,.

Indian Journal of Experimental Biology Vol. 40, January 2002, pp. 49-52

Nutritional evaluation of extruded faba bean (ViciaJaba L.) as a protein supplement in cereals based diet in rats

Ameeta Kushwah*, Prakrati Rajawat & Hukum Singh Kushwah Department of Animal Biochemistry and Biotechnology, College of Veterinary Science and Animal Husbandry, "

Jabalpur 48200 1 , India

Received 13 February 2001; revised 28 September 2001

The quality of extruded faba bean (EFB) (Viciafaba L.) as a protein supplement in cereals diet was evaluated. Growth rate and protein efficiency ratio was better in 20% EFB blended dietary group of rats than those fed either on cereals alone or at 40% EFB supplementation. Subsequent studies on digestibility co-efficient, biological value, net protein utilization and net protein ratio also confirmed biological utilization of EFB proteins in a better way at low level (20%).

Recently faba bean (Vicia faba L.) is being advocated as a substitute after soybean products I being rich source of protein for human2 and livestock consump­tion3• However, processed faba bean upon heat treat­ments is reported to be nutritionally superior4•5•

Extrusion cooking, a modem high temperature short time technology, is indicated to affect chemical composition of faba bean. The protein content was significantly increased6•7. It also proved to be useful in eliminating some toxic anti-metabolites8.9 and was effective in enhancing in vitro protein digestibility, to09• However, information on the biological utiliza­tion of faba bean, especially upon extrusion cooking is scanty. Earlier studies indicated better utilization of processed faba bean in rats than raw faba bean as sole source of protein 10. Moreover, multicomponents in diet are being preferred since they are considered to be better organoleptically and nutritionally, toOI l . The present investigation was therefore, undertaken to assess the nutritional utilization of cereals blended with extruded faba bean (EFB), as a protein supple­ment, in rats.

Materials and Methods

Animals-Thirty colony bred weaning albino rats, 2 1 -day old, weighing 25 to 35g 'of either sex procured from the animal colony of College of Veterinary Sci­ence and Animal Husbandry, Mhow, were divided into five groups of six each and housed in individual cages and were allowed to feed on variable experi­mental diets as detailed below and were offered water ad libitum.

*Correspondent author: Fax. 0761 - 492 1 00 E.Mail : prakrati_raj@hotmail.com

Composition and extrusion conditions-Pure seeds of three varieties of faba bean ( Vicia faba L.) namely N- l , JV-2 and JV-3 procured from the De­partment of Plant Breeding and Genetics, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur were de­hulled separately, ground in a Mini Dal Mill and sieved to obtain uniform particle size. The flour of all the three varieties was analysed for proximate compo­sition7 and anti-nutritional components9 and mixed in equal ratio ( 1 : 1 : 1 ) to over-rule inter-varietal differ­ences9• The mixed flour was subjected to extrusion cooking at extrusion temperature of 75°C and feed moisture of 20% on a WENGER X-5 model extruder keeping screw speed of 400 rpm and a residence time of 5 to 1 0 sec constant9• At this combination, extruded faba bean flour exhibited minimal anti-nutritive effect with satisfactory nutritional quality7.9. The extrudate was air dried, ground and mixed with cereals for for­mulation of biological diets. Cereals, namely maize (Zea mays), kodo (Paspalum scrobiculatum) and kutki (Panicum miliare), being the staple diet, were procured from the local market and analysed for their proximate composition by earlier adopted methods7 (Table 1 ). These were mixed in equal ratio ( 1 : 1 : 1 ) before utilizing for preparation of diets.

Diet composition-The ingredient composition of experimental diets is shown in Table 2. Casein, a bio­logically active protein source, formed the standard diet (Gr. I). Groups of six rats each were fed on sepa­rate diets constituting cereals alone (Gr. II), cereals supplemented with either 20% or 40% EFB (Gr. III and Gr. IV, respectively) and non-prote�n (starch) diet (Gr. V). The level of supplementation of EFB was selected on the basis of organoleptic testing of

50 INDIAN J EXP BIOL, JANUARY 2002

EFB blended cereals recipes 1 2. All the diets were steamed for 1 5 min before feeding to animals. All diets were nutritionally complete at 1 0% protein level 1

3 containing fat (refined groundnut oil), vita­

mins-mineral mixture, crude fibre (non nutritive cellu­lose) and starch (Table 2).

Biological analysis-The feeding experimenta­tions lasted for 28 days. Diet composition was moni­tored daily. The body weights of all the animals were recorded at the start and end of feeding trial. Protein efficiency ratio (PER) was calculated as per standard methodl3. Additionally, the rats were housed in indi­vidual metabolic cages and fed on 1 0% isoproteinic diet separately as indicated above, for a period of three days. On each day, urine samples were also col­lected in separate containers. Nitrogen content of urine and faecal samples was determined by Microk­jeldahl method 1

3 (NX 6.25). The digestibility co­

efficie;lt (DC), biological value (BV), net protein utilization (NPU) and net protein ratio (NPR) were calculated using standard formulae13• The data were subjected to analysis of variance after calculating mean and standard error using conventional formu­lael4.

Results and Discussion Feeding experiments on weaning rats reflected that

animals fed on 20% EFB blended cereals diet exhib­ited remarkably higher feed intake than control casein group (Table 3). In another Vicia jaba dietary group with 40% EFB, feed intake was higher too, but dif­fered insignificantly from control animals (Table 3). Results on protein intake were also similar. However, rate of growth of animals fed on 20% EFB blended diet was much higher, whilst that on 40% EFB diet was lower than casein fed group. Feeding of animals on casein diet reflected a remarkably higher PER and was the lowest in cereals fed animals; supplementa­tion of cereals constituting kodo, kutki and maize with EFB increased its ratio, more so at 20% (Table 3).

The results indicated the outstanding growth inhib­iting effect on growing rats when fed on millets and maize alone. Millets are well known for their poor nutritional values l5, containing 8 - 1 1 % protein (Ta­ble 1 ) and therefore, exhibited poor growth promoting capabilities (Table 3) and thus, is correlated with poor dietary protein utilization by experimental animals. Millets and maize protein may not, therefore, be effi­ciently transformed into body protein.

A similar trend was observed when animals were fed on EFB supplemented diets, however, supplemen­tation at 40% level reflected the lowest weight gain in animals but PER was better than cereals fed animals (Table 3). It indicated that growth inhibitors and poor nutrient utilization cannot be attributed to the differ­ences in protein consumed by experimental animals. It seems therefore, that the organoleptic properties, which in principle could be related to palatability, smell, texture etc. of diet may not necessarily be cor­related with their nutritional effects. The results fur­ther indicated the beneficial and nutritionally superior effects of blending of EFB in cereals diet, at 20% level it proved to be better as indicated by their PER values (Table 3). Earlier studies have also shown in­creased weight gain and feed efficiency in rats upon heat treated faba beans feeding

4. In the present study,

extrusion cooked dehulled faba beans were utilized that has earlier indicated marked increase in in vitro protein digestibility by suppressing anti-nutritional metabolites9• Heat treatment improved the availability or digestibility of several nutrients including carbohy­drates and proteins, tool6.

A subsequent study on nitrogen balance parameters indicated that digestibility coefficient (DC), biological value (BV), net protein utilization (NPU) and net pro­tein ratio (NPR) were more or less similarly depicted by animals maintained on EFB supplemented diets (Table 3). Values were comparable to that of control casein group. However, rats fed on cereals diet alone exhibited a marked reduction in these values

Table 1 -Proximate composition of cereals used

[Values are mean ± SE of six observations along with their mean difference test]

Proximate Princi21es (g %)

Cereals Crude protein Fat Moisture Ash Crude fibre Nitrogen free extract

Kodo 8.69 ± 0.038" l .05 ± 0.012" 13 .04 ± 0.02 1 " 2. 1 8 ± 0. 1 05" 8.75 ± 0.058" 66.29 ± 0.049'

Kutki 8.22 ± 0.1 1 1 b 4.7 1 ± O.Ol 7b 13 . 14 ± 0.0 I 7b l .50 ± 0.019b 6.89 ± 0.023b 65.54 ± 0.027b

Maize 1 1 .25 ± 0.074c 2.05 ± 0.022c 13 .29 ± 0.023c 1 .84 ± 0.082c 2.26 ± 0.083c 69.3 1 ± 0.048c

Values with different superscripts in a column are significantly different (P < 0.05)

!(

t

-..

KUSHWAH et uf.: EXTRUDED VICIA FABA AS PROTEIN SUPPLEMENT 5 1

indicating thereby, a pronounced anti-nutritive effect of minor millets and maize as measured by the growth rate and nitrogen balance parameters (Table 3). Millets are well known for their poor protein contents l5 .

Moreover, presence of some anti-nutritional factors 15

may not permit them to be made available to the bio­logical system thereby, interfering with protein utili­zation and growth inhibition in experimental animals.

Constituents (gl100g)

Protein source

Fat (mll l OOg of diet)

Vitamin + Mineral Mixture***

Crude fibre

Starch

Total

* Extruded Faba Bean ** Kodo + Kutki + Maize

Table 2-Composition of experimental diets (Isoproteinic at 1 0%)

Gr. I Casein

10.3 1

6.59

0.60

1 .00

8 1 .50

1 00.00

Gr.1I Cereals** based diet

1 00

1 00.00

Gr. I I I Gr. IV Cereals + Cereals +

20% EFB* 40% EFB*

69.56 53.33

6.33 6.98

0.60 0.60

1 .00 1 .00

22. 1 5 38.09

1 00.00 1 00.00

Gr. V Non-protein

6.59

0.60

1 . 00

9 1 .8 1

100.00

*** Composition of vitamin - mineral mixture Mixture I Mixture-II(B-complex)

Q t y . ( g ) Mixture-III(Salt)

Vitamin Q t y . ( g ) Q t y . ( g )

Vit A 4.5 Thiamine-HCI 1 .0 NaCI 1 39.3

Vit D 0 . 2 5 Riboflavin 1 . 0 K I 0 . 7 9

Vit E (a-Tocopherol ) 5.0 Niacin 4.5 KH2P04 389.0

Vit K 2.25 Pyridoxine-HCI 1 .0 MgS04.7H2O 57.3

Vit C 45 Calcium pentothenate 3.0 CaC03 3 8 1 . 4

Inositol 5.0 FeS04.7H20 27.0

Chlorine chloride 75.0 MnS04.7H20 4 . 0 1

Folic acid 90.0mg ZnS04.7H20 0.548

Vit B I 2 1 .35mg CuS04.5H20 0.477

Biotin 20.0mg CaCI2·6H2O 0.023

P A B A 5 . 0

Note: Vitamins A , D , E , K and C were weighed and mixed (I) and made up to l00g with mixture I I which was prepared separately. The salts were mixed thoroughly and ground to a fine powder (III) and mixed with vitamin mixture.

Table 3 - Bio-nutritional values in weaning rats maintained on variable dietary regimens

[Values are mean ± SE of six observations along with their mean difference test]

Dieta!! Regimens Gr. I Gr. I I Gr. I I I

Casein (control) Cereals** Cereals + 20%EFB*

Feed intake (g)@ 1 67.88 ± 2.528a 280.60 ± 1 .367b 275.47 ± 5 .37 1 b

Protein intake (g)@ 1 5.57 ± 0.234a 26.02 ± 0. 1 26b 25.55 ± 0.498b

Weight gain (g)@ 35.00 ± 1 .29 1 a 30.00 ± O.OOOa 50.00 ± 3.461b

Protein efficiency ratio@ 2.24 ± 0.067a 1 . 14 ± 0.007b 1 .94 ± 0. 100c

Digestibility coefficient@ 98.60 ± 0.256a 86.45 ± 0.424b 98.42 ± 0.043a

Biological value@ 75.34 ± 3 .409" 49.62 ± 1 .630b 77.46 ± 1 .208"

Net protein utilization@ 74.29 ± 3.465' 42.86 ± 1 .086b 76.23 ± 1 . 158"

Net Protein ratio@ 3.25 ± O. 1 32a 1 .75 ± 0.052b 2.56 ± 0. 1 39c

@ Values with different superscripts are significantly different (P<0.05) ** Kodo + Kutki + Maize * Extruded Faba bean

Gr. IV Cereals + 40% EFB*

1 96.84 ± 1 .8 1 4a

1 8 . 1 6 ± 0. 1 70c

26.66 ± 1 .667c

1 .45 ± 0.096d

99.06 ± 0. 149"

73.87 ± 0.992a

73. 1 8 ± 1 .050a

2.3 ± 0. 136c

52 INDIAN J EXP BIOL, JANUARY 2002

Strikingly, the protein efficiency ratio and subse­quent net protein ratio was the highest in casein die­tary group. Among other dietary groups, EFB blended at 20% level approached near to that of control ani­mals, whilst un supplemented group depicted their lowest ratio. This implies the maximal biological utilization of the reference protein despite low protein intake. Extruded faba bean supplementation at 20% in cereals diet seemed also to be efficiently transformed into body proteins, though not completely, that may be ascribed to the non-alleviation of the anti­nutritional metabolites completely9, at the present ex­trusion conditions employed.

Supplementation of cereals diet with EFB im­proved all the nutritional values remarkably and sig­nificantly and was at par with casein dietary group. Moreover, capacity of animals to retain nitrogen was also significantly higher in EFB dietary group than in cereals fed rats (Table 3) . Removal of certain anti­nutritive factors in faba bean upon extrusion cooking9 along with a little heating and cooking of the diet be­fore being distributed to the animals must have helped in exhibiting these effects. Thus the ability of animals to absorb, retain and utilize food nitrogen was more efficient when extrusion cooked beans formed a part of cereals diet (Table 3).

Blending of EFB in cereals diet at either level pro­duced similar impact on nutritional parameters (Table 3). Elevating EFB content to 40% in the diet failed to affect these parameters appreciably (Table 3) . Biological utilization of EFB protein at 20% level was better (Table 3). This may be ascribed to deficiency of tryptophan and methionine as well as a negative effect of moderate concentration of phenolic compounds and phytates in faba bean extrudatesl l . Moreover, at the present extrusion conditions employed, anti­nutritional metabolites were not completely allevi­ated9 and thereby, may hinder complete protein utili­zation and therefore, its nutritive effect. Extrusion of faba bean at more drastic conditions may prove bene­ficial.

References I Zuiliehem D L & Moscicki L, Cooking extrusion of horse

bean and a feed diet formulation, In Thermal Processing and Quality Foods, edited by P Zeuthen, J C Cheftel, C Eriksson, M Jull, H Leniger, P Linko, G Varela and G Vos (Elsevier App. Sci. Pub. Ltd., England) 1 984, 1 98.

2 Della A, A review of the present status and future prospects of Vicia faba L. in Cyprus. FABIS, I I ( 1 985) I .

3 Adsule R N & Akpapunam M , Faba bean (Viciafaba L.), in Food and feed from legumes and oi/seeds, eidited by E Nwokola and J Smartt (Chapman and Hall, London) 1 996, 1 97.

4 Rani N & Hira C K, Effects of various treatments on nutri­tional quality of faba bean (Viciafaba L.), J Food Sci Tech­nol, 30 ( 1 993) 4 1 3.

5 Kushwah A, Kushwah H S & Rajawat P, Effect of domestic processing on anti-nutritional components and in vitro pro­tein digestibility of faba bean (Viciafaba L.), Indian Vet Med J, 25 (200 1 ) 1 79.

6 Kolodziej J, Nutritive value of coarse-grained legumes (pea, horse bean, lupin) in feeding pigs: Polish experience, Krmiva. 39 ( 1 997) 241 .

7 Rajawat P, Kushwah A & Kushwah H S, Effect of extrusion cooking variables on biochemical composition of faba bean (Viciafaba L.), J Food Sci Technol, 37 (2000), 373.

8 Camire M E, Camire A & Krumhar Kim, Chemical and nu­tritional changes during extrusion, Fd Sci Nutr. 29 ( 1 990) 35.

9 Rajawat P, Kushwah A & Kushwah H S, Effect of extrusion cooking variables on anti-nutritional components and in vitro protein digestibility of faba bean, Indian J Anim Nutr, 1 6 ( 1 999) 301 .

1 0 Kushwah A, Kushwah H S, Rajawat P & Shroti S, Composi­tion of faba bean (Vicia faba L.): Nutritional response upon processed beans feeding in rats. lnd J Anim Sci, (200 1 ) Ac­cepted.

1 1 Borowska J, Zdunczyk Z, Fornal L & Kozlowska H, Quality of multicomponent extrudates with faba bean (Viciafaba L.) Pol l Food Nut, 3 ( 1 994) 1 19.

12 Rajawat P, Kushwah A & Kushwah H S, Organoleptic and nutritive scoring of extruded faba bean (Vicia faba L.) sup­plemented cereals recipes. The Indian J Nutr Diet, (2000) Communicated.

1 3 AOAC, Official Methods of Analysis. Association of Official Analytical Chemists, Washington, D C ( 1990).

14 Snedecor G W & Cochran W G, Statistical Methods. Indian edn. 8th edn. (The Iowa State University Press, USA) 1 994, 324.

1 5 Rao N B S, Deosthale Y G & Pant K C, Nutrient Composi­tion of Indian Foods, National Institute of Nutrition. I.C.M.R. Hyderabad, India ( 1 989).

1 6 Marquardt R R & Ward A T, Chick performance as affected by autoclave treatment of tannin containing free cultivars of faba beans, Can J Anim Sci 59 ( 1 979) 7 8 1 .