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HomePosts Tagged "foods"
Acquaculture, Agro Universities, R&D

The sensor has been tested for adulterated fish at lab scale as well on fish available in the fish markets of the Guwahati region.

Nanomaterials and Nanoelectronics Laboratory, headed by Dr Hemen Kr. Kalita, Assistant Professor, Department of Physics, Guwahati University, Assam has developed a cost-effective formalin sensor using tin oxide-reduced graphene oxide composite that can effectively detect the presence of formalin in adulterated fishes.

A new low-cost sensor made of metal oxide nanoparticles–reduced graphene oxide composite can detect formalin adulteration in fishes at room temperature in a non-invasive way. The sensor shows long-term stability with a low detection limit.

Food adulteration is the practice of adding illegal or harmful substances to food to make it appear more appealing or to increase its shelf life. Formaldehyde is a colourless, pungent gas that is used in a variety of industrial processes, including as a preservative in some foods, commonly in fish in developing countries. However, the use of formaldehyde in food is illegal in many countries, as it is a known carcinogen.

Commercial formalin sensors for fish are primarily electrochemical-based or colorimetric-based. Electrochemical sensors are extensively used but are expensive. On the other hand, calorimetric sensors are less expensive. But both methods are invasive. Moreover, low-level detection and selective detection are two major issues with these sensors. The development of 2D materials-based gas sensors has created a new avenue of effective detection of toxic vapours at room temperature. These sensors have the potential to detect the formalin evaporated from adulterated food products.

Graphene oxide (GO), the oxidized form of graphene, exhibits high solution processability and ease of chemical modification with other materials such as metals, metal oxides, or polymers. However, the low electrical conductivity of GO posed a challenge and the scientists overcame this by developing the tin oxide-reduced graphene oxide composite (rGO- SnO2).

While reduced graphene oxide (rGO) has been used to detect various toxic gases and VOCs, tin oxide (SnO2) has been extensively investigated for formaldehyde detection in pristine form and by incorporating it with various compounds, including graphene, due to its high stability and high sensitivity toward low concentrations of formaldehyde.

The researchers synthesised graphene oxide (GO) through a process called the wet chemical approach and tin oxide-reduced graphene oxide composite (rGO- SnO2) was synthesised by hydrothermal route followed by calcination of the obtained product. They found that the sensor made of tin oxide decorated reduced graphene oxide effectively sensed formaldehyde vapour at room temperature.

The sensor has been tested for adulterated

AgroPolicy, Sustainability, World

The 154-country study makes a case for true cost accounting to guide policy

Our current agrifood systems impose huge hidden costs on our health, the environment and society, equivalent to at least $10 trillion a year, according to a ground-breaking analysis by the Food and Agriculture Organisation of the United Nations (FAO), covering 154 countries. This represents almost 10 per cent of global GDP.

According to the 2023 edition of The State of Food and Agriculture (SOFA), the biggest hidden costs (more than 70 per cent) are driven by unhealthy diets, high in ultra-processed foods, fats and sugars, leading to obesity and non-communicable diseases, and causing labour productivity losses. Such losses are particularly high in high- and upper-middle-income countries.

One-fifth of the total costs are environment-related, from greenhouse gas and nitrogen emissions, land-use change and water use. This is a problem that affects all countries, and the scale is probably underestimated due to data limitations.

Low-income countries are proportionately the hardest hit by hidden costs of agrifood systems, which represent more than a quarter of their GDP, as opposed to less than 12 per cent in middle-income countries and less than 8 per cent in high-income countries. In low-income countries, hidden costs associated with poverty and undernourishment are the most significant.

The report makes the case for more regular and detailed analysis by governments and the private sector of the hidden or ‘true’ costs of agrifood systems via true cost accounting, followed by actions to mitigate these harms.

There have been other attempts at measuring the hidden costs of agrifood systems, producing similar estimates as FAO. The new FAO report, however, is the first to disaggregate these costs down to the national level and ensure they are comparable across cost categories and between countries.

For the first time, FAO will dedicate two consecutive editions of The State of Food and Agriculture to the same theme. This year’s report presents initial estimates, while next year’s will focus on in-depth targeted assessments to identify the best ways to mitigate them. Governments can pull different levers to adjust agrifood systems and drive better outcomes overall. Taxes, subsidies, legislation and regulation are among them.

The report urges governments to use true cost accounting to transform agri-food systems to address the climate crisis, poverty, inequality and food security. It notes that innovations in research and data, as well as investments in data collection and capacity building, will be needed to scale the application of true cost accounting, so it can inform decision-making transparently and consistently.

The 154-country study makes a case for