The Proximate And Phytochemical Analysis Of Soursop (PDF/DOC)
Numerous bioactive compounds and phytochemicals have been reported to be present in Annona muricata (Soursop). Some of these chemical compounds have been linked to the ethnomedicinal properties of the plant and its antioxidant properties. The aim of this study was to assess the proximate composition and phytochemical constituents of A. muricata using standard biochemical procedures. The defatted Annona muricata crude methanolic extracts of the different parts of the plant were used for the estimation of proximate composition and phytochemical screening. The crude methanolic extracts of the different parts of the plant were also fractionated using solvent–solvent partitioning. Petroleum ether, chloroform, ethyl acetate, methanol, and methanol-water (90:10) were the solvents used for the fractionation. The leaf methanolic extract had a higher lipid content, whereas its chloroform fraction demonstrated a better ability to quench DPPH free radical. The root-bark methanol-water, leaf methanol, fruit pulp chloroform, and leaf petroleum ether fractions demonstrated potent ferric reducing properties. The leaf and stem-bark petroleum ether fractions demonstrated better hydroxyl-free radical scavenging abilities. The leaf and fruit pulp of Annona muricata have a very potent antioxidant ability compared to the other parts of the plant. This can be associated with the rich phytochemicals and other phytoconstituents like phenols, flavonoids, alkaloids, and essential lipids, etc. Significant correlations were observed between the antioxidant status and phytochemicals present. These results thus suggest that some of the reported ethnomedicinal properties of this plant could be due to its antioxidant potentials.
Introduction
1.1 Background of the Study
Edible wild indigenous plants become an alternative source of food with high potential of vitamins, minerals and others interesting elements particularly during seasonal food shortage (Umaru et al., 2007). Wild fruits are also known to have nutritional and medicinal properties that can be attributed to their antioxidant effects and they can be used to fortify staple foods particularly for malnourished children (Barminas, 1998). There is much evidence that the quality and composition of food may contribute to present and future health benefits of young children.
According to the World Health Organization, malnutrition is the cellular imbalance between the supply of nutrients and energy and the body’s demand for them to ensure growth, maintenance, and specific functions (Tierney et al., 2010). The term protein-energy malnutrition (PEM) applied to a group of related disorders that include marasmus, kwashiorkor, and intermediate states of marasmus-kwashiorkor (Tierney et al., 2010). The most common form of malnutrition in Africa is protein energy deficiency affecting over 100 million people, especially 30 to 50 million children under 5 years of age (Jildeh et al., 2010). Some legumes such as soybean, bean, and peanut, are important sources of protein and can therefore help to increase the protein intake of the diet of population. However, the low-income group, especially in rural areas, sometimes cannot afford these protein foods. Soursop (Annona muricata) belongs to the family Annonaceae, and it is wide spread in the tropics and frost–free subtropics of the world (Samson, 1980). The soursop plant is cultivated mainly in home gardens. The tree yields up to 10 tons/ha and each fruit weighs 0.5 to 2 kg (National Academy of Science, 1978). The fruit is compound in and covered with reticulated, leathery-appearing but tender, inedible bitter skin from which protrude few or many stubby, or more elongated and curved soft, pliable “spines”. The skin is dark-green in the immature fruit, becoming slightly yellowish-green before the mature fruit is soft to the touch. In aroma, the pulp is somewhat pineapple-like, but its musky, subacid to acid flavor is unique (Schultes and Raffauf, 1990).
It is indigenous to most of the warmest tropical areas in South and North America including Amazon, A. muricata has become naturalized in many countries, and now has a wide distribution throughout tropical and subtropical parts of the world. The fruit makes an excellent drink or ice cream after straining. Several studies have described the medicinal purposes of Annona muricata and have outlined the social history of the plants’ use (Ayensu, 1981). All parts of the A. muricata tree are used in natural medicine in the tropics including the bark, leaves, root and fruit-seeds. The crushed seeds are used as a vermifuge and anthelmintic against internal and external parasites and worms. The bark leaves and roots are considered sedative, antispasmodic, hypoglycemic, hypotensive, smooth muscle relaxant and nervine and a tea is made for various disorders for those purposes (Holdsworth, 1990). Many bioactive compounds and phytochemicals have been found in A. muricata and its many uses in natural medicine have been validated by many scientific researches (Heinrich, 1992; Sundarrao, 1993). Generally the fruit and fruit juice is taken for worms and parasites, to cool fevers, to increase mother’s milk after childbirth (lactagogue), and as an astringent for diarrhea and dysentery. Due to the fact that the fruit has a wide distribution throughout tropical and subtropical parts of the world and mainly in developing country, the aim of this study was to investigate the physicochemical, the nutritional potential and mycoflore associated with Soursop (Annona muricata L.) from Benin. An emphasis has been placed on its use as food supplement against Protein-Energy Deficiency. For its valorization, the physicochemical and microbial changes in soursop puree which has been pasteurized at optimum thermal condition (Umme et al., 1997) were also investigated. This study also aims to make available an improved industrial technology for the production of soursop puree, which retains all the nutritional potential of the fruit during storage.
The bark, leaves, fruit, roots, and fruit seeds of the soursop tree are known since long for various medicinal uses. The fruit and juice is used against worms and parasites, to cool down fevers, to increase lactation after childbirth. The seeds can be crushed and then used against internal or external parasites, head lice, and worms[6].The tea prepared from the leaves are used as a sedative and a soporific (inducer of sleep) in the West Indies and Peruvian Andes. This infusion is also used to relief pain or for antispasmodic purposes. For liver problems a leaf tea is used in the Brazilian Amazon[7]. Traditionally it is used in medicinal herbal drugs to cure various diseases such as for diarrhea (fruit), cough, hypertension, rheumatism, tumors, cancer, asthma, childbirth, lactagogue (fruit), malaria, tranquilizer, skin rashes, parasites (seeds), worms (seeds), liver problems, arthritis (used externally) etc[8]. It contains a variety of components which attribute to the various biological activities. The roots and bark can be of aid for diabetes, but can also be used as a sedative. The purpose of the present review is to highlight the various traditional uses, phytochemistry and pharmacological reports on Guyabano (A. muricata).
1.2 Problem Statement
There is dearth of information on the health beneficial constituents of the edible and non-edible portions of soursop fruits in Nigeria to make any substantial claim for their optimal use (WHO/FAO, 2004; Abebrese et al., 2007). Endeavours in research works to enhance the commercial production and subsequent value addition of fruits, have been skewed towards the hackneyed ones leaving no room for variety for consumers. This challenge is exacerbated by recent policy that focuses on the common few fruits such as pineapple, citrus and pawpaw in a bid to diversify the nation’s agricultural export base to ensure food security through non- traditional export commodities (Aboagye et al., 2006; FASDEP II, 2007).
1.3 Justification
Investigating key parameters for assessing the health potential of the underutilized fruits will complement literature in making known the potential of the soursop as well as provide a stepping-stone for further research works in other uses of the fruits.
Currently, consumers choose diets based on the associated nutritional and health benefits instead of taste (Katan and De Roos, 2004) and it is postulated that the published information obtained on the not-so-known fruits will offer diversity to the health-conscious consumer. This will curtail the challenges of monotony associated with fruit consumption and poor availability associated with seasonal variations. The knowledge obtained from the study, will also aid policy-makers in making informed decisions in the agricultural sector aimed at broadening the nation’s food security basket.
1.4 Objectives
The overall aim of this research is to carry out a proximate and phytochemical analysis of soursp..
Specifically, the study seeks to:
- Determine the dietary fibre fractions and proximate composition of the edible portions of soursop
- Assess the phytochemical composition of soursop.
Discussion, Conclusion and Recommendation
5.1 Discussion
Researchers have pointed out the possible link between the antioxidant potentials of Annona muricata and its health benefits. However, the antioxidant properties of Annona muricata have been observed to have rich phytoconstituents such as annonaceous acetogenins, essential oils/fatty acids and other phytochemicals including, alkaloids, polyphenols, flavonoids, tannins, etc., (Fang, Rieser, Gu, Zhao, & Mc Laughlin, 1993; Gupta et al., 2011; Rupprecht et al., 1990).
Information about the comparative studies of antioxidant profile of the various parts of the Annona muricata is very limited. Thus this formed the basis for this study. The abilities of fractions of Annona muricata to mitigate free radical damage, to chelate and reduce metals, and to quench deleterious hydroxyl radicals were assayed as markers of antioxidant potentials. This research was able to identify and established that Annona muricata possesses potent antioxidant properties.
The observations in this study on the antioxidant potentials of Annona muricata could provide a mechanistic explanation of its reported ethnomedicinal importance (Agu, Okolie, Eze, et al., 2017; Agu, Okolie, Falodun, et al., 2017; Ahalya et al., 2014; Fang et al., 1993; Gupta et al., 2011; Okolie et al., 2013; Rupprecht et al., 1990; Vit et al., 2014). It is also expected that the data and findings from this research will provide a base-line information for researchers who have reported possible links of antioxidant properties of Annona muricata with antineoplastic, wound healing, antihyperlipidemic, antiplasmodial, antileishmanial, etc. This could open up further investigations into other health benefits of the plant.
Phytochemical screening and proximate analysis
All the phytochemicals tested for were present except phlobatannins and anthraquinones. This finding confirms the report of George et al. (2012). The proximate composition of the various parts of Annona muricata (fruit pulp, leaf, stem-bark, and root-bark) showed that the fruit has the highest moisture content followed by leaf. The stem-bark has the lowest moisture content. The root-bark has the highest ash content followed by the stem-bark and fruit in decreasing order. The moisture and ash contents of the fruit and root-bark, respectively, were expected. This is due to the high fluid content of the fruit pulp and the proximity of the root to the soil as source of mineral elements.
Capillary action of the transporting vessels of the plant against gravity could also be a major contributory effect to the transport of minerals from the root, through the stems and branches, and then to the storage sites, that is, the leaf and fruit for metabolic usage.
Crude fiber content was highest in root. This was followed by the stem-bark, leaf and fruit, in decreasing order. The root and the stem of the plant play among other functions, the major role of transport needed nutrients for plant metabolism. Thus, it houses a very large network of woody and fibrous transport vessels (xylem and phloem). The fruit and leaf sections of the plant play the major roles of general plant metabolism, storage of metabolites and biomolecules. Consequently, there is less requirement of these woody materials.
Lipid content was highest in leaf. This was followed by fruit and root-bark, in decreasing order. The presence of high amount of essential oils in the fruit pulp of Annona muricata have been reported by Kossouoh, Moudachirou, Adjakidje, Chalchat, and Figuérédo (2007). The high lipid contents in the fruit pulp and leaf corroborates the findings of Kossouoh et al. (2007) considering that Annona muricata is very rich in annonaceous acetogenins which are derivatives of long chain fatty acids (C32 or C34) (Chao-Ming et al., 1998; Gupta et al., 2011; Rupprecht et al., 1990). This partially suggests that Annona muricata possesses a high fatty acids and lipid synthetic and storage ability, especially in the fruit. Fekam, Amvam, Menut, Lamaty, and Bessière (1996) and Soheil, Mahmoud, and Rodney (2004) also pointed out that terpenoids, esters of aliphatic acids and volatile oils are the major types of lipids present in the leaf and fruit pulp of Annona muricata. However, 10.9 g/100 g and 9.1 g/100 g were the amount of crude protein recorded for fruit and leaf, respectively, and 6.8 g/100 g for stem-bark.
Root-bark had the least level of crude protein (5.9 g/100 g). The fruit pulp protein content of this research disagrees with an earlier report of 1.0 g/100 g (Chao-Ming et al., 1998). Carbohydrate levels were relatively within the same range (43.9–46.9 g/100 g) for root-bark, leaf and stem-bark, with the lowest level recorded for fruit (34.4 g/100 g).
The observed fruit pulp carbohydrate level contradicts the reported level of 16.8 g/100 g by Chao-Ming et al. (1998). The high level of moisture in the fruit pulp of Annona muricata could be responsible for the low carbohydrate compared to other parts.
5.2 Conclusion
The studied on soursop had appreciable soluble and insoluble dietary fibre fractions with corresponding high total dietary fibre contents of 21.6 g/ 100g for soursop,. They also showed considerable moisture, protein, ash and carbohydrate contents with values ranging from ( (2.63 to 6.71%).
Generally, the samples showed positive inferences to the major phytochemicals tested except for the presence of alkaloids. This included the detection of cardiac glycosides in soursop. Thus, there are potential health beneficial constituents to be derived from the incorporation of soursop fruits into diets and this indicates the need for their exploitation in seeking optimum health of the populace.
5.3 Recommendation
From the findings of this study, it is recommended that, in-depth quantitative studies of the detected phytochemicals especially that of the phenolic compounds be done on the soursop to further evaluate their associated health benefits.
Click the button below to INSTANTLY subscribe and download the COMPLETE MATERIAL (PDF/DOC)!