重要事实
- 食品添加剂是添加到食物中以保持或提高其安全性、新鲜度、味道、质地或外观的物质。
- 使用食品添加剂之前需要检查其对人类健康的潜在有害影响。
- 粮农组织/世卫组织食品添加剂联合专家委员会是负责评价食品添加剂安全性的国际机构。
- 只有食品添加剂联合专家委员会根据食品法典委员会制定的最高使用限量，评估和认为安全的食品添加剂，可用于国际贸易的食品。
什么是食品添加剂？
添加到食物中以维持或提高食品的安全性、新鲜度、味道、质地或外观的物质被称为食品添加剂。有些食品添加剂已经使用了几百年，用来保存食物——如盐（用于培根等肉类或干鱼），糖（用于果酱）或二氧化硫（用于葡萄酒）。
随着时间推移，为满足食品生产的需要开发出许多不同的食品添加剂，因为大规模食品加工与小规模家庭制备食品非常不同。需要用添加剂来确保加工食品在从工厂或工业厨房，经运输送到仓库和商店并最终抵达消费者的整个过程中保持安全和良好状况。
食品添加剂的合理使用必须满足以下条件：有技术需要，不会误导消费者，并且发挥明确的技术功能，例如保持食品的营养质量或提高食品的稳定性等。
食品添加剂可以衍生自植物、动物或矿物质，也可以是合成的。它们被有意添加到食物中以发挥某些技术用途，消费者往往已将此视为理所当然。目前使用的食品添加剂有数千种，所有都旨在使食品更安全或更有吸引力。世卫组织与粮农组织一道根据食品添加剂的功能将其分为3大类。
调味剂
调味剂被添加到食品中以改善香味或味道，是食品中使用最多的添加剂。各种食品，从糖果和软饮料到谷物、蛋糕和酸奶中使用的调味品有数百种。天然调味剂包括坚果，水果和香料混合物以及来自蔬菜和葡萄酒的调味剂。另外还有模仿天然口味的调味品。
酶制剂
酶制剂是一种添加剂，可能会也可能不会出现在最终食品中。酶是天然存在的蛋白质，通过将较大的分子分解成较小的结构单元来促进生化反应。它们可以通过从植物或动物产品或细菌等微生物中提取而获得，并且用以替代基于化学的技术。它们主要用于烘焙（改善面团的效果），制造果汁（提高产量），制酒和酿造（更好地发酵）以及奶酪制造（改善凝乳的形成）。
其它添加剂
其它食品添加剂的使用有各种理由，如保存，着色和增加甜味。它们在制备，包装，运输或储存食品时被添加进去，并最终成为食品的一部分。
防腐剂可以减缓由霉菌、空气、细菌或酵母引起的分解。除了保持食品的质量外，防腐剂有助于控制可能导致食源性疾病的污染，包括危及生命的肉毒杆菌中毒。
在食品中添加着色剂是为了代替在制备过程中丢失的颜色，或使食物看起来更有吸引力。
通常将非糖甜味剂用作糖的替代品，因为将它们添加到食品中可使卡路里较少或根本没有。
世卫组织的应对
评价食品添加剂的健康风险
世卫组织与联合国粮食及农业组织（粮农组织）合作，负责评价食品添加剂对人类健康的危害。食品添加剂的风险评估由一个独立的国际专家科学小组，即粮农组织/世卫组织食品添加剂联合专家委员会进行。
只有经过食品添加剂联合专家委员会的安全性评估并且被认为不会给消费者带来明显健康风险的食品添加剂才能得到使用。这对无论是天然来源还是合成的食品添加剂都适用。根据食品添加剂联合专家委员会的评估或国家评估，国家当局可以准许在特定食品中按规定限量使用食品添加剂。
食品添加剂联合专家委员会的评估以对特定添加剂的所有现有生物化学、毒理学和其它相关数据的科学审查为依据——需要考虑对动物的强制性测试，科学研究以及对人类的观察。食品添加剂联合专家委员会要求进行的毒理学试验包括紧急、短期和长期研究，以确定食品添加剂被吸收、分配和排泄的方式，以及添加剂或其副产品在某些暴露水平下可能产生的有害影响。
要确定食品添加剂是否可以使用而不产生有害影响，首先要建立每日允许摄入量。每日允许摄入量是对可以在一生中每天安全消费，而不会对健康造成不良影响的食品或饮用水中添加剂含量的估计值。
安全使用食品添加剂的国际标准
食品添加剂联合专家委员会完成的安全性评估由粮农组织和世卫组织的联合政府间粮食标准制定机构，即食品法典委员会使用，以确定食品和饮料中添加剂的最大使用限量。法典标准是国家消费者保护标准和国际食品贸易标准的参照，这样世界各地的消费者才能确信，他们所吃的食物，不论产地都符合商定的安全和质量标准。
某种食品添加剂一旦被食品添加剂联合专家委员会确认为安全可用，并且在《食品添加剂通用法典标准》中确定了其最高使用限量后，则需要实施国家食品法规，允许实际使用这种食品添加剂。
如何能知道自己的食品中有哪些添加剂？
食品法典委员会还制定了有关食品标签的标准和指南。这些标准在大多数国家得到实施，食品制造商有义务说明其产品中含有哪些添加剂。例如，在欧洲联盟，设有法规，根据一套预先界定的“E编号”监管食品添加剂标签。对某些食品添加剂过敏或敏感的人员应仔细检查标签。
世卫组织鼓励国家当局监测并确保其国家生产的食品和饮料中的食品添加剂符合允许的使用标准、条件和法规。国家当局应监督食品业，该行业对确保安全使用食品添加剂并遵守法规负有主要责任。
资料来源：https://www.who.int/zh/news-room/fact-sheets/detail/food-additives
Key facts
- Food additives are substances added to food to maintain or improve its safety, freshness, taste, texture, or appearance.
- Food additives need to be checked for potential harmful effects on human health before they can be used.
- The Joint FAO/WHO Expert Committee on Food Additives (JECFA), is the international body responsible for evaluating the safety of food additives.
- Only food additives that have been evaluated and deemed safe by JECFA, on the basis of which maximum use levels have been established by the Codex Alimentarius Commission, can be used in foods that are traded internationally.
What are food additives?
Substances that are added to food to maintain or improve the safety, freshness, taste, texture, or appearance of food are known as food additives. Some food additives have been in use for centuries for preservation – such as salt (in meats such as bacon or dried fish), sugar (in marmalade), or sulfur dioxide (in wine).
Many different food additives have been developed over time to meet the needs of food production, as making food on a large scale is very different from making them on a small scale at home. Additives are needed to ensure processed food remains safe and in good condition throughout its journey from factories or industrial kitchens, during transportation to warehouses and shops, and finally to consumers.
The use of food additives is only justified when their use has a technological need, does not mislead consumers, and serves a well-defined technological function, such as to preserve the nutritional quality of the food or enhance the stability of the food.
Food additives can be derived from plants, animals, or minerals, or they can be synthetic. They are added intentionally to food to perform certain technological purposes which consumers often take for granted. There are several thousand food additives used, all of which are designed to do a specific job in making food safer or more appealing. WHO, together with FAO, groups food additives into 3 broad categories based on their function.
Flavouring agents
Flavouring agents – which are added to food to improve aroma or taste – make up the greatest number of additives used in foods. There are hundreds of varieties of flavourings used in a wide variety of foods, from confectionery and soft drinks to cereal, cake, and yoghurt. Natural flavouring agents include nut, fruit and spice blends, as well as those derived from vegetables and wine. In addition, there are flavourings that imitate natural flavours.
Enzyme preparations
Enzyme preparations are a type of additive that may or may not end up in the final food product. Enzymes are naturally-occurring proteins that boost biochemical reactions by breaking down larger molecules into their smaller building blocks. They can be obtained by extraction from plants or animal products or from micro-organisms such as bacteria and are used as alternatives to chemical-based technology. They are mainly used in baking (to improve the dough), for manufacturing fruit juices (to increase yields), in wine making and brewing (to improve fermentation), as well as in cheese manufacturing (to improve curd formation).
Other additives
Other food additives are used for a variety of reasons, such as preservation, colouring, and sweetening. They are added when food is prepared, packaged, transported, or stored, and they eventually become a component of the food.
Preservatives can slow decomposition caused by mould, air, bacteria, or yeast. In addition to maintaining the quality of the food, preservatives help control contamination that can cause foodborne illness, including life-threatening botulism.
Colouring is added to food to replace colours lost during preparation or to make food look more attractive.
Non-sugar sweeteners are often used as an alternative to sugar because they contribute fewer or no calories when added to food.
WHO response
Evaluating the health risk of food additives
WHO, in cooperation with the Food and Agriculture Organization of the United Nations (FAO), is responsible for assessing the risks to human health from food additives. Risk assessment of food additives are conducted by an independent, international expert scientific group – the Joint FAO/WHO Expert Committee on Food Additives (JECFA).
Only food additives that have undergone a JECFA safety assessment, and are found not to present an appreciable health risk to consumers, can be used. This applies whether food additives come from a natural source or they are synthetic. National authorities, either based on the JECFA assessment or a national assessment, can then authorize the use of food additives at specified levels for specific foods.
JECFA evaluations are based on scientific reviews of all available biochemical, toxicological, and other relevant data on a given additive – mandatory tests in animals, research studies and observations in humans are considered. The toxicological tests required by JECFA include acute, short-term, and long-term studies that determine how the food additive is absorbed, distributed, and excreted and possible harmful effects of the additive or its by-products at certain exposure levels.
The starting point for determining whether a food additive can be used without having harmful effects is to establish an acceptable daily intake (ADI). The ADI is an estimate of the amount of an additive in food or drinking water that can be safely consumed daily over a lifetime without adverse health effects.
International standards for the safe use of food additives
The safety assessments completed by JECFA are used by the joint intergovernmental food standard-setting body of FAO and WHO, the Codex Alimentarius Commission, to establish levels for maximum use of additives in food and drinks. Codex standards are the reference for national standards for consumer protection, and for the international trade in food, so that consumers everywhere can be confident that the food they eat meets the agreed standards for safety and quality, no matter where it was produced.
Once a food additive has been found to be safe for use by JECFA and maximum use levels have been established in the Codex General Standard for Food Additives, national food regulations need to be implemented permitting the actual use of a food additive.
How do I know which additives are in my food?
The Codex Alimentarius Commission also establishes standards and guidelines on food labelling. These standards are implemented in most countries, and food manufacturers are obliged to indicate which additives are in their products. In the European Union, for example, there is legislation governing labelling of food additives according to a set of pre-defined “E-numbers”. People who have allergies or sensitivities to certain food additives should check labels carefully.
WHO encourages national authorities to monitor and ensure that food additives in food and drinks produced in their countries comply with permitted uses, conditions and legislation. National authorities should oversee the food business, which carries the primary responsibility for ensuring that the use of a food additive is safe and complies with legislation.
Source: https://www.who.int/news-room/fact-sheets/detail/food-additives
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