University of Nigeria Virtual Library

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1 - Serial No University of Nigeria Virtual Library Author 1 OBIZOBA, Ikemefuna Christopher. Author 2 NZOMIWU, Ngozi R. Author 3 Title Nutrition Responses of Rats Fed Mitures of Plant and Animal Proteins Keywords Cereal-Legume Proteins, Crayfish Supplementation, N Nutriture, Rats Description Nutrition Responses of Rats Fed Mitures of Plant and Animal Proteins Category Publisher Publication Date Agriculture Martinus Nijhoff Publishers 1987 Signature

2 Plant Foods for Human Nutrition 37: (1987) Martinus NijhoK Publishers, Dordrecht - Printed in the Netherlands Nutritional responses of rats fed mixtures of plant and animal proteins NGOZI R. NZOMIWU & IKEMEFUNA C. OBIZOBA* Dcpmtnrct~i Home Scietrce md ~V~tlriiion, Utliversiiy (?/'Nigeria, Arsltkka, Nigeritr i*outhor,fiv oflirints) Received 12 March 1986; in reviscd form 12 June 1987 Key words: cereal-legume proteins, crayfish-supplementation. N nutriture, rats Abstract. Twenty four male rats (45-65g) were used to determine the nutritional responses to mixed plant and animal protein diets. Rats were fed various mixtures of sorghum (S), pigeon pea (PP). bread fruit (TAP) plus crayfish (CR) to provide 1.6g N/100g of daily diet for a 35-day study period. Three dilrerent diets were fed to 6 rats assigned to each diet on the basis of body weight. Combination of PP:CR caused increases in N intake and retention, weight gain, and PER higher than for those of the other test groups. Its values for N intake and retention, and BV were higher than for those of the control except for food intake, NPU, weight gain and PER. Substitution of CR (20%) with TAP and PP as supplements to S decreased food intake, weight gain and PER and increased N intake. digested and retained N, NPU and BV. The results appear to indicate that (a) PP:CR blend was better than other blends as judged by the parameters, and (b) TAP and PP were superior to CR alone as supplement to S. Introduction The fight against protein malnutrition the world over is based on bridging the gap between protein needs and supplies. As a result, it has become a special task of nutrition research to develop and test nutritionally adequate diets from commonly consumed foodstuffs, locally and readily available, cheap, and acceptable to the population groups [l]. The development and test of diets based on commonly consumed foodstuffs have been receiving considerable attention in this laboratory. Among the several types of cereals commonly consumed in Nigeria is sorghum bicolor. It provides an important staple diet in northern Nigeria where it is the principal food crop 121. About 5O0/0 of the total area devoted to cereal crops in Nigeria is used for the cultivation of sorghum. Presently, 95% of Nigerian sorghum production is consumed as human food with differential preference for certain varieties [3]. Compared to casein or other well balanced protein sources: the relative nutritive value of sorghum protein is low [4]. Wall and Blessin [5] have

3 shown that the sorghum protein is low in lysine, tryptophan, and threonine than human requirements like those of other cereals. For a more balanced diet sorghum food must be supplemented with other foodstuffs which are rich in the deficient amino acids. Legume foods are ideal complement to sorghum food. They are rich in lysine, threonine, valine, and other essential amino acids (EAA) 161. Legumes are also good sources of thiamine, riboflavin, iron, and calcium [7, 81. Thus, the simultaneo~s~ingestion of cereals with legumes and cheap animal protein like crayfish has a complementary effect and offers a technique for improving protein nutrition within the economic and cultural patterns of families. The practice of eating cereals in conjunction with legumes is very common in Nigeria, however, the methods of preparation, particularly legumes are inadequate. This may have some important nutritional consequences for the vulnerable groups, mostly the children. Breadfruit (Treculia africana) is a tree legume locally called "ukwa". It is a popular traditional food amongst the Igbos of the Southern part of Nigeria. The seed grains are consumed only among the Igbos. Very little information is available in the literature on its chemical compositon in relation to its nutritive value and possible application in food processing [9]. Makinde et al. [9] observed that "ukwa" seed grain appears to be low in sulfur containing amino acids (SAA) while it is fairly high in aromatic amino acids when compared to provisional FAO/WHO requirements [lo]. However, its SAA are higher than for most pulses [l l]. The protein content of 19% of the defatted meal compared favourably with that of most pulses (22%) an indication that the protein could be employed favourably in mixed diets [12]. In Nigeria, pigeon pea (cajanus cajan) is consumed alone sometimes and at other times with cereals or cheap animal protein like crayfish (Astacus Fluviatilis). Crayfish is generally used as a food condiment and at times cereals and legumes are consumed locally in combination with it as the only animal protein within the reach of everybody in this part of the country. In some parts of Southern Nigeria, however, it forms the main source of dietary protein [13]. The crude protein content of crayfish has been shown to be within 60-70%. However, few, if any, works have been done to evaluate the supplementary value of crayfish. Obizoba [I 31 recently observed that at 20% supplementation of rice protein with crayfish produced protein that was comparable to casein as judged by growth. It was reported that above this level (20%) brown bean protein was superior to crayfish as a supplement to rice protien. The major objectives of the present study were to evaluate the supplementary value of crayfish to sorghum and pigeon pea alone and replacement of

4 CR with TAP and PP as supplements to S. Growth, food and nitrogen (N) intakes, digested and retained N, weight gain, PER of rats were the criteria of evaluation selected for use. Materials and methods Animu1.r md housing The 35-day investigation included a 28-day growth period followed by a 7-day N balance period. Twenty four male albino weanling rats g whose supplier has been cited previously [13] were divided into four groups of six rats each on the basis of body weight. The rats were weighed prior to being allotted io the control and their respective test diets dnd at weekly intervals until the end of the investigation to establish weight changes. The animals werehoused in individual metabolism cages and fed diets and water ad libitum for 35 days. The cages were of the type previously described [13]. The sorghum, pigeon pea, African breadfruit (Treculia africana), and crayfish were purchased from local retailers. The sorghum grain (S) was boiled for 90mins in a 1 :3 water after sorting to remove extraneous materials. When the grains were soft enough for consumption they were removed from fire and there were little or no cooking water left in the cooking utensil. The pigeon pea (PP) was treated as S and cooked for 130mins. The African breadfruit (TAP) was bought already dehulled and cooked for 50 rnins when it was soft for consumption. The crayfish (CR) (Astacus spp) was dried in an oven at 95'C for 20mins and then ground into a fine powder in a laboratory hammer mill (70-mesh screen). The boiled grains were then dried separately to 99% dry matter in an oven at 85'C for 8 h and then ground into a fine powder using the same machine and screen size as for crayfish. Table 1 presents the ingredient composition of the experimental diets. The control diet contained casein as the sole source of protein. The three test diets had 80% of their protein from S and PP and the remaining 20% from CR alone or 10% each from TAP and PP. These three diets regardless of protein source were isonitrogenously formulated to provide 1.6g N daily (10% protein) for the entire study period. Another group of rats were fed regular rat chow for 28 days and then switched over to a N-free diet for 7 days. After a 2-day adjustment period, the urine and feces collected from this group were analyzed for total N.

5 Tuhle I. Composition of sorghum, pigeon pea, crayfish and breadfruit (Treculia Africans) fed to rats (g) Diet component Protein sources and ratios of legume, cereal, and crayfish C A S:CK S:TAP:PP PP:CK loo* (80:20) (80: 10: 10) (80:20) S' TA' TAP PP CK' C' Vitamin Mineral' ,, Oil' Corn starch' Sucrose' Casein g I Purchased from local market retailers; sorghum, pigeon pea, crayfish, and African breadfruit protein was based on 6.25 N to protein conversion factor. Purchased from Teklad Harlan Sprague Dawley Inc., Box 8156, Madison. Wisconsin, 53708, USA. * From previous work in this laboratory. The values obtained were used to make corrections for endogenous N losses of the 3 test and the casein control groups. Both control and test groups were fed their respective diets for 35 days. Food intakes were recorded twice weekly and the data were used for calculating protein intakes for each animal. The procedures for collection and treatment of feces and urine; estimation of N content of the diets, feces, and urine; all statistical analysis of the data used in this study were the same as those cited elsewhere [14, 131. Analysis of variance was used to test the differences in nutritional value of the protein mixtures. Duncan's Multiple Range Test [15] was used to test for significant differences between diets in food and N intakes, weight gain, digested and retained N, protein efficiency ratio (PER), NPU, and BV.

6 Results and discussion The crude protein contents of the foods used in this study as sources of N were as follows: crayfish (CR) 56.00%; sorghum (S) 16.19%; pigeon pea (PP) 20.13%; and Treculia Africana (TPP) 16.63%. The weight gain, food and N intakes; fecal and urinary N; digested and retained N; biological value (BV); net protein utilization (NPU); and protein efficiency ratio (PER) of the rats are presented in Table 2. The food intake of the group of rats fed casein diet was highest and those rats fed the S:TAP:PP (80: 10: 10) diet was the least (277 vs 242.6g). The PP:CR group ate more than any of the other two test groups. The reduction in food intake when CR was replaced with equal amounts of TAP and PP was very difficult to explain; however, the reduction appears to suggest palatability to be the probable reason. The N intakes of all groups of rats differed. The rats fed diet PP:CR (80:20) had higther N intake than for those fed the other test and control diets. The slightly higher N intake of rats fed diet based on PP appears to indicate that PP diet was more acceptable and palatable than other diets based on sorghum. The fecal N excretion of the animals fed the PP:CR (80:20) diet was highest and those fed the control diet the least. The fecal N excretion of all groups of animals varied, however, the variations were insignificant (P > 0.05). The digested N values for all groups varied. The groups fed the PP:CR (80:20) and the casein diets were similar. The similarity in digested N of these groups might be attributed to better quality protein; high food intake, Tcrhlr 2. Food and N intake; fecal and urinary N; digested and retained N; BV; NPU; PER, and weight gain of rats fed sorghum. pigeon pea, crayfish. and african breadfruit proteins* Protein sources CA S:CR S:TAP: PP PP:CR Nitrogen ratios :20 80: 10: 10 80:20 Food intake (g) Nitrogen (g)' Fecal N (g)h Digested, N (g)h Urinary N (g)b N balance (g)b NPUb BVh Weight gain (g) PERd Weans SEM (six rats/group). True. 7-day N intake. "rotein efficiency ratio; corrected to a value for casein of 2.5.

7 and low fecal N excretion relative to food intake. The digested N values for other groups differed, however, the differences were not significant (P > 0.05). The slightly higher digested N values for the rats fed the S:TAP:PP (80: 10: 10) diet and those fed the S:CR (80:20) diet might be that TAP and PP synergistically produced a better balanced EAA than those produced by CR alone. The lower urinary N excretion value for the rats fed the S:TAP:PP (80: 10: 10) blend is very interesting when compared with those of the rats fed the S:CR (80:20) blend. This appears to suggest that there was a better mutual supplementation effect between TAP and PP than CR alone to S protein. The urinary N excretion of the rats fed the S:TAP:PP (80: 10: 10) diet was the least. This significantly increased its retained N as compared to the S:CR group. The N balance bf the animals fed the PP:CR mixture was higher than for those of casein and other test diets. There appears to be an upward trend in all parameters when TAP and PP supplemented S than CR alone except for weight gain and PER. This further shows that TAP and PP are superior to CR as a supplement to S protein. The NPU values for all groups of rats differed. The group fed the S:TAP:PP (80: 10: 10) diet had the highest NPU value even when conlpared with the control group. However, the differences were insignificant (P > 0.05). The higher NPU value for the rats fed the S:TAP:PP (80: 10: 10) diet as compared to those fed the S:CR (80:20) mixture appears to indicate further that TAP and PP produced a better balanced EAA than CR alone. The result also confirmed the fact that if plant proteins were carefully selected such that EAA deficit in one could be compensated for the excess in another, the protein so produced could be equal to or better than animal protein (80.3 vs 78.28). The higher NPU for the S:TAP:PP group as compared to that of the S:CR might be due to lower fecal, urinary. and high N intake. The lower NPU value for the PP:CR group might be attributed to higher fecal and urinary N excretions. The replacement of CR by TAP and PP as supplements to S caused increase in BV which was significantly different from those fed the control and test diets (P < 0.05). The weight gain and PER values for all groups of rats differed. The control group had the highest weight gain and PER. The PP:CR (80:20) group had higher weight gain and PER than the S:CR and S:TAP:PP groups. This might be that the PP:CR (80:20) group had better quality protein and higher food intake. The lower weight gain and PER for the S:TAP:PP group might be attributed to lower food intake when compared to the S:CR group. The comparable PER of the control and the PP:CR group appears to suggest that these two proteins had comparable balanced EAA which was conducive to optimal body protein synthesis. As judged by

8 food and N intakes, digested and retained N, weight gain, and PER; the PP:CR (80:20) diet appears to contain much more desirable pattern of EAA than the other test diets. The results showed that it could be of great economic importance to low income areas where these foods are staple. References I. Ganapathy SN, Brooker LK, Graven R, Edwards CN (1980) Trace elements, amino acids, plasma protein in adult men fed wheat diet. J Am Diabetic Assoc 78: Haikerwal L, Matheson AR (1971) The protein content and amino acid composition of sorghum grain. Am Assoc Cereal Chem 48: Obilana CT (1982) Sorghum production in Nigeria. In: Proceedings of the International Symposium on Grain Quality. 28th Ociober, Patanchera AP, India. Krisat 4. Hegsted DM (1969) Nutritional value of cereal proteins in relation to1 human rfeeds. In: ~Milner M (ed.) Protein Enriched Cereal Foods for World Needs. p. 39. Am Assoc Cereal Chem, St Paul, MN 5. Wall JS. Blessin CW (1969) Composition and structure of sorghum grains. Cereal Sc Today 14: Ma Y, Bliss FA (1978) Seed proteins of common beans. Crop Sc 18: Raja T, Salah AS, Abdul HC (1978) Nutritional quality and itnportancc of food legumes in the Middle Eastern diet. In: Hawtin GC, Chancellor GJ (eds.) Food Legume and Developments, pp Proceedings of workshop held at the University of Syria, 2nd 7th March 8. Walker AF, Kochhar N (1982) Effect of processing including domestic cooking on nutritional quality of legun~es. Proc Nutr Soc Makinde MA, Elemo BO, Arukwe U, Peller P (1984) Ukwa seed (Treculia africana) protein: I. Chemical evaluiltion of the protein quality. Nig J Nutr Sc 5: FAOIWHO pattern of amino acid requirements (1973) Geneva, FA0 nutrition meetings. Report Series, 52 I I. Evans RJ, Bandemer SL (1967) Nutritive value of legume seed proteins. J Agric Fd Chem 15: FA0 (1970) Amino acid contents of foods and biological dat on proteins. Food policy and food sicence service, Nutrition Division, Rome. Italy 13. Obizoba IC (1985) Evaluation of the protein quality of rice supplemented with bean or crayfish in rats. Qual Plant Plant Foods Hum Nutr 35: AOAC (1975) Oficial imethods of Analysis. 12th edn. Association Oflicial Agricultural Chemists, Washington D.C. 15. Steel RGD. Torrie JH (1960) Principles and procedures of statistics with special reference to the biological sciences. imcgraw-hill Rook Co. Inc. New York, Toronto and London