1. MATERIALS AND METHODS Emmanuel Ohene Afoakwa*, Justice Asomaning & Esther Sakyi-Dawson Department of Nutrition & Food Science, University of Ghana, Legon-Accra. *Email: e_afoakwa@yahoo.com INFLUENCE OF THE ADDITION OF CEREAL MALTS AND COWPEA (VIGNA UNGUICULATA) ON THE NUTRITIONAL, FUNCTIONAL AND PHYSICO-CHEMICAL PROPERTIES OF FERMENTED TRADITIONAL WEANING FOODS CONCLUSION UNIVERSITY OF GHANA ABSTRACT Traditional weaning foods are made from cereals resulting in gruels of high density with viscosities that are not suitable for infant feeding. Reducing the bulk density in fermented weaning foods will facilitate the production of infant porridges of improved caloric density and lower viscosity but reduced nutritional value. Cowpea addition to the formulated weaning food is suspected to improve the nutritional value with similar functional and physico-chemical properties. The objective of this study was to investigate the influence of the addition of cereal malts and cowpea flour on the nutritional, functional and physico-chemical properties of cereal-based traditional weaning foods. A 3x3x3x2 factorial experiment with sprouting time, cereal malt, cowpea concentration and malt concentration was used. Samples were analysed for their proximate composition, viscoelastic properties and functional properties (pH, acidity and water holding capacity) using standard methods. Sorghum malt in comparison to millet and maize malts was not effective in terms of lowering the hot and cold paste viscosities of the fermented weaning food. Maize and millet malt liquefied the dough considerably during and after gelatinization. Addition of cowpea to the maize dough led to increases in protein, ash and water holding capacity from 9.63-14.53%, 1.85–3.67% and 94– 180 g/100g respectively. The pH of the products decreased (5.23–3.85) with concomitant increase in acidity (0.238–0.665 gLactic acid/100g) with increasing malt concentration and no significant effect was noted for the type of cereal malt. ANOVA revealed that addition of cereal malts and cowpea flour to the weaning foods significantly (p<0.05) lowered the bulk density and improved the nutritional, functional and physico-chemical properties of the weaning gruels.  Materials  Sorghum (Sorghum bicolor), millet (Eleusine coracana) and maize (Zea mays) were obtained from the Centre for Food Safety and Quality Enhancement (CFSQE), University of Georgia, Atlanta, U.S.A.  Experimental Design  A 3 x 3 x 3 x2 factorial experimental design was used.  The principal factors investigated were:  i. Cereal malt: maize, millet and sorghum.  ii. Sprouting time: 2, 3, and 4 days.  Iii. Cowpea concentration : 0, 10, and 20%  iv. malt concentration: 10% and 20%.  Maize (Zea mays) or corn is the most important cereal grain in tropical Africa.  They are vital to the survival and food security of a large segment of the population in Africa, contributing over 55% of the total energy intake.  The main problem associated with maize-based foods are the lack of adequate protein quality or essential amino acids and the viscosity that limit intake, especially in weaned infants.  Fermented maize products by tradition constitute an important part of the diet of people in Africa.  One of the primary objectives for the traditional fermentation of maize is to cause souring of the dough with its associated improvement in taste, flavour and texture.  These fermentations as carried out traditionally, are spontaneous.  Malting is a traditional practice in developing countries primarily used in the production of alcohol and non-alcoholic beverages and during malting of grains, α- amylase and β -amylase activity is developed.  These enzymes effectively degrade starch granules reducing their water binding capacity.  The incorporation of a small amount of germinated grain, amylase rich flour (ARF) to a cereal gruel has been reported to produce a remarkable reduction in viscosity.  This research therefore sought to investigate the influence of the addition of cereal malts (maize, sorghum, and millet) and cowpea on the nutritional, physico- chemical and functional properties of fermented maize and its suitability for the preparation of infant weaning foods.  Methods  Proximate analysis  Moisture, Ash, Crude fat, Crude protein, Carbohydrate contents of the foods were determined using AOAC (1990) methods.  Functional properties  Water absorption capacities at 25°C and 70°C.  Physico-chemical properties  pH  Titratable acidity  Cooked paste viscosity  The viscosities of the samples were determined using the American Association of Cereal Chemists Method 22-10 (AACC, 1983) with slight modifications.  Statistical analysis  The data were statistically analyzed using Statgraphics (Graphics Software System, STCC, Inc. U.S.A). Comparisons between sample treatments and the indices were done using analysis of variance (ANOVA) with a probability p<0.05.  Proximate analysis  The moisture content of the germinated seedlings increased with increase in malting period for all three cereals used.  The crude fat content decreased with increase in both cowpea and malt levels.  The protein content also increased with increase in cowpea level but decreased slightly with increase in malt level.  There was an increase in ash content with an increase in cowpea level and malt level.  Carbohydrate content decreased with increasing cowpea level but increased with increasing level of malt.  Functional properties  Water absorption capacities increased with increase in cowpea level but decreased with increase in malt level at both 25ºC and 70ºC.  Pasting temperature decreased with both increasing cowpea level and malt level.  Peak viscosity, viscosity at 50ºC and viscosity at 95ºC all increased with increasing cowpea level but decreased with increasing malt level.  pH increased with increase in both malt level and cowpea level  Titratable acidity decreased with increase in both malt level and cowpea level  Cowpea-fortification and malt addition can be used to effectively improve nutrient content as well as decrease the viscosity of cereal gruels which are used as traditional weaning foods from maize. Presented at the 2 nd ITANA Conference, September 16 th - 18 th, 2005, Cape Town, South Africa INTRODUCTION Table 1. Chemical composition of the fermented traditional weaning food SAMPLE% moisture Composition (g/100g dry sample) % cowpea% maltCrude fatProteinAshCarbohydrate 006.895.169.371.2484.24 26.404.909.311.3784.42 56.284.899.311.4384.37 2007.094.2311.721.8082.25 27.024.1011.691.9381.96 57.194.0711.732.0182.18 Table 2. Physico-chemical and functional properties of the fermented traditional weaning foods SAMPLEpHTitratable acidity (g lactic acid/100g) Water absorption capacity (g/100g dry sample) % Cowpea % Malt25ºC70ºC 004.030.431167.43217.69 24.120.425165.59198.20 54.360.423155.06190.54 2004.810.403175.02242.40 24.850.395173.18224.76 54.880.391169.23197.32 RESULTS AND DISCUSSION