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J. Agric. Food Chem. lg85, 33, 122-124
sensory quality, but their practicability is questionable because a correlation coefficient indicates only an association and not a cause-and-effectrelationship. More data are required to prove the practicability of these tests. From numerous testa and data presented in this study, the following guidelines are suggested: grade quality days in ice MOR
NPN, mg/100 g AAN, mg/100 g TVB, mg/100 g TMA-N, mg/100 g Pi, mg/100 g PH TPC
I
I1
I11
prime
acceptable
poor
0-8 8.1-7.4 520-400 360-230 9.0-22.5 0.3-0.7 295-144 6.5-6.7 9 X lo41.4 X lo6
9-1 1 >11 0.7-1.1 6.9 >1.4 X lo6- >7 X lo6 7
X
lo6
Our studies indicate that if the lobster shell on tails are stored in ice, these could be kept in good condition for up to 8 days and in an acceptable condition up to 11 days. Registry No. TMA-N, 75-50-3; Pi, 14265-44-2; NPN, 772737-9;glycogen, 9005-79-2; hypoxanthine, 68-94-0;inosine monophosphate, 131-99-7. LITERATURE CITED AOAC. “Official Methods of Analysis”, 12th ed.; AOAC: Washington, DC, 1975a;Method 2.049,p 15. AOAC. “Official Methods of Analysis”, 12th ed.; AOAC: Washington, DC, 1975b;Method 18.021,p 309. AOAC. “Official Methods of Analysis”, 12th ed.; AOAC: Washington, DC, 1975c;Method 24.003,p 417. Baily, M. E.; Fieger, E. A.; Novak, A. F. Food Res. 1956,21,611. Beuchat, L. R. J. Agric. Food Chem. 1973,21 (3), 453. Bligh, E. G.; Dyer, W. J. Can. J. Biochem. Physiolg. 1959,37(8), 911. Cobb, B. F., III; Alaniz, I.; Thompson, C. A., Jr. J. Food Sci. 1973, 38,431.
Cobb, B. F., 111; Vanderzant, C. J . Food Sci. 1975,40,121. Dyer, W. J. J . Fish. Res. Board Can. 1945,6,351. Faber, L. In “Fish as Food”; Borgstrom, G., Ed.; Academic Press: New York, 1965;Vol. IV, p 518. Farooqi, B.; Qadri, R. B.; Fatima, R.; Razia, R.; Khan, A. H. Pak. J. Sci. Ind. Res. 1978,21,33. Fieger, E. A.; Friloux, J. J. Food Technol. (Chicago)1954,8,35. Fieger, E. A.; Novak, A. F. In “Fish as Food”; Borgstrom, G., Ed.; Academic Press: New York, 1961;Vol. I, p 561. Fiske, C. H.;Subbarow, Y. J. Biol. Chem. 1925,66,375. Flick, G.J.; Lovell, R. T. J. Food Sci. 1972,37,609. Flores, S. C.; Crawford, D. L. J. Food Sci. 1973,38,575. “Handbook of Fisheries Statistics of Pakistan”. Marine Fisheries Department, Government of Pakistan: Karachi, 1980;p 9. Holland, B. F.; Yelverton, G. F.; McCoy, E. G.; Webb, N. B. Department Natural and Economic Resources, North Carolina, 1972,Ser. No. 5. Hoogland, P. L. Fish. Res. Board Can., Circ. 1956,No. 3. Montgomery, R. Arch. Biochem. Biophys. 1957,67,376. Sidhu, G. S.;Montgomery, W. A.; Brown, M. A. J. Food Technol. 1974a,9 (3),357. Sidhu, G. S.; Montgomery, W. A.; Brown, M. A. J. Food Technol. 1974b,9 (3),371. Simidu, W. In “Fish as Food”; Borgstrom, G., Ed.; Academic Press: New York, 1961;Vol. I, p 358. Spies, J. R.; Chambers, D. C. J. Biol. Chem. 1951, 191, 787. Spinelli, J.; Kemp, B. J. Agric. Food Chem. 1966,14 (2), 176. Thomas, J. Food Technol. N . 2. 1969,4 (5),139. Vandenant, C.; Nickelson, R. J. Milk Food Technol. 1971,34(3), 115. Velankar, N. K.; Govindan, T. K. Curr. Sci. 1957,26,385. Velankar, N. K.; Govindan, T. K. Curr. Sci. 1958a,27,451. Velankar, N. K.; Govindan, T. K. Roc.-Zndiun Acad. Sci. 1958b, 478 (4),202. Vyncke, W. J., Proceedings of the Congress on Refrigeration Institute, Ostlend, Belgium, 1968. Walker, P.; Cann, D.; Shewan, J. M. J. Food Technol. 1970,5(4), 375. Received for review April 6,1984. Accepted October 29,1984.
Preliminary Nutritional and Chemical Evaluation of Raw Seeds from Mucuna solanei: A n Underutilized Food Source Oladapo A. Afolabi,* Bolanle A. Oshuntogun, Stephen R. Adewusi, Omololu 0. Fapojuwo, Fola 0. Ayorinde, Felix E. Grissom, and Olusegun L. Oke One method, which has often been negelected, of alleviating malnutrition in tropical Africa is the use of underutilized food sources. One such abundant, underutilized, but potential food source is Mucuna solanei seeds. Raw seeds of M. solanei were analyzed for proximate composition, amino acid profile, mineral content, lipid classes, fatty acid spectrum, and feeding trial. The crude protein content was 24%, fat 6.5%, crude fiber 5.3%, and ash 3.0%. The seeds appear to be a rich source of minerals, most especially calcium. The chemical score is generally low; however, lysine and phenylalanine are high, 198.66% and 270.77%, respectively. The major lipid class is triglycerides. The major fatty acid is C16:O. A major setback is that all rats fed the raw seeds died within 72 h of commencement of the experiment. It is now generally accepted that few of the challenges facing the Third World countries are larger or more important than the problem of hunger and malnutrition. The Department of Chemistry, University of Ife, Ile-Lfe, Nigeria (O.A.A., B.A.O., S.R.A., O.O.F., and O.L.O.), Department of Chemistry, Howard University, Washington, DC 20059 (F.O.A.), and Department of Physiology and Biophysics, Howard University, Washington, DC 20059 (F.E.G.). 002 1-8561/85/1433-0122$01.50/0
prevention of malnutrition in rapidly expanding populations such as Nigeria is a task of staggering proportions. Several countries are advocating different nutritional policies to augment available food through the introduction of high-yielding seeds, pest control, and preservation. However, one method that has often been neglected is the use of underutilized food sources. Mucuna solanei, studied here, is widespread in the tropics and exists in thick forests near villages (or farmlands abandoned for 2-3 years), in forests along rivers or streams, and also along footpaths and walks of rural areas. 0 1985 American Chemical Society
J. Agric. Food Chem., Vol. 33, No. 1, 1985
Evaluation of Raw Seeds from Mucuna solanei
The yield is reasonable even in poor soils. The seeds of this plant are known to be used as condiments or directly as part of the main dish by a few ethnic groups such as the Igbos in Nigeria. We estimate an annual consumption by the Igbos alone at 7.3 tons. Despite this high consumption and the potential of the seeds as a popular food source, no information is available on its nutritional and chemical qualities. It is, therefore, the aim of the present study to determine the nutritional and chemical composition of the seeds of M. solanei. MATERIALS AND METHODS
Sample Treatment. The hard shells of M. solanei seeds purchased from the local markets were cracked open with a hammer. The endosperm was groun to a fine powder and used for studies in this form. Proximate Composition. The moisture content in decaplicate 1-g samples was determined according to the AOAC (1980). Crude fiber was determined as described by the AOAC (1970). Similarly, the oil content in decaplicate 10-g samples was determined by method of Folch et al. (1957). Crude nitrogen content was determined by the Kjeldahl procedure as described by Eastoe and Courts (1963). The ash content was determined by incineration of a 5-g sample at 500 "C for 5 h in a muffle furnace. The mineral content was determined by the dry ashing method (AOAC, 1970) after which the minerals were brought into solution. Estimation of the mineral content was done by atomic absorption spectrophotometry using a Perkin-Elmer 290. Phosphorus was determined in aliquota of original mineral solution by the method of Gomori (1942). Lipid Class Determination. Oil extracted as described by Folch et al. (1957) was separated into individual lipid classes by one-dimensional TLC on precoated silica gel plates previously activated at 100 "C overnight (Skipski et al., 1964). The plates were developed with hexanediethyl ether-acetic acid, 9030:2 (v/v). Spots were detected by spraying with H2S04-CH3C02H,5050 (v/v), air-drying for 15 min, and oven-heating at 150 "C for color development. The charred spots were scanned with an Ortec densitometer (Model 4310). Cut paper tracings were weighed and relative percentage lipid classes quantitated. Amino Acid Analysis. Total amino acid analysis was carried out on the samples after acid hydrolysis by refluxing for 24 h under nitrogen with a Durrum amino acid analyzer as previously described (Afolabi and Oke, 1981). Gas-Liquid Chromatography-Mass Spectroscopy (GC-MS). A total of 2 g of powdered seeds was continuously extracted with 300 mL of methylene chloride. The resulting extract, dried over anhydrous sodium sulfate, was exposed to a steady stream of nitrogen gas to afford a light yellow oil. The oil was redissolved in 200 pL of methylene chloride for GC-MS. Extracts were analyzed on a Finnigan 3200 GC-MS, interfaced with an Incos data system, utilizing a 1.5 m X 1 mm 3% OV-17 on Gas-Chrom Q 60/80 column. Temperature was programmed from 50 to 300 "C at 12 "C/min. In addition, a 10% SP-1000 on Supelcoport 80/ 100 column, temperature programmed from 59 to 210 "C,was used. The helium flow rate was 25 mL/min, the injection port temperature was 250 "C, and the ion source electron energy was 70 eV. Compounds were identified by comparison of their mass spectra and rentention times with those of standard samples (Wheeler et al., 1982). Quantitation of major components was performed by using standard calibration graphs (Ayorinde et al., 1982). Nutritive Evaluation. The nutritive evaluation was determined by an animal assay technique using weanling
123
Table I. Proximate ComDosition of M . solanei Seeds 70 dry weight crude protein 24.0 f 2.6 6.5 f 1.5 ether extract (oil) 5.3 f 1.5 crude fiber 3.0 f 0.7 ash minerals (mg/100 g) Na 25.00 f 0.8 4.50 f 0.3 Fe 20.02 f 0.1 Mn 3.07 f 0.6 cu
Zn
3.38 f 0.3 222.00 f 5.8 160.18 f 0.6 180.65 f 4.3 850.06 f 8.4
K M€! P Ca
Table 11. Amino Acid Composition of M . solanei (g/100 g of Protein) chemical scoreo CY5
ASP Thr Ser Glu Pro GlY Ala Val Met Ile Leu Tyr
Phe His LYS A%!
1.72 f 0.90 6.94 f 0.28 2.04 f 0.61 3.32 f 0.59 10.03 f 0.68 3.3 f 0.95 3.08 f 0.43 3.61 f 0.18 3.65 f 0.67 1.18 f 0.54 2.70 f 0.21 5.16 f 0.66 11.16 f 1.93 14.81 f 1.56 1.13 f 0.29 13.47 f 2.55 11.81 f 0.92
41.04
55.07 36.17 44.23 60.20 270.77 47.87 198.66
The chemical score was calculated as earlier described (Afolabi and Oke, 1981). Table 111. Percentage Lipid Classes of M . solanei phospholipids 12.30 f 4.2 unknown 7.07 f 3.9 unknown 10.22 f 1.6 fatty acids 17.69 f 4.3 cholesterol 10.35 f 1.1 triglycerides 42.36 f 4.8
litter mate rats of the Wistar strain from our animal colony. The technique was the same as that previously described (Afolabi and Oke, 1981) in which powdered seed samples were used as the main source of protein. The rats were collected at 23-24 days age, numbered, and housed individually in wire-screen-bottomcages. They were weaned to the stock diet in the experimental cages for a week so that on commencement of feeding trial the rats were always 30-31 days old and weighed 50-60 g. RESULTS AND DISCUSSION
The mean values of the proximate composition for M . solanei seeds are shown in Table I. Values obtained are similar, in terms of standard food chemistry, to those of other plant food sources (Oyenuga, 1968: Oyenuga and Fetuga, 1975; Longe et al., 1983). The crude protein is sufficiently high (24.0 f 2.6%) to make it a rich source of plant protein. M . solanei seeds appear to be a rich source of minerals for Na, Mn, Cu, K, P, and most especially Ca. The amino acid pattern and chemical scores are shown in Table 11. The chemical scores, compared to whole hen's egg, are generally low. The chemical scores of total sulfur amino acids (Cys plus Met) and the aromatic amino acids (Phe plus Tyr) are 45.74 and 242.24, respectively. The plant appears to be a rich source of lysine and phenylalanine plus tyrosine. Considering the adequacy of essential amino acids, threonine appears to be limiting.
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J. Agric. Food Chem., Voi. 33, No. 1, 1985
100
288
368
488
588
608
Afolabi et ai.
78lr
:
