1.1 Economic and social impact
1.4 Secondary and derived product
1.5 Requirements for export and quality assurance
Plantains and other cooking bananas, staple foods grown throughout the tropics, constitute a major source of carbohydrates for millions of people in Africa, the Caribbean, Latin America, Asia and the Pacific. Due to the perishable nature of the fruits, the rate of plantain post-harvest losses varies from one country to another according to the organisation of market chains and modes of consumption. In many producing countries, there are no data on post-harvest losses. The assessment of these post-harvest losses is rather complex because green mature plantains are consumed as well as overripe fruits. However, some factors are likely to depreciate quality and provoke post-harvest losses. These include poor transportation and distribution facilities in the production areas, harvest at maturity close to fruit ripening, and poor storage conditions.
In Cameroon, the most evident post-harvest losses are registered at the producer level in enclave sites during the rainy season (N'da Adopo, 1993). These losses should be less than 35 percentage) in developing countries as previously estimated by FAO (1987).
In plantain production, labour distribution according to sex varies with producer traditions and the economic role of production. In Cameroon, men and boys over 12 years olds are generally in charge of land clearing, land preparation and planting. Women and girls over 15 years old step in go to the planting site and to monitor crop growth. Men and women both perform the transport and sale of products.
1.1 Economic and social impact
Plantains (AAB) as well as other cooking bananas (AAB and ABB), East Africa cooking bananas, beer bananas (AAA) and dessert banana (AAA) belong to the Musa genus. Figure 1 shows great diversity among plantains and cooking bananas.
Figure 1:
Bunches of plantains and cooking bananas from the germplasm collection of CRBP in Njombé, Cameroon (Photo R. Achard)
Bananas and plantains are grown in more than 120 countries, in backyards or in mixed cropping systems by smallholders, and occasionally in monoculture (INIBAP, 1992). The total production is about 64 million tons with 23 percentage of AAB plantains, 16.5 percentage of cooking bananas, and 18 percentage of highland cooking bananas and beer bananas. The most prevalent combination of mixed cropping systems is cultivating plantains with coffee and cocoa. In Latin America for example (Colombia, Costa Rica, Venezuela), mixed cropping with coffee is common, but association with cocoa and pure stand of plantains are also found (Costa Rica and Panama). Table 1 presents some data on the production and the consumption of plantains and other cooking bananas in some producing countries.
Table 1 : Main producing and consuming countries of plantains and other cooking bananas
Countries |
Yearly Production
|
Consumption (kg/person/year) |
Plantain Calories Consumption (Calories/person/day) |
Africa
|
600
2463
1150
|
67
82
66
|
111
197
115
|
* These countries produce mainly cooking and beer bananas.
Sources : FAO (1989), United Nations (1991), Ganry (1990) and Lescot (1993).
According to Treche (1997), 69.4 percentage of plantains and other cooking bananas are used for human consumption while 8.0 percentage are used for animal feed. Post-harvest losses and transformed quantities in the world are 11.5 percentage and 11 percentage, respectively. In most cases plantains are locally consumed. Plantain also shows great adaptation to urban consumption and exportation to specific markets. This will vary from one country to another because of prevailing eating habits:
- Ripe or unripe plantain pulp cooked in water or vapour;
- Pastry from unripe plantain cooked in water and pounded in a mortar;
- Elastic pastry prepared from plantain flour and boiling water;
- Ripe or unripe plantain pulp roasted on charcoal fire;
- Unripe plantain pulp cooked with water, meat or fish, palm oil, salt and various spices;
- Slices of unripe or ripe plantain pulp fried in palm oil or other vegetable oils.
The available food energy (AFE) from plantains and other cooking bananas in some producing countries is shown in Table 2 (Treche, 1997).
Table 2 : Available food energy (AFE) from plantain and other cooking bananas in selected producing countries
|
Countries |
AFE from plantains and other cooking bananas
|
Uganda
|
436
|
Boiled plantain
The fingers of ripe plantain or unripe plantain are peeled and cooked in boiling water or in vapour for 20 to 50 minutes depending on the cultivar and ripening stage of the fruit. Plantains boiled in this way are consumed with various sauces or other accompanying dishes. This mode of cooking and eating is quite common in most plantain producing countries in Africa.
Green mature fruits after peeling can be cooked in water mixed with palm oil, goat or cow meat, salt and diverse spices (condre in Cameroon). It is a classical dish for the people of West Cameroon during weddings, funerals and other traditional ceremonies. The pulp of unripe plantains cut into pieces can also be cooked with water, salt, palm or groundnut oil, groundnut paste, tomatoes and spices, fresh or smoked fish or meat. This makes a porridge or one-course meal.
Plantain pastry
Unripe plantain pulp after cooking in water or vapour is pounded in a wooden mortar to be transformed into a homogenous flexible pastry. The addition of a few pieces of cooked cassava can be needed to improve the elasticity of the pastry. This food called "ntuba" in Cameroon (Figure 7), "foufou" in Côte d'Ivoire, "fufu" in Nigeria and Ghana is always eaten with a sauce which is somewhat rich in proteins. It is a staple food in certain regions of these countries.
Figure 7:
Plantain pastry (ntuba) prepared in Cameroon from the pulp of plantain boiled and pounded (photo S. Morelle)
Plantain Pastry lined with green leafy vegetables
Plantain fingers, generally of the horn or false horn type, are cooked in water with leafy vegetables (pumpkin leaves, amaranth leaves, etc.). After cooking, the plantains are peeled and pounded hot in a mortar. Vegetables, which were before hand washed in cold water and drained by hands are then added to the pastry as well as salt, pepper and unrefined palm oil. All of this is well mixed and served for eating.
Plantain pastry mixed with beans
The preparation is the similar to the preceding recipe, except cooked kidney beans are substituted for vegetables. The people in the West Cameroon prepare this recipe.
Roasted Plantains
The entire pulps of unripe or half-ripe plantains are roasted on heated charcoal. About fifteen minutes is enough to prepare simultaneously 2 to 4 fingers of plantain depending on the customers. Women on the roadside generally sell this plantain which is consumed warm with other delicacies (roasted plums, avocado, roasted fish, meat kebab). The cooking and selling of roasted plantain constitutes a major commercial activity for some women in Cameroon, Côte d'Ivoire and other plantain producing countries.
Fried plantains
Ripe or unripe plantain are peeled and cut into slices and fried in palm oil or other vegetable oil for 4 to 5 minutes at 160-180_C. Roasted fish, chicken or meat kebab are sometimes served. Fried ripe plantain or aloko in Côte d'Ivoire, red-red in Ghana and dodo in Nigeria is a meal well cherished by children and in restaurant. Fruits of certain cooking bananas (Topala, Pelipita, Popoulou, Kalapua N_2, etc) also produce good quality fried plantains.
Plantain fritters
The pulp of over ripe plantains are pounded and mixed with a small quantity of maize or other local cereal flour (about 1/4 of pulp weight) and salt to form a homogeneous pastry. The fritters obtained by deep frying of small pastry balls in palm oil (160-180_C for 4 to 5 minutes) are eaten hot or warm alone or with other dishes (sauce, spices, fried beans, etc). Over ripe fruits of dessert or cooking bananas can also be used.
Plantain Chips
Plantain chips are the most popular plantain products in Nigeria (Onyejegbu and Olorunda, 1995). They are prepared by frying round slices of unripened or slightly ripened plantain pulp in vegetable oil (Figure 8). Best quality plantain chips have been obtained in Cameroon by frying round slices of pulp (2 mm thick) in refined palm oil between 160 and 170_C for 2 to 3 minutes (Lemaire et al, 1997). These generally absorb less frying oil than chips from cooking banana and dessert banana. The antioxydising treatment (soaking in citric acid solution) which is indispensable to inhibit the action of polyphenoloxydase responsible for the browning of the pulp of dessert banana before frying is not necessary when making chips from plantains and certain cooking bananas (Lemaire et al, 1997). The plantain chips prepared in this way and packed in plastic sachets or in hermetic aluminium sachets (Figure 10) can stay crispy and conserve all their quality for more than 4 months at room temperature and away from light. They generally contain less than 35 percentage of fats and between 1 to 3 percentage residual humidity.
The production and marketing of plantain chips in Africa (Cameroon, Nigeria, Ghana, and Côte d'Ivoire) is principally a feminine activity, which has greatly developed these past years. They are generally eaten as snack food. Industries producing banana and plantain chips have equally been developed in Cameroon and Colombia to give more value to this perishable food product. These industrial or semi-industrial units use various equipment making it possible to mechanise certain activities in the production chain. The "robot-coupe" (models R 502, R 602, or R 602 VV) used for the rapid slicing of banana or plantain pulp into round sizes of uniform thickness is an example (Figure 9). In industry, frying can be done using continues or discontinues electric or gas deep fryers, whereas vacuum packaging with appropriate apparatus is welcome.
Green mature plantain bunches |
| Separation into individual fingers |
| Washing and manual peeling |
| Slicing into round pieces (2 mm thick) |
| Salting (optional) |
| Frying in vegetable oil |
| (Refined palm oil, 2 to 3 minutes at 160-170_C) |
| Plantain chips (golden colour) |
| Draining and cooling |
| Hermetic packaging |
| (Plastic or aluminium sachets) |
| Storage and commercialisation |
Figure 8: Flow chart for the preparation of plantain chips (Lemaire et al., 1997)
,Figure 9: A "robot-coupe" used for rapid slicing of banana and plantain pulp into round sizes of uniform thickness (reproduced from the catalogue of ROBOT-COUPE S.N.C., France).
Figure 10:
Traditional and industrial packaging of plantain chips produced in Cameroon (photo. J. Tchango Tchango)
| Green mature plantain bunches | ||
| Separation into individual finger | ||
| Washing and manual peeling | ||
| plantain pulp | ||
| _____________________ | _____________________ | _____________________ |
| Blanching (80_C for 5 minutes) | Slicing into round pieces (2 mm thick) | |
| Slicing into round pieces (2 mm thick) | Antioxidant treatment (3 minutes in critic acid solution) | |
| _____________________ | _____________________ | _____________________ |
| Drying (for some days in the sun, 65_C for 48 hours in an oven) | ||
| Grinding | ||
| Plantain flour | ||
| Packaging and storage |
Figure 11: Plantain flour production flow chart (Ngalani, 1989)
Unripe plantain is traditionally processed into flour in Nigeria (Ukhum and Ukpebor, 1991) and in other west and central African countries. This traditional technology is equally present in Amazonian Bolivia. The preparation method consists of peeling of the fruits with the hands, then cutting the pulp into small pieces, and air drying them for few days. The dried pulp is then ground in a wooden mortar or a corn grinder. The flour produced is mixed with boiling water to prepare an elastic pastry (alama in Nigeria and foufou or fufu in Cameroon) which is eaten with various sauces. The colour of the flour obtained is more or less dark due to the action of browning enzymes. Some improvement of this traditional method (Figure 11), by blanching the plantain pulp at 80_C for 5 minutes and cutting them into round pieces (or by soaking the round pieces for about 3 minutes in a sodium metabisulfite solution (41 g/1) containing 3 g citric acid, followed by draining and drying in a drying oven at 65_C for 48 hours or in the sun for some days resulted in the production of a more or less whitish flour (Ngalani, 1989). Plantain flour containing 10 percentage of residual humidity and hermetically packed in plastic sachets can be kept for many months without deterioration of its qualities. Plantain flour can be used in different ways.
Flour made from ripe plantain (stage 4 to 5 of ripeness) has been used in making bread, biscuits and instant flour (Ngalani and Crouzet, 1995). Bread obtained by partial substitution of wheat flour by 7.5 percentage plantain flour was not significantly different from that made with wheat flour alone. Extruded biscuits had equally been made with a mixture of millet flour (33.2 percentage), plantain flour (17 percentage), groundnut cake (25 percentage), sucrose (20 percentage) coconut (4 percentage) and sodium chlorite (0.8 percentage). The rehydration properties of instant flour obtained by grinding extruded biscuits were comparable to those of commercial flour, with initial absorption rates two to three times higher (Ngalani and Crouzet, 1995). The soyamusa, a baby food from plantain flour (60 percentage), full fat soybean flour (32 percentage), sucrose (8 percentage), fortified with 0.15 percentage of multivitamins and 0.85 percentage calcium carbonate have been made and used in Nigeria (Ogazi et al., 1991; Ogazi, 1996). Recent work carried out at CRBP Njombé (Cameroon) have defined simple formulations for fritters and cakes from plantain flour (Figure 12) well appreciated by consumers (Morelle, 1997). The cakes were obtained by cooking a homogeneous pastry in the oven at 150_C for about 50 minutes. Pastry for cakes was made from 100 g plantain flour, 60 g sugar, 40 g fresh semi-skimmed milk, 10 g butter, 5.5 g baking powder, 3 g of pieces of lemon peel and 1 egg. The pastry for fritters can be made with either a mixture of 250 g plantain flour, 100 g fresh semi-skimmed milk, 75 g sugar, 50 g butter, 5.5 g baking powder, 2 g of pieces of lemon peel, 0.5 g salt and 3 eggs ("beignets merveillés") or 63 g water, 32 g plantain flour, 25 g butter, 7 g sugar, 0.5 g salt and 1 egg ("beignets soufflés"). The fritters are thus obtained by frying small balls of these homogeneous pastries in refined vegetable oil (palm, groundnut and cotton) at 140-150_C for about 10 minutes. The quantities of the ingredients in the mixture for the various fritters and cakes can be modified and adapted according to the taste of the consumers.
Figure 12:
"Beignets merveilles" and cakes from plantain flour produced in Cameroon (photo. J. Tchango Tchango)
1.4 Secondary and derived product
Other uses of plantains
Jams, marmalades, juice, vinegar, beer and alcohol can be made from ripe plantain fruits. In some towns and villages in the region of Ife in Nigeria, a non-alcoholic drink called "sekete" is prepared by women. They take ripe plantain fruits that have been peeled and soaked in water for 2 to 3 days, then filter this mixture to obtain a drink which is bottled and sold locally (Ohiokpehia, 1985). Also in Nigeria, Ogazi (1996) reported the production of beer from over ripe plantain pulp with alcoholic content of 5 percentage v/v and specific gravity between 0.998 and 1.0034. These uses are however more typical of banana than plantains. In Uganda and other East African countries (Burundi and Rwanda) for example, beer bananas are very often used for the domestic production of beer frequently consumed in these regions (Davies, 1993).
1.5 Requirements for export and quality assurance
Bunches or fruit qualities of plantains are judged by important criteria at all stages in the market chain irrespective of the cultivars (N'da Adopo, 1993). Different standards are applied by individuals in the distribution network to assess plantain quality: (1) bunches with well filled fingers and sufficiently round fruits at the time of harvest, (2) fresh fruits without cracks, (3) fruits without mechanical damage, (4) well defined orange rose pulp, and (5) fruits without pest or fungal attacks.
Besides market trends, it was noticed in Cameroon that other factors affect the price of a bunch of mature green plantains (N'da Adopo et al., 1996). These factors include bunch quality at harvest (size, weight, level of finger filling and the colour of the pulp) and its freshness given transportation and storage conditions. A good bunch can cost twice the price of a poor bunch.
Plantains for exportation are carefully handled and transported to preserve the original fruit quality. Handling of those sold locally contrasts sharply with the fragile and perishable nature of the product.
Certain diseases significantly affect fruit qualities. Cercospora diseases caused by Mycosphaerella fijiensis and M. musicola reduce the filling of fingers resulting in about 30-percentage yield reduction. (Momambo, 1993). All known plantain cultivars are susceptible to these fungi. Good disease control can be achieved with fungicides belonging to triazole and benzimidazole groups. As costs continue to rise, the need for resistant hybrids becomes imperative. Cultural practices used to control such diseases include good drainage (Jeger et al., 1995) and frequently stripping off the leaves with necrotic tissues. Some fungi are responsible for post-harvest diseases, which affect the quality of the banana and plantain fruits. For example anthracnose caused by Colletotricum musae provokes the decay of fruits during ripening. Incidence of anthracnose may be reduced by removal of inoculum laden banana and plantain trash from packing areas and by avoiding injury to fingers and pedicels during harvesting and packing (Jeger et al., 1995). Anthracnose may also be controlled chemically after harvest with spray or dip treatments using fungicides (thiabendazole, imazalil, etc). Cigar-end rot disease caused by Trachysfera fructigena and Verticillium dahliae renders fruits unsatisfactory for consumption. Placing polythene sleeves over the stems before the hands come out (Jeger et al., 1995) effectively controls cigar-end rot disease.