Influence of Partially Substituting Wheat Flour with Tiger Nut Flour on the Physical Properties, Sensory Quality, and Consumer Acceptance of Tea, Sugar, and Butter Bread

Abstract

Tiger nut is a valuable source of fiber, lipids, minerals, and carbohydrates. However, avenues for incorporating tiger nuts into food remain underexplored, especially in several tropical countries where the plant grows well. The current study investigated the effects of partially substituting wheat flour (WF) with tiger nut flour (TNF) on the physical and sensory properties of different bread types to evaluate the more amenable system for tiger nut incorporation. The substitution was done at WF:TNF ratio of 100 : 0, 90 : 10, 85 : 15, 80 : 20, 75 : 25, and 70 : 30 for butter bread (Bb), tea bread (Tb), and sugar bread (Sb). The results show that WF substitution with TNF increased bread brownness and color saturation and decreased lightness, showing the highest impact on Sb, followed by Tb and Bb. Additionally, bread-specific volume decreased significantly after 20% (Bb), 25% (Tb), and 30% (Sb) TNF substitution. Furthermore, substituting WF with 30% TNF increased crumb hardness from approx. 1.87 N to 3.64 N (Bb), 3.46 N to 8.14 N (Tb), and 6.71 N to 11.39 N (Sb) and caused significant increases to 17.80 N (Tb) and 21.08 N (Sb) after 3 d storage. Only a marginal effect on storage hardness (4.32 N) was observed for Bb. Substituting WF with 10% TNF for Bb or 25% TNF for Tb led to significantly higher consumer ( N = 56 ) scores for all attributes and overall acceptability. However, no significant effect on the overall acceptability of Sb was observed. Flash profiling showed frequently used descriptors for Bb as firm, moist, buttery, smooth, and astringent. After 10% TNF substitution, descriptors were chewy, firm, sweet, porous, dry, and caramel, and that of 30% TNF were grainy, chocolate, brown, nutty, and flaky. Substituting WF with TNF increased the lipids, fiber, and minerals content but decreased the protein and carbohydrate contents of bread. TNF substitution led to different physical and sensory effects depending on bread type, showing that Bb with 10% or Tb with 25% TNF is more comparable with the overall acceptance quality of 100% WF. The study is relevant for utilizing tiger nuts as an ingredient in bread products.

Effects of sprouting duration on the nutrient, functional, and phytochemical properties of tiger nut flour, and the sensory properties of bread made thereof

“…Withdrawn TNs were sorted for germinated rhizomes, which were thoroughly rinsed four times, each time in fresh water. It was then dried in an oven at 60 • C for 6 days before milling using a locally fabricated hammer mill (Gratis Foundation, Mc Lean, VA, USA) as previously described (Kizzie-Hayford et al, 2023). Flour from native (day 0) and sprouted TN were kept zip-locked in plastic bags and stored at 4-6 • C in a refrigerator.…”

“…Then the salt (18.0 g), sugar (136 g), and yeast (1.2 g) per 3.8578 kg dough were dispersed in a measured portion of water (811.8 g per 3.8578 kg dough) before adding to the mixed flour. After kneading the mixture to obtain a fine-textured dough, 120 g portions were molded in baking pans, covered with clean cloths, and proofed for 60 min at ambient temperature (30 • C) (Kizzie-Hayford et al, 2023). The dough was then baked for 30 min at 230 • C in a locally fabricated gas oven (Gratis Foundation).…”

“…The weight of bread, w (g), was measured on a mass balance and the volume, v (cm 3 ), by measuring the volume of millet grains displaced by the bread in a measuring cylinder (Kizzie-Hayford et al, 2023). The specific volume was then calculated according to Dabels et al (2016) using the following equation:…”

“…Recent investigations on some of the ways of processing TN show possibilities to produce milklike beverages (Kizzie‐Hayford, Ampofo‐Asiama, et al., 2021; Martín‐Esparza & González‐Martínez, 2016) or lactic acid fermented systems (Kizzie‐Hayford, Dabie, et al., 2021; Ndiaye et al., 2019) from the aqueous extracts of TN. Furthermore, TN powder was used as an ingredient for the processing of chinchin, a sweet, crispy, deep‐fried dough (Adebayo‐Oyetoro et al., 2017), gluten‐free biscuits (Ahmed & Hussein, 2014), and for several types of bread (Ade‐Omowaye et al., 2008; Ahemen et al., 2018; Kizzie‐Hayford et al., 2023). The use of the whole TN powder, containing all of the nutrients and the nuts’ bioactive phytochemical compounds (Oyedara et al., 2022), is of particular interest because it may serve as an ingredient for several bakery products.…”

“…bread crust and crumb were determined based on the CIE-Lab parameters (L*, a*, and b*) using a colorimeter (CHN Spec, CS-10, Hangzhou, China). The browning index (BI) was computed as described previously(Kizzie-Hayford et al, 2023) using the following equation according toMaskan (2001):…”