted environment (cf. Chapter 9) which can become inhibitors under some circumstances. These possibilities should be taken into account when enzymatic food analysis is performed. 

Thiols are important constituents of food aroma because of their intensive odor and their occurrence as intermediary products which can react with other volatiles by addition to carbonyl groups or to double bonds. 

Compounds which are found only in particular foods are discussed where they play a distinctive role while food additives and contaminants are treated in their own chapters. The physical and chemical properties of the important constituents of foods are discussed in detail where these form the basis for understanding either the reactions which occur, or can be expected to occur, during the production, processing, storage and handling of foods or the methods used in analyzing them. An attempt has also been made to clarify the relationship between the structure and properties at the level of individual food constituents and at the level of the whole food system. 

The purpose of this article is (a) to describe briefly some of the prokaryotic and eukaryotic systems in current use (b) to indicate where and how such systems have been used to determine biological properties of food additives and food constituents (c) to indicate how such systems can also be used in conjunction with food processing research and development and (d) to speculate on possible research problems for the future. 

The three most important constituents of FYM are nitrogen, phosphate and potash. Additionally, there are the bulky organic parts derived mainly from the straw and the part of the food that has resisted digestion. Granstedt (2002) showed that the majority of the N (about 90%) in farmyard manure served to maintain the soil humus store and the long term capacity to supply nutrients. 

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