Cassava or manioc, scientifically named as Manihot esculenta, was originally a perennial shrub of the New World. It’s out-breeding species having 2n=36 chromosomes (El-Sharkawy, 2003).
By Wahaj Fatima 1 Muhammad Waheed Iqbal 2
Cassava is also recognized as yucca, manioc or tapioca, and its production is mostly fall out in developing countries globally (FAO 2014). In 2016, FAO reported that over half of the world’s cassava is produced in Africa (54%), with nearly 13% in the US and 33% in Asia. The five countries, including Barbados, Cook Islands, China, India, and Suriname, produce the highest yield of cassava. Cassava is a crop grown in tropical and subtropical areas where people are affiliated with malnutrition, so it is a potentially excellent food source for developing countries. After rice, maize, and sugarcane, Cassava is one of the most significant staple crops grown in the Caribbean and tropical Africa. It is now grown in more than 90 countries and most important forth dietary source of calories in Africa, Asia, Caribbean and Latin America (Scott et al. 2000). According to Food and Agriculture Organization, cassava ranks second in its production after sweet potato in roots and tubers (FAO, 2008). In Africa, 95% of produced cassava is entirely used for food consumption (Cock 2011; Hillocks 2002).
Cassava is composed of two tissues; roots (50%) and leaves (6%). However, both parts have distinct nutritional composition. In Africa, about 65% of the total population are using cassava roots as an essential source of calories (Nweke 2005). Not only in Africa but also 70% of cassava root is used for human consumption worldwide while the remaining 30% is used as animal fodder (El-Sarkawy, 2003; FAO, 2008) and produced other industrial products such as alcohol, glucose, and starch. In addition to the roots, cassava leaves are used as an important vegetable in the Congo and Tanzania. Cassava roots are mostly white, but these are also found in different colors assortment from white to yellow. As far as its nutrition is concerned, as a source of energy, it occupies sixth place worldwide due to its 80% starch content on a dry basis (El-Sarkawy, 2003). Cassava roots are consumed either directly after cooking or in processed forms. Their leaves are high in protein supplements. According to research by Ravindra (1993), leaf protein content ranges from 21% to 39% on a dry basis among cultivars. Leaves are used for animal nutrition either as fresh forage or in feed formulation (Ravindra, 1993). Moreover, Cassava varieties are classified into two categories; either “sweet” or “bitter” (Mkumbira et al. 2003). Some Cassava varieties can be eaten as a raw form without pre-preparation or processing due to their low cyanogenic glucosides content, generally regarded as sweet varieties in the scientific literature (Carmody 1900). Other varieties need some preparations to make the final product safe and regarded as bitter varieties due to much higher cyanogenic glucosides (Chiwona‐Karltun et al. 2004; Dufour 1989; von Hagen 1949).
In today’s world, infectious diseases are evolving rapidly, with tremendous effects on people’s health and well-being throughout the world. Emerging viral infections, such as severe acute respiratory syndrome-related coronaviruses (SARS and MERS), pose a great threat to public health due to the high mortality rate. Recently evolved coronavirus from Wuhan city in late 2019 belongs to the family of viruses that includes the common cold and SARS (severe acute respiratory syndrome). Now, the whole world is under COVID-19, a global pandemic condition affecting many developed and developing countries. According to recent researches, a strong immunity system is a key weapon to minimize the risk of infection. Preexisting illnesses like diabetes, cardiovascular diseases, hypertension, chronic kidney disease, chronic lung disease, diabetes, hemoglobin disorders, and respiratory issues are high-risk factors to COVID-19, but it all depends on an individual’s immunity. People having strong immunity can fight against COVID-19 when compared to people with lowered immunity.
The immune system consists of collecting cells, different biological processes, and chemicals that defend the body against invading pathogens, including bacteria, viruses, and other toxins. Many factors are responsible for lowering immunity, including micronutrient deficiencies, poor nutrition, smoking, alcohol consumption, infections, illnesses, major burns, emotional and physical stress, and medications, such as chemotherapy to treat cancer and post organ transplantation. Infection and diseases can easily be prevented by keeping the immune system healthy and strong by consuming nutritious food and getting enough sleep and exercise. All these ways are used to boost the immune system. Nutrition is intricately associated with immunity. Consuming good quality diets is always desirable and important during the COVID-19 pandemic. Vitamin C, vitamin D, zinc, turmeric, garlic, medicinal mushrooms, and along with this sound sleep, regular exercise, and meditation will also boost and improve your immune system to fight against infections.
There are some immunity-boosting foods and supplements that would be important to consider for fighting against COVID-19. Eat fresh fruits, vegetables, whole grains, nuts, and traditional fermented products on a daily basis can boost the immune system. Various micro and macro ingredients in the diet are determinants of gut microbial composition that ultimately shape the immune responses in the human body. Essential elements in maintaining immune function are adequate intake of Zinc, Iron, and Vitamins, A, B12, B6, C, and E. Vitamin C is a significant component of water-soluble vitamins to make a strong immune system (Noorush Shifa Nizami,2020). African Indigenous Leafy Vegetables are very rich in vitamins, minerals, and other nutrients contributing to the healthy functioning of the body, immune-boosting, and good nutrition. Cassava, an African tuber, is a rich source of many micro and macronutrients. The cassava root tubers are fundamentally a storehouse for starch and a major source of dietary energy. Raw cassava roots have ample carbohydrates about 15 to 45 mg/100 g relatively high in range. According to research for concerning minerals, it has been reported that cassava roots also have iron ranging from of 8 to 24 mg/kg and zinc levels 3 to 140 pm (Doss and Morris 2000). Compared with other root crops, cassava is a good source of carotenoids such as pro-vitamin A. Yellow root tubers enriched with β-carotene than white root tubers.
On a dry weight basis, the protein content is shallow in cassava roots range from less than 1% to 5%, depending on the variety. But these proteins have low levels of the essential amino acids leucine and lysine as well as of the sulfur-containing cysteine and methionine (Diasolua Ngudi et al. 2002; Gomez and Noma 1986; Yeoh and Chew 1976). The nutritive value of cassava leaves is similar to other dark green leaves and is an extremely valuable protein source (Latham 1979). Besides protein, cassava leaves comprise many vitamins, minerals, and carotenoids such as vitamin A, vitamin C, vitamins B1 and B2, niacin, and β-carotene and minerals, including ferric oxide and calcium. Leaves contain major carotenoids were the non-vitamin A carotenoid lutein (86-290 mg/kg fresh weight (FW) and the pro-vitamin A carotenoid β-carotene (13-78 mg/kg FW) (Adewusi and Bradbury 1993). Cassava leaves also have low level of tryptophan but contain excellent amount of lysine, a limiting essential amino acid in cereal-based diets (Rogers and Milner 1963).
Besides used as leaves and roots, cassava is also used as a fermented food. Fermentation of cassava generates unique food products, mostly limited to the region/ethnic group of origin. Fermented cassava products marketed include Peujeum, Chicha, Mingao, fufu, Kpokpo Gari, Lafun, etc. (Ibok Nsa Oduro). Different levels of verifications have supported the role of nutrition and fermented foods in balancing and promoting immunity. In addition to their improved nutritional quality, fermented foods provide viable microorganisms as probiotics to balance the gut microbiota. As a result, the gut microbiota and the immune system developed a mutualistic relationship and cooperated to support. Probiotics restore the composition of the gut microbiome and have the potential to boost immunity, which protects against infectious diseases like COVID-19 and other diseases (P.N. Anyiam1, 2020).
Cassava applications are different in different regions; however, the most important is its use in human consumption. Particularly in Africa and Latin America, cassava is used directly for human consumption in the form of snacking or simple cooking. Sweet cultivars are low in cyanogen, used directly as food to avoid health hazards. But In bitter cultivars, cyanogenic glycosides and their toxic products of degradation are removed using a mix of complex traditional methods and modern technologies during food processing and preparation (Essers, 1995). According to Nweke (2005), cassava is generally used as five different types of products like granulated products, pasty products, cassava leaves, fresh and dried roots. These products have different characteristics and are differently marketed. The fresh sweet-cassava roots typically eaten in various forms; raw, roasted, or boiled in water or oil. Dried-cassava roots are further marketed as fermented and unfermented products. Pasty cassava products are further classified into uncooked and steamed pastes (Nweke 2005). Cassava has much non-food utilization too. It is also a remarkable source of commercial animal feed, fiber for textile and paper industries, and starch for many pharmaceutical and food plants (Jakrawatana et al., 2016).
Authors : Wahaj Fatima 1 and Muhammad Waheed Iqbal 2 1 National Institute of Food Science and Technology, University of Agriculture Faisalabad 2 School of Food and Biological Engineering, Jiangsu University, Zhenjiang, China