J. Chem. Soc. , Vol. 41, No. 1, pp 125-129 [2016]

THE NUTRITIONAL ASSESSMENT OF THE SEED OF WALNUT ( conophora) SEED PURCHASED IN AN OPEN MARKET IN WARRI, DELTA STATE. NIGERIA.

1J. O. Akpoghelie, 2J. U. Esemedafe, R. Okoh and 3G. C. Ugochukwu 1Department of Chemistry, Delta State University, P. M. B 1, Abraka. Delta State, Nigeria 2Department of Environmental Science, Federal University of Petroleum Resources, Effurun, Delta State, Nigeria 3Integrated Science Department, College of Physical Education, Mosogar. Delta State. Nigeria Accepted:01/01/2016 *Corresponding author: [email protected]

Abstract The nutritional assessment of the walnut seed (Plukenetia conophora) purchased in an open market in Warri, Delta State, Nigeria was evaluated. Moisture content was determined by drying to constant weight before subjecting for ashing. Oil content by soxhlet extraction; protein by kjeldahl method; vitamins by scalar analyzer 2000. Minerals content was determined by Atomic Absorption Spectrometry. The result for the nutritional composition reveals that the raw seeds contain 3.18% of ash content, 39.27% of moisture content; 8.40% of crude fibre; 5.19% of fat content; 20.74% of protein content and 23.22% of carbohydrate content. The minerals content reveals the constituent to be K = 4029.14mg / kg; Na = 3480.00mg / kg; Ca = 3014.28mg / kg; Mg = 726.11mg / kg; Fe = 68.00mg / kg; Zn = 24.01mg / kg; Mn = 19.00kg / kg and Cu = 14.00mg / kg. The phytochemical constituent reveals the presence of alkaloid to be 1.92mg / kg; Tannin to be 0.042mk / kg and galic acid to be 0.019mg / kg. There were no traces of flavonoids, cardiac glycosides, saponin, ellagic acid, caffeinic acid and anthraquinones. The vitamin composition reveals that the seed contains ascorbic acid (C) = 1.98mg / 100g; thiamine (B1) = 66.47 g / 100g; riboflavin (B2) = 0.05 g / 100g; Niacin = 0.02 g / 100g; Cyanocobalamin (B12) = 0.07 g / 100g; The result of the nutritional composition of the Plukenetia conophora seed reveals that it is safe for public consumption and could be a potential source of useful drugs formulation.

Keyword: Proximate composition, Plukenetia conophora, Tetracarpidium conophorum, phytochemical composition, vitamins, seed.

Introduction nutrient and sensory quality of the nut. The proximate African walnut (Tetracarpidium conophorum), now composition, ascorbic acid and heavy metal contents of called Plukenetia conophora, is a small flowering , the nut as earlier had been reported [3]. The amino acid a tropical rambling, a woody perennial climber that is and fatty acid components of the nut and the use of its important for the nut and timber it produces [1]. It leaf juice for the treatment of prolonged and constant belongs to the family Euphorbiacea and it is widely hiccups has been reported [8, 9]. Walnuts are considered distributed and consumed by the inhabitant of the to be an herb in Traditional Chinese medicine. They are Southern, Western Nigeria and the western . said to tonify kidneys, strengthen the back and knees, This plant is cultivated principally for the nuts which moisten the intestines and move stool. It is believed to are cooked and consumed as snacks [2, 3]. It is stop asthma and is prescribed to be taken between bouts contained in a pod which may house; one shelled nut of asthma, but not for acute asthma. It is used for the (single), two shelled nut (double) and three shelled nut. elderly as a constipation cure [10]. The bark is used in The walnut shells could be black or brown from the tea as laxative and chewed for toothache. It helps to plant. The nut is whitish upon cracking from the shell. prevent and control high blood pressure. Though, The nut has a thin layer in between two halves (when a Plukenetia conophora nut are generally eaten in nut is divided into two equal parts) of nut. A bitter taste Nigeria, little work has been done on the nutritional is usually observed upon drinking water immediately assessment of this nut sold in an open market in the oil after eating the nuts. This could be attributed to the rich city of Warri of the Niger Delta region of Nigeria. presence of chemical substances such as alkaloids [4]. Thus, this work is aimed at analyzing and assessing the Several works had been done on the walnut seed such as nutritional Composition of the seed of African Walnut the effect of processing methods on the biochemical, (Plukenetia conophora) with the view of ascertaining functional and anti - nutritional properties of African the effects of its consumption on the health of the walnut by [5]. [5] Reported the presence of oxalates, inhabitance of Warri, Delta State. Nigeria. phylates and tannin in raw T. conophorum nuts.[7] reported the impact of traditional processing on the

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Materials and Methods chromium solutions were determined using the atomic The Plukenetia conophora nut used in this study were absorption spectrophotometer. purchased from the Effurun main market, about a Vitamin Analysis kilometer from the Petroleum Training institute, The composition of the water - soluble vitamins such as Effurun, Uvwie local government area in the oil rich thiamine (B1), riboflavin (B2), niacin (B3), city of Delta State, Nigeria. This market point serves as cyanocobalamin (B12) were determined by the method a central market where nut are purchased and of scalar analyzer (2000) While ascorbic acid (vitamin transported within the locality. Twenty nut samples C) content was determined by the AOAC method [11]. purchased were thus transported to the laboratory where The [14] method was used for the determination of analysis was carried out in composite. tannins, while Saponin was analyzed using that of [15]. Sample Preparation The nut were washed with deionize distilled water and Results and Discussion wiped with kitchen towel. The nuts were chopped into The results of the proximate, Phytochemical, minerals pieces with knife with steel blade. Large portion was and vitamins analysis of the Plukenetia conophora taken for moisture and ascorbic acid content (African Walnut) Seed is shown in table 1 – 5 determination. The rest of the chopped samples were dried under room temperature for one week before Table 1: Chemical Composition (%) milling to a coarse powder and stored in an air tight Chemical Composition Sample (%) bottle prior to analysis. Proximate Analysis Ash content % 3.18 Moisture content was determined by drying 3g of the Moisture Content % 39.27 fresh sample to constant weight at 60 - 80oC in a Crude Fibre % 8.40 circulating oven, for ash, 3g of the prepared sample Fat Content % 5.19 were placed in a ceramic crucible that had been Protein Content % 20.74 previously heated and cold until a constant weight was Carbohydrate Content % 23.22 obtained. The samples were then subjected to ashing in a muffle furnace maintained at about 550oC until a Table 2: Mineral Composition of the Seed on a constant final weight for ash was achieved. Oil content Dry Weight (mg/kg) was determined by soxhlet extraction with hexane as Minerals Concentration (mg / kg) solvent, protein by the kjeldahl method, and crude fibre by the acid and alkaline digestive methods [11]. The Potassium 4029.14 total carbohydrate content was estimated by difference Sodium 3480.00 obtained after subtracting protein, fat, water, crude fibre Calcium 3014.28 and ash percentage from one hundred. Magnesium 726.11 Phytochemical Analysis Iron 68.00 Phytochemical screening was done on the sample using Zinc 24.01 methods as described by [11, 12]. Alkaloids were Manganese 19.00 extracted using a slightly modified method [13]. The Copper 14.00 dried sample was homogenized and the alkaloid extracted from 10g of the sample for 4hr, using 20% v/v Table 3: Phytochemical constituent of Walnut acetic acid in ethanol. The extract was filtered to Seed (mg/kg) remove cellulose debris and then concentrated to about Constituent Quantity w/w (mg / kg) one quarter of the original volume. One percent NH4OH was added drop wise until a precipitate occurred. The Alkaloids 1.920 crude alkaloid was dried to constant weight in an oven Saponin 0.000 and the percentage alkaloid calculated. Tannins 0.042 Mineral Analysis Anthraquinones 0.000 The mineral content of each samples were determined Gallic acid 0.019 by atomic absorption spectrophotometry after 2g of the dry ash samples was transferred quantitatively into a The result obtained from table 1 reveals that Ash conical flask and dissolved in 10 ml of 3 N HCl, and the Content amount to 3.18%, Moisture Content 39.27%, mixture was heated on a hot plate. Crude Fibre 8.40%, Fat Content 5.19%, Protein Content The solution was filtered into a 100 ml volumetric flask 20.74% and Carbohydrate Content amount to and made up to the mark with distilled water. The 23.22%.The results reveal that the P. Conophora is a mineral content of Calcium, sodium, potassium, rich source of carbohydrate while it has a moderate magnesium, iron, zinc, manganese, copper and

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amount of protein with low ash content. This implies exploited and used as as pharmaceuticals, stimulants, that the seed could be used as boost for carbohydrate narcotics, and poisons due to their potent biological and protein content of most food product sold in the activities [24]. This is why the seed is believed to stop market. asthma and is prescribed to be taken between bouts of asthma, but not for acute asthma, it is used for elderly as Table 4: Vitamin composition of the raw seed on a a constipation cure [10].The presence of tannins in the dry weight basis (mg/kg) seed of p conophora can support its strong use for Vitamin Amount healing of haemorrhoids, frost bite and varicose ulcers AscorbicAcid (vitamin C) mg /100g 1.98 in herbal medicine [25, 26]. Tannic acid is taken by Tocopherol (vitamin E) g/100g 66.47 mouth and applied directly for bleeding, chronic diarrhea, dysentery, bloody urine, painful joints, Thiamine(B1) g/100g 0.05 persistent coughs, and cancer. Vaginally, tannic acid is Riboflavin (B2) g/100g 0.02 used as a douche for white or yellowish discharge Nacin (B3) g/100g 0.02 (leukorrhea). The result of mineral composition clearly shows that P. conophora seed contains rich source of Pantothenic Acid (B5) g/100g 0.00 mineral elements. This result become so important when Pyridoxine (B6) g/100g 0.00 the usefulness of such minerals like Ca, Mg, Na, K in Folic acid (B9) g/100g 0.00 the body are considered, However, the low Na and K content of P. conophora is an added advantage because Cyanocobalamin (B12) g/100g 0.07 while Sodium is essential for normal heart and muscle

function, potassium helps in muscles contract, maintain Also, results from table 2 reveal that P. conophora fluid balance, and maintain a normal blood pressure (African Walnut) Seed is a good source of manganese Normal potassium levels in the body help to keep and copper. Magnesium is an antidote to stress. It is the the heart beating regularly [27]. Potassium may help most powerful relaxation mineral available and it help reduce your risk of kidney stones and also bone loss as to improve sleep. It is also responsible for the reaction you age but too much sodium has adverse effects on of over 300 enzymes found in the tissue, but mainly in your heart and a direct relationship with hypertension in the bones, muscles and brain. Most of all, it is required human [27, 28, 29 and 30]. This may be the reason why by the cell to make energy. Copper is an essential trace the fruit is administered to patient to prevent and control mineral present in all body tissue. It plays an important high blood pressure [31] while noting that the Na role in the formation of connective tissue, the normal constituent of the P. Conophora Seed is below the daily functioning of the muscles, the immunes system and the intake for adult as recommended by [32]. The presence nervous system. Manganese is used in the management of copper may be responsible for the absorption of iron; of diabetes [3]. The ascorbic acid content was it is therefore often seen with iron naturally. Copper is 1.98mg/100g. As a result of the presence of ascorbic important for cellular defense and protection of the acid in the seed, the plant can be used in herbal mucous membrane, antianaemic and essential for the medicine for the treatment of skin conditions, including formation of haemoglobin from iron [33]. The presence eczema, pruritus, psoriasis, common cold and parasitic of manganese shows that the plant can be used to skin conditions [16, 17, and 18]. It had been reported by protect bone disease [34]. The activity of this element is [19] that the presence of this vitamin in the walnut seeds noticed in the metabolism of food incorporated into the may help reduced not only the risk of prostate cancer, bone. According to [34], manganese is necessary for the but breast cancer as well. There is also an interesting functioning of the pituitary gland, the pineal gland and ability of ascorbic acid as an antioxidant, to prevent or the brain, it promotes hepatorenal function, combat at least minimize the formation of carcinogenic anaemia and also essential for growth. The presence of substances from dietary material. Deficiency of ascorbic zinc is an indication that the seed may have some effect acid is associated with pains in the joint and defect in on the nerve function and male fertility. It is important skeletal calcification, anaemia, manifestation of scurvy for normal sexual development, especially for the haemorrhage from mucous membrane of the mouth and development of testes and ovaries, it is also essential for gastrointestinal track [20]. The presence of vitamin E in reproduction. Zinc stimulates the activity of vitamins, the seed supports its use in southern Nigeria formation of red and white corpuscles, healthy ethnomedicine as a male fertility agent [21]. Other functioning of the heart and normal growth [35]. Hence, vitamins, though in trace amount, are essential for body the result of this work have far reaching importance as metabolism. Walnut is used in treatment of indigestion, this could support the numerous nutritional and constipation and diarrhea [22]. Alkaloids are efficient medicinal roles attributed to this all important nut. plant substances used therapeutically [23]. Pure isolated alkaloids and the synthetic derivatives are widely

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13. A. Maxwell, M. P. Seepers, D. R. Mootoo, and N. E. Conclusion Aminospirosola., (1995). Steroidal Alkaloids from The present study has shown the proximate, vitamins, SolanumTrists. J. Nat. Product, 56: 821 - 25. minerals and phytochemical compositions of P. 14. B. A. Bohm, and R. Kocipai - Abyazan, (1994). conophora (Nigerian walnut) seed. This partly shows Flavonoid and Condensed tannins from Leaves of the use of this seed in herbal medicine. As a rich source Vaccinum Raticulation and Vaccinum Calcyimium of alkaloids, coupled with the presence of the essential .Pacific Sci.; 48:458 - 63. vitamins and minerals, ascorbic acid, carbohydrate and 15. J.P. Peng and H. Kobayasli, (1995). Novel a moderate source of protein, P. conophora can be seen Furastonol Glycosides from Allium Anacros Tenon as a potential source of useful food and drugs. Hence, Plant Media, 6: 58-61. the result of this work have far reaching importance as 16. F.S. D,Amelio, (1999). Botanical; A Phytocosmetic this could support the numerous nutritional and Desk Reference, Boca Raton, FL,CRC Press. 209 medicinal role attributed to this all important nut. 17. D. E. Okwu, and M. E. Okwu, (2004). Chemical Composition of Spondia mombin . J. Sustain. References Agri. Environ.6: 140 - 47. 1. C. C. Ekwe, and A. Ihemeje (2013). Evaluation of 18. D. E. Okwu, andO. Okeke, (2003). Phytochemical Physiochemical Properties and Preservation of Screening and Mineral Composition of Chewing African Walnut (T. Conophora). Academic Research Sticks in South Eastern Nigeria.Global. Journal of International 4 (6): 501-512 Pure Applied Science. 9: 235 - 38. 2. O. L. Oke (1995). Leaf Protein Research in Ibadan, 19. J. Mercola, 7 Benefits of Walnut. Retrieved 19th Nigeria. University of Ibadan Press. May,2014from 3. C. A. Edem,,M. I. Dosunmu, and F. I. Bassey, http://articles.mercola.com/sites/articles/ (2009). Determination of Proximate Composition, archive/2013/04/01/breakfast-mistakes.aspx Ascorbic Acid and Heavy Metal Content of African 20. S. Hunt, J. L. Goff, and J. Holbrook (1980). Walnut (Tetracarpidium conophorum). Pakistan Nutrition Principles and Chemical Practices. John Journal of Nutrition 8 (3): 225 – 226. Wiley and Sons. New York. 49 - 52. 4. O. O. E. Onawum., O. O. P. Faboya, and P. B. 21.E.O. Ajaiyeoba, and D.A. Fadare, (2006). Ayoola, (2013). Chemical evaluation and nutritive Antimicrobial potential of extracts and fractions of values of African walnut leaf (Plukenetia conophora the African walnut- Mull.arg.). International Journal of Herbal Medicine. Tetracarpidiumconophorum.Afric. Journal of 1 (3): 122-126 Biotechnology. 5(22): 2322 - 2325. 5. A. Ihemeje, S. U. Okorie, and C. Charles, (2012).The 22. K. Wolters,(2009). Walnut. Review of natural effects of Processing Method on the Biochemical, products. Facts and comparism.Accessed April 23rd, Functional and Antinutritional properties of African 2008. Walnut (Tetracarpidium conophorum). Journal of 23. F. R. Magaret and M. Wink (1998). Alkaloid: Biological Science and Bioconservation. 4:55 – 64. Biochemistry, Ecology and Medical Application. 6. O.B. Ayodele, (2003). Nutrition in Plenum Press. New York and London. 1 - 6 Nigeria.IbadanCatoon publishers. Nigeria. 24. H. D James (2012). Phytochemicals: Extraction 7. E. A. Nwokolo, (1987). Composition and availability Methods, Basic Structures and Mode of Action as of nutrients in some tropical grains and Potential Chemotherapeutic Agents. Available at oilseeds.Nutr. Rep. Int., 36 (3) : 631 - 640 www.intechopen.com 8. V. A. Oyenuga,(1997). Nigeria Food and feeding 25. D.O. Igboko, (1983). Phytochemical studies on stuffs, Ibadan. University press Ibadan. Garcinia kola Heckel. M.sc. Thesis. University of 9. P. B. Ayoola., O. O. Onawumi, and O. O. P. Nigeria, Nsukka. 202 Faboya.(2011). Chemical evaluation and nutritive 26. I. Maduiyi, (1983). Biochemical and values of Tetracarpidium conophorum (Nigerian pharmacological studies of active principles of the walnut) seeds. Journal of Pharmaceutical and seeds of Garcinia Kola Heckel.M.sc Thesis Biomedical Sciences. 11(15): 2230 – 7885. University of Nigeria, Nsukka. 108. 10. Wikipedia. (2015). Redirected from African walnut 27. WebMD Medical Reference from Healthwise. from free encyclopedia. Retrieved August 29th, 2013 from 11. Official Methods of Analysis. 13th Edn. Association http://www.webmd. com/a-to-z-guides/potassium- of Official Analytical Chemists. Washington D.C content-of-fruits-vegetables-and-other-foods-related- 12. A. Sofowara, (1993). Medicinal Plants and information. Traditional Medicine in African. Spectrum book. 28. L. K. Dahl, (1972). Salt and Hypertension.Am. 2nd Ed, 110 - 58. Clin. Nutr. 5 : 231 - 38.

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