NUTRIENT COMPOSITION, EFFICACY, AND CONSUMER ACCEPTABILITY OF SOY FORTIFIED COMPLEMENTARY FOODS FROM WESTERN KENYA

Abstract

Protein Energy Malnutrition accounts for half of the annual deaths of children aged below five years. Complementary foods for such young children should be protein rich and nutrient dense. Compositing complementary flours with legumes of high protein quality such as soy can be effective in abating malnutrition. The objective of this study was to develop soy-fortified complementary flours using locally available foods from Western Kenya and to determine the effect soy fortification on proximate composition, protein nutritional quality, growth, rehabilitation, and consumer acceptability. Two exploratory focus group discussions were carried out to establish how complementary foods are prepared in Western Kenya. To determine proximate composition, protein, fat, moisture, carbohydrate and energy were analyzed according to standard AOAC International methods. For the efficacy trials, eleven isonitrogenous diets containing 10% protein were formulated from six foods, maize (Zea mays), pearl millet (Pennisentum glaucum), finger millet (Eleusine coracana), sorghum (Sorghum bicolor), cassava (Manihot esculentum), and banana (Musa sp) at ratios of 70:30 flour and soy with milk powder as control and fed to weanling male albino rats. Another group was fed on a protein free diet. Protein Efficiency Ratio (PER), Food Efficiency Ratio (FER), Net Protein Retention Ratio (NPRR), True and Apparent Protein Digestibility, Protein Digestibility Corrected Amino Acid Score (PDCAAS) and growth were the indices of protein quality determined. Acceptability of porridges made from fortified flours was evaluated for colour, taste, texture, and smell by 50 consumers who were mothers and caregivers of young children using a 9-point hedonic scale. Soy fortification yielded a dramatic increase in protein content ranging from 63.25% in finger millet: soy to 797.63% in cassava: soy. Finger millet: soy had the lowest increase in oil content at 22.78% while the highest was 614.29% in pearl millet: soy. The increase in mineral content was lowest in banana: soy with 48.22% while maize: soy was on the highest with an increase of 562.65%. Banana: Soy diet had significantly superior protein nutritional quality, with a PER of 1.46, FER of 0.15, and NPRR of 0.48. Powdered milk had a PDCAAS of 100% while Maize: soy had 70%, the acceptable benchmark for foods for young children. Banana: soy recorded significantly high growth rate in rats with a weight gain of 32.27g while unfortified maize flour resulted in zero growth. True Protein Digestibility (TPD) of the fortified diets ranged from 88.81% in sorghum: soy flour to 95.59% in maize: soy flour, a range that is acceptable for cereal: bean mixtures. Sorghum soy had significantly high faecal bulk which was consistent with its low digestibility of 88.81%. On rehabilitation, the rats fed on protein free diet gained 45.10% on catch up growth. All the soy fortified porridges had total quality of above 65% and were also well accepted by the consumers. The findings show that soy fortified complementary flours have increased protein quality and nutrient density, and their porridges are acceptable to the target population. Fortification with soy improves PER of flours in rats, and by extrapolation could support growth of young children if used as complementary foods. It is recommended that soy fortified foods be used to alleviate PEM in Western Kenya.