Why caution needs to be observed in the consumption of gari

The Nigerian fried Cassava flakes, popular known as gari remain one of the most popular foods among all the tribes and ethnic groups in all the regions of the country. Despite massive inflation in the prices of foods, including the gari itself, it remains the cheapest, easily accessible, easily prepared, and arguably the most versatile food in terms of conversion to different food products.

Gari is popular for drinking, making a local dish known as 'eba' among the Yorubas, as an adjuvant in other foods such as beans, as a component of pastries, and many other applications. The staple food is made from cassava, Manihot esculenta, which is first peeled and washed after harvesting. The peeled and washed cassava is then milled. During milling, the final product can be influenced by adding palm oil. This essentially differentiates yellow gari from white gari with the former being yellow as a result of the addition of palm oil.

After milling, the cassava paste is put in a breathable sac and allowed to stand for a period of time which range from a few hours to a few days. During this period microorganisms carry out fermentation activities and break down of what otherwise could have been toxic substances to the human body. One of the most important reactions is the release of the enzyme linamarase through the activities of the microbes. This enzyme simply breaks down the cyanogenic glucoside of cassava, which releases hydrogen cyanide and thus detoxifies the product. At the end of the day, the organoleptic property of the final product is also improved.

^{Gari processing unit. The woman on the right is sieving the semi-dried, fermented, milled casavva while the two other women are frying. By Liberty photography - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=64431576}

After the standing period, the sac containing the milled and now detoxifies cassava is placed under heavy objects in order to drain off moisture from it. The liquid that drains off is a mixture of water and starch. The draining period varies depending on the moisture content of the cassava itself. Thereafter, the semi-dry and now semi-solid product is transferred to the frying station where it is broken up using the hand and sieved. The sieved product is then fried and thus, the gari is ready.

Instead of adding palm oil during the milling stage in order to arrive at yellow gari, some people add the oil during the sieving stage. While the final product in both cases is yellow gari, the former usually appears more uniform in its yellowness than the latter which is usually characterized by whitish grains among the seas of yellow ones.

Why caution needs to be exercised with gari consumption

The procedure for making gari described above represents the standard procedure which can only vary slightly from one place to another, perhaps depending on the available technology. However, many people indulge in the practice of adulteration of the final product. The adulterations are solely carried out in order to make more economic gain than usual. The most common form of adulteration is to mix the final fried product with unfried ones in order to increase volume.

Frying removes moisture significantly and reduces the volume in the same magnitude. Hence, mixing fried products and unfried ones increases volume and makes it economically more advantageous. The unfried one used in mixing is often allowed to dry a bit in the sun, however.

Frying further breaks down any other toxic component of the cassava and makes the fried product safe for consumption. Hence, mixing with the unfried products makes it a bit dangerous for consumption, especially when it is direct.

Apart from adulteration, handling and storage of the fried product also have the tendency to cause contamination. Locally, it is rare to see manufacturers taking any form of precautions in the handling of the read-to-consumed product in order to prevent contamination. Some store the ready-for-the-market product in opened containers where rodents and other pests get free access to feed, defecate, and cause contamination.

Utmost caution, therefore, needs to be observed in the consumption of gari, especially in its drinking and direct consumption that does not involve further processing. Foods made from gari that involve heating might be safe because heat kills of microbes and any form of pathogen that might be present in the original gari as well as destroying any toxic chemical that might be present as a result of adulteration.

A real-life proof that cross-contamination of gari is a common occurrence is exemplified in the work of Olopade and her colleagues in 2014. The researchers carried out the microbial analysis of 36 different samples of gari consisting of both yellow and white products. A good number of the samples were found to contain either bacteria or fungi or even both. The bacterial species isolated includes Bacillus spp, Enterobacter spp, Pseudomonas, Staphylococcus and Klebsiella spp while the fungal species isolated includes Aspergillus niger, Aspergillus fumigatus, Fusarium, Rhizopus and Penicillium spp.

The research of Olopade et al clearly shows the need to be cautious in the consumption of gàárì by the populace and, most importantly, the need for good manufacturing practice as well as hazard analysis and critical control points during the process of manufacturing, storage, and marketing.

Thank you all for reading.