INTRODUCTION

The most common baby foods used to feed preschool children in developing countries  are starchy gruels produced from traditionally refined cereal grains (Delgado and Saldivor., 2000).

However, vegetable protein are characterized by their low nutritional value due to presence of antinutritional factors such as inhibitors, phytic acid, unbalanced amino acids composition and low digestibility. Therefore blending or mixing two or more different materials together will help to solve and overcome the deficiency proplem of cereals and legumes if used as food protein source (Pipes and Trahms., 1993).

Also, germination is considered a suitable procedure to improve the nutritional value of legumes seeds by reducing levels of antinutritional factors (Donangelo et al., 1995), and the bulk of its gruels (Marero et al., 1988). While protein content increased (King and Puwastein., 1987).

Cooking process after germination of legumes caused reduction of phytic acid and trypsin inhibitor, and improved the digestibility of protein (Ismail et al., 2000 and Zahran, 2000).

Faba bean is an abundant and economical source of food protein and some mineral elements (Finney et al., 1988 and Youssef et al., 1987).

Chickpea and cowpea are important cheap source of vegetable protein which contained adequate amounts of most essential amino acids for preschool children (Paredes –Lopez et al., 1991, Clement et al., 1998 and Abd El Akher et al., 1995).

The aim of this investigation is to produce nutritionally balanced baby foods from locally available raw materials at low cost.

MATERIALS AND METHODS

1 – Materials:

a )     Cereals: Wheat (Triticum species), sorghum variety Giza 15 and rice (Oryza sativa).

b )  Legumes: Faba bean (vicia faba), chickpea (Cicer arietinum) and cowpea (Vigna unguiculato) cereals and legumes were obtained from AgricultureResearchCenter, Giza, Egypt.

D)     Dried skim milk was obtained from the NationalResearchCenter, Dokki- Giza, Egypt.       

2 – Methods:

a )     Preparation of the different materials:

Dry cereals and dry legumes were cleaned from impurities and then washed thorough with tap water. The washed cereals seeds were separately soaked in tap water overnight and the legumes were separately germinated according to the method of Marero et al., (1988).Germinated seeds were husked by hands under running water.

Germinated legumes seeds (faba bean, chickpea and cowpea), and cereals seeds (wheat, sorghum and rice) were cooked in a pressure cooker also separately for 10 and 8 minutes respectively.

Thereafter , the cooked materials were dried in an air dryer at 65-70^oC and milled in an electrical mill, then sieved through  a 35 mesh seiver (425 microns).

b)      Preparation of baby food mixtures:

         The baby food mixtures were prepared to be as preschool children. The quantity of each ingredient of these mixtures were chosen according to essential amino acid contents of each material and the Pattern of amino acid requirements for preschool children, (Table 4).

c)      Preparation of baby food diets:

              To produce 100 g of the prepared baby food diet, 75 ml water was added to 25 g of the mixture, then mixed directly to produce a thick gruel.

d)     Chemical analyses:

*   Moisture, crude protein , fat, fiber, total ash and minerals were determined according to the AOAC (1990). Total carbohydrates were calculated by difference.

*   Amino acids were identified through the acid hydrolyzate with 6 N. HCl at 110^oC for 24 hr. according to the procedure of Moore, et al., (1958).

*   Phytic acid was determined according to the methods of Wheeler and Ferrel (1971).

*   Trypsin inhibitor was determined according to the method of Roy and Reo, (1971).

*   The in-vitro-protein digestibility index by pepsin and trypsin enzymes in a single system was assessed according to the method of Saunder, et al., (1973).

*   Total energy in the resultant products was expressed in calories, and was calculated according to Tamime, et al., (1987).

e)      Organoleptic evaluations.

Organoleptic tests of baby food mixtures were scored according to Notter et al., (1959).

RESULTS AND DISCUSSION

*  Chemical  composition of raw, germinated and cooked materials.

The raw, germinated and cooked materials under investigation, i.e., cereals (rice flour, wheat flour and sorghum flour) ; legumes (faba bean flour, chickpea flour and cowpea flour) and dried skim milk were analyzed for protein, fat, ash, moisture, carbohydrate and fibers. The results are presented in Table (1), it could be noted that rice flour, wheat flour and sorghum flour had the highest  carbohydrates content being 89.7, 81.9 and 80.4% respectively. But chickpea flour, cowpea flour and faba bean flour had almost the carbohydrate content ranged from 58.0 to 62.6.

High protein levels were observed in dried skim milk (36.0%), faba bean (33.4%), cowpea (29.0%) and chickpea (24.3%). While in wheat, rice and sorghum ranged from 8.0 to 13.5.

Dried skim milk had the highest level of ash (8.4%), followed by faba beans ( 3.6%), cowpea (3.4%) chickpea (2.8%) sorghum (1.6%), wheat (1.4%) and rice (0.7%).

The highest level of fiber content was in cowpea (3.7%), followed by faba bean (3.5%), but chickpea, sorghum, wheat and rice contained 2.8, 1.6, 1.3 and 0.8% respectively, while dried skim milk had no fiber content.

The germinated legumes possess a higher amount of the protein than the ungerminated ones, as that found by Finey et al., (1980) . These increment may due to the effect of germination process which lead to a slight increase in curde protein as compare to the raw samples (Khalil and Mansour, 1995). On contrary , fat, ash, carbohydrate and fiber content are decreased slightly.

Cooking process, which is followed the germiantion process, lead to decrease in protein by about 5.03% , 5.98% and 6.98 % for faba bean, cowpea and chickpea respectively. Also , moisture, fat, fiber and ash content showed a decrement of all tested materials.

Morever, carbohydrates content of tested materials was increased due to cooking process. This trend seeamed to be the same as reported by Cardoso-Santiago and Areas (2001) in chickpea.

Table (1): The chemical composition of raw, germinated and cooked materials (Calculated on dry weight).

Essential amino acids content of the materials

The nutritive value of protein mostly would depend on its amino acids profile, in general and the  quantities of the essential amino acids in particular. Protein requirements can be satisfied by providing the total essential amino acids rather than increasing the intake of protein.

Table (2) showed the ten amino acids content in cooked legumes (chickpea, faba bean and cowpea) and skim milk powder compared with FAO/WHO (1985) pattern.

The data revealed that the essential amino acids content of the materials exceeded their corresponding quantities in FAO pattern except for methionine, cystine and tryptophane in cooked faba bean flour and threonine in cooked chickpea flour.

Table (2): Essential amino acids content of the tested materials compared with FAO pattern of preschool children.

         Antinutritional factors affected by germination and cooking processes:

Nutritional value of legumes limited by the content of antinutrients such as phytic acid and trypsin inhibitors (Rincon et al., 1998). The effect of the pretreatment (germination and cooking) processes on phytic acid content  for cowpea, chickpea and faba bean was studied. Data presented in Table (3) showed that there was dramatically  reduction in phytic acid in all legumes due to the germination process. These results are agreed with that found by Shabib, (1999) and Ravindran et al., (1994).

It could be illustrated as Khan et al., (1988) reported that , during legumes germination, the phytase activity increased with concomitant decrease in phytate.

The present study showed, also that the germination process followed by cooking process lowered the phytic acid value in the chickpea,  cowpea and faba bean to 1.4, 0.7 and 0.5 gm/100gm respectively. The effect of cooking process could be illustrated by the finding of Sandberg et al., (1987) who reported that during cooking, about 25% of hexaphosphate was hydrolyzed to pentatetra phosphate.

 Results in Table (3) showed ,  also that the trypsin inhibitor value in the faba bean flour seemed to be higher in that found in chickpea and cowpea flour (39.9, 34.7 and 26.5 mg/g sample; respectively). Germination process leads to an extensive reduction in trypsin inhibitor in all  of the tested samples.

The cooking process after germination process seemed to give a nearest reduction impact on trypsin inhibitor in tested materials, 96.2% in cowpea, 96.2% in faba bean and 92.5 in chickpea flour .

Table (3) : Effect of germination and cooked process on phytic acid content and trypsin inhibitor (on dry weight basis)

Preparation of baby food mixtures:

Ingredients content (gm and percent %) and protein content (g and percent %) of each blend is found in Table (4), whole amount of all ingredients suggested to be 10g protein to be an adequate source to meet recommendation of protein as described by FAO/WHO (1985). Dried skim milk was predominantly used in all formulas to recover the shortage of protein. Moreover, Khalil and Mansour, (1995) reported that the nutritive value of many legumes was enhanced by heat processing and germination

Table (4): Ingredients of the prepared baby food mixtures.

Chemical composition of baby food mixtures

The nine mixtures were chemically analysed in order to determine the main chemical composition. The data obtained are shown in Table (5). It could be noted that the moisture content ranged between 3.72 and 5.31%  however, this low moisture content is of great importance for good keeping quality of reasonablie shelf life period for the final product. The protein content of the formulated mixtures was ranged between 19.0 and 22.0%.

Data presented in Table (5) showed also , that the tested mixtures could be categorized into two groups according to their fat content. The first group was included mixtures No. (1), (2), (3) and (8) which its fat was lower than 2%. On the other hand, the second groups, which its fat was higher than 2% was included mixtures No. (4), (5), (6) ,(7) and (9). These results are in agreement with those reported by Ismail et al., (2000).

Table (5): Chemical composition of the baby food mixtures (calculated an dry weight)                

It could be also, seen from Table (5) that the highest  value for carbohydrates content was in mixture No.(8) (73.68%) , while mixture No. (2), (5), (1), (4),(3) and (6) had contained values 72.32, 72.23, 70.83, 70.48, 70.37 and 70.32% respectively. Mixtures No. (7) and (9) showed lower values of carbohydrates content (69.68 and 69.84%), respectively.

The ash content ranged between 5.30 and 3.99% . The highest values were for mixtures No. (5), (2), (6) and (4) (5.30, 5.03, 4.56 and 4.54% respectively). The lowest values were in mixtures No. (8) and (1) ( 4.03 and 3.99%  respectively). The curde fiber content for the nine formulated mixtures ranged between 1.39 and 1.90%. The highest values were in mixture No,. (3), (1), (6), (9), (7) and 4 respectively. While the lowest values were in mixtures No.(8), (5), and (2) respectively.

Essential amino acids content of baby food mixtures:

It is clear from Table (6) that the different formulated mixtures contained high proportions of essential amino acids comparing with FAO provisional pattern except tryptophane was detected as a limiting amino acid. The same table showed, also that the mixture No. (5) contained the highest  content of total essential amino acids (50.39 gm/100gm protein) followed by mixtures No. (6), (4), (2),(3) and (1) respectively.

Nutritional evaluation of baby food mixtures

a)Nutrientcontent    From the results in Table (7) it could be noted that, 100gm from each tested mixture provides about one third of the energy daily requirement. The same amount of each of the tested mixtures provides about 1.3 fold nearly of the protein requirements. Data in Table (7) also, revealed that 100 gm of the individual mixture possessed by about 1.5 to 1.7 folds of daily requirement of the total essential amino acid as reported FAO/WHO (1985). The same table showed, also that magnesium content in 100gm of all mixtures was higher than that recommended by FAO/WHO (1985). All tested formulas covered one third of the daily requirement for zinc content from 100gm . Also, it gave from 50% of the daily requirement of calcium and iron content.