Editorial 1 : Liquid nitrogen in foods draws Tamil Nadu’s ire, yet again
Context
The Tamil Nadu Food Safety Department has issued a circular on the use of liquid nitrogen saying the substance can only be used to preserve packaged food.
Liquid Nitrogen Facts
- Liquid nitrogen is the liquefied form of the element nitrogen that's produced commercially by the fractional distillation of liquid air.
- Like nitrogen gas, it consists of two nitrogen atoms sharing covalent bonds (N2).
- Sometimes liquid nitrogen is denoted as LN2, LN, or LIN.
- At normal pressure, liquid nitrogen boils at 77 K (−195.8° C or −320.4° F).
- The liquid-to-gas expansion ratio of nitrogen is 1:694, which means liquid nitrogen boils to fill a volume with nitrogen gas very quickly.
- Nitrogen is non-toxic, odorless, and colorless. It is relatively inert and is not flammable.
- Nitrogen gas is slightly lighter than air when it reaches room temperature. It is slightly soluble in water.
- Liquid nitrogen is stored in special insulated containers that are vented to prevent pressure buildup.
- LN2 displays the Leidenfrost effect, which means it boils so rapidly that it surrounds surfaces with an insulating layer of nitrogen gas. This is why spilled nitrogen droplets skitter across a floor.
Liquid Nitrogen Safety
- When working with liquid nitrogen, taking safety precautions is paramount:
- Liquid nitrogen is cold enough to cause severe frostbite on contact with living tissue. One must wear proper safety gear when handling liquid nitrogen to prevent contact or inhalation of the extremely cold vapor. Cover and insulate skin to avoid exposure.
- Drinking liquid nitrogen can be lethal. While it freezes tissues, the real issue is the rapid expansion from a liquid into a gas, which ruptures the gastrointestinal tract.
- Because it boils so rapidly, the phase transition from liquid to gas can generate a lot of pressure very quickly. Do not enclose liquid nitrogen in a sealed container, as this may result in it bursting or an explosion.
- Adding large quantities of nitrogen to the air reduces the relative amount of oxygen, which may result in an asphyxiation risk. Cold nitrogen gas is heavier than air, so the risk is greatest near the ground. Use liquid nitrogen in a well-ventilated area.
- Liquid nitrogen containers may accumulate oxygen that is condensed from the air. As the nitrogen evaporates, there's a risk of violent oxidation of organic matter.
Liquid Nitrogen Uses
- Liquid nitrogen has many uses, mainly based on its cold temperature and low reactivity. Examples of common applications include:
- The freezing and transporting of food products
- The cryopreservation of biological samples, such as sperm, eggs, and animal genetic samples
- Use as a coolant for superconductors, vacuum pumps, and other materials and equipment
- Use in cryotherapy to remove skin abnormalities
- The shielding of materials from oxygen exposure
- The quick freezing of water or pipes to allow work on them when valves are unavailable
- A source of extremely dry nitrogen gas
- The branding of cattle
- The molecular gastronomy preparation of unusual foods and beverages
- The cooling of materials for easier machining or fracturing
Government’s role in misuse of LN2
- Food safety departments have issued bans on the use of liquid nitrogen in food preparation, except for specific purposes like storing food items.
- The Food Safety and Standards Act 2006 empowers designated officers to take enforcement action against any food business operator found using liquid nitrogen for direct consumption without proper precautions.
- The Food Safety and Standards (FSS) Act, 2006 consolidates various acts & orders that had earlier handled food-related issues in various Ministries and Departments.
Way forward
- Alternatives to food preservation may be encouraged like
- Mechanical Refrigeration: Provides safe, even cooling without the risks associated with chemical agents.
- Cryogenic Freezing with CO2: While still using extreme cold, CO2 does not have the same rapid expansion risks and is less likely to cause asphyxiation.
Editorial 2 : Why are Indian spices facing the heat?
Context
- At least five countries — including Singapore, Hong Kong and the U.S. — have announced an investigation into possible contamination of spice mixes sold by Indian brands, MDH and Everest.
- The complaints cite the presence of ethylene oxide (EtO), a toxic chemical used as a food stabiliser, beyond permissible limits.
Health concerns
- MDH and Everest’s spice mixes allegedly contain high levels of EtO, a prohibited pesticide.
- EtO is a colourless, flammable gas that was originally intended for sterilising medical devices.
- It is used as a chemical in industrial settings, agriculture, and as a sterilising agent in food products, including spices, dried vegetables and other commodities.
- The chemical lends life to the spice industry — it reduces microbial contamination, and in turn, extends products’ shelf life.
- However, this process is not always airtight. The improper and excessive use of EtO may leave behind residues, causing toxic and even carcinogenic compounds to form, thus contaminating the product.
- One such compound is ethylene glycol, an ingredient which was found in Indian-made cough syrups that were linked to the deaths of more than 300 children in Cameroon, Gambia, Indonesia and Uzbekistan.
- Long-term exposure to ethylene oxide is associated with cancers including lymphoma and leukaemia, some evidence shows.
How has India responded?
- On April 25, the Spice Board in India announced a slew of corrective measures including initiating mandatory testing of consignments shipped to Singapore and Hong Kong and gathering technical details and analytical reports from the relevant food and drug agencies.
- It also sought to propose corrective measures to the concerned exporters and initiate inspections to ensure adherence to relevant standards.
- A circular dated April 30 contains guidelines to exporters on preventing EtO contamination.
- The guidelines prescribe norms for testing at raw and final stages, storage of EtO treated products and use of alternate methods curtailing the use of the chemical compounds.
- The Spices Board issued a similar advisory in September 2021, after the EU observed EtO contamination in certain Indian exports.
- Furthermore, the FSSAI has directed state regulators to collect samples of major spice brands, including MDH and Everest, to test for EtO.
Is food safety in India lacking?
- The collectively underscore the persistent nature of food safety challenges across various sectors of the food industry.
- One challenge is operational — India’s diverse food landscape, the lack of standardised record-keeping and intentional food fraud may prevent manufacturers from tracing ingredients and assessing potential risks which compromise the safety of the entire food supply chain.
- Traceability is particularly challenging for small and medium sized businesses with limited resources.
- Some are logistic barriers. At least 10 States/Union Territories lack government or private notified food testing labs, as mandated under the Food Safety and Standards Act 2006.
- These labs are distributed unevenly across regions; have insufficient number of food safety officers; and were found to operate ineffectively due to resource constraints, showed the FSSAI Annual Report of 2021-22.
- FSSAI’s operations often lack transparency, which hinders efforts to meet safety standards build accountability and trust.
Way forward
- With nearly $700 million worth of exports to critical markets at stake, and potential losses soaring to over half of India’s total spice exports due to cascading regulatory actions in many countries, the integrity and future of India’s spice trade hang in delicate balance.
- It’s high time that our country makes stringent laws and mechanisms to deal with these violations and ensure health safeguards of all people.