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1 Serial No Author 1 University of Nigeria Virtual Library NNAM, M. Ngozi Author 2 Author 3 Title Keywords Description Category Publisher Publication Date Chemical Evaluation of Multimixes Formulated from some Local Staples for use as Complementary Foods in Nigeria. Amino acid scores, Complementary foods, Multimixes, Nutrients, Protein scores. Chemical Evaluation of Multimixes Formulated from some Local Staples for use as Complementary Foods in Nigeria. Agriculture Kluwer Academic Publishers Signature

2 Plmt Food.s for Humar~ Nutrition 55: , Klrrrver Acaderrric Publishers. Printed in the Nerherlands Chemical evaluation of multimixes formulated from some lo'bal staples for use as complementary foods in Nigeria N.M. NNAM Depctrtmerrt of Horne Science and Nutrition University of Nigeria, Nstrkka Received 4 September 1998; accepted in revised form 13 December 1999 Abstract. The nutrient compositions of eight multimixes formulated for use as complementary foods from processed soybeans, cowpeas, maize, sorghum, yams, cocoyams, plantains and sweet potatoes were examined. The foods were processed by sprouting, cooking and fermentation. The samples were separately dried and milled to fine flours. A ratio of 65% cereal, 30% legume and 5% starchy staple (65:30:5) calculated on a protein basis was used to formulate the multirnixes. The blends were chemically analyzed using standard procedures. The mixtures containing soybeans had higher protein, lipid, energy, crude fiber and calcium levels but lower carbohydrate content than those mixtures without soybean. The protein and energy levels of the multimixes were higher than those of some commercial infant foods (Cerelac, Farex and Nestrum) in Nigeria but were comparable to that of 'soy-ogi'. The multimixes contained fair quantities of calcium and phosphorus and an adequate amount of some of the essential amino acids. Methionine was the most limiting amino acid in all the mixtures. Blending cowpeas with maize produced a higher protein score than blending cowpeas or soybeans with sorghum. The cowpedmaizelsweet potato mixture had the highest protein score. Key words: Amino acid scores, Complementary foods, Multimixes, Nutrients, Protein scores Introduction Breast milk is the best food for babies, providing sufficient nutrients for growth, energy and prevention of diseases in the first few months of life. However, with the gradual introduction of complementary foods, some babies develop problems. Protein-energy malnutrition accompanied by mineral and vitamin abnormalities begin to develop in some infants. This is often accompanied by diarrhea [I]. These problems are the result of infants being fed complementary foods that are nutritionally inadequate. In Nigeria, the common complen~entary foods for babies are mainly unsupplemented starchy tubers (yams, cocoyams, sweet potatoes), plantains and cereal paps. Animal proteins are rarely given due to the high cost. The food staples cannot adequately meet the nutritional requirements of infants

3 when consumed singly. However, judicious combination of the plant foods to produce multimixes for use in preparation of porridges or gruels could improve nutrient intake. Of concern, however, is the bulkiness of the porridges. Such porr?dges have low protein and energy density per unit volume of food consumed. This limits protein, energy and other nutrient intake, particularly for infants who consume small quantities of porridge at a time due to their limited stomach capacity. Germination and fermentation have been identified as traditional food processing methods that can improve nutritional quality, increasing energy and nutrient densities of plant foods [2]. The purpose of this study was to process some local staples by germination and fermentation and use the resulting products to formulate nutrient dense multimixes for use in infant feeding. The multimixes were evaluated chemically for nutrient content. Materials and methods Materials. Soybeans (Glycine max), cowpeas (Vipa iuigiiiculatcr), maize (Zea mays L.), sorghum (Sorghum hicolor), water yams (Discorea alata), cocoyams (Colocasia esculenm), sweet potatoes (Ipornoeu hcrratcrs) and plantains (MLISC~ sapienrum var Paradisiaca Linn) were used for the study. They were obtained from the Nsukka market in Enugu State, Nigeria. Preparariorz of marerials. One kg of each legume (soybeans and cowpeas) and two kg of each of the cereals (maize and sorghum) were separately cleaned and soaked for 8 hrs in deionized water in a ratio of 1:3 (wlv) grain to water. After soaking, each cereal and legume sample was spread on wet jute bags and covered with muslin cloth moistened with deionized water to sprout for 48 hours at an average room temperature of 30.0 f 2.0 "C. The grains were washed twice daily with deionized water to avoid the growth of mold. After sprouting, maize and sorghum were wet-milled separately in a laboratory hammermill (Thomas Wiley Mill, Model ED-5) and mixed with deionized water in the ratio of 1:3 (wlv) cereal to water. The mixtures were then allowed to ferment, using the microflora present in the paste, for 48 hours at an average room temperature of 30.0 f 2.0 "C. The legumes were dehulled and boiled separately. Cowpeas were boiled with deionized water in a ratio of 1 :3 (wlv) until soft when compressed between two fingers (35 min). Soybeans were boiled for 30 min with the same quantity of water as cowpeas. The cereal and legume samples were dried separately in a hot air oven (Gallenkamp BS Oven 250 "C, Model No. 320) at 55 "C for 12 h to 96% dry matter. Each sample was separately milled in a laboratory hammermill (Thomas Wiley Mill, Model ED-5) to a fine flour (70 mm mesh screen). The samples were

4 stored in separate air tight polyethylene bags of about 250 cm3 capacity for 3 days at -15 "C before the formulation of the multimixes. One kg of each of the starchy staples were cleaned and boiled in deionized water in a ratfo of 1 :2 (w/v) until soft (yams - 30 min; cocoyams - 45 min; sweet potatoes - 30 min and plantains - 20 min). The samples were hand peeled separately, wet-milled in a laboratory hammermill (Thomas Wiley Mill, Model ED-5) and mixed with deionized water in a ratio of 1:3 (w/v). The mixtures were allowed to ferment, using the microflora present in the paste, for 24 h at an average room temperature of 3O.Of 2.0 "C. The fermented samples were dried and remilled as described earlier and stored separately in air tight polyethylene bags of about 250 cm3 capacity for 3 days at -15 "C before the formulation of the mixtures. For-nz~dation qf the multimixes. The crude protein level of each flour was estimated by the microkjeldahl procedure [3]. Eight multimixes were formulated from the processed flours based on the protein ratio. The multimixes consisted of a ratio of 65% cereal, 30% legume and 5% starchy staple (65:30:5 ratio, protein basis). The composites were formulated as follows: Soybean/Sorghum/Yam (SSY), Cowpea/Maize/ Yam (CMY), Soybean/Maize/ Plantain (SMP), Cowpea/Sorghum/Plantain (CSP), Cowpea/Maize/Sweet potato (CMS), Soybean/Sorghum/Sweet potato (SSS), Cowpea/Maize/Cocoyam (CMC) and Soybean/Sorghum/ Cocoyam (SSC). Chemical ~iiinlysis. Proximate and mineral compositions of the multimixes were analyzed according to the standard procedures of AOAC [3] (Method Nos , , , ). All analyses were performed in triplicate. The energy values of the foods were calculated using the Atwater conversion factors. The amino acid scores, protein scores and net protein values of the multimixes were estimated using the method of Plahar and Hoyle 141. Amino acid scores were obtained by dividing the amount of each amino acid in a blend (g/16g N) by the corresponding value (g/16g N) for the FA0 (1 973) reference pattern, and multiplying by 100. mg of amino acid in 1 g of test protein amino acid score = x 100 mg of amino acid in 1 g of reference pattern Protein score was equal to the lowest amino acid score (i.e, the most limiting amino acid score). Net protein value (NPV) was obtained by multiplying the protein score by the protein content of a blend and dividing by 100. protein score (%) x protein content of blend (%) net protein value = 100

5 Statistical anulysis. Analysis of variance (ANOVA) was used to determine the effect of treatments on nutrient components. Duncan's New Multiple Range Test (DNMRT) [5] was used to compare means. Significance was accepted at > Results and discussions The proximate composition and energy values of the multimixes on a dry weight basis are shown in Table 1. The protein values of the multimixes were high and ranged from 14.32% in CMC to 23.00% in SSC. These values are higher than those for other commercial infant foods, including Cerelac (10.50%) [6], Farex (14.20%) and Nestum (14.00%) [7], available in Nigeria. The protein values were also higher than those published for millet and maize paps and millet, guinea corn and maize porridges (4.20% to 8.00%) [6] and other multimixes developed for use as weaning foods in Nigeria (10.60 to 13.40%) [8]. The protein values were influenced by the protein source. The protein content of the multimixes containing soybeans (20.30 to 23.00%) were higher than those containing cowpeas (14.32% to 16.84%). This was due to the high protein content of soybeans (44.08%) relative to cowpeas (24.67%). The soybean multimixes had comparable protein values with those of soyogi (20.30%) and corn-soy meal (20.90%) [7] but were higher than that of millet pap supplemented with soy flour (15.80% [6]. The higher protein content of the soy containing multimixes compared to millet pap supplemented with soy flour showed the beneficial effect of processing. Germination and fermentation have been reported to increase the protein content of foods [ The carbohydrate (CHO) composition of the multimixes varied from 61.99% in SSY to 78.15% in CMS. The values were lower than those reported by Eka [6] for millet pap supplemented with soy flour (78.70%). The lower values reported in the present study were due to the synergistic effect of fermentation and germination. During these processes, there is increased activity of a-amylase which hydrolyzes starch to simpler sugar for use by the fermentating microorganisms and other metabolic processes in the sprouting seeds. The multimixes containing cowpeas had higher (p < 0.05) CHO than those containing soybeans. This is because the food energy in cowpeas is stored as starch while the food energy in soybeans is stored as lipid. The cowpea/maize/sweet potato (CMS) blend contained the highest (p < 0.05) CHO (78.15%). This was due to the high CHO content of the food sources. The lipid contents of the mixtures were influenced by the legumes used. The soybean based multimixes had higher (p < 0.05) lipid values than the

6 TLI!IIP I. The proximate composition and energy values of the multirnixes on dry weight basis ~Multimix Protein, Carbohy- Lipid Ash Crude Energy (loo&) I%) drate (96) (%) (%) fiber (%) (KJ) SSY' cbly2 SM$ CSP" CMS" sss" CMC~ ssc" means f SEM of 3 determinations. Means not followed by the same letters in the same column were significantly different from each other (p ). I Soybean/Sorghum/Yam. Cowpea/Maize/Yam. ' Soybean/Maize/Plantain. CowpeadSo~~ghumlPla~~itain. Cowpea/Maize/Sweet potato. Soybean/Sorghum/Sweet potato. Cowpea/Maize/Cocoyam. 'Soy bea~ll~or~hurnl~oco~ am. cowpea blends, containing about 3 times the lipid levels of the cowpea mixtures. This was because soybeans are oil seeds with higher lipid content than cowpeas [ The ash levels varied from 2.98% in CSP to 4.02% in SMP. The values were higher than those of Cerelac (2.00%) [6], but comparable to those of soy-ogi (3.00%) and Nestum (3.50%) [7]. The food sources influenced the crude fiber levels of the multimixes. The blends containing soybeans and sorghum (SSY, SSS and SSC) had higher (p < 0.05) fiber contents compared to the cowpedmaize mixtures (CMY, CMS and CMC). The lower fiber levels of the blends containing cowpeas and maize might be desirable in infant feeding because fiber contributes to dietary bulk and is not digested in the human gastrointestinal tract. Combining soybeans and sorghum with either yams or cocoyams resulted in multimixes with similar (p > 0.05) fiber contents. Combinations of cowpeas and maize with either of the starchy staples resulted in multimixes with equivalent (p > 0.05) fiber contents. This phenomena suggests that the cocoyams and yams have similar crude fiber contents.

7 - The energy values of the rnultimixes varied and were influenced by the legumes used for the formulations. The blends containing soybeans had higher energy than the cowpea based mixtures. This was due to the high lipid content of soybear& [[I I]. Lipids supply more than two times the energy obtained from either carbohydrate or protein. The multirnixes had higher energy values ( 1,662-1,742 KJI100 g) than those reported for Nestum (1,537 KJII 00 g) and Farex (1,499 KJ1100 g) but were comparable with that of 'soy-ogi' (1,680 KJI100 g) [7]. This suggests that the multimixes can provide adequate energy for infants since 'soy-ogi' has been tested and confirmed suitable for weaning children [7]. Ketiku & Olusanya [8] reported significantly lower values (877 to 1,222 KJI100 g) in some multimixes developed for use as weaning foods in Nigeria. The mineral compositions of the multimixes are shown in Table 2. The calcium (Ca) values ranged from mg in CMS to mg1100 g in SSY. The mixtures containing both soybeans and sorghum had higher (p < 0.05) Ca than others. All the soybean based mixtures (SSY, SMP, SSS, and SSC) were superior to the non-soybean based mixtures in terms of Ca nutriture (70.60 mg to mg1100 g) and were considered to be good sources of the mineral. The blends containing cowpeas, maize and sweet potatoes or yams (CMS and CMY) had the lowest (p < 0.05) Ca levels (32.26 mg and mg1100 g). The mixtures consisting of soybeans, sorghum and sweet potatoes (SSS) and soybeans. sorghum and cocoyams (SSC) had equivalent Ca levels (81.46 mg1100 g). These results indicate that the starchy staples (yams, cocoyams and sweet potatoes) have similar Ca composition. The phosphorus (P) levels in the products were high and varied from mg in CSP to mgi100 g in SMP. The multimixes appear to be good sources of P. The maize containing mixtures (CMY, SMP, CMS and CMC) had higher (p < 0.05) P levels than the others. This suggested that relative to P, maize appears to be a better food supplement than either soybeans or cowpeas which were higher than sorghum. The iron (Fe) levels were influenced by the food sources. The plantain based multimixes (SMP and CSP) had higher (p < 0.05) Fe than the others. This is because plantain contains more Fe than the other starchy staples (yams, cocoyams and sweet potatoes) [12]. The plantain mixtures appeared to have an edge over the other blends for potentially minimizing the incidence of anemia among infants. The mixtures based on cowpeas and maize had higher Fe than those of soybeans, and sorghum. This might be due to the synergism between cowpeas and maize. Table 3 data show the amino acid scores, protein scores and net protein values of the multimixes. The amino acid compositions of the mixtures were compared with the provisional amino acid scoring pattern [I31 in order to

8 TLible 2. Mineral composition of the multitnixes Multimix (IOOg) Calcium (mg) Phosphorus (mg) Iron (mg) ' SSY' f 0.09" f ' CMY~ f 0.13' f 0.13bc O.Olb SMP~ " i 0.00" 3.66 i 0.01" CS? i i 0.24' 3.66 i 0.03" CMS" i 0.1 l"18. I0 i 0.31' 2.78 i 0.02" SSS~ 81.46fO.19" f0.09a 2.41i0.@IC CMC~ f 0.09~ f 0. l lb 2.77 f O.Olb SSC~ " ~ 2.40 i 0.01" Means i SEM of 3 tlererminations. Mcens not k)llowed by the same letters in the same column were signiticmtly different from each other (p < 0.05). I Soykan/Sorghutn/Yam. ' Cowpea/Maize/Yam. Soyk:in/lMaize/Plunt;rin. Cowpe:dSorghum/Pl;~ntain. Cowpea/Maize/Sweet potato. Soybean/SorgI~unl/Sweet potato. Cowpe;~/Mai~e/Cocoy am. * Soybean/Sorghun1/Cocoyan1. establish the limiting amino acids and to determine the protein scores and the net protein values. The multimixes contained adequate amounts of some of the essential amino acids, however they all appeared to be limiting in methionine. CMY, CSP and CMS had lysine as the second limiting amino acid while CMC had tryptophan and SSY, SMP, SSS and SSC had phenylalanine. The amino acid results obtained were not surprising since lysine, total sulfur-containing amino acids and tryptophan are found to be the first limiting amino acids in most plant based foods and diets [13]. The sorghum based mixtures had very low protein scores (30.97% to %). This might be due to the poor supplementation effect of the food sources. The net protein values (NPV) followed the same trend as the protein scores. NPV indicate the approximate percentage protein in the mixture that could be fully utilized by the body. Relative to the protein content, the sorghum based mixtures had lower NPV than the other multimixes. This can again be attributed to a lack of mutual supplementation effects between the food sources. The multimixes had promising nutritional attributes. They contained reasonable quantities of most of the nutrients tested. The protein levels were higher than those of commercial infant foods available in Nigeria including Cerelac, Farex and Nestum. The energy and protein values were compar-

9 . TLII~P 3. Amino acid scores, protein scores and net protein values of the ~nulti~nixes Scores and SSY' CMY~ SMP~ CSP~ CMS~ SSS~ CMC' SSC' values jn % Histidine Isoleucine Leucine Lysine Phenylalanine Methionine Threonine Tryptophan Valine Proteincontent Protein score Net protein value Most limiting Methio- Methio- Methio- Methio- ~Methio- Methio- Methio- Methioamino acid nine nine nine nine nine nine nine nine I Soybean/Sorghum/Yam. Cowpea/Maize/Yam. Soybean/Maize/Plantain. CowpedSorghum/Plantain. CowpedMaizeISweet potato. ti Soybean/Sorghum/Sweet potato. CowpedMaize/Cocoya~n, Soybean/Sorghun~/Cocoyarn. able with those of 'soy-ogi', a complementary food developed, tested and confirmed suitable for infants in Nigeria [7]. The multimixes contained appreciable amounts of the minerals tested and adequate amounts of some of the essential amino acids. However, the protein scores and NPV were low, particularly for the sorghum based multimixes. The blends are being investigated further to standardize their composition for use as complementary foods for infants. References 1. Bradley J, Baldwin S, Armstrong H (1987) Breastfeeding: A neglected household-level weaning-food resource. In: Improving Young Child Feeding in Eastern and Southern Africa. Household Level Food Technology. Proceedings of a Workshop Held in Nairobi, Kenya, October, 1987, pp 7-33.

10 Luhila F, Chipulu P (1987) High energy, low-bulk weaning food development in Zz~mbia. In: Improving Young Child Feeding in Eastern and Southern Africa. Household Level Food Technology. Proceedings of a Workshop Held in Nairobi, Kenya October. 1987, pp AOAC (1990) Official Methods of Analysis. Washington, DC: Association of Official Analytical Chemists. Plahar WA, Hoyle NT (1987) Estimation of protein quality in weaning foods prepared from local raw materials. F.R.J. Technical Report No. WFI Accra. Steel RGD, Torrie JH (1960) Principles and Procedures of Statistics. New York: McGraw-Hill Book Co. Inc. Eka OU (1978) Chemical evaluation of nutritive value of soya paps and porridges the Nigerian weaning foods. Food Chem 3: Akinrele IA, Edwards CCA (197 1) An Assessment of the nutritive value of a maize-soya mixture 'soyogi', as a weaning food in Nigeria. Brit J Nutr 26: Ketiku AO, Olusanya JO (1986) Nutrient composition of multimixes for use as weaning foods in Nigeria. Food Chem 21: Obisoba IC, Nnam N (1992) The effects of sprouting times on nutritive value of two varieties of African yam bean (Spkerrost.ylis strrwccrrpa). Plant Foods Hum Nutr 42: Nnam NM (1995) Evaluation of nutritional quality of fermented cowpea (Vi~iicr rmgiricwluttr) flours. Ecol Food Nutr 33: Elegbede JA (1998) Legumes. In: Osagie AU, Eka OU (eds), Nutritional Quality of Plant Foods. Benin City: Post Harvest Research Unit Publication, pp 6M3. Eka OU (1998) Roots and tubers. In: Osagie AU, Eka OU (eds), Nutritional Quality of Plant Foods. Benin City: Post Harvest Research Unit Publication, p 10. FA0 (1973) Energy and protein requirements. FA0 Nutrition Meetings Report Series. No. 52. WHO Technical Report series No. 522.