ABSTRACT
Extracts and powders produced from the leaves of two indigenous vegetables – ‘atama’ (Heinsia crinata) and ‘uchakoro’ (Vitex doniana) were evaluated. Four groups of processes were applied on the vegetables to obtain the samples: blanching, oven drying and milling; oven drying and milling; steam blanching, wet-milling, filtration, and fermentation; fermentation, wet-milling and filtration. After, a preliminary study to evaluate the antinutritional factors at different intervals of blanching and fermentation was carried out, five samples, fresh dried leaf powder (FDPL), blanched (8 mins) dried sample at 500c, fermented (5 days) leaf extract, blanched leaf (10mins)/fermented (5days) extract and blanched (10mins) leaf extract were selected for further studies, fresh leaves (FL) served as control. These were evaluated for proximate composition, mineral, and vitamin contents. Two samples each (fresh dried and blanched extracts) were selected for rat bioassay based on their iron content. Body weights were taken and blood samples collected from the animals on days 0, 14, 18, 21 and 24. Internal organs were weighed at the end of the experiment. The antinutritional studies revealed that blanching, fermentation, and drying reduced alkaloid, phytate, tannin, and oxalate contents of the processed leaf and leaf extracts to a safe level. The proximate analysis showed that the crude protein content of all the samples ranged from 0.02±0.00-17.29±0.01%; crude fibre of the powders ranged from 1.68±0.03-10.15%, ash contents varied from 0.26±0.01-6.55±0.01%, while total carbohydrate varied from 3.61±0.06-65.55±0.33%. The contents of sodium, calcium, and iron in the samples varied from 0.24±0.01-1.29±0.03mg/100g, 11.69±0.01-63.00±0.22,mg/100g and 3.00±0.00-31.26±0.01mg/100g respectively. The vitamin analysis showed that vitamin C ranged from 1.52±0.37-32.98±0.78mg/100g, vitamin E (0.12±0.00-53.31±0.02mg/100g), vitamin B2, (0.01±0.00-9.13±0.00mg/100g) and vitamin A (55.50±0.64-3583.26±4.68µ/mg). The bioassay results showed that all the samples caused a significant increase (p<0.05) in red blood cell (6.42-7.15 106/µl) and hemoglobin concentration (10.96-15.04 g/dl) in relation to the anemic controls. Body weight evaluation showed that there was significant increase (p<0.05) in weights of all the rat groups fed with the samples at different doses (153.70-177.45g). Relative organ weights of the test rats were observed to show significant differences (p<0.05) among samples for mean liver and kidney weights; and no significant differences (p>0.05) for mean heart and spleen weights respectively. Most of the liver and kidney function tests revealed that the samples did not cause any deleterious effect on the organs. This study has successfully demonstrated that ‘atama’ and ‘uchakoro’ leaves and their extracts have potentials for alleviating anaemia.
CHAPTER
ONE
- INTRODUCTION
Nutraceutical
can be defined as “a food (or part of food) that provides medical or health
benefits, including the prevention and / or treatment of a disease (Defelice,
1989).
The term “nutraceutical” was coined from “nutrition”
and “pharmaceutical” in 1989 by Stephen Defelice, MD, Founder and Chairman of
the Foundation for Innovation in Medicine (FIM) Cranford, New Jersey. There are
many ways to think about food. In the simplest sense, food is organic fuel,
that is, it provides the energy needed to perform daily functions and maintain
normal metabolic processes. Food contains nutrients that are essential to
prevent diseases, for example, scurvy will not occur if vitamin C is
continually present in the human diet. Similarly, blindness can occur where
diets are deficient in vitamin A. The essential nutrients that the body needs
to prevent specific disease have been a major focus of human nutrition research
for the past century (Beecher, 1999).
What is interesting, however, is
that the link between diet and disease, or more important, diet and health,
cannot be entirely explained by the absence or presence of the various
essential nutrients in our diets. Today, multitudes of components that are
found in foods are being studied to determine the role they play in maintaining
health and reducing the risk of disease. “Nutraceuticals” and “Functional
Foods” are two new terms used to describe health promoting foods or their
extracted components (Ames et al.,
1993). The beneficial role of many nutraceuticals and functional foods may
relate to their protective effects against degenerative diseases, such as
cancer and cardiovascular diseases. The interest in nutraceuticals and
functional foods continues to grow powered by diverse research efforts to
identify properties and potential application of nutraceutical substances, with
the public interest and consumer demand (Brower, 1998).The use of
nutraceuticals as an attempt to accomplish desirable therapeutic outcomes with
reduced side effects as compared to drug -based therapeutic agents, has met with
great success (Nelson, 1999; Whiteman, 2001). However, nutraceuticals still
need support of an extensive scientific study to prove their effects with
reduced side effects (Heyland, 2001)
Examples of claims made from
nutraceutical are resveratrol from red grape products as an antioxidant and an
anticholesterolemic broccoli (Sulforaphane) as a cancer preventive agent and
many others. Several nutraceuticals are known, some examples are flavonoids,
antioxidants such as gamma-linolenic acid, beta-carotene, anthoxyanins. Others
include tocopherols and poly-phenolics which are extremely effective
antioxidants. These antioxidants are found in various levels in fruits,
vegetables and non-food plants. (Hasler, 1998; Dixon and Steele, 1999).Most of
the nutraceutical products in Nigeria market are made by Tianshi, Tasly, GNLD,
Noni, Green World, Natural Pharmacy, among others, are imported and hence very
expensive and out of reach of an average Nigerian. The main raw materials for
the production of these products are from natural ingredients (Bull et al., 2001).There is a need for
extensive research to explore the nutraceutical potentials of our locally
available plant resources. Heinsia
crinata (atama) and Vitex doniana
(uchakoro) are two leafy vegetables eaten and grown abundantly in Nigeria.This will help to provide vital data
for food processors and nutrition workers as well as the consumers for
selection of these green leaf vegetables.
1.1 Problems Statement
These
vegetables are perishable and are mostly used locally for preparing dishes like
soup, porridge and many others. There is need to improve identify the
nutraceutical potentials of these leaves.
- Objectives
of the Study
- The general research objective is
aimed at the evaluation of nutraceutical potentials of ‘Uchakoro’ (Vitex doniana) and ‘Atama’ (Heinsia crinata) leaves.
Specific
Objectives
- To produce nutracetuical base from raw and processed ‘Uchakoro’ (Vitex doniana) and ‘Atama’ (Heinsia crinata) leaves and their extracts.
- To evaluate the effect of various processing methods on the antinutritional factors of the leaves and their extracts
- To determine the effect of processing on the nutritional contents of the samples.
- To determine the effects of the products on the red blood cell and other selected physiological body changes through rat bioassay.
EVALUATION OF NUTRACEUTICAL POTENTIALS OF “ATAMA” (Heinsia crinata) and “UCHAKORO” (Vitex doniana) LEAVES
