Evaluation of weaning foods based on white rice and germinated low starch high protein chickpea flours
Esam H. Mansour (1), Essam A. Hussein (2) and Fawzy A. H. El-Soukkary (3)
(1) Department of Food Science and Technology, Faculty of Agriculture, Menofiya University, Shibin El-Kom, Egypt
(2) Department of Nutrition and Food Science, Faculty of Home economics, Menofiya University, Shibin El-Kom, Egypt
(3) Department of Food Science, Faculty of Agriculture, Minia University, El-Minia, Egypt
Abstract Three weaning foods were formulated by blending white rice and germinated low starch high protein chickpea flours at 50:40 (F1), 40:50 (F2) and 30:60 (F3) (w/w ratio). The nutritional value of these weaning foods was evaluated by estimating their proximate composition, protein efficiency ratio (PER), corrected protein efficiency ratio (CPER), net protein ratio (NPR), true digestibility (TD), biological value (BV), net protein utilization (NPU), in-vitro protein digestibility (IVPD), essential amino acid, chemical score (CS) and sensory properties. The crude protein and energy contents of the formulated weaning foods ranged from 25.32 to 29.91% and from 402.28 to 405.35 kcal/100g respectively. The PER, CPER, NPR, TD, NPU and BV of F2 and F3 did not significantly (P > 0.05) different and very closed to those of casein. The IVPD and amino acid scores of these weaning foods varied from 93.42 to 95.14% and 87.66 to 88.59% respectively. Lysine and threonine were the limiting amino acids for F1, while threonine was the only limiting amino acid for F2 and F3. The data of the statistical analysis showed that chemical score was strongly correlated (r = - 0.93** to - 0.99**) with all studied biological parameters. Therefore, a simple regression equation correlated between CS and each of other biological parameters was reported. The sensory properties of the formulated weaning foods were well comparable with those of Cerelac, the common weaning food over world.
Key Words: Rice, Low starch high protein chickpea flour, Protein quality, Chemical score, Sensory properties
Introduction
Development foods rich in energy and protein is necessary to overcome the malnutrition problem in developing countries. Selecting and combination of suitable vegetable protein sources can solve the less availability and high costs of animal protein materials in these countries.
Cereals and legumes consider the major consumed plant protein sources by a large section of the population in developing countries. Chickpea (Cicer arietinum) is an important one member of legume family. It ranks the third in legumes production over the world to dry beans and peas (Singh et al., 1991). It is high in starch, protein, lysine and deficient in methionine (Mansour, 1996).
Germination of chickpea eliminates its content of the antinutritional and indigestible factors, improves its cooking quality, starch digestibility, organoleptic properties and enhances its shelf life (Hesseltime, 1983, Reddy et al., 1986, Nnanna and Philips, 1990, Trugo et al., 1993).
According to Mansour (1996) treatment of germinated chickpea with a-amylase enzyme gave chickpea rich in protein (55.5%), high in lysine (7.5 g/16 g N), low in starch and methionine (1.9 g/16 g N).
On the other hand, white rice is one of an essential cereal food. It is rich in starch (89.8%) and methionine (3.0 g/16 g N), low in protein (8.3%) and deficient in lysine (4.7 g/16 g N), (Hussein, 2000). Therefore, this study aimed to prepare high protein weaning food with good nutritional quality and acceptable organoleptic properties using proper combinations of these two plant sources. Chickpea was first germinated then treated with a-amylase enzyme before combined with rice flour.
Materials and Methods
A- Materials:
1- Chickpea: It was obtained from local market in Shibin El-Kom city, Egypt.
2- Low starch high protein chickpea flour: It was prepared as described in figure (1). Chickpea seeds were cleaned by hand to remove foreign materials, immersed in 95% ethanol for 1 min to become aseptic, then soaked in distilled water at 3:1 v/w water to seed ratio for 12 h at room temperature (20±2°C) before germination between two thick layers of cotton cloth in dark for 3 days at room temperature (20±2°C). To reduce the starch and soluble sugars and increase the protein level, the resulted beans were first treated with a-amylase enzyme then, extracted with 70% ethanol followed by water at pH 4.5, neutralized to pH 7.0, dried and ground to pass through a 80-mesh sieve as described by Mansour (1996).
3- White rice: The white cleaned rice grains were obtained from local market in Shibin El-Kom city, Egypt and ground to pass through a 80-mesh sieve.
4- Cerelac: The Cerelac was obtained from pharmacy in Shibin El-Kom city, Egypt.
5- Sucrose powder and vanillic flavour: They obtained from local market in Shibin El-Kom city,
6- Weaning foods: The suggested recipes for formulating weaning food are reported in Table (1).
Table (1): The suggested recipes for formulating weaning food
Ingredients (%) / Formula 1 (F1) / Formula 2(F2) / Formula 3
(F3)
White rice flour / 50 / 40 / 30
Germinated low starch high protein chickpea flour / 40 / 50 / 60
Sucrose powder / 8.5 / 8.5 / 8.5
Mineral mixture1 / 1.0 / 1.0 / 1.0
Vitamin mixture2 / 0.2 / 0.2 / 0.2
Vanillic flavour / 0.3 / 0.3 / 0.3
B- Methods:
1- Analytical Methods: All analysis were carried out in triplicate. Moisture (method No. 925.09), crude protein N x 6.25 (method No. 960.52), crude oil (method No. 920.39c), crude fiber (method No. 924.05) and ash (method No. 923.03), were estimated according to AOAC (1995). Carbohydrate was calculated by difference. Energy values were calculated from protein, carbohydrate and fat contents.
Amino acids were determined after hydrolyzing the samples with 6 N HCl at 110 °C for 22 h in nitrogen atmosphere using Beckman amino acid analyzer (Model 118/119 CL) according to the method described by Moore and Stein (1963). Sulfur containing amino acids were determined after performic acid oxidation. Tryptophan was chemically determined by the method of Miller (1967). In-vitro protein digestibility (IVPD) was determined according to Salgó et al., (1984) by measuring the decrease in pH during digestion with trypsin and pancreatin. Chemical score (CS) was calculated using FAO/WHO (1973).
2- Biological evaluation of protein quality:
Seventy two male weanling albino rats of Wistar-strain, 5 week old with an average body weight of 70 ± 4g, were used to estimate true digestibility (TD), biological value (BV) and net protein utilization (NPU) after dividing into 12 groups each group having 6 rats (Eggum, 1973).
Fig (1): Preparation diagram of germinated low starch high protein chickpea flour
Rats were housed in individual cages at room temperature 20±2°C with a 12 h cycle of light and dark. The rats were weighed at the beginning of the experiments and at the end of preliminary (4 days) and balance periods (5 days). The urine and feces of each rat were collected through the balance periods and their content of nitrogen was determined according to AOAC (1995).
The experimental diets are weighed out into plastic boxes with tightly fitting lids and weighed each day through the preliminary and the balance periods. The remaining feed was weighed and taken into consideration during calculation of the experimental results.
Under the same experimental conditions, the changes in weight and protein consumption over the four weeks were used to estimate protein efficiency ratio (PER), corrected protein efficiency ratio (CPER) and net protein ratio (NPR).
The compositions of the basal diet, casein and suggested weaning foods are presented in Table (2). The tested proteins were incorporated into the basal diet at expense of corn starch to give a final 10% crude protein in all formulated diets. The following equations were used to calculate the true digestibility (TD), net protein utilization (NPU), biological value (BV), protein efficiency ratio (PER), corrected protein efficiency ratio (CPER) and net protein ratio (NPR)
N absorbed I- (F – FK)
TD = ¾¾¾¾¾ = ¾¾¾¾¾
N intake I
N retained I- (F – FK) – (U – UK)
NPU = ¾¾¾¾¾ = ¾¾¾¾¾¾¾¾¾¾
N intake I
N retained I- (F – FK) – (U – UK)
BV = ¾¾¾¾¾ = ¾¾¾¾¾¾¾¾¾¾
N absorbed I- (F – FK)
Weight gain of test group
PER = ¾¾¾¾¾¾¾¾¾¾¾
Protein consumed
2.5
CPER = PER ´ ¾¾¾¾¾¾¾
PER for casein
Weight gain of test group + weight loss of control group
NPR = ¾¾¾¾¾¾¾¾¾¾¾¾¾¾¾¾¾¾¾¾¾¾¾
Protein consumed by test group
Where are: I = intake nitrogen, F = Faecal nitrogen, FK = endogenous faecal nitrogen, U = urinary nitrogen, UK = endogenous urinary nitrogen
Table (2): Composition of the experimental diets
Ingredients (%) / Basal diet / Casein / (F1) / F2 / F3Corn starch / 80 / 67.6 / 40.5 / 44.1 / 46.6
Test sample / - / 12.4 / 39.5 / 35.9 / 33.4
Corn oil / 10 / 10 / 10 / 10 / 10
Non-nutritive cellulose / 5 / 5 / 5 / 5 / 5
Mineral mixture1 / 3.8 / 3.8 / 3.8 / 3.8 / 3.8
Vitamin mixture2 / 1 / 1 / 1 / 1 / 1
Choline bicarbonate / 0.2 / 0.2 / 0.2 / 0.2 / 0.2
1Each kg of mineral mixture contains: tricalcium phosphate 493 g, potassium citrate 246.9 g, potassium chloride 98.8 g, magnesium chloride 37 g, sodium chloride 117.3 g, ferrous sulfate 6.17 g, zinc sulfate 2.36 g, manganese sulfate 69.14 g and potassium iodine 18.52 g.
2Each kg of vitamin contains: vitamin A 2000 IU, vitamin D 200 IU, vitamin K 10 IU, inositol 10 mg, niacin 4 mg, Ca-pantothenate 4 mg, riboflavin 0.8 mg, thiamine HCl 0.5, pyridoxine HCl 0.5 mg, Folic acid 0.2 mg, biotin 0.04 mg, vitamin B12 0.03 mg, choline chloride 200 g and b-amino benzoic acid 10 g.
3- Sensory evaluation of weaning foods:
Twenty nursing mothers attending Ali Bin Abi Taleb child Care Home, Sumoha, Alexandria, Egypt were asked to evaluate the colour, aroma, taste, viscosity and overall acceptability of the prepared porridges (11g in 130ml hot water, 70°C) of the suggested weaning foods, in addition to that prepared from Cerelac, (15g 130ml hot water, 70°C) as a control using hedonic rating test scale (Rangana, 1977)
4- Statistical Analysis:
The data were subjected to statistical analysis using SAS, (1988). When a significant main effect was detected, the means were separated with the Student-Newman-Keuls test. Differences between formulas of (P £ 0.05) were considered significant. Comparison among crude protein, in-vitro protein digestibility, chemical score and biological assays were evaluated by multiple regression analysis.
Result and discussion
1- Proximate composition:
Data presented in Table 3 show the proximate composition of white rice flour, low starch high protein chickpea flour and the three suggested prepared weaning foods. Comparing with white rice flour, chickpea had higher crude protein, oil, fiber, ash and lower carbohydrate. The crude protein content and the caloric value of the three suggested prepared weaning foods ranged from 25.32 to 29.91% and from 402.28 to 405.35 kcal/100g respectively. An intake of 100g of the three suggested weaning foods is capable of supplying more than the requirement of protein for the 6-11 months (24.9g) and for the 1-3 years (25.8g) children (PAG, 1971). However, an intake of 100g of the suggested weaning foods is capable of supplying about 31-35% of the Recommended daily allowances (RDA) for the 6-11 months (1149 kcal/day) and for the 1-3 years (1311 kcal/day) children (PAG, 1971). Generally, significant variations were noticed among the proximate composition and calories of white rice, chickpea flours and suggested weaning foods.
2- Amino acid content:
Table 4 shows the essential amino acids content of white rice flour, low starch high protein chickpea flour, the three suggested prepared weaning foods and the FAO/WHO (1973) reference pattern. Contradiction to rice flour protein, chickpea protein was higher in lysine and deficient in sulfur containing amino acids. Similar findings were reported by Mansour (1996) and Hussein (2000). The combination of white rice flour and low starch high protein chickpea flour to formulate the suggested weaning foods gave efficient complementation of most of the essential amino acids, of the FAO/WHO (1973) reference pattern. The suggested weaning foods were slightly deficient in threonine (12-12.5%) and isoleucine (7.25-9.75%) and a marginally deficient in leucine (2.28-3.0%). Generally, increasing the ratio of low starch high protein chickpea flour in the weaning food formulation increased lysine content and lowered sulfur containing amino acids. Therefore, F1 was a marginally deficient in lysine content (4.0%) and F3 in sulfur containing amino acids (2.28%).
3- In-vitro protein digestibility and chemical score:
Data presented in Table 5 show that the IVPD values of the three suggested weaning foods ranged from 93.42 to 95.14%. F1 had the lowest IVPD value (93.42%), however F3 had the highest IVPD one (95.14%). According to Rodríguez-Bürger et al., (1998) weaning food based on 53% fermented black bean and 47% cooked rice had 86% IVPD. Results of Mansour (1996) indicated that germination; extraction and a-amylase treatment improved significantly the IVPD of chickpea. Lysine and threonine were the limiting amino acids for F1, while threonine was the limiting one for both F2 and F3. In contract, the chemical score of the three suggested weaning foods was very closed. Mbithi-Mwikya et al., (2002) prepared weaning food based on mixing 65.2, 19.1, 8.0, and 7.7% of finger millet, kidney beans, peanuts, and mango, respectively. The protein of this food had 90.2% in vitro protein digestibility and 84% an amino acid score.
4- Biological quality of the three suggested weaning food proteins:
Results of biological quality of the three suggested weaning food proteins are given in Table 6. No significant (P > 0.05) differences were found in PER, CPER, NPR, TD, NPU and BV among rats fed either on casein diet or weaning foods F2 and F3. Generally, the PER value of the three suggested weaning foods ranged from 2.10 to 2.78. According to FAO/WHO (1985) mixtures of cereals, legumes and/or oilseed flours should not less than 2.1 and preferably above 2.3 PER to use a weaning food.
Hussein (2000) found that PER, CPER and NPU values were 2.64, 2.81 and 3.06 respectively for the formulated weaning food from 80% rice, 5% defatted soybean, 5% chickpea and 10% sugar. TD value (90.77-94.64%) of the three suggested weaning foods in this study was similar with that of milk-based infant formulas prepared by Sarwar et al., (1989) and that based on cooked-germinated beans and cooked rice (Kannan et al., 2001)