Determined to diversify and advance the economy, the Raw Materials Research and Development Council (RMRDC) is working to improve soy sauce to reduce the unemployment rate in the country. BINTA SHAMA reports
About soy sauce
Soy sauce is a liquid seasoning agent currently used in cooking worldwide. It contains bioactive components in addition to taste and aroma compounds. It also has various biological functions, including anticarcinogenic, antimicrobial, antioxidative and antiplatelet activities.
Soy sauce is a fermented soybean product that is indispensable in the nutrition of East Asian countries. With a deep reddish-brown and liquid-like appearance, it is used for enhancing the delicious taste and color of cuisines derived from various cultures. Soybeans together with wheat and brine are the starting materials for the production of the seasoning agent.
Fermentation process
Soy Sauce is a product of a fermentation process involving the hydrolysis of soybean and wheat flour by various microorganisms. It is a mixture of cooked soybean and wheat flour inoculated with Aspergillus enzyme, incubated at appropriate temperature for 3-5 days and then placed in a brine solution, whereupon an anaerobic fermentation takes place with the aid of halophilic yeasts and bacteria. After a period of fermentation which may last from 3 months to a year depending of the characteristics or properties of the seasoning required, the liquid obtained is siphoned out, filtered, pasteurized and bottled as soy sauce. Four major stages are involved in the process. These include soybean meal steaming, koji-making, brine fermentation, and sauce extraction with the help of a micro flora which consists of Aspergillus enzyme. Salt-tolerant yeast and bacteria thereafter convert the ingredients in the starting materials into the flavor and aroma compounds associated with soy sauce.
The global soy sauce market size was $40.63 billion in 2019 and is projected to reach $56.67 billion by 2027, exhibiting a CAGR of 7.63% during the forecast period (2020-2027). Presently, however, the global pandemic caused by the outbreak of COVID-19 has affected the purchasing patterns of soy sauce in the overseas market negatively. According to the World Trade Organization, the global trade scenario was expected to fall between 13% to 32% in 2020. Nevertheless, the relentless effort by governments to improve their national economies in the post COVID 19 pandemic era is gradually leading to increase in international trade and consequently, trade in soy sauce. This shows the importance of the product in global cuisine. Global trade is dominated by countries in the Asia-Pacific region, with China, Japan, Singapore, and Hong Kong among the major exporters. The largest manufacturers and retailers of soy sauce are based in the United States of America and the Netherlands, both of which have become major exporter nations.
Glycine max
The major raw material, soybean (Glycine max), is one of the most valuable, versatile, and most nutritionally important legumes globally. It can be grown in a multitude of environments, using a variety of management practices, and, for diverse end-user purposes. In 2018, roughly 398 million tons of soybeans were produced worldwide. This accounted for 61% of the overall global oilseed produced and 6% of the world’s arable land use. The United States, Brazil, and Argentina produced approximately 81% of the total global output, producing 34%, 32%, and 15% of world’s soybeans output respectively. Soybean seed composition and its main components such as the meal and oil, are the driving forces behind the intensive cultivation of the crop production whose output has increased by nearly 350% since 1987. Soybean meal is intricately connected to the food supply of both humans and livestock owing to its natural properties such as a rich source of protein, carbs, and others. According to the Food Climate Research Network (FCRN) at the University of Oxford, approximately, 6% of total soybean produced is utilized for human consumption every year. Soy oil provides great versatility with uses in the food and beverages, wax, construction, cosmetics, plastics, and fuel industries.
In Nigeria soybean is cultivated in nearly all the parts of the country with soybean production across Nigeria’s south, largely due to the efforts of the International Institute for Tropical Agriculture (IITA) and other international research institutes. Soybean yields have been increasing in recent years in the country, and USDA attributed this to increasing private sector investment in soybean cultivation to meet the growing needs of local feed millers and poultry farmers. USDA further reported that soybean production in year 2021-2022 in Nigeria is likely to be about 1.25 million tonnes, a 43% increase from the most recent 2020-21 estimate. The area to be harvested is projected at 1.2 million hectares, also; up by 20% from the 2020-21 estimates.
Poor production of soybean
Despite the high level of soybean production in Nigeria, the production of soy sauce locally has not been encouraging. In 2017, a total of 22,000 tonnes of Soy sauce was consumed locally while local production was about 11,000 tonnes, culminating in expenditure of about $35m for soy sauce importation. In 2018 and 2019, consumption values increased to 28,000 and 30,000 tonnes respectively, while local production increased to 13,000 and 16,000 tonnes culminating in the expenditure of $58m and $62m in foreign exchange equivalent. The major country where soy sauce was imported into the country during these periods was India and the major imported soy sauce products were dark soy sauce with HS code 21031000 and TEMPTIN soy sauce with HS Code of 21039020.
In view of the increasing scarcity of foreign exchange in the country, coupled with the prohibitive cost of wheat flour, it is imperative to promote the production of soy sauce from locally available commodities. As a result of this, the Council initiated a project with the primary purpose of promoting soy sauce production from locally available commodities such as soybean and tubers like cocoyam, sweet potato and cassava, as substitutes for wheat flour in the production of soy sauce. This was expected to reduce the production cost, while at the same time established a useful purpose for the lesser industrially utilized tubers.
RMRDC intervention
It was in this regard that RMRDC, in collaboration with a research team from the Lagos State University, Nigeria, assiduously carried out a research and development project that span about 5 years to substitute wheat with potato the soy sauce production process. After the conclusion of the project, the team designed and fabricated a small-scale soy-sauce production plant to produce soy sauce from 100% locally sourced raw materials. This has resulted in production of 100 percent locally sourced flavor to meet the needs of the food industry. The process developed involved the utilization of Aspergillus enzyme to ferment a mixture of soybean and sweet potato extracts to produce the food flavor. The flavor was found to be very good and consumer-friendly and its commercialization has the inherent inbuilt capacity to reduce the importation of food flavors into the country.
The design and fabrication of the plant have been completed and soy sauce samples produced analyzed by independent analysts. The samples have properties reminiscent soy sauce imported into the country. The specifications of the samples as submitted by analysts are as follows: Raw Materials: Cassava, Soybeans, Rice and Table salt. Fermenting agent: Aspergillus enzyme (Food grade). Flavour: Parsley, Celery. Preservatives: Sodium Metabisulphite. Aflatoxin: Free from poisonous materials. Proximate: Contains – moisture – 75.6%, fat negligible- protein 0.7, Total Ash-13.2 and total carbohydrate 10.5%.
Sensory evaluation shows it is widely accepted, however, the work is continuing to ensure and sustain the high level of acceptance of the product. In this regard, the Council is already promoting investment in the commercial production of soy sauce in Nigeria, using the combination of the raw materials identified, the process and the production equiment developed. A feasibility study prepared indicated that the return on investment could be high. The cost of establishing the plant is low and it is within the definition of small and medium enterprises in Nigeria.
