Nutritional studies are frequently designed and carried out to examine the quantity and quality of nutrients present or available in food samples. In developing countries, the tendency or emphasis is now drifting from the quality (i.e. adequate proportions of nutrients) of food taken to the quantity. This has led to some diseases which could have been prevented by effective feeding in such countries. A thorough knowledge of the importance of these nutrients and their easily accessible sources will go a long way to help correct the situation (Karger, 1979). Human body needs nutrients to help the body for the production of energy to meet the demands of everyday physical activities and ensure mental efficiency, growth and development (Wiley, 1977). For man, the sole source of nutrients is food (Sinclair and Howat, 1980). A person who is hungry and sluggish due to lack of energy cannot do anything effectively (Marralle et al., 1986). This situation is compounded by lack of awareness of the Public on the nutritive values of a number of food items that are readily available but not generally consumed. Several people are ignorant of the nutrients they could derive from the consumption of certain foods.
A lot of work has been done on chemical composition of Nigerian foods (Oyenuga, 1978; Osifo, 1970; Oke and Ojofeitimi, 1984). In developing Countries like Nigeria, many foods put up for sales to the public lack standard both in term of quality and quantity. For instance, a loaf of bread bought in this Country does not even have a standard weight. To the average consumers in Nigeria, these determinations have little, if any meaning to their diets; hence the problem of malnutrition especially in children is one of great concern (Oke and Ojofeitimi, 1984). According to Sir Robert Namara (1973), President of the World Bank in an address to his board of governors on the World food situation, Y.Malnutrition is widespread, it is a major cause of high mortality among young children, it limit the physical and mental growth of hundreds of millions of those who survive it, reduces their productivity as adults; it is therefore a major barrier to human development. Although the causes of malnutrition are not always based on food availability or economic circumstances alone in the developing Countries; choice of food is strongly influenced by religion, custom, habit and prejudice, all of which stem from the particular cultural pattern and often result in poor selection of food and hence poor feeding practices (Allan, 1971; Casper and Waker Field, 1976; Alfred and Bogi, 1986). Hence, man must eat good food to grow and to live through the rigors of life. A good food is the one that contains the nutrients in the required proportions. i.e. balanced diet (Oyeleke, 1984).
This study was therefore undertaken to determine the nutrient (macronutrient) compositions of Amala served with okro soup and Jollof beans that are commonly consumed in almost all parts of Nigeria and other developing Countries and to relate the nutrients so determined with the standard calorie requirements for different population groups.
MATERIALS AND METHODS
Source of material: The two meals were obtained from Ikeji-Arakeji, Osun
The samples were dried in an Oven and the dried materials were grounded in a
mortar into powdered forms and then stored at low temperature in desiccators
until required. Proximate analysis was carried out with 0.3g each of the two
meals using A.O.A.C. (2005) methods. The determinations were made only on dry
samples except moisture determination and the results were obtained in terms
of dry weight and wet weight of the samples. Carbohydrate, protein, fat, fibre,
ash and water contents of the meals were estimated.
RESULTS AND DISCUSSION
The proximate analyses of Amala served with okro soup (no meat) and Jollof beans are shown as Table 1 (dry weight basis) and Table 2 (wet weight basis) respectively.
Compositions of Amala Served with Okro Soup and Jollof Beans (Dry Weight)
are expressed as means of five determinations (Appendix 1).
Composition of Amala Served with Okro Soup and Jollof Beans (Wet Weight)
are expressed as means of five determinations (Appendix 2)
Although the analyses (except moisture determination) were done of dry samples, it is only reasonable to convert the results to wet weight (as shown in appendix 2) since meals are consumed in wet forms.
Emphasis is placed on the wet weight data for the discussion of the results because meals are taken in such forms. Nutrients (in grams) and derivable energy (Table 3) from the meals were compared with the Recommended Dietary Allowance (Table 4) and the standard energy/calorie requirements for different age groups (Table 5) respectively.
The large percentages of moisture contents of Amala served with okro soup (61.80%)
and Jollof beans (79.60%) were expected because cooking is always done with
derived from Amala Served with Okro Soup and Jollof Beans (g) and derivable
calorie from carbohydrate only (Kcal)
derivable from carbohydrate only (Appendixes 3 and 4)
Dietary Allowance (RDA) of different nutrients
Institute of Medicine of the National Academy of Science (13th
August, 1997), Washington
The ash content of Jollof beans (5.00%) was high compared to that of Amala
served with okro soup (2.19%). This may possibly be due to high amount of salt
(and at time potash) added during preparation of Jollof beans. However, this
amount may vary from one person to another since addition of salt, potash and
other condiments to foods during cooking depends on the taste of individuals.
The high value of lipid content of Jollof beans (15.00%) was not surprising
due to the fact that a lot of palm oil must have been used to prepare the meal.
However, the lipid content of Amala served with okro soup (5.90%) must have
come mainly from the oil added to the okro soup. Jollof beans is a protein-rich
meal, hence, its high percentage (16.06%) compared with that of Amala served
with okro soup (1.76%), a rich source of carbohydrate.
The estimated amount of energy from carbohydrate part of the meals was 283.42 and 136.34 Kcal. in Amala served with okro soup and Jollof beans respectively. The difference in calorie arises from the difference in caloric values of the starting raw materials. The Amala which is a condensed source of carbohydrate, an energy giving diet, was made from yam, while Jollof beans was prepared with oil and beans, a diet that is richer in protein (Baptist, 1984). Another nutritional importance of the carbohydrate load of these meals is that not all carbohydrate is available for energy, since energy from fibre was not estimated, hence the caloric value obtained.
The nutrient composition and the subsequent nutritional value of any food depend
on the type of raw materials used and the method of preparation (Oguntona and
energy/calorie requirements for different age groups with typical day-to-day
life style (Kcal)
Dietary Guidelines for Americans, 2005. a-Sedentary means a lifestyle
that includes only the light physical activity associated with typical
day-to-day life. b - Moderately active means a lifestyle that includes
physical activity equivalent to walking about 1.5-3 miles per day at 3-4
miles per hour, in addition to the light physical activity associated
with typical day-to-day life. c- Active means a life style that includes
physical activity equivalent to walking more than 3 miles per day at 3-4
miles per hour, in addition to the light physical activity associated
with day-to-day life
In addition, what an individual feeds on is further determined by the available
foods and his socio-economic status (Casper and Waker Field, 1976; Alfred and
Bogi, 1986). However, the general consideration in meal selection is whether
the food class (es) meet the nutritional requirements necessary for normal growth
of the relevant population groups.
Comparing the results (Tables 2 and 3) obtained from this study with the Recommended Daily Allowance (RDA) of different nutrients (Table 4) and energy requirements of the various age groups (Table 5), it becomes obvious that the energy derived from Amala served with okro soup and Jollof beans is grossly inadequate for these age groups. Moreover, it does not meet the energy demand of any persons. When viewed against the background that the analyzed meals were meant for the adults who are always involved in farming activities and other hard labour, it therefore becomes glaring that their energy needs cannot be met. The total amount of carbohydrate that is derivable from Amala served with okro soup and Jollof beans is 70.85 g and 34.09 g which corresponds to 283.42 and 136.34 Kcal respectively (Appendix 3 and Table 3). This is grossly inadequate for the population groups that the meals are meant for. The consequence of this may lead to malnutrition (FAO, 1972; 1974) especially in children, a major cause of high mortality among young children. Furthermore, other inadequate nutrient like proteins may be channeled to meet the energy needs/demands while that of fats and oils in the diet may lead to malformation of the brain. This may also limit the physical and mental growth of many children who survive it and reduces their productivity as adults (Sir Robert, 1973). This may be a major barrier to human development.
Conclusion: The results obtained from this study compared with the information data on the standard nutritional requirements of different age groups (Tables 4 and 5) concluded that the meals did not meet the nutritional needs of individuals especially in terms of primary purpose of food-energy. The public in the developing Countries need to be educated on the importance of meal selection. They should be educated on the importance of balanced diet, especially the rural settings of these developing Countries. It is also important that consumers multi-disciplinary scientific efforts be made at the Governmental level to solve food problem of substandard in quality in these Countries.
These levels are based on Estimated Energy Requirements (EER) from the Institute of Medicine Dietary Reference Intakes Macronutrients report, 2002.
Calculation of percentage dry weight
Therefore, 1 ml of the sample solution contained 0.84mg of carbohydrate. Then
250ml of the sample solution would contain 0.84 x 250 = 210mg/250 ml.
* = Dilution factor.
Similarly, percentage dry weight of carbohydrate in Jollof beans meal = 62.21% e.t.c.
Calculation of percentage wet weight: Calculation of percentage Wet weight
of carbohydrate in Amala served with okro soup:
Percentage of wet weight = 32.09%
* = Moisture content
Similarly, percentage wet weight of carbohydrate in Jollof beans meal = 12.69% e.t.c.
Estimation of the amount of the nutrients based on wet weights from the meals:
0.3 g of analyzed Amala meal sample contained 32.09% of carbohydrate. i.e. 32.09%
of 0.3 g of analyzed sample is equivalent to 32.09/100 x 0.3 of carbohydrate
= 0.09627 g.
Therefore if 0.3 g of analyzed sample contained 0.09627 g of carbohydrate, Then 220.80 g (total weight) of analyzed Amala meal would contain
Similarly, amount of carbohydrate in Jollof bean = 34.08534 g e.t.c.
APPENDIX 4: Calculation of derivable calorie from carbohydrate content based on wet weight:
1 g of carbohydrate is equivalent to 4 Kcal. i.e. 1 g = 4 Kcal. Therefore 70.85472* g = 4 x 70.85472 = 283.42 Kcal. Similarly, for Jollof beans meal, derivable calorie = 136.34 Kcal. *Obtained from Appendix 3.