Production and Nutritional Value of Weaning Foods from Mixtures of Pearl Millet and Cowpeas'

Cereal Chem. 70(1):14-18 Weaning foods were produced by mixing decorticated and press-dried for the preparation of porridgelike weaning foods. Sorghum malt hydropearl millet (70%) and cowpea (30%) with and without sorghum malt. lyzed the starch and produced a beverage that contained 17% protein Decorticated millet and cowpea flours were cooked into a slurry and with 90% of the essential amino acids required for infants less than one press-dried to produce flakes. The heat applied during cooking of the year old. slurry and press-drying was designed to develop proper paste properties Cereals and legumes, individually or as composites, are the main source of nutrients for weaning children in developing countries (Aguilera and Lusas 1981, King et al 1985, Morales et al 1988, Malleshi et al 1989). Among cereals, pearl millet (Pennisetum glaucum, syn. P. americanum, P. typhoideum) is considered to have one of the best protein quality or amino acid scores. The nutritional value of pearl millet is greatly enhanced when mixed with legumes because the latter complement its profile of essential amino acids (Serna-Saldivar et al 1991). Due to their availability and popularity, cowpeas (Vigna unguiculata) are an option for use in weaning foods in Africa and India (Guiro et al 1987, Boeh-Ocansey 1989). Most weaning food technologies, e.g., drum drying and extrusion cooking, are either too complicated or too expensive for low-income families in developing countries. Thus, practical, low-technology processes for production of weaning foods with adequate paste viscosity and nutrient density are needed. Malting, dry roasting, popping, steaming, boiling, and flaking are simple processes proposed for weaning food production (Malleshi and Desikachar 1982, Sefa-Dedeh 1984, King et al 1985, Morales et al 1988, Malleshi et al 1989). The objectives of this work were: 1) to develop a practical process to produce dehydrated, precooked millet and cowpea flours and 2) to prepare and evaluate the properties and nutritional value of weaning foods from composites of precooked millet and cowpea with and without sorghum malt. MATERIALS AND METHODS Raw Materials Grains used included: pearl millet (grain moisture = 11.3%, density = 1.49 g/cm , and test weight = 78.8 kg/hl), grown in Kansas in 1988; commercial cowpea, also called blackeyed peas (moisture 9.9%, density = 1.46 g/cm , and test weight = 71.6 kg/hl), grown in California in 1989; and Dorado sorghum (Sorghum bicolor, moisture = 11.6%, density = 1.36 g/cm , and test weight = 78.7 kg/hl), grown at Halfway, Texas in 1988. Commercial high-protein (soy-wheat-oat blend) dry baby food (Gerber Products Co., Fremont, MN) was used for comparison. Decortication Process Pearl millet (in 5-kg batches) was decorticated for 4.2 min to remove 25% of its weight (75% yield) with an IDRC abrasive mill (International Development Research Centre, Ottawa, Canada) equipped with eight disks 24 cm in diameter. Decorticated kernels were cleaned with a Clipper seed cleaner (Seedburo, model 400-1, Chicago, IL) equipped with round-holed screens, numbers 'Contribution TA 30057 from the Texas Agricultural Experiment Station. 2 Cereal Quality Lab, Soil and Crop Sciences, Texas A&M University, College Station, TX 77843-2474. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. American Association of Cereal Chemists, Inc., 1993. 1/15 (2 mm) and 6 (3 mm). Top and medium fractions were collected and hammer milled (Fitzpatrick hammer mill, model D. Fitzpatrick Co., Chicago, IL) to pass through an 0.8-mm screen. The resulting flours were bagged and stored in a freezer (-10°C). Likewise, cowpeas (5 kg) were decorticated for 1.5 min (75% yield) with an IDRC mill and sieved and aspirated to remove hulls with a Clipper seed cleaner equipped with a number 8 (3.05 mm) round-holed screen. Press-Drying Process Millet flour (500 g) was mixed with tap water (1,500 ml, 260C) and heated for 9 min on a hot plate (3250C surface temperature) with continuous stirring (Fig. 1). The slurry temperature increased linearly (slope = 5.5 C/min) up to 75°C after 9 min of heating. Portions (80 g) of the cooked slurry were spread and pressed with a spatula on a gas-fired griddle (80 X 45 cm) set at a surface temperature of 1100 C to produce dry flakes. Hand pressure was applied with a spatula during spreading of the slurry to produce a thin (about 1 mm thick) flake that dried within 15-30 sec.