Food Safety: Is Detection of Metals in Food & Beverages Important?
The Food Safety and Standards Authority of India has issued a new notification fixing, among other parameters, the maximum limit for metals like Lead, Copper, Arsenic, Mercury, Tin, Cadmium & Zinc in food items like Noodles, Pastas & Macaroni and other such items which had previously been classified by FSSAI under “Foods Not Specified”
The Food and Beverage (F&B) services market in India is expanding at a rapid pace. The compounded annual growth rate is currently 25% and is expected to remain so over the next few years. The overall F&B scenario in India has evolved dramatically over the past decade. While in the past there were only a handful of brands to choose from, now consumers have difficulty in choosing from the multitude of brands on offer! The F&B industry has also attracted good investments in recent years. So, with the booming F&B industry, comes the issue of food safety. In order to ensure that the F&B market keeps flourishing, it is important to focus on the quality of food offered to consumers.
It is of utmost importance that the food we eat and the beverages we drink are absolutely safe for human consumption. Therefore, carrying out food safety checks is a mandatory requirement for ensuring food safety. Food and beverages need to be tested for a large number of contaminants. Of these, contaminating metals are very important, as they have a deleterious effect on health if the levels are above the specified values. Many metals act as co factors for enzymes involved in various metabolic pathways. It follows that large quantities of contaminating metals can have an adverse effect on these metabolic pathways, leading to health problems especially with continuous, long term exposure.
The issue of metal contamination hit the headlines following reports of lead contamination in Maggi instant noodles. Lead can be particularly harmful to young children, especially if there is long term exposure. The test results from government laboratories proved beyond doubt that Maggi was contaminated with lead over and above the permissible safety limits. However, it should be borne in mind that it is not only lead, but also various other metals like copper, arsenic, mercury, tin, cadmium, zinc, chromium and nickel, which can cause contamination of the human food chain.
The various types of metals, in particular the heavy metals, are widely distributed in our environment, and can enter our food chain though various ways. For example, heavy metals in streams, rivers and lakes can accumulate in fish, which in turn are consumed by humans, leading to heavy metals entering the human food chain. This is only one example out of the myriad. However, regardless of the mode of entry into the food cycle, they disturb the normal functioning of the body metabolism and can accumulate in the body, causing severe toxicity.
FSSAI safety limits for heavy metals
To protect consumers, regulatory bodies across the world have established regulations with stringent limits on the permitted levels of heavy metals in different items of food. The Food Safety and Standards Authority of India (FSSAI), the apex regulatory body on food in India, has recommended safety limits for metal contaminants in F&B, which should not be exceeded. For example, there is a specified upper limit for lead in beverages such as soft drinks, juices and tea; and food items like ice creams, canned fish & meat, sugar, edible oils, etc. Similarly, the limits for other metal contaminants have also been specified for F&B.;
In the light of the recent lead contamination controversy, the FSSAI has issued a new notification that has fixed, among other parameters, the maximum limits for the metals Lead, Copper, Arsenic, Mercury, Tin, Cadmium & Zinc in food items like Noodles, Pastas & Macaroni and other such items (Table 1), which had previously been classified by FSSAI under “Foods Not Specified”.
How are metals tested in F&B?
The presence of heavy metal contaminants in F&B makes it important for the food industry to ensure that their products are free from these toxic elements by regularly testing their ingredients and products for compliance with the regulatory requirements.
Testing for metals in foodstuff essentially involves following four steps:
* Sampling: The objective of this step is to obtain a small and representative portion from the large sample in such a way that any subsequent test on the sample will give reproducible results.
* Destruction of organic matter: The commonly used methods of destruction of organic matter can be broadly grouped into wet oxidation, dry ashing and microwave digestion.
* Separation and concentration of the metal: Once the organic component is destroyed, the element of interest may be concentrated by applying physico chemical methods.
* Measurement and determination of the metal: The concentrated element is then subjected to analytical methods to determine its actual level in the original sample of food.
The FSSAI has recommended a number of methods for testing metal contamination in foodstuff , which have been approved and validated internationally by leading agencies like the USFDA and the European Food Safety Authority (EFSA) of the EU. It is important to note that approval by international agencies in various countries means that the methods have been standardised and harmonised as per global standards. Therefore, when Indian food products are exported to these countries and retested before distribution, they will pass the quality and safety checks easily. Some of the approved methods include Atomic Absorption Spectrometry (AAS) for testing lead, cadmium, copper and zinc. Besides mercury and arsenic, the other four metals can also be estimated by colorimetric methods.
The most advanced method for testing metals, which is considered the “Gold Standard” is a combination of Microwave Digestion for sample preparation, followed by Inductively Coupled Plasma Mass Spectrometry (ICP MS) for sample analysis. ICP MS gives the advantage of analyzing all the metals at the same time with minimum manual intervention. It also offers unparalleled low detection limits, in the parts per trillion levels range, allowing for the use of smaller sample quantities which can be properly digested giving better recovery and reproducibility of results. Both AAS and ICP MS are quantitative methods and are highly sensitive and very accurate.
From the foregoing discussion, it is evident that testing for metal contamination is an important aspect of maintaining food safety and heavy metals should not exceed the permissible limits in F&B.;
The FSSAI is reviewing existing standards set for caffeine and toxic contaminants and residues in various food products. It is also setting up standards for imported food products, so that only safe food items are made available to the Indian citizens.
The FSSAI is also in the process of finalizing 12,000 standards for food additives and ingredients in line with global safety standards, so that the lengthy process of product approval can be averted. Currently, there are standards prescribed for ~380 food items, but there are none for the various ingredients and food additives. This will help the food business community to be more proactive to conform to the prescribed new standards, thereby alleviating the need to apply for product approval. These new FSSAI standards are in harmony with the global standards, as these follow the Codex Alimentarius Commission of the United Nation’s FAO and WHO. Importantly, there is a need for greater co ordination of the food industry players with the FSSAI, so that the best quality food reaches the consumers.