FIIRO scientists develop technology to beat metal contamination of food products

Worried by the rise in heavy metal contamination of food products and its attendant health consequences, Nigerian scientists at the Federal Institute of Industrial Research Oshodi (FIIRO) Lagos have designed and fabricated stainless steel pepper grinding machine to address the issue.

The FIIRO multipurpose commercial pepper grinding machine is an all in one food milling machine fitted with accessories capable of both dry and wet milling food processing operations and it comprises of: a cylindrical barrel, a conical hopper, a set of knives/blades, a stepped shaft, a mechanical seal, a seal retainer, a barrel cover, a discharge chute, a bearing frame, a set of pulleys, a set of bearings, a main frame, a prime-mover (electric motor or an internal combustion engine), a hopper cover, an interlocking safety device, a hammer (dry milling accessory), a barrel cover with toothed cutting edge (dry milling accessory), a mesh holder.

According to the World Health Organisation (WHO), heavy metals such as lead, cadmium and mercury cause neurological and kidney damage.

Also, local studies have shown that foods contamination is on the increase in Nigeria. Common ready to eat and foods prone to metal contamination include fried yam, fried bean cake (akara), roasted plantain (bole), roasted meat (suya), roasted fish, cassava flour (fufu), yam flour (amala), garri (eba), beans and herbal drink (agbo jedi jedi) and of course milled products like pepper, tomato, onion and so on.

Comprehensive assessment of heavy metal contamination in ground tomato, pepper and onions mix milled with locally fabricated pepper grinding machines in Lagos metropolis, in 2013, by FIIRO scientists, showed the presence of both heavy (lead, copper, chromium, nickel, cadmium, manganese and non heavy metals (calcium, magnesium, zinc, iron.

The results of the analyses did not show presence of heavy metals at toxic level as insinuated but the quantity of iron found in the samples was higher than required threshold. Iron toxicity has been associated with depression, rapid and shallow respiration, coma, convulsion, respiratory failure, cardiac arrest and cancer. The toxicity of iron on cells could lead to iron mediated tissue damage involving cellular oxidizing and reducing mechanisms and their toxicity towards intracellular organelles such as mitochondria and lysosomes.

A reduction in the maximum permissible limits of metals especially heavy metals in food, therefore, becomes imperative.

FIIRO with core mandate to conduct research in food and agro-allied processing technologies; pulp and paper technologies; product design and packaging and equipment prototype design and fabrication rose to the challenge and deployed its cross cutting mandate to address the issue.

Director General of FIIRO, Dr. Gloria Elemo, told The Guardian that the newly designed and fabricated pepper grinding machine has been fully characterized and tested to examine whether the machine is able to meet the objective of the project which was mainly to eliminate metal contamination and improve the aesthetic of the machine.

To test the presence of metals in the milled products from the new machine, pepper mix comprising of pepper, tomatoes, and onions were selected and purchased from 50 different markets in and around Lagos. The pepper mix were washed thoroughly with clean water, drained and shared into three different portions of about 500g. Each portion of the pepper mix was milled with three different types of milling machines, namely: FIIRO multipurpose commercial pepper grinding machine; stainless steel blender/grinder and local disc mill fabricated pepper grinding machine. Each sample was grinded without adding water to the ground product. Samples of the ground product were collected from each of the machines and were taken to FIIRO Analytical Services Division Laboratory for determination of the following metals: calcium, magnesium, zinc, iron, lead, copper, chromium, nickel, cadmium and manganese. The results indicated that milling with FIIRO multipurpose pepper grinding machine is the best in terms of efficiency and quality of the milled products since heavy metals were not detected.

The Institute is currently at the stage of commercializing the newly designed and fabricated commercial stainless steel pepper grinding machine by transferring the technology to indigenous fabricators who can mass-produce based on the Institute’s specifications.

Elemo said the Federal Ministry of Science and Technology, the Institute’s supervising Ministry shall be willing to collaborate with other relevant ministries such as the Federal Ministry of Agriculture and Rural Development; Federal Ministry of Health; Federal Ministry of Industry, Trade and Investment; the National Assembly; Local and State Governments; Development Institutions both government and non government among others to make this product a national success and truly Nigerian product that will be found in nooks and crannies of this country.

The FIIRO DG said: “We cannot over emphasis the potential benefits of the newly designed and fabricated stainless steel pepper grinder to the national economic development in term of poverty alleviation, job creation, wealth creation and attendant multiplier effect. It would also improve the health and wellbeing of the populace arising from reduction in food contamination as well as conserve foreign exchange through importation of inferior pepper grinder especially from China.”