Optimization of the Physical Properties of Gluten-Free Snack Bars Made from Malted-Sorghum, Sprouted-Mung Bean and Date-Fruit Flour Blends Using Mixture Design

Ntukidem VE, Edima-Nyah AP, Bello FA and Anana UE

Published on: 2025-07-22

Abstract

This study investigated the physical properties of composite snack bars produced from varying proportions of malted sorghum flour (MSF), sprouted mung bean flour (SMF), and date fruit powder (DFP) using a mixture design approach. Fourteen formulations (SMD1-SMD14) were developed and evaluated for key physical parameters, including diameter, thickness, weight, width, and spread ratio. The aim was to determine the influence of different blend ratios on the structural characteristics of the snack bars and to identify optimal compositions for desirable textural properties. A basic comparison showed significant (p<0.05) differences among the samples. Diameter ranged from 8.10 to 8.50 cm, thickness from 1.80 to 2.31 cm, and weight from 43.08 to 49.11 g. The spread ratio, an important indicator of dough expansion, ranged from 3.52 to 4.50, with the highest observed in SMD 8, a formulation with 62.5% MSF, 30% SMF, and 7.5% DFP and the lowest in SMD 9 (65.63% MSF, 18.13% SMF, and 7.25% DFP) and SMD 11 (60% MSF, 30% SMF, and 10% DFP). The width also varied significantly, between 2.70 and 2.90 cm. Model fitting revealed that the spread ratio was best predicted by a cubic model (R²=0.9385, Adjusted R²=0.8002, p=0.0405), while reduced quadratic and reduced cubic models adequately described the thickness (R²=0.8564, p=0.0322) and weight (R²=0.9091, p=0.0024), respectively. The 3-dimensional response surface plots highlighted the complex interactions between MSF, SMF, and DFP on the measured properties. These findings demonstrate that careful formulation using these nutrient-rich ingredients can significantly influence the quality of functional snack bars, offering potential for product development targeting improved physical attributes and nutritional enhancement.