ABSTRACT
The thrust of this work was to identify some popular and lesser-known cultivated and forest green leafy vegetables consumed in Igbo-ukwu, Aguata LGA, Anambra State, Nigeria. Those identified include ugbogulu, eliemionu, ariraa, okpa okuku, ugu oyibo and abuba ji nwannu, used in this study. These vegetables were purchased in bulk from Igboukwu daily market, cleaned and divided into 3 portions. Fresh portions served as the controls. The sun and the shade dried samples were the processed portions.
These cleaned vegetables and their products were analysed for various nutrients, anti-nutrients and food toxicants using standard methods. Both nutrient contents of the vegetables and their dishes as well as the organoleptic attributes of the dishes were ascertained. The data generated from both the vegetable and their yam dishes were analysed using percentages, means, standard deviation and the standard error of the mean. New multiple Duncan’s studentized range test was applied to separate and compare means.
Ugbogulu, ( Curcubita pepo), ariraa. ( Corchorus trideus tiliaceae) eliemionu. (Celosia argentea), ugu oyibo. (Jatropha aconitisolia), okpa okuku (Uvarae chamae) and abuba ji nwannu ( Ipomoea batatas) were identified by Igbo-ukwu women as wild and cultivated edible vegetables. Both parents and grandparents form major sources of information about cultivation, harvesting, processing, preparation and utilization of yam dishes based on these vegetables. These vegetable are on the verge of extinction due to poor nutrition education, migration of youths and young adults, seasonality, change in lifestyles, nutrition transition and food habits. Sun and shade drying increased many nutrients such as protein from 10.70 to 19.40%. These processes also increased some micronutrients. Iodine, copper, and calcuium increased from traces to 5.08 and 4.43mg; 0.2 to 2.4 and 1.7mg; from 0.2 to 11.5 and 22.00mg, respectively.
These processes increased phytate, oxalate, tannins and saponins from 0.00mg to 125.58 and 116.5mg; traces to 135.50mg and 112.3mg; traces to 0.15 and 0.16mg and from traces to 0.05 and 0.05mg, respectively.
The yam dishes prepared with fresh, sun and shade dried, as well as pulverized vegetables had increased protein from 5.4 in A-102 –yam dish prepared with sun dried ugu oyibo to 12.6% in A-101 –yam dish prepared with shade dried and ash from 4.6 in in A-103- yam dish prepared with shade dried okpa okuko to 9.50% in A-105-yam dish prepared with fresh sweet potato.. These dishes had traces of phytate, oxalate, tannins and saponins. However, dish prepared with sun dried ugu oyibo leaves had increases in phytate oxalate, tannins and saponins and food toxicants from (traces to 1.21,4.34,16.6 and 14.5g, respectively).
Iron, zinc, copper and calcium in these dishes increased. Iron increased from 3.5 to 33.5mg, zinc from traces to 4.2mg, copper from traces mg to 1.4mg and calcium from 2.00 to 25.50mg, respectively. The dishes prepared with fermented oil bean seeds, fresh okpa okuku leaves and fresh sweet potato leaves had increases in beta-carotene that ranged from traces to 52.00, 25.3 and 24.9mg each.
The dishes prepared with fresh
sweet potato leaves and that prepared with fresh ugu oyibo leaves had the best
organoleptic attributes and general acceptability. (7.5 and 7.3, respectively).
CHAPTER ONE
INTRODUCTION
1.1 Background information
Inadequate food and nutrient intake, improper feeding practices, poor nutrition education, insufficient food availability at household level, domestic processing techniques and food preparation methods are among the major causes of malnutrition (NDHS, 1990). Nutrition and nutrition-related diseases continue to be a problem of public health significance in Nigeria.
Several efforts are in place to reduce malnutrition. These efforts amongst others are studies undertaken in Nigeria to assess the prevalence of malnutrition in the target population.
Some of these studies were the Nigeria Demographic and Health Survey (NDHS, 1990), the Participatory Information Collection study (PIC, 1993), the Multiple Indicator Cluster Survey (MICS, 1995), the Benchmark Survey (1996) and the most recent, National Food Consumption and Nutrition Survey (NFCNS) (IITA, 2004) among others.
These studies over the years established high prevalence of protein-energy malnutrition (PEM), especially in children 0-5 and pre-school (IITA, 2004). PEM contributes to as much as 52% of all deaths (Micro Nutrient Initiative, 2004).
National Demographic and Health Survey (NDHS,1990 ) reported 43% stunting among children under five, the UNICEF/OAU Participatory Information Collection study (PIC, 1993) reported 52% stunting, 9% wasting and 36% underweight among children of the same age group.
UNICEF (2004) estimated that approximately one out of three of the children younger than five years are chronically malnourished. They are trapped early in life pattern of ill health and poor development.
It is widely accepted that PEM is associated with a number of micronutrient deficiencies. Micronutrient deficiencies, for example iron deficiency anaemia (IDA), Iodine deficiency disorders (IDD), Vitamin A deficiency (VAD) are also common and contribute to poor physical, emotional and mental development of children as well as reduction in productivity and decreased efficiency in adults, especially mothers.
The UNICEF (1993) study reported that 35% of mothers and 29% of children were anaemic, 7.3% of mothers and 9.2% of children were Vitamin A deficient.
The National Micronutrient Survey (1993) reported even higher figures – 62% women and 75% children were anaemic and 1 out of every 3 children was Vitamin A deficient.
The results of Nigeria Food Consumption and Nutrition Survey (IITA, 2004) showed that despite the advances made over the years in agriculture, research and production, 29.5% of children under 5 were suffering from Vitamin A deficiency, 13.1% of mothers and 19.2% of pregnant women at national level were considered at risk of Vitamin A deficiency, respectively.
About 27.5% of children under 5 were at different stages of iron deficiency. Approximately, 24.3% of mothers and 35.5% of pregnant women were at different stages of iron deficiency
Zinc is now recognized as an essential micronutrient critical in human nutrition (UNICEF, 2002). The clinical syndromes associated with zinc deficiency include growth retardation, male hypogonadism, skin changes, mental lethargy, hepatosenomegaly, iron deficiency anaemia and geophagia (WHO/UNICEF, 2002).
Apart from low zinc levels due to rapid growth, pregnancy and lactation cause zinc deficiency if these increased needs are not met.
At the national level 20% of children under 5 are zinc deficient. Zinc deficiency was highest in pregnant women (43.8%). More than one-quarter (28.1%) of the mothers were zinc deficient.
What these data show is that in spite of all efforts aimed at improving the nutritional status of children and women, prevalence rates of nutritional deficiencies are on the increase and remain unacceptably high. The consequences of malnutrition include childhood morbidity and mortality, poor physical and mental development, poor school performance and reduced adult size with reduced capacity for physical work (WHO, 1995).
If no action is taken, these conditions would spell enormous consequences for national productivity, economic growth and human development (IITA, 2004).
Anambra state shares a common border with Imo state where the survey work was done. This recent Nigeria food consumption and nutrition survey (IITA, 2004) was not conducted in Anambra state. There is limited documented evidence concerning micronutrient status of the members of the communities in Anambra. The result of the survey in the neighbouring/adjoining states, Imo and Akwa Ibom, showed some pockets of micronutrient deficiencies. These deficiencies are not restricted to only these states. Anambra community has almost common culture and food habits with these states where the study was conducted.
Besides, clinical signs observed during the community Health, Profile, Participatory learning and action seminars/health observational tour (NPHCDA, 2005) in some wards of Aguata LGA showed that there are clinical signs of malnutrition, especially those of micronutrients. This development is surprising because the people of Aguata LGA particularly cherish vegetables, which are the richest plant sources of micronutrients in almost all dishes for eye appeal most importantly and to a lesser extent for their nutrient concentrations.
Micronutrient deficiencies are global issues. They require fundamental approach such as assessment of people’s traditional meals. This will ascertain the nutrient contents of various foods to plan adequate intervention strategies to virtually eliminate malnutrition.
Identification of the commonly, traditionally and culturally accepted consumed foods to determine their nutrient levels is imperative. It is also necessary to determine the factors that affect consumption such as poor nutrition education, seasonal variation and processing and preparation methods.
The identification of some lesser-known vegetables (“Okpa-okuko”, “ugu oyibo” and sweet potato leaves) readily available and rich in micronutrients is considered important for dietary diversification and to ensure that they are not extinct. “Ugbogulu”, “eliamionu” and “arira” leaves are among the other more commonly consumed vegetables.
Any domestic food processing methods to preserve and retain both macro and micro-nutrients of these vegetables would go a long way to reduce micronutrient deficiencies and be valuable in Igbo-Ukwu and Nigeria in general. Sun and shade-drying are among the domestic food processing methods shown to preserve and retain nutrients in seasonal green vegetables (Udofia, 2005; Wachap, 2005). The thrust of this study is to select both known and lesser-known seasonal green leafy vegetables, sun and shade-dry and pulverize them, prepare dishes and determine their nutrient content as consumed.
1.2 Statement of the problem
Micronutrient malnutrition is implicated in more than half of all childhood deaths worldwide – a proportion unmatched by any infectious disease (Smith and Haddad, 2003). Improving micronutrient status can make enormous difference on the health consequence of these nutrients. The question then is, how much nutrients do our traditional dishes contain? World Health Organization (2002) observed that diet and nutrient are important in the promotion and maintenance of good health throughout the entire course of life.
In Anambra state, there are limited studies to determine the prevalence of micronutrient deficiency among the communities. These are “hidden hunger” and have more to do with the quality of diet rather than the quantity of food produced and consumed. The observational tour of community health profile participatory learning and action (NPHCDA, 2005) depicts that pockets of micronutrient deficiency exist. This position supports the result of Nutritional Status of Children in Anambra State – A Comprehensive Treatise (Nnanyelugo, 1980) reported that vitamin A intake of children in the state was 70% of the FAO requirements. Even though some progress had been made nationally to combat micronutrient deficiency, urgent action is needed to accelerate the efforts to bring micronutrient malnutrition under control. One of these efforts will be to assess the nutrient content of the foods that are often consumed. This is because the quantity of each nutrient in a diet is important and the quantity available for cellular utilization is equally important
Fruits and vegetables are the richest sources of micronutrients. Vegetables are not usually consumed alone, they are often served as accompaniment to main dishes such as in soup meals, casseroles and sauces. They are served with basic staples such as maize meal, cassava foofoo, gari and yam. They are equally served in combination as some of the vegetable provide bounding effect to complement the other vegetables.
Yam (Dioscora spp.) is one of the basic and common staples cherished in Aguata LGA by all members of families. Yam could be used as breakfast, lunch and supper dishes. It is prepared traditionally in combination with vegetables or with just plain palm oil and spices when vegetables are not available. Yam is a well appreciated staple in the local government to the extent that culturally new yam festivals are celebrated to usher in new yam harvest season. Combination of yam and vegetables provides adequate diet. However, at times, it is consumed with only palm oil and spices as boiled or roasted yam or plain yam pottage due to scarcity of vegetables. The consumption of yam without vegetables is of low nutritional quality.
Varieties of green leafy vegetables cultivated or wildly grown and consumed are available especially during the rainy season. Some of these green vegetables are more common, popular and regularly consumed more than others which are lesser known but have similar or even more nutrient value. These vegetables are lesser known and are rarely consumed despite their nutrient content and their ability to withstand draught better than most of the popular known and commonly consumed green vegetables. These lesser known vegetables are going extinct and therefore needed to be studied to ascertain the nutrient content as base for the promotion of its production and continued utilisation.
It is pertinent to apply sun and shade-drying to preserve and retain the nutrient content of these lesser-know vegetables as well as the commonly used vegetables to ensure availability of vegetable at affordable cost year round and in all season
Various yam dishes based on large quantities of these vegetables would be prepared. The nutrient content and their availability would be determined in adult rats.
1.3 Justification
Plant foods are the major sources of nutrients in Igbo-Ukwu, Aguata LGA. However, the availability of the nutrients, especially in fruits and vegetables vary with seasons and locations. Fruits and vegetables are abundant during rainy season and are scarce in dry season. This seasonal variation affects consumption and levels of micronutrient of the consumers.
There are lesser-known edible vegetables that are readily available during dry season in Igbo-Ukwu. Uvaria chamae “Okpa-okuko”, Ipomoea batata – sweet potato leaves “Abuba ji nwanue” and Jatropha aconitifolia “ugu oyibo” leaves are among these lesser-known vegetables; but they are rarely consumed .There are some popular green vegetables that are commonly consumed mainly in yam dishes such as Curcubita pepo broad pumpkin leaves “ugbogulu”, Corchorus trieus “Arira” and Celosia argentea “Eliamionu” but are not as draught resistant as the lesser known green vegetables. It is imperative to study the effect of domestic food processing techniques on the nutrient content of some popular and commonly consumed vegetables (Curcubita pepo, Corchorus trieus and Celosia argentea leaves) as well as lesser-known vegetables (Uvaria chamae, Ipomoea batata leaves and Jatropha aconitifolia leaves) to preserve and make them much more available all year at affordable prices. There is need to determine the food potentials of these vegetables, especially those of the lesser-known vegetables to encourage communities to consume them to meet their nutrient requirements. The result of this study will encourage farmers to diversify food use of these vegetables and to produce more for sale to generate income for other family needs.
1.4 Objectives of the study
1.4.1 General objective
The general objective of this study is to identify and determine the nutrient composition of both popularly known and lesser-known vegetables that Igbo-Ukwu community in Aguata L ocal Government Area use to prepare various yam dishes and determine their nutrient composition.
1.4.2 Specific objectives
The specific objectives were:
1. to identify common popular yam (Dioscorea rotundata) dishes prepared with vegetables as consumed in Igbo-Ukwu-
2. to identify common and lesser-known vegetables used in preparing various yam dishes consumed in Igbo-Ukwu.
3. sun and shade-dry and pulverize these vegetables and determine their nutrient and anti-nutrient composition.
4. compare the effects of processing on the nutrient composition of these vegetables and yam dishes.
5. prepare eight (8) yam dishes using fresh and processed (sun and shade-dried and pulverized) vegetables as consumed in Igbo-Ukwu community.
6 determine their nutrient content of these dishes, micronutrient in particular.
7. determine the organoleptic attributes of the dishes among non-Igbo-Ukwu indigenes in UNN for diversification of use of the dishes.
