Development of a Nutritious Composite Flour From Pearl Millet (pennisetum glaucum) and Pumpkin Fruit (cucurbita pepo-variety styriaca)

Abstract

Malnutrition continues to be a serious problem in Kenya today among children, the elderly, as well as expectant and lactating mothers, especially in resource poor settings including the urban poor, arid and semi-arid areas. These groups normally do not have access to a wide variety of foods, and the bulk of their diets consists of cereal staple foods especially maize, which mainly provides starch. This is due to their low purchasing power, high reliance on maize as a staple and lack of awareness of importance of drought tolerant crops. Therefore, the development of nutritious composite flours from cereal and non-cereal foods using cheap techniques may greatly improve the nutritional status of these vulnerabe groups. For children, such composite flours may be good for complementary feeding. The aim of this study was to develop a nutrious composite flour from pearl millet and pumpkin fruit. Germination, fermentation and roasting of pearl millet grains, as well as soaking, preboiling and roasting of pumpkin seeds were used to enhance the nutrition and sensory properties of the product. Effects on nutritional and sensory properties of germination of pearl millet grains at various time- temperature combinations followed by fermentation and roasting were studied. Also the effects of soaking, preboiling and roasting of pumpkin seeds were evaluated.A composite flour was developed from germinated, fermented and roasted pearl millet grains, dried pumpkin flesh and roasted pumpkin seeds. The treated pearl millet flour gave porridge of superior nutritional and sensory quality than flour from untreated pearl millet. Roasting of pumpkin seed enhanced development of a desirable nutty flavour in the porridge. The treated pearl millet had significantly lower phytic acid and calcium levels (p< 0.05) and higher crude protein, total ash, crude fiber, iron and zinc levels than untreated millet flour. The pumpkin flesh enhanced the flour’s nutritional quality in terms of beta carotene which is a major precussor of vitamin A. The composite flour was developed from the treated flours that exhibited superior nutritional based on recommended daily allowances for xv infants aged 7-12 months as well as well as based on their sensory qualities. This group (7-12 months old infants) was considered because it is a critical window period of growth where proper nutrition is key. The developed composite flour had a pearl millet: pumkin flesh: pumpkin seed ratio of 7: 1: 2. It contained 11.4 % protein, 5.2 % fat, 4.7 % crude fiber, 3.6 % crude ash, 67.0% carbohydrate, and 8.0 % moisture. It had 3 mg/100g zinc, 9.8 mg /100g iron, 78.8 mg/100g calcium and 131.3μg/100g retinol activity equivalent. The phytate content was 175mg/100g. The product had a phytic acid: zinc, phytic acid: iron, and phytic acid: calcium molar ratios of 6.5, 1.5, 0.15 respectively. Phytate:zinc, phytate: iron, and phytate: calcium rations of <18, <1, and < 0.17 have been suggetsed as desirable for proper mineral bioavailability. Therefore this product may have acceptable bioavailability of zinc a nd calcium, and a recommendation of a little supplementation with an animal food such as milk may help towards achievement of adequate levels of iron.