Descriptive sensory analysis of instant porridge from stored wholegrain and decorticated pearl millet flour cooked, stabilized and improved by using a low‐cost extruder

Abstract

Pearl millet flour, particularly wholegrain flour, is highly susceptible to development of rancid aromas and flavors during storage. Grain decortication and extrusion cooking using a friction-heated single-screw extruder were investigated as potential flour stabilization processes. Raw and extruded wholegrain and decorticated grain pearl millet flours were stored at ambient (25 • C) and elevated (40 • C) temperatures for 6 months. A trained descriptive sensory panel developed a lexicon of 44 attributes to profile the aroma, flavor, and texture of porridges prepared from the flours. Grain decortication alone did not show an effect on the aroma and flavor profile of porridge. Extrusion cooking of both wholegrain and decorticated flours increased cereal-like aromas (branny, canned sweetcorn, sweet, and wheaty) and flavor (starchy), as well as stiffness and cohesiveness of the porridges. The porridges from the extruded pearl millet flours stored for up to 6 months at ambient and elevated temperatures did not show any indications of rancidity. In contrast, rancidity-associated aromas (chemical, painty, and soapy) and flavor (chemical) increased in porridges from the raw flours stored for 4 weeks and longer. These results indicate that grain decortication did not sufficiently reduce fat content to prevent oxidation, while extrusion cooking stabilized the pearl millet flours. In addition, intensified "cereal-like" aromas and flavors were probably due to Maillard reactions occurring during extrusion cooking. Resulting aroma compounds could have been immobilized in the extruded matrix and not released during flour storage. The application of extrusion cooking with a simple friction-heated single-screw extruder is a viable process for both precooking and extending the shelf life of pearl millet flours.Practical Application: This study demonstrates the potential of extrusion cooking to precook wholegrain pearl millet while preventing fat rancidity in wholegrain pearl millet flour, thereby improving the sensory quality and stability of pearl millet food products. The extensive sensory characterization of pearl millet porridge-type foods can serve as a guidance tool for development, improvement, and quality control of pearl millet foods. Furthermore, it establishes the efficacy of simple friction-heated, single-screw extruders for commercial manufacture of 3824

Novel pearl millet couscous process for West African markets using a low‐cost single‐screw extruder

“…Another benefit of the extruded millet couscous is that it can be rehydrated easily by simply adding room temperature water, whereas couscous prepared using the traditional process requires additional steaming step before consumption. Using the same extruder, a recent study showed the retardation or prevention of oxidative rancidity in extruded instant decorticated and whole grain pearl millet flours (Onyeoziri et al, 2021), and one would also expect stabilised couscous for this process and even for whole grain couscous.…”

“…Over the last few decades, processing technologies have been developed to make consistent quality convenient foods, such as traditional agglomerated products, couscous and degue, by the Institut de Technologie Alimentaire (ITA), Senegal and Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD), France (Aboubacar & Hamaker, 1999). Additionally, extrusion processing and continuous high‐temperature high‐shear cooking have been used to make instant flours for reconstitution to traditional thin and thick porridges (Moussa et al ., 2011; Onyeoziri et al ., 2021). However, none of these are widely used at a commercial scale and available in markets.…”

Development of ready‐to‐reconstitute carrot pomace blended sweet corn porridge

“…Several researchers have developed instant porridges from stored wholegrain (Onyeoziri et al, 2021), banana rice bean porridge (Borbi et al, 2020), sweet potato–soybean–moringa composite porridge (Gebretsadikan et al, 2015), multigrain porridge (Mandge et al, 2014), mango flavored instant porridge (Gandhi et al, 2013), maize meal porridge (Faber et al, 2005), Pajala porridge (Wisten & Messner, 2005), sorghum–cowpea instant porridge (Pelembe et al, 2002). However, no information has been reported for the development of carrot pomace‐fortified sweet corn porridge.…”