Techno-Functional and Gelling Properties of Acha (Fonio) (Digitaria exilis stapf) Flour: A Study of Its Potential as a New Gluten-Free Starch Source in Industrial Applications

Abstract

Fonio (Digitaria exilis Stapf) is an ancient African cereal that represents a rich source of carbohydrate, fat, fiber, vitamins, minerals, and sulfur-containing amino acids. Processing and utilization of fonio require adequate knowledge of its structural, chemical, and nutritional characteristics. The present work evaluates the structural, techno-functional, and gelling properties of fonio and compares them to other major gluten-free cereals (rice, maize, sorghum, and millet). Fonio flour presented significantly higher water absorption index and swelling power, while it scored a lower water solubility index than the reference flours. The pasting viscosity profile of fonio was similar to that of rice, with equivalent peak viscosity but a breakdown viscosity 24% lower than rice, indicative of higher stability and resistance to shearing and heating. Rheological properties demonstrated that fonio generates gels with remarkably strong structures. At 15% concentration, fonio gel withstood stress 579% higher than those observed in the reference flours without breaking its structure. Fonio flour presented the highest gelatinization enthalpy (11.45 J/g) and a narrow gelatinization temperature range (9.96 °C), indicative of a better-packed starch structure than the other analyzed flours. The texture of the gels made with fonio showed higher firmness over the evaluated period. These combined results suggest that fonio is a suitable ingredient for gel-like food formulations.

Gel Rheological Properties and Storage Texture Kinetics of Starches Isolated from Anchote (Coccinia abyssinica (Lam.) Cogn.) Cultivars

“…The increase in terms of firmness with storage time was observed in all of the studied gels ( Figure 2 A), and this could be mainly related to amylopectin recrystallization [ 25 , 26 ]. Variations were also observed in the rate of firmness increase with storage time among the starches of anchote cultivars themselves and with gels from PS, which could be attributed to the high dependence of amylopectin recrystallization process, which is greatly reliant on the starch composition and botanical origin [ 27 ]. The hardening kinetics of the gels can be directly evaluated from k or t 1/2 .…”

“…Springiness is a mechanical textural characteristic that shows the quickness and degree of retrieval from a deforming force [ 27 ]. The initial springiness of anchote starch gels varied between 0.801 and 0.850 for D01S and REDS, respectively, and showed no appreciable differences.…”

Application and functional properties of millet starch: Wet milling extraction process and different modification approaches

“… Spherical [ 147 ] Foxtail ( Setaria italic) China Pale yellow and orange 2 mm long Ovoid [ 20 ] Proso ( Panicum Miliaceum) Asia Creamy, yellowish and orange 3 mm long & 2 mm dia. Spherical to oval [ 148 ] Minor millets Kodo ( Paspalum Scrobiculatum) India and Africa Dark brown 1.2–9.5 μm long Elliptical to oval [ 149 ] Barnyard ( Echinochloa Crusgalli) India and Japan Light brown and white 2–3 mm long Tiny round [ 1 , 150 ] Fonio ( Digitaria iburua and Digitaria exilis) Africa White, pale brown or purplish 1 mm Oblong to globose [ 151 ] Teff ( Eragrostis tef) Ethiopia Light brown 0.9–1.7 mm long & 0.7–1.0 mm dia. Oval [ 152 , 153 ] Little ( Panicum Sumatrense) Asia Grey to white 1.8–1.9 mm long Elliptical to oval [ 154 ] Browntop ( Brachiaria or Urochloa ramose) …”

Phenotypic characterisation and comparative non-targeted GC-MS-based metabolomic profiling of two contrasting seedling fonio millet (Digitaria exilis) accessions: an insight to drought tolerance in small millets

“…The grains are gluten-free, suitable for use in the diet of celiac patients. It is also rich in vitamins, minerals, and sulphur (Deriu et al 2022). Despite its low agronomic yield capacity, fonio millet is gaining importance as a crop and food ingredient due to its higher nutritional qualities compared to other cereals, the growing market interest in traditional foods, and its adaptability to marginal soils (Cruz 2016;Deriu et al 2022).…”

“…It is also rich in vitamins, minerals, and sulphur (Deriu et al 2022). Despite its low agronomic yield capacity, fonio millet is gaining importance as a crop and food ingredient due to its higher nutritional qualities compared to other cereals, the growing market interest in traditional foods, and its adaptability to marginal soils (Cruz 2016;Deriu et al 2022). However, despite being one of the oldest and richest cereals in West Africa, fonio millet is still unknown to many people and neglected by research and extension services, which has affected its cultivation (CIRAD 2004 One of the major limiting factors for crop production is drought, especially in the current wave of climate change and water scarcity in arid regions, so understanding the mechanism of drought tolerance is important for breeding drought-tolerant varieties (Yadav et al 2021).…”