Changes in nutritional and physico-chemical properties of pearl millet (Pennisetum glaucum) Ex-Borno variety flour as a result of malting

Abstract

The effect of malting periods on the nutritional composition and physico-chemical properties of flour from pearl millet (Ex-Borno) variety was evaluated. Grains were steeped at 25 °C for 24 h and germinated for different durations (12, 24, 36, 48, 60, 72, 84 and 96 h) before kilning at 55 °C for 18 h. The kilned seeds were devegetated, milled, sieved and analysed for their proximate composition, amino acid composition, total phenolic content, functional and pasting properties. The carbohydrate, fat and total phenolic contents of the pearl millet flour samples decreased while protein content increased with increased malting periods. Leucine was the dominant amino acid in the flour and 48 h-malted flour had the highest total amino acid (6.72). Peak viscosity significantly decreased as the malting period increased. Solubility index, pasting temperature and phenolic content of the flours ranged from 5.13 to 17.24%, 69.05 to 89.5 °C and 130.20 to 169.90 mg/100 g, respectively. Malting offers a means of improving the nutritional profile of Ex-Borno pearl millet flour with an increased protein and fibre and reduced fat content. Malting also enhanced the functional and pasting properties of the flour.

Potentials of Lactobacillus plantarum and Pichia kudriavzevii in co‐fermentation of sourdough from millet

“…The malted and unmalted grains were milled using a hammer mill into flour. The flour was sieved to obtain a particle size between 0.2 and 0.6 mm (Obadina et al ., 2017).…”

“…This agrees with the observations of Obadina et al . (2017) who reported an increase of 0.82%–1.38% over 96 h malting stage, which might be due to the fusion of the structural components such as cellulose and hemicellulose present in the grains. The ash contents of the breads ranged from 2.2 to 4.5 g/100 g ( P < 0.05).…”

“…Dhingra & Jood (2001) reported an approximation of 10.6 to 11.4 g/100 g protein content for bread made from the combination of wheat and barley flours. The increase in the malted flour can be associated with the buildup of protein reserves during sprouting because of proteolytic enzyme activities (Obadina et al ., 2017). The was no significant difference ( P < 0.05) among the malted and unmalted bread samples for the crude fibre content, while the malted flour is significantly higher ( P < 0.05) than the unmalted flour samples.…”

“…Huge differences in ash contents (1.6–4.8 g/100 g) have been reported for bread samples made from the combination of wheat and sweet potato flours (Hathorn et al ., 2008). The activities of the ash content maybe due to integration of mineral elements into the cell constituents of the cereal (Akinola et al ., 2017; Obadina et al ., 2017). In this study, the highest value of fat content (4.1 g/100 g) was observed in unmalted bread fermented with L. plantarum MLd27 only.…”

“…In this study, the carbohydrate contents of the bread samples were significantly different ( P < 0.05) from the flour samples. This may be due to enzymes hydrolytic activities, which breaks down starch granules and converts it to simple sugars during a fermentation process (Obadina et al ., 2017). The difference in the constancy of the microorganisms and the metabolism of carbohydrate due to acidification rates in gluten‐free sourdoughs is dependent on several factors which cannot be controlled (Tamani et al ., 2013; Bender et al ., 2018).…”