CHEMICAL COMPOSITION OF PROCESSED TENDER LEAVES AND HUSKS OF COWPEA AND ORGANOLEPTIC ATTRIBUTES OF THEIR SOUPS AS CONSUMED IN TIV COMMUNITIES BENUE STATE NIGERIA

ABSTRACT

The study examined the chemical composition of fresh, sundried tender leaves and husks of cowpea

‘Adengee’ (Vigna unguiculata) and organoleptic attributes of their traditional soups. Information on processing, preparation and utilization of soup meals based on cowpea leaves and husks were obtained during  the  focus  group  discussion.  The  tender  leaves  and  husks  were  parboiled  and  sundried. Proximate, micronutrients, phytochemicals and antinutrient levels were determined using standard procedures. The soups based on fresh and sundried leaves and husks were analysed prior to sensory evaluation. The data collected were statistically analysed using means, standard deviation and standard error. All values were based on residual moisture. Protein for dried leaves was higher (p<0.05) (39.24 vs. 21.98 and 13.95%) than those of fresh leaves and dried husks. Dried leaves and husks had lower fat than the control (1.31 and 0.75 vs. 9.10%) (p<0.05). Sun drying increased ash in both dried leaves and husks (14.74 and 10.86 vs. 4.82%). The lower value for fibre in the dry samples was rather surprising (14.20 and 20.42 vs.25.13%) (p<0.05). Carbohydrate significantly increased more in dried husks than in dried leaves. (53.76 Vs. 30.22%) (p<0.05).The micronutrients in both dried leaves and husks were reduced due to their volatile nature. Tannins, saponins, flavonoids and polyphenols decreased significantly (p<0.05) in processed samples due to drying. Soups based on dried leaves (DS) had higher protein (p<0.05) relative to the soup based on dried husks (HS) and fresh leaves (FS) (34.40 vs.34.10   and   33.30%).   Similarly,   husks   based   soups   had   higher   fat   (34.10   vs.34.05   and

31.44%)(p<0.05) Ash was higher in dried leaves based soup(7.83%) and fresh leaves soup (7.20%). Fibre for the husks based soup was higher (p<0.05) relative to   fresh and dried leaves based soups (6.13 vs.5.58 and 6.11%, respectively). The carbohydrate levels were generally appreciable. All soups had appreciable levels of calcium, phosphorus and iron. These minerals varied significantly amongst the soups (p<0.05). Zinc and iodine also differed (p<0.05).β-carotene content of soup based on fresh leaves was higher (p<0.05) relative to those based on dried leaves and husks (6.08 vs.5.07 and

5.46RE).Vitamin C varied significantly (0.90 to 1.10mg) in soups based on fresh leaves and dried husks. Tannins, saponins, polyphenols and flavonoids in soups based on fresh leaves and dried husks were comparable. Anti nutrients levels in all soups were generally low. Scores for all organoleptic attributes of the three soups were more than half (6.17 to 7.70) of the 9-point scale. The soups were generally acceptable. As judged by the results, cowpea leaves, husks  and their soups have high nutrient potentials to justify its cultivation, consumption promotion and diversification. Consumption related information such as nutritional properties should be packaged and extensively promoted to broaden the knowledge of health and nutritional benefits of consuming cowpea leaves and husks. The results demonstrate that, there is a potential in developing multi-purpose varieties with good performance, which are well-yielding in both leaves and seeds. Therefore, production related information, such as variety, yields and cultivation practices as well as processing should be packaged and made available to extension personnel and governmental agricultural research institutes that often have a good outreach to farmers.

CHAPTER ONE

1.0   INTRODUCTION

1.1       Background to the study

The scarcity of documented information on the nutrient potentials of most of the foods consumed in Nigeria has greatly contributed towards the ineffectiveness of nutrition education programmes to meet the nutrient needs of a vast segment of the Nigerian population. This lack of documented nutrition information has precipitated wrong choices of foods, low nutrients intake and delay in embracing food diversification. The knowledge of the influence of processing on the chemical composition of foods is also necessary for optimizing nutrient reiteration during handling and processing of our local food materials (Ibok,Ellis & Owusu,2008).

Recently, researchers have become convinced that nutrients found in fruits and vegetables do more than just prevent diseases such as beriberi or rickets. The most publicized finding reveals that certain vitamins or vitamin precursors, notably vitamin C; beta-carotene as well as  polyphenols are powerful antioxidants (Consumer Report on Health, 1998). Antioxidants prevent molecular damage caused by oxidation in that, the protection offered may fend off many diseases and muscular degeneration (Islam et al., 2002).

Cowpea (Vigna unguiculata L. Walp), an annual herbaceous legume originated in Africa and is wildly grown.  Drought  tolerance;  short  growing period  and  its  multi-purpose use make  cowpea a very attractive crop to farmers who cultivate in marginal, drought-prone areas with low rainfall and less developed irrigation systems where infrastructure, food security and diminishing malnutrition are major challenges (Hallensleben, Polrech, Heller &, Maass, 2009). Lawrence and Whitbread (2006) described cowpea as one of the most important tropical dual-purpose legumes, being used as leafy

vegetable, grain, as fresh cut-and-carry foliage, and for hay and silage.

Cowpea has much variability within the species. The specie under study is local specie with coiled pods (Adengee in Tiv,). The fresh seeds are greenish but golden brown when dried and relatively small in size compared with the common black eyed beans. This crop can be used at all stages of growth as a vegetable crop. The tender green leaves are an important food source in Tiv communities in Benue State. The green leaves serve as an ingredient in egusi (melon) soup just like spinach is used in egusi soup; or the leaves are blanched and sun dried for with egusi soups all year round. The immature pods are boiled, the boiled seeds are eaten as vegetable and the husks are sun dried, prepared as egusi soup.

1.2       Statement of the problem

Cowpea leaves and husks have not received the needed research-based attention in Nigeria. Despite the  abundance  of  this  vegetable  crop  in  the  Nigerian  communities,  particularly  in  Tiv  land, information on their processing for preservation, uses in preparation of traditional soups and   their nutrient composition is scanty in Nigeria literature. Although lately, some researches were carried out on  African  indigenous  vegetables,  especially leafy ones,  cowpea research  continued  to  focus  on improvement of the grain and/or the entire herbage for animal feed (Singh, Ajeigbe, Tarawali, Fernandez-rivera & Musa, 2003). According to Hallensleben et al. (2009), cowpea is an important food legume and its use as a leafy vegetable is essential. Utilization of cowpea as a leafy vegetable and grain crop may provide nutritional and harvest versatility not available with purely vegetable crops such  lettuce  or  monocarpic  crops  such  as  wheat  (Bubenheim,  Mitchell  and  Nielson,1990).  The populace unaware of the high nutrient potentials of this vegetable grows cowpea, wait for the harvest of the  matured dry seeds, and discard the leaves. However, it is the leaves of some legumes, including cowpea, that showed much promise for providing part of the vastly increased supplies of nutrients that the world population needs(Bubenheim, Mitchell and Nielson,1990). The need remains to further intensively  research  on  these  vegetable  and  their  health  benefits.  It  is,  therefore,  imperative  to

elucidate information on the effect of processing on the chemical composition of these cowpea leaves and husks and their soups.

Most Nigerian diets are based on starchy roots, tubers and cereals pounded to produce paste or dried and ground to get fine flour. The flour is stirred with hot water to produce paste. These are consumed with the soups as accompaniment. Nigeria uses food composition tables from American and European countries to calculate nutrient needs of patients in hospitals or public health settings. The information on the processing, preparation, recipe and nutrient content of this local specie of Vigna unguiculata (Adengee) will be very useful in this regard.

1.3       Objectives of the study

1.3.1    General objective

This study focused on the food potentials of fresh and processed tender cowpea leaves, husks and organoleptic attributes of their traditional soup meals.

1.3.2    Specific Objectives

The specific objectives of this study were to:

i. collect information on processing, preparation and utilization of cowpea leaves and husks in soup meals;

ii. process cowpea leaves and husks using parboiling and sun drying;

iii. determine chemical composition of both the fresh and processed leaves and husks;

iv. prepare soups with these samples and determine their nutrient composition; and

v. assess the organoleptic attributes of the soups and their accompaniment (pounded yam).

1.4    Significance of the Study.

The result from this study would provide base-line data for compiling nutrient content of Nigerian foods and dishes in the food composition table. This would provide for dietitians an easy tool to calculate nutrient needs for patients in hospitals and clinics. The information from this work would also enable public health nutritionists and dietitians to know how best to use these soups for improvement of feeding habits and diversify diets. This information would assist plant breeders in

targeting attributes and characteristics of this cowpea specie for improvement. It would support the identification of traits of local importance, which are crucial for site- specific / local breeding approaches by the public sector both within National Agricultural Research Systems (NARS) and international research institutions

₦8,000.00 – DOWNLOAD FULL PROJECT DOWNLOAD FULL PROJECT Added to cart

---

---

---

---

Related Project Topics :