Formulation and consumer acceptability of biofortified maize (Zea mays L.) and sugar bean (Phaseolus vulgaris L.) blend as supplementary food for children aged 6-59 months.

Abstract

Globally, about 2 billion people experience micronutrient deficiency due to the consumption of poor quality foods that lack diversity and essential micronutrients. Biofortified crops offer a potential route for tacking micronutrient malnutrition in at-risk population subgroups particularly children. This study aimed to formulate biofortified maize-sugar bean blendsand evaluate their consumer acceptability as supplementary food for children aged 6-59 months. The grains of locally available provitamin A-biofortified maize, iron-biofortified sugar beans and white maize (control) were analysed for carotenoids, iron and zinc using standard or referenced methods. The analysis results showed that biofortified maize had significantly high total provitamin A carotenoid concentration (9.958 µg/g DW ) compared to both iron biofortified sugar beans (0.071 µg/g DW) and white maize (0.013 µg/g DW) which served as a control. The biofortified sugar bean had significantly higher iron and zinc concentrations (32.680 µg/g and 77.203 µg/g DW respectively) compared to both biofortified maize (0.045 µg/g and 0.261 µg/g DW respectively) and white maize (0.070 µg/g and 0.040 µg/g DW respectively). These findings indicate that biofortified maize is a superior source of provitamin compared to biofortified sugar beans and white maize. The findings also indicate that biofortified sugar beans is a superior source of iron and zinc compared to biofortified maize and white maize.

The biofortified maize and sugar bean were then combined in different proportions (50:50 and 67:33) to formulate meal blends meeting at least 20% of the recommended daily intakes of vitamin, iron and zinc for children aged 5 years and below. A cross-sectional survey was conducted to evaluate the consumer acceptability of the blends as supplementary food in the form of thin porridge. Thin porridges prepared from sole white maize and sole biofortified maize meal were used as controls. The thin porridges were evaluated for appearance, taste, aroma, texture and overall acceptability using a 5 point hedonic scale by 30 untrained adult women caregivers in Mbare, Harare. Thin porridge prepared using biofortified maize:sugar bean blend (ratio 50:50) had the highest mean score for overall acceptability (3.59) among all the thin porridges. Interestingly, both thin porridges prepared using biofortified maize:sugar bean blends were more accepted by the caregivers than thin porridges prepared using sole white maize meal and sole biofortified maize. Such blends of biofortified maize and sugar bean had never been evaluated before and hence their high acceptability among women caregivers is a new and important finding. The high acceptability of blends of biofortified maize and sugar beans suggests they can potentially be used to deliver provitamin A, iron and zinc to vulnerable individuals particularly children under the age of 5. Findings from this study also suggest that there is a low level awareness on biofortified crops among urban consumers. There is need for nutrition awareness and education programmes on biofortification targeting urban areas as current efforts are mainly focused on rural areas.

The more accepted blend (50:50) was then analysed for proximate composition. The blend had an acceptable crude fibre content of 4.5 g/100g as per the Codex Alimentarius guidelines on formulated complementary foods for children. The blend also had a low moisture content of 7.7% indicating that it has good keeping qualities. The proximate analysis results indicate that biofortified maize-sugar bean blends are good sources of energy, protein and carbohydrates and should be used in tackling protein energy malnutrition (PEM).

Key words: biofortified, supplementary food, sensory evaluation