ABSTRACT
Samples from Nturukpa leaf were processed using different processing methods. The first portion was oven dried at 50oC for 8 hours while the second portion was further divided into four parts and steam blanched at 100oC for 2, 4, 6 and 8 minutes, respectively. After blanching, each part was also oven dried at 50oC for 10 hours. Each dried sample was milled into flour. The third portion was wet milled (1:2 leaf: water, w/v), filtered and the filtrate was pasteurized at 65oC for 30 minutes. The fourth portion was further divided into four parts and each part was steam blanched at 100oC for 2, 4, 6 and 8 minutes, respectively. After blanching, each part was also wet milled (1:2 leaf: water, w/v) filtered and each filtrate was pasteurized at 65oC for 30 minutes. Fresh, unblanched macerated sample served as control. Samples from all the treatments were analyzed for chemical composition. Effects of the samples on haematological characteristics were evaluated using albino rats. Chemical composition of the samples revealed that untreated dried vegetable flour showed the highest value of crude protein (19.63%) which differed significantly (P<0.05) from the values exhibited by treated samples. The level of iron (17.77mg/100g) in untreated dried leaf flour was also significantly (P<0.05) higher than the level in the macerated sample (control). The untreated dried leaf flour showed 29.81mg/100g of vitamin C content which was significantly (P<0.05) different from the values exhibited by the treated samples. Processing also influenced the phytochemical contents of the samples. The phytochemical constituents of the untreated dried leaf flour sample was significantly (P<0.05) higher than the levels of phytochemicals in the blanched and pasteurized samples. The bioassay data showed that the group of rats treated with high dose of untreated dried leaf flour had higher values of heamoglobin concentration (13.66g/dl) and red blood cell count (6.01× 106 /µl) which differed significantly (P< 0.05) from those treated with blanched and pasteurized samples.
CHAPTER ONE
INTRODUCTION
The role of diet and nutrition as determinants of chronic diseases is well documented, (Thiam et al., 2006). The cost of these diseases has resulted in social distress, loss of productivity and economic burden on health. The factors contributing to the rapid change in disease pattern include urbanization, shift in diets and adoption of a more westernized lifestyle due to economic development and market globalization (WHO/FAO, 2003). This has resulted in the abandonment of indigenous foods that are rich in nutrient and health protecting components. These components are derived from plant foods and microbial sources and provide medicinal benefits that are valuable for healthy life. Nutraceutical has become a more mainstream supplement to the diet. Research has begun to show evidence that these components found in foods are often effective when processed effectively (Brower, 1998).
The term, nutraceutical was coined from nutrition’ and pharmaceutical in 1989 by Dr. Stephen DeFelice, a founder and chairman of the foundation of innovation Medicine (FIM), Crawford, New Jersey. He defined nutraceutical as a food or food product that provides health and medical benefits, including the prevention and treatment of diseases (DeFelice, 1992). Such products may range from isolated nutrients, dietary supplements and specific diets to genetically engineered foods, herbal products, and processed foods (Hardy, 2000). Kathleen and Stephen (2009) also defined nutraceutical as any non-toxic food component that has scientifically proven health benefit, including disease treatment and prevention. The chronic diseases related to diet and nutrition includes diabetes, high blood pressure, cardiovascular disease, stroke and some cancer (Thiam et al., 2006). The steady increase in the prevalence of these diseases has been linked to increasing intake of diets that are rich in energy but poor in micronutrients, health promoting and protecting compounds provided by such dietary component as pulses, fruits and vegetables (Frison et al., 2006). Examples of these food components with reported medicinal value are antioxidants such as resverastrol , flavonoids, anthocyanins, sulforaphane, iso-flavones, alpha-linoleic acid, soluble dietary fiber and products such as psyllium seed husk that reduce hypercholesterolemia (Weingartner et al., 2008).
Antioxidants have become synonymous with good health. They are a class of compounds thought to prevent certain types of chemical damage caused by excess free radicals and charged molecules that are generated by a variety of sources, including pesticide, smoking and exhaust fumes. Destroying free radicals may help to fight cancer, heart disease, stroke and other immune compromising diseases (Odukodya et al., 2010). Many natural antioxidants, especially flavonoids have been shown to be very important in the prevention of these diseases.
There are many nutraceutical products marketed in Nigeria, such as Tianshi; GNLD, forever living product etc. The main raw materials for the production of these products are natural ingredients (Bull et al., 2002). Some commonly consumed green leafy vegetables in Nigeria contain substantial amount of nutraceuticals but their nutraceutical potentials are yet to be determined.
- Statement of Problem
Despite the abundant green leafy vegetables in our communities and their use in preparation of traditional soups and dishes, information on their nutraceutical benefit is scanty in literature. The need to increase the utilization of these vegetables cannot be over emphasized. At present, utilization is constrained by the perishable nature and the inability to identify their nutraceutical benefits. It is against this background that this work was designed to achieve the following objectives:
1.2 Objectives of the Study
The general objective was to evaluate the nutraceutical potential of “Nturukpa” (Pterocarpus santalinoides) leaf and the effect of processing on the leaf.
Specific Objectives
- To determine the effect of drying and blanching on the nutritional and phytochemical composition of “Nturukpa” leaf.
- To determine the effect of treated “Nturukpa” leaf on heamatological and biochemical indices using rat bioassay.
