A comparative study was carried out on the nutritional contents of the seeds and fruits of Cucumis melo

(L.),Lagenaria breviflora (Benth) and Citrullus lanatus (Thunb). Proximate composition, Vitamin C content

and phytochemical analysis of air-dried, powdered epicarp, mesocarp and seeds of the mature fruits were also

carried out using standard procedures. Data on nutritional and phytochemical characteristics were collected

andsubjected totwo - way analysis of variance (ANOVA)at p<0.05. Means were compared using LSD.Total

sugar and vitamins C were detected in the other parts of the fruits except the seeds in the three Cucurbits.

Percentage dry matter, fat, ash and crude protein were significantly (p<0.05) higher in the seeds than in the

epicarp and mesocarp. Crude fibre was highest in the epicarp for C. melo(1.75 0.13), L. breviflora (1.85

0.07)and C. lanatus (2.18 0.07)

Agboola, D.A.

Ajiboye, A. A.

Bello, Oluwakemi A.

Fawibe, O.O

Ojo, E.S.

Covenant University Repository

FULafia Journal of Science & Technology Vol. 3 No. 1  March 2017134ISSN (Print): 24490954ISSN (Online): 26364972NUTRITIONAL STUDY ON THE SEEDS AND FRUITS OF THREE CUCURBITS IN SOUTH WESTERN NIGERIA.1Ojo,E.S.,  2Ajiboye,A.A.,  1Fawibe,O.O., 3Adetutu Bello and 1Agboola,D.A.1Department of Pure and Applied Botany, Federal University of Agriculture,  Abeokuta, Nigeria.2Department of Plant Sciences and Biotechnology, Federal University, Oye  Ekiti3Department of Biological Sciences, Covenant University Otta, Nigeria.ABSTRACTA comparative study was carried out on the nutritional contents of the seeds and fruits of Cucumis melo (L.),Lagenaria breviflora (Benth) and Citrullus lanatus (Thunb). Proximate composition, Vitamin C content and phytochemical analysis of air-dried, powdered epicarp, mesocarp and seeds of the mature fruits were also carried out using standard procedures. Data on nutritional and phytochemical characteristics were collected andsubjected totwo - way analysis of variance (ANOVA)at p<0.05.  Means were compared using LSD.Total sugar and vitamins C were detected in the other parts of the fruits except the seeds in the three Cucurbits. Percentage dry matter, fat, ash and crude protein were significantly (p<0.05) higher in the seeds than in the epicarp and mesocarp. Crude fibre was highest in the epicarp for C. melo(1.75   0.13), L. breviflora (1.85 0.07)and C. lanatus (2.18   0.07). FULafia Journal of Science & Technology Vol. 3 No. 1  March 2017135INTRODUCTIONCucurbitaceae comprises both cultivated and wild species. Many of these have been domesticated and grown as vegetables forming basic ingredients for human diet (Thoenissen et al., 2009).They are herbaceous vines (Khan et al., 2013),commonly called the “gourd family” of flowering plants and collectively known as cucurbits (Kocyan et al., 2007). They contain about 125 genera and 980 species (Deyo and O’Malley, 2008) and are well represented in Nigeria by 21 genera, many of which are considered economically important (Ogbonna et al., 2007).They are cultivated in different parts of the world for their nutritional valueas food, plantrich in vitamins, phosphorus, calcium, protein, carbohydrates etcMATERIALS AND METHODSFruit and seed collectionMature fruits of the three members of the Cucurbitaceae family (Lagenaria breviflora, Cucumis melo, Citrullus lanatus) were randomly selected and bought from local farmers at Osiele market in Abeokuta, Ogun State. The seeds were extracted manually from their mature fruits which were left for 10 days to rotten in the case of Lagenaria breviflora and Cucumis melo. The seeds of Citrullus lanatus were also extracted manually after the mature fruit have been cut longitudinally with a knife. Ten grammes (10g) of the seeds was grounded using a sony electric blender into powdery form which wasused for proximate analysis. Each longitudinally dissected mature fresh fruit was peeled to collect their epicarp and mesocarp which were oven dried and ground seperately to powdery form for proximate analysis.Nutritional compositionProximate Analysis Test was carried out using the spectrophotometer according to the method described by A O A C (2000). The component of the analysis made include; moisture content, fat content, ash content, crude fibre content, crude protein, carbohydrate and soluble sugar content.Soluble sugar contentDry samples (epicarp, mesocarp and seeds) of 0.020 – 0.025 g each were weighed into separate centrifuge tubes and moistened with 1.0 ml ethanol.  2.0 ml distilled water and 10 ml hot ethanol was then added and vortex. The mixture was centrifuged for 10 minutes at 2000 rpm, after which the supernatant was decanted into a test tube and made up to 20 ml extract. 0.8 ml of distilled water, 0.5 ml of 5 % phenol respectively was added to 0.01 – 1 ml of extract and vortexed. 2.50 ml of conc sulphuric acid was added and vortexed, mixture was allowedto cool for the absorbance to be read at 490nm.Calculation was carried out thus;  % Sugar =  (A-I) x  D.F  x  V  x 100                             B  x  Wx  1000000Where;  A  =  Absorbance of sample,                I   =  Intercept of sample,                   D.F =  Dilution Factor,              V    =  Volume,                  B    =  Slope of the standard curve and                        W    =  Weight of the sampleCrude protein The principle behind this method is the conversion of the nitrogen of the nitrogenous substance into ammonia by boiling with conc sulphuric acid fixed by excess of acid as ammonium sulphate. Dried samples of (epicarp, mesocarp and seed) 0.2 g of each were weighed seperately into three Kjeldahl flask. 1g of CuSO4 added to each flask followed by 1tablet of kjeldahl catalyst selenium (each tablet contains 1g Na2SO4 – 0.05 g selenium).To the mixture 25 ml concentrated sulphuric acid and 5 glass beads was introduced (glass beads helped prevent bumping during heating) The mixture was heated in a fume cupboard very gently at first and then increased with occassional shaking till the solution assumed green colour, the solution was then cooled. The black particle accumulated at the mouth and neck of the flask was washed down with distilled water. Heating was repeated first gently and then increased again until the green colouration disappeared. This was then allowed to cool, after which the digest was transferred with several washings into a 100ml volumetric flask and made up to mark by adding distilled water. Distillation was then carried out using Markham distillation apparatus.Distillation The Markham distillation apparatus was steamed for 15minutes before use. A 100 ml conical flask containing 20 ml boric acid indicator was placed under the condenser such that the condenser tip was under the liquid.  The digest (10 ml) was pipetted into the body of the apparatus via the small funnel aperture and then washed down with distilled water, followed by NUTRITIONAL STUDY ON THE SEEDS AND FRUITS OF THREE CUCURBITS IN SOUTH WESTERN NIGERIAFULafia Journal of Science & Technology Vol. 3 No. 1  March 201713620 ml of 40 % NaOH. This was steamed through for 5 – 7 minutes in other to collect enough ammonium sulphate. The receiving flask was removed afterwards and the condenser tip washed down into the flask. The flame was removed so as to bring about development of a vacuum for the removal of the condensed water.Solution in the receiving flask was titrated using N/100 (0.01 N) hydrochloric acidCrude protein was calculated thus;%N = T.V x (N acid) x 0.01401 x DM x Volume of digest/Volume of digest used                                                 W (Sample weight)Where;  N acid   =  0.01N,   DM   =  Dry matter content, Volume of digest  =  100ml  Volume of digest used  = 20ml,  Sample weight (W)  =  0.2gTherefore; Crude protein (Cp) = % N x 6.25Moisture contentEach sample (epicarp, mesocarp and seeds) were thoroughly mixed and ground seperately using laboratory mortar and pestle.  5 g of each sample were then rapidly transferred into three pre- weighed drying dish, after which each was dried to a constant weight at 95 – 100 0C under pressure (100 mmHg) for about 5 hours. At the end of drying, each dish was placed in a desicator to cool. Each samples were reweighed and loss in weight was reported as moisture.% Moisture content = W2 - W3    x   100                                         W1Where; W1 = Initial weight of empty crucible, W2 = Weight of crucible + food before drying, W3 = Final weight of crucible + food after drying.                                                % Total dry matter = 100 - % moisture content.Ash contentFinely dry ground samples of 2.5 g of the epicarp, mesocarp and seeds were weighed seperately into three porcelain crucibles. Each sample was charred on a Bunsen flame inside a fume cupboard to drive off smoke.  Each sample was then transferred into a pre-heated muffle furnance at 5500C and left for two hours until white or light grey ash was observed.%Ash(dry basis) =  Weight of ash (W3 – W1)          x 100                            Weight of original food(W2 – W1) Where;   W1 = weight of empty crucible,                   W2 = weight of crucible + food before drying,                    W3 = weight of crucible + ashFat content,A clean 250 cm³ boiling flasks was dried in the oven at 105 – 1100C for 30 minutes. It was then cooled in a desicator. 2 g of each sample (epicarp, mesocarp and seeds) were weighed into separate labeled thimbles correspondingly, cooled boiling flasks were weighed and filled with 300 cm³petroleum ether boiling at 40 – 600C. The extraction thimbles were plugged lightly with cotton wool, the soxhlet apparatus was assembled and allowed to reflux for 6 hours. Each thimble was removed with care and the petroleum etheron top was collected for re-use. After each flask was almost free of petroleum ether, they were removed and dried at 105 – 110 0C for one hour, after which each was transferred from the oven to the desiccators and were allowed to cool. % Fat content was calculated thus;                 =    Weight of fat          x 100                        Weight of sample   Crude fibre contentWell ground sample (epicarp, mesocarp and seeds) each of 1 g were weighed into a 500 ml Conical flask and 1 ml digestion reagent was added washing down the sides of the flask.It was then boiled and refluxed for 40 minutes, a water jacketed condenser was used to prevent loss of liquid, the flask wsas then removed from the heater and was cooled under cold tap, filtered and washed six times with hot water and once with methylated spirit. The residue was taken out with a spatula and transferred to a silica dish and dried overnight at 1050C. It was then transferred to a desiccators where it was cooled and weighed.% Fibre= Difference in weighing x   100                      Weight of Sample Carbohydrate contentwas calculated by difference that is;Carbohydrate = 100 – (MC + FC + AC + CF + CP)Where;     MC =Moisture content,                   FC   =   Fat content,                  AC   =   Ash content                 CF   =   Crude fibre content,                   CP   =   Crude protein contentNUTRITIONAL STUDY ON THE SEEDS AND FRUITS OF THREE CUCURBITS IN SOUTH WESTERN NIGERIAFULafia Journal of Science & Technology Vol. 3 No. 1  March 2017137Statistical AnalysisAll data collected from the above experiments were analyzed using two way analysis of variance (ANOVA) and means were compared using LSD. P value was set at ≤ 0.05.RESULTSNutritional composition of the epicarp, mesocarp and seeds of C. melo, L. breviflora and C. lanatusNutritional composition of the epicarp, mesocarp and seeds of C. melo, L. breviflora and C. lanatus is shown in Table 1.  Seeds of C. lanatus had significantly highest dry matter (95.79 g) and carbohydrate (25.52 g)while seeds of L. breviflora had the highest fat (3.72 g) content. On the other hand, seeds of C. melo had significantly the highest ash (3.72 g) and crude protein (28.10 g ).  Moisture content was highest (91.02) in the mesocarp of C. melo while crude fibre content was highest (2.18) in the epicarp C. lanatus.  Sugar and Vitamin C were not detected in the seeds of C. melo, L. breviflora and C. lanatus. High sugar content was recorded in the mesocarp of C. melo and L. breviflora than in theirepicarps. Sugar was only detected in the epicarp of C. lanatus. However, vitamin C content were highest (38.82 g) in the epicarp of L. breviflora.Table 1: Nutritional composition of the epicarp, mesocarp and seeds of C. melo, L. breviflora and C. lanatusNutritional content Epicarp Mesocarp                          SeedCucumis melo Lagenaria brevifloraCitrullus lanatus Cucumis meloLagenaria brevifloraCitrullus lanatus Cucumis meloLagenaria brevifloraCitrullus lanatusMoisture 76.96±1.27ᵇ 73.17±0.28ᵇ 71.70±0.22ᵇ 91.02±0.16ᶜ 90.05±0.14ᶜ 90.45±0.21ᶜ 5.48±0.36ᵃ 4.90±0.02ᵃ 4.22±0.11ᵃDrymatter 23.05±1.27ᵇ 26.83±0.28ᵇ 28.30±0.22ᵇ 8.98±0.16ᵃ 9.95±0.14ᵃ 9.56±0.21ᵃ 94.52±0.36ᶜ 95.10±0.02ᶜ 95.79±0.11ᶜFat 0.40±0.02ᵃ 0.59±0.03ᵃ 0.53±0.06ᵃ 0.20±0.02ᵃ 0.21±0.03ᵃ 0.22±0.02ᵃ 46.58±0.32ᶜ 59.02±0.41ᵇ 42.04±0.13ᶜAsh 1.19±0.06ᵇ 1.19±0.05ᵇ 1.55±0.04ᵇ 0.32±0.02ᵃ 0.76±0.02ᵃ 0.65±0.03ᵃ 3.72±0.06ᶜ 3.19±0.07ᶜ 2.72±0.14ᶜCrude fibre 1.75±0.13ᶜ 1.85±0.07ᶜ 2.18±0.07ᶜ 0.43±0.02ᵃ 0.91±0.02ᵃ 0.83±0.02ᵇ 0.79±0.04ᵇ 1.20±0.07ᵇ 0.64±0.03ᵃCrude protein 1.97±0.05ᵇ 1.81±0.09ᵇ 1.30±0.07ᵃ 0.61±0.07ᵃ 0.84±0.03ᵃ 0.52±0.04ᵃ 28.10±0.18ᶜ 26.32±0.20ᶜ 12.06±9.73ᵃCarbohydrate 17.74±1.52ᵃ 21.40±0.51ᵇ 22.76±0.45ᶜ 7.42±0.06ᵃ 7.25±0.23ᵃ 7.62±0.44ᵃ 7.56±7.56ᵃ 5.34±0.68ᵃ 25.52±3.74ᵇ% Sugar 1.40±0.10ᵇ 2.00±0.10ᵇ 1.50±0.10ᵇ 6.35±0.15ᶜ 7.70±0.10ᶜ ND ND ND ND8.22±0.04ᶜ 38.82±0.11ᶜ 8.39±0.06ᶜ 8.00±0.02ᵇ 36.64±0.19ᵇ 8.14±0.03ᵇ ND ND NDabcMean values (± Standard Error) with the same superscript  in the same row for each species are not significantly different(p>0.05) (ND = Not Detected)DISCUSSIONCrude protein were found to be significantly high in the seeds of C. melo, L. breviflora and C. lanatusthan in their epicarp and mesocarp. This could be attributed to the fact that they arethe food reserve center that is where food is stored for the later growth of the embryo (Kaur et al., 1988).The seed being a major sink and must possesses the highest store of the yield components. Badifu (1993)reported that Cucurbits were rich in nutrients such as protein.This result conforms with the reports of Oyeleke et al. (2012), Ojokoh and Lawal (2010) and Nzikou et al. (2009). The fat content of the seeds of L. breviflora was highest. These seeds have been reported to contain high fat deposits and hence valued as oil seeds (De Mello et al., 2001). This is also similar to the report on the fat content of some varieties of C. pepoby Murkovic et al. ( 1996). Crude fibre was found to be higher in the epicarp of C. lanatus compared to that recorded for Jatropha cathartica (Oladele and Oshodi, 2007). Fibre is an important part of food eventhough it cannot be digested, it reduces cholesterol levels and aids the normal functioning of the intestinal tract by increasing stool bulk and decreasing the duration for which the waste can stay in the gastrointestinal tract (Bello et al., 2008). It may have helped to boost the protective role of the epicarp, giving it rigidity which helps give the fruit its shape.  C. lanatusalso recorded highest carbohydrate content in the seed compared to the other parts. Carbohydrates are energy renewers, a very good source of human nutrition. This was almost the same as the 26% content reported for sunflower (FAO, 1982) but varied with the report of Okoye (2013) where the carbohydrate content of Cucumis sativus, Cucurbita pepo, Cucurbita moschata and Trichosanthescucumerina were very high. Sugar and vitamin C were not detected in the seeds of C. melo, L. breviflora and C. lanatus analysed in this study. However, the Vitamin C content of epicarp of L. breviflora was significantly higher. Vitamin C is an antioxidant with therapeutic properties which aids the formation of connective tissues, bones and boold vessels (Fadimu et al., 2012). Its high content in the epicarp may further aid the protective functioning of the epicarp.NUTRITIONAL STUDY ON THE SEEDS AND FRUITS OF THREE CUCURBITS IN SOUTH WESTERN NIGERIAFULafia Journal of Science & Technology Vol. 3 No. 1  March 2017138REFERENCESA.O.A.C. (2000). Association of Official Analytical Chemist, Official Methods of Analysis,Washington DC.Badifu G.I.O. (1993). Food potentials of some unconventional oilseed grown in Nigeria, a brief review.Plant  Food Human Nutrition. 43:211-224Bello, M.O., Falade, O.S., Adewusi, S.R.A. and Olawore, N.O. (2008).Studies on the chemical compositions  and anti-nutrients of some lesser known Nigerian fruits.African Journal of Biotechnology, 7(21): 3972  –3979.De-Mello, M.L.S., Bora, P.S., Narain, N. (2001).Fatty and amino acids composition of melon (Cucumis melo  var. saccharinus) seeds.Journal of Food consumption and analysis, 14: 69-74Deyo, A. and O’malley, B. (2008). Cucurbitaceae in college seminar 235 food for thoughts: the science,  culture & politics of food Pp 1 – 15Fadimu, O.Y., Ajiboye, A.A., Abgoola, D.A., Kadiri, M. and Adedire, M.O. (2012). Effect of some combination  of phytohormone on some growth parameters and vitamin C, carbohydrate, protein, and chlorophyll  contents of Spondias mombin (Linn.) seedling.Ife Journal of Science, 14(2): 397-403.FAO (1982). Food Composition Table for the near East. Nuts and Seeds. FAO Food and Nutri. Paper,  26.ISBN92-5-101277-6 p. 85.Kaur, M., Mann, S.K., Hira, C.K. and Bajaj, S. (1988). Effect of muskmelon (Cucumis melo) seed  supplementation in the nutritive value of wheat chapatti.Journal of Food Science and Technology, 25:  263 – 266.Khan, A. R., Anwar, M. and Khan, M. J. (2013). Study of phytochrome mediated seed germination of  cucurbitaceaepepo L. and citrullus vulgaris thumb. Found in balochistan International Journal of  Basic and Applied Sciences,13(2): 28-35.Kocyan, A., Zhang, L., Schaefer, H. and Renner S. (2007).A multi locus chloroplast phylogeny for the  Cucurbitaceae and its implication for character evolution and classification.Molecular Phylogenetics  and Evolution. 44:553-557.Murkovic, M., Hillebrand, A., Leither, J. and Pfannhanster, W. (1996). Variability of fatty acid content in  Pumpkin seeds (Cucurbita pepo L.). Zeistchriff- fuer – lebensmittel – untersuchung – und – forschung,  203(3): 216 – 219.Nzikou,J. M., Mate, L., Bouanga-kalou, G., Ndangui, C. B., Pambou-tobi, N. P. G., Kimbonguila, A., Silo, T.,  Linder, M. and Desobry, S. (2009). Chemical composition of the seeds and oil of Sesame (Sesamun  indicum L.) grown in Congo-Brazzaville. Advanced Journal of Food Science and Technology, 1(1):  6 – 11.Ogbonna, P.E. and Obi, I.Ojokoh, A. O. and Lawal, R. T. (2010). Changes in nutrient content of popcorn and  groundnut composite flours subjected to solid substrate fermentation. Inter. J. Tropical Med. and Pub.  Health, 1(1): 50 – 53.Ojokoh, A.O. and Lawal, R.T. (2010). Changes in nutrient content of popcorn and groundnut composite flours  subjected to solid substrate fermentation. Inter. J. Tropical Med. and Pub. Health, 1(1): 50 – 53.Okoye, N.F. (2013). Proximate analysis and protein solubility of four Cucurbits found in Nigeria.Pakistan  Journal of Nutrition, 12(1): 20 – 22.Oladele, P.E and Oshodi, A.A. (2007). Nutritional potential of Jatropha cathartica. Pakistan Journal of  Nutrition, 6(4) : 345 – 348.Oyeleke, G.O., Olagunju, E.O., Ojo, A. (2012). Functional and physiocochemical properties of watermelon  (Citrulluslanatus) seed and seed oil. Journal of Applied Chemistry, 2(2): 29-31.Thoennissen, N.H., Iwanska, G.B., Doan, N.B., Okamoto, R.Lin, P., Abbassi, S., Song, J. H., Yin, D., Toh,  M., Xie, W. D., Said, J. W. and Koeffler, H. P. (2009). Cucurbitacin B induces apoptosis by inhibition  of the JAS/STAT pathway and potentials antiproliferativeeffects of gemcitabime on pancreatic cancer  cells. Cancer Research, 69: 5876.NUTRITIONAL STUDY ON THE SEEDS AND FRUITS OF THREE CUCURBITS IN SOUTH WESTERN NIGERIA

NUTRITIONAL STUDY ON THE SEEDS AND FRUITS OF THREE

CUCURBITS IN SOUTH WESTERN NIGERIA.

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NUTRITIONAL STUDY ON THE SEEDS AND FRUITS OF THREE CUCURBITS IN SOUTH WESTERN NIGERIA.

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