Research, shows that cassava is a major factor of the substitution of producing sorbitol. Despite the fact that Nigeria is a major producer of cassava, the country is said to expend about N40 billion annually to import sorbitol. Thus, the Raw Materials Research and Development Council (RMRDC), is making efforts to boost production in order to reduce its importation. BINTA SHAMA reports.
Sorbitol (C6H14O6) is a sugar alcohol (polyol) with six-carbon atoms and six hydroxyl groups. Sorbitol occurs naturally in fruits such as apples, pears, peaches, apricots, and nectarines. Other natural sources include dried fruits like prunes, dates and raisins, and in some vegetables. Sugar alcohol is a polymerised sugar with an alcohol functional group. There are seven sugar alcohols approved globally for use in food products. These are sorbitol (E420), mannitol (E421), isomalt (E953), maltitol (E965), lactitol (E966), xylitol (E967) and erythritol (E968). They are Generally Recognized As Safe (GRAS). Sorbitol (E420) is approximately 60% as sweet as sucrose (table sugar) with an average caloric value of 2.7 kcal/g compared to 4 kcal/g for sucrose. It is highly hygroscopic, chemically inert, and stable at high temperatures. Its safety profile is generally recognized by the World Health Organization, the European Union and the designated authorities of Australia, Canada, Japan as well as the U.S. Food and Drug Administration (FDA).
The global sorbitol market size was valued at USD 1.66 billion(N1.2 trillion) in 2022 and is projected to grow at a compound annual growth rate (CAGR) of 6.7% from 2023 to 2030 in view of the high demand. The market is expected to witness significant growth over the forecast period owing to the rising usage in diabetic and dietetic food and beverages. The increasing use as a substitute for sugar in consumer food products is also driving demand for the product. Sorbitol is also increasingly being used in oral care products as it metabolized at a slower rate, compared to other sugar alcohols. This prevents dental problems such as cavities and tooth decay. Another factor propelling the increase in demand for sorbitol is that it is non-cariogenic due, to its resistance to digestion by oral bacteria. It also serves as a major raw material in the manufacture of Vitamin C. Other uses include parenteral preparations used in osmotic diuretics in the prevention and treatment of renal failure, shock, and the treatment of intoxications. Approval from safety regulatory and human health bodies such as the FDA and the U.S. Department of Agriculture (USDA) for its use in medicines and bakery foods is expected to further drive the market. Other factors propelling the increasing demand for sorbitol are its increasing industrial utilization the food and beverage industry for nutritive sweeteners. It is widely used to increase shelf life and maintain the freshness and color of various confectionery and bakery products and in the production of canned fruit. Its low glycemic index of 9 as compared to sugar with a glycemic index of 69 makes it suitable as part of a diabetic diet. This explains the increasing consumer preference towards low-calorie foods as a result of the global increase of patients with diabetes.
Commercially, sorbitol is generally available and marketed in the form of 70% solution –polyhydric alcohol with a colorless to faint yellowish appearance. Liquid sorbitol remains mostly inert to humidity fluctuations. The aqueous solution replicates many properties of glycols and glycerol, thus acting as suitable possible substitute. Sorbitol liquid is also a good humectant and water stabilizer which enables its utilization in the gelatin capsule industry and cosmetic emulsions.
Sorbitol is produced at commercial scale by reduction of d-glucose from biomass in a high-pressure reactor using hydrogen gas in the presence of a catalyst. However, epimerization of glucose in an alkaline medium into mannose can easily occur and subsequently hydrogenated into mannitol. Therefore a pH of 7.5 is mostly used for glucose conversion to avoid epimerization. Although, enzymatic production of sorbitol from Z. mobilis and Candida boidini has also been reported, glucose remains the best source of sorbitol production due to its availability and low cost. Starch-rich materials such as corn, wheat, potato and cassava are used as raw material for the production of sorbitol.
Statistics of imported sorbitol
Nigeria imported sorbitol item no. 2905.44 of over $6,743.17K in 2019 when about 12,088,200 kg was imported from Indonesia ($2,113.67K , 3,978,190 Kg), India ($1,916.43K , 3,014,570 Kg), Turkey ($1,260.35K , 2,376,310 Kg), China ($1,233.79K , 2,421,100 Kg) and the United States ($145.23K, 259,394Kg). According to Volza’s 2022 Nigeria Import data, sorbitol product of category of HSN Code 29054400 was imported at a cost of USD 1.4K by 74 Nigeria Importers from 33 suppliers. Nigeria imports most of its Sorbitol of HSN Code 29054400 from India, United Kingdom and China.
RMRDC, collaborating with other stakeholders
These developments combined with RMRDC initiative on cassava productivity boosting programme in collaboration National Root Crops Research Institute, Umudike, will futher increase cassava output locally. In view of this it is imperative to expand the cassava value chain development to include production of industrial raw materials that are in very high demand locally and that also have competitive export potential. One of such products require by numerous manufacturing companies in the country is sorbitol. Although some companies are presently producing it locally, the high industrial requirement presently necessitates its importation. To stem this occurrence and place the country on an economically sound track, the Council in collaboration with stakeholders in research institutes and in the industry has put in place, plans to promote investment in sorbitol production from cassava. In view of this, the Council has designed and developed a process for the local production of sorbitol. A pilot plant with production capacity of 75kg/batch has been installed at the RMRDC Technology and Innovation Complex. The plant can produce both liquid/syrup and crystal/powder sorbitol products which are locally required and also have high potential for export. The equipment has been tested and the products compare favorably to international quality standards. The Council is presently engaging stakeholders on the establishment of the plant in major cassava producing ecologies in the country. The beauty of the investment is that it can be operated at small, medium and large scales. As a result, it is within the capacity and capability of local government areas, state governments and private sector investors in the country to key into the investment plan. This will enable the proliferation of the production plants in the country. When this is achieved, this initiative will save the nation more than 40 billion naira annually in foreign exchange equivalent, apart from export potential to generate foreign exchange. It will also promote job creation and consequently, poverty reduction in the country. This is expected to grow geometrically within the next few years according to the strategic plans put in place by the Council and other stakeholders.
Nigeria represented 21% of the world’s total production of cassava
In 2018, Nigeria was the largest producer of cassava globally. Cassava was produced in 24 of the country’s 36 states. During the period, Nigeria produced about 59.5 million tons of cassava. This represented 21% of the world’s total. However, about 90% of cassava produced in Nigeria is consumed locally without any value addition. Other major producers of cassava roots include Thailand (31.7%) and the Democratic Republic of Congo (30.0%). In Nigeria, cassava is grown throughout the year, making it preferable to the seasonal crops of yam, beans or peas. It also displays an exceptional ability to adapt to climate change, with tolerance to low soil fertility, resistance to drought conditions, pests, and diseases, and suitability to store its roots for long periods underground even after they mature. The use of fertilizers is limited, and it is also grown on fallow lands and the harvesting of the roots after planting varies from 6 months to 3 years. Government at all levels has been promoting self-sufficiency in cassava production. According to the Nigerian Presidential Initiative 2002, the cropped area of cultivation of cassava has been on the increase and this is expected to reach 5 million hectares with a projected annual yield of 150 million tones in few years to come if the initiative is maintained and sustained. More recently, the concession on cassava biomass and bio-ethanol value chain development was approved by the Federal Executive Council. As disclosed by the Infrastructure Concession Regulatory Commission (ICRC), the concession aims to create wealth, provide jobs, reduce poverty, improve food security and nutrition, provide renewable energy and reduce carbon footprint. The cassava bio-ethanol value chain is expected to generate a total of 105 billion naira within five years concession period. This is expected to be done on a pilot phase by building a bio-technology pack on a 20 ha plot across 20 universities, academia and Research and Development Institutions.
