Quality Characteristics of Heat-moisture Treated Finger - Millet and Its Use in Bread Production

Abstract

Finger millet is a small seeded non - gluten cereal donned with nutritional, health and ecological advantages. Antinutrient presence in finger millet is however, a food safety concern since Tannins and Phytates inhibit the bioavailabity of minerals as well as the digestibility of starch and proteins. Bread a common breakfast in Kenya, is mostly made from wheat, while finger millet is majorly used for Ugali (Thick Porridge) and Uji (Thin porridge). Production of wheat and heat - moisture treated finger millet bread will therefore see a diversity in diet and finger millet products. Heat - moisture treatment (HMT) is an alternative processing technique that shows promise in enhancing the nutritional and functional properties of finger millet, making it suitable for a variety of acceptable foods. The main objective of this study was to determine the quality characteristics of HMT finger millet and its use in bread production. The first objective was to determine the effect of heat - moisture treatment on finger millet while the second objective was to determine the rheological properties of bread made from wheat and HMT finger millet. Three finger millet varieties brown, reddish-brown and black, from Kisumu and Bungoma counties were tempered in water (10:1) for 3, 6 and 9 days at 80o C followed by subsequent drying to 12-14% moisture content. Composite bread was made from wheat and HMT finger millet in the ratio of 70:30 respectively. Carbohydrate content decreased in brown and black millet to 63.81% and 65.95%, respectively as well as Fat and Tannin content, which decreased with increased time. HMT had no effect on calorie content but had slight effect on ash content, phytate content and protein digestibility over the 9-day treatment period. The lightness (L*) values decreased, with ranges of 71.97-37.73 for brown, 38-36.9 for black and 40.9-37.36 for reddish - brown varieties. Similarly, Mineral content varied significantly (p≤0.05) with 3-day treatments recording the highest calcium values across the varieties. Peak, trough and setback viscosities declined as well as DDT and DS while bread firmness and chewiness increased with increased heat - moisture treatment time. Variety did not have an effect on the pasting, Farinogram and extensogram properties. Wheat bread (control) had the highest volume of 4.03g/cm3 while composite breads had increased fibre and contents HMT finger millet has enhanced nutritional and functional properties hence, consumption of HMT finger millet and adoption of HMT technique is necessary.