Physico-Chemical and Sensory Characteristics of Extruded Cereal Composite Flour Porridge Enriched with House Crickets (Acheta domesticus)

Abstract

This study assessed the physico-chemical and sensory effects of enriching composite cereal porridges, typically consumed in Uganda, with undried house crickets (Acheta domesticus), a rich source of protein and vitamin B₁₂. Composite flours containing 8.3% undried crickets, 66.7% maize, and 25.0% millet were compared to a control formulation with 73.0% maize and 27.0% millet, both extruded at 140 °C. Cricket enrichment slightly reduced lightness L* (59.99 vs. 61.28) and significantly increased aroma intensity (23,450 × 10⁴ AU vs. 18,210 × 10⁴ AU; p < 0.05), attributable to higher extrusion-induced Strecker degradation, Maillard reaction, and lipid oxidation. Rheological analysis revealed that paste made from cricket-enriched flour had lower critical strain (≈0.01%) and softened sooner than the control paste (≈0.03%) without becoming fragile. Both flours displayed stable paste-like behavior at stresses >10 Pa, with elastic moduli under 10⁴ Pa, which is typical for soft pastes. Reduced pasting values relative to native flours are attributable to starch pre-gelatinization during extrusion. Sensory evaluation showed positive hedonic ratings for both porridges, and a choice test indicated no significant consumer preference. Generally, physico-chemical and sensory changes were minimal, supporting the use of house crickets for nutrient enrichment of composite cereal porridges.

Keywords: aroma compounds; color parameters; edible insects; pasting properties; porridge acceptability; visco-elastic moduli.

Figure 1

Pasting properties of flours with (140U) and without (140C) undried house crickets both extruded at 140 °C (n = 3). The error bars indicate standard deviations. Statistical differences were not observed based on p ≤ 0.05.

Figure 2

Visco-elastic moduli (elastic/storage modulus, G′, and viscous/loss modulus, G″) as a function of strain amplitude, γ, for porridges containing undried house crickets (140U) and the control without house crickets (140C) (n = 3). γC_u represents the critical strain for sample 140U = 0.01% obtained at G′ = 2685 Pa, γC_c represents the critical strain for sample 140C = 0.03% obtained at G′ = 1711 Pa. γX_c (0.30%), and γX_u (4.23%) represents the strain amplitudes at cross-over points X_c and X_u, respectively. Different superscripts (bold) indicate significant differences for critical strain and strain at cross-over (p ≤ 0.05).

Figure 3

Strain amplitude (%) as a function of stress (Pa) for porridges containing undried house crickets (140U) and the control without house crickets (140C) (n = 3). Yield strain: γ_yU = 0.21%, γ_yC = 0.07% for 140U and 140C, respectively. Yield stress: σ_yU = 3.99 Pa, σ_yC = 1.12 Pa for 140U and 140C, respectively. Similar superscripts in bold indicate no significant differences (p ≤ 0.05).

Figure 4

Visco-elastic moduli (elastic/storage modulus, G′, and viscous/loss modulus, G″) as a function of angular frequency, rad/s, for porridges containing undried house crickets (140U) and the control without house crickets (140C) (n = 3).

Figure 5

Sensory acceptability profile of a semi-trained sensory panel (n = 60) for extruded composite cereal porridges containing undried house crickets (140U) and the control without crickets (140C). The error bars indicate standard deviations. Statistical differences were not observed based on p ≤ 0.05. The x-axis represents sensory attributes. The y-axis represents ratings based on the 9-point hedonic scale: 1 = dislike extremely, 2 = dislike very much, 3 = dislike moderately, 4 = dislike slightly, 5 = neither like nor dislike, 6 = like slightly, 7 = like moderately, 8 = like very much, 9 = like extremely.

Figure 6

Preference characteristics of porridges with undried house crickets (140U) and control without house crickets (140C) (n = 60).