1.0  INTRODUCTION

Masa is a traditional fermented cereal-based food widely consumed in West Africa, particularly in northern Nigeria. It is a soft, pancake-like product typically prepared from fermented grains such as rice, maize, millet, or sorghum [36]. The protein, fat, carbohydrate, and calorie value of the groundnut-maize enriched masa increased from 9.56 to 13.59 %, 9.48 to 13.23 % and 64.62 to 66.98 % and 382.04 to 441.53 cal/g, respectively, but it is often limited in essential micronutrients such as iron, zinc, and B-vitamins, as well as dietary fiber [16]. The consumption of masa is deeply rooted in cultural practices, often served during festive occasions, religious celebrations, and as a staple breakfast or snack food in both rural and urban communities. Despite its popularity, traditional masa formulations are primarily based on polished white rice or unmalted cereals, which lack sufficient nutrient density to address prevalent micronutrient deficiencies in the region. 

The nutritional limitations of masa, coupled with its high glycemic index, pose significant health concerns, particularly for individuals managing diabetes or other metabolic disorders [39]. Additionally, the reliance on rice, which is often imported or subject to price volatility, underscores the need for alternative locally available and climate-resilient cereals such as sorghum. Sorghum (Sorghum bicolor L. Moench) is a drought-resistant crop with superior nutritional potential, including higher protein content (10–12 %) and significant levels of iron and zinc. However, its utilization in masa production is hindered by anti-nutritional factors such as phytates and tannins, which reduce mineral bioavailability [39]. 

To address these challenges, malting (controlled germination) has been identified as an effective processing technique to enhance the nutritional quality of sorghum by reducing anti-nutrients and improving digestibility [26]. Furthermore, the incorporation of baobab (Adansonia digitata) pulp, a nutrient-dense indigenous ingredient, offers a promising solution to fortify masa. Baobab pulp is exceptionally rich in vitamin C (150–300 mg/100g), dietary fiber (40–45 g/100g), calcium (250–350 mg/100g), and polyphenols, which enhance iron absorption and provide antioxidant benefits [20]. Its natural acidity also promotes fermentation, potentially improving masa’s shelf life and microbial safety. 

2.0 MATERIALS AND METHODS

2.1 Materials

2.1.1 Material Collection

Materials used in this study include Sorghum [Sorghum bicolor (L.) Moench], rice (Oryza sativa], sugar (saccharum officinarum), salt (Sodium chloride), yeast (saccharomyces cerevisiae), triona (Natural sodium sesquicarbonate) and Baobab fruits (Adansonia digitata) were purchased from New Market, Wukari, Taraba state,  Nigeria.

2.2 Sample Preparation

2.2.1 Preparation of Sorghum flour

Sorghum flour was prepared following the method described by [21]. The sorghum grains were sorted and thoroughly washed. The washed grains were dried in an oven drier and then milled using an attrition mill, allowing the flour to pass through a 250 μm mesh. The resulting sorghum flour was packaged in multilayer polythene bags and stored until further use.

2.2.2 Preparation of Rice Flour

Rice flour production. The method described by [15]. was used to produce rice flour. The rice grains were sorted manually to remove extraneous materials. The rice was washed with potable water, sundried, and milled using a hammer mill to pass through a 60 µm mesh sieve. Flour was stored in an airtight plastic container at room temperature until needed.

2.2.3 Preparation of Baobab Pulp Flour

Baobab pulp was produced as described by [8]. The fruit was broken to obtain the pulp, fermented, dried, milled, and sieved to produce fermented baobab powder.

2.2.4 Production of Masa

The production of masa followed a modified method adapted from [36]. Incorporating two control groups and variations in malted sorghum flour. The first control utilized rice flour mixed with 600 ml of clean water and 15 g of yeast, while the second control employed sorghum flour combined with 600 ml of water and baobab pulp as a starter culture. The batters underwent a 24-hour fermentation period to allow beneficial microorganisms from both the baobab pulp and malted sorghum flour to develop, contributing to the characteristic flavor, improved texture, and overall quality of the masa. Following fermentation, trona (kanwa water) was incorporated into the batter along with sugar (5 g) and salt (2 g) to enhance flavor by balancing the natural acidity from fermentation, providing a subtle sweetness to counteract any residual bitterness, and creating a more rounded savory profile. The batter was then vigorously stirred using a mortar and pestle to achieve a smooth, well-aerated consistency before being apportioned with a medium-sized spoon onto a preheated shallow masa pot. A small quantity of vegetable oil (3 ml) was added to the pot, and each portion was fried for approximately 2 minutes on each side until achieving a golden brown color and full cook-through. This standardized preparation method was consistently applied to all experimental samples (C through G) while varying their specific ingredient formulations to maintain comparability across test groups.

2.3. Determination of Functional Properties

2.3.1 Water absorption of capacities

The sample tube was vigorously agitated using a vortex mixer for 2 minutes to ensure thorough homogenization. Following agitation, the mixture was centrifuged at 1250 ×  g for 20 minutes to separate the phases. The resulting clear supernatant was carefully decanted and its mass recorded. Any residual water droplets adhering to the container were removed, and the sample was reweighed to obtain an accurate measurement. Water absorption capacity (WAC) was calculated and expressed as the weight (in grams) of water absorbed per gram of sample, as described by [31]. 

2.3.2 Oil absorption capacity

About 1g of the flour samples was mixed with 20 ml of oil in a blender at high speed for about 30 seconds. samples was allowed to stand at 30 °C for 30min and then centrifuged at 1000rpm for 30minutes. The volume of supernatant in a graduated cylinder was noted. The  density of water was taken to be 1 g/ml, and that of oil was determined to be 0.93g/ml. Means of the triplicate determinations were reported [31].

2.3.3 Determination of Bulk density

The method of [33]. was adopted in the determination of bulk density. Bulk densities of samples was determined by weighing 25 ml capacity graduated measuring cylinder, gently filling the cylinder with the sample and tapping the bottom of the cylinder on the laboratory bench several times until there was no further diminution of the sample level after filling the 25 ml mark. The final volume is expressed as g/ml.

2.3.4 Swelling capacity determination

The swelling capacity of the samples was determined as described by [1]. 10g of the flour sample was weighed and poured into a 100 ml measuring cylinder and the initial volume was taken. 60 ml of water was then added and allowed to stand for 4h after stirring and then the level of swelling was observed.

Swelling index = Vol. `after soaking Vol. before soaking 100 Weight of sample

2.3.5 Gelation Capacity

The method of [33]. was adopted in the determination of gelation capacity. A sample suspension of 0.2 %, 0.4 %, 0.6 %, 0.8 % and 1% (w/v) in 5ml of distilled water was prepared in test tubes. The samples were heated for 1h in a boiling water bath followed by rapid cooling under running cold tap water. The test tubes will then be cooled further for 2h at 4 °C. The gelation capacity is the least gelation concentration determined as the concentration when the sample from the inverted test tube will not fall or slip.

3.0 Results and Discussion

3.1 Functional Properties of Malted Sorghum and Fermented Baobab Pulp Flour Blends

The functional properties of the flour blends, including water absorption capacity (WAC), oil absorption capacity (OAC), swelling capacity (SC), and bulk density (BD), were evaluated, and the results are presented in Table 2. These functional properties are critical quality parameters that determine the suitability of flour blends for various food applications, particularly in the production of masa. The observed variations in these properties among the different flour blends can be attributed to their distinct compositional and structural characteristics resulting from the inclusion of malted sorghum and fermented baobab pulp.

The WAC, OAC, SC, and BD of the produced samples decreased from 2.50 to 1.50 g/g, 1.76 to 1.23 cm³/g, 4.50 to 1.50   cm³/g, and 36 to 31.00 g/g, respectively, with an  increase (0 -25%) in the added malted sorghum flour. In the current study, Sample B, which consisted of 100% unmalted sorghum flour with baobab pulp, exhibited the highest WAC value of 2.50 g/g. This superior water absorption can be explained by the synergistic interaction between the high fiber content of baobab pulp and the bran components of sorghum. Baobab pulp is particularly rich in soluble dietary fibers, especially pectin, which has exceptional water-binding properties due to its high content of hydrophilic carboxyl groups [23]. Furthermore, the bran layer of unmalted sorghum contains numerous hydroxyl groups that readily form hydrogen bonds with water molecules [37].

The progressive decrease in WAC observed in samples with increasing proportions of malted sorghum flour (Samples C-G, ranging from 2.10 to 1.50 g/g) can be attributed to several biochemical transformations that occur during the malting process. Malting involves controlled germination of grains, which activates endogenous enzymes such as α-amylase, β-amylase, and proteases [35]. These enzymes catalyze the breakdown of complex starch molecules into simpler sugars and modify protein structures, thereby reducing the availability of water-binding sites. Additionally, the drying step in malting may induce protein denaturation, exposing hydrophobic amino acid residues that repel water molecules [6]. The observed trend aligns with the findings of [28]. who reported that extensive enzymatic modification during malting decreases the water-holding capacity of cereal flours.

Values represent mean ± SD of duplicate scores. Means within a row with different superscripts were significantly different (p < 0.05). Different letters indicate significant differences between samples at the 0.05 level based on the Duncan test. Sample A was composed of 100% rice flour and served as the control. Sample B consisted of 100% unmalted sorghum flour. Sample C was prepared using 5% malted sorghum flour and 95% unmalted sorghum flour. Sample D contained 10% malted sorghum flour and 90% unmalted sorghum flour. Sample E included 15% malted sorghum flour and 85% unmalted sorghum flour. Sample F was made with 20% malted sorghum flour and 80% unmalted sorghum flour. Sample G comprised 25% malted sorghum flour and 75% unmalted sorghum flour.

The WAC values obtained in this study compare favorably with previous research on cereal-based flour blends. [3]. reported WAC values of 2.3-2.6 g/g for sorghum-baobab composite flours, which is consistent with our findings for Sample B. However, some studies have reported contradictory results regarding the effect of malting on WAC. For instance, [25] observed increased WAC in malted millet flour, attributing this to the formation of porous structures during germination that enhance water absorption. This discrepancy may be explained by differences in the malting conditions (time, temperature) or variations in the composition of the cereal grains used.

The WAC of flour blends has significant implications for masa production. Higher WAC, as seen in Sample B, suggests better dough consistency and improved moisture retention during processing, which could enhance product yield and texture. However, the reduced WAC in malted samples might require formulation adjustments, such as increased water addition or the incorporation of hydrocolloids, to achieve the desired batter viscosity. Food processors should carefully consider these functional properties when developing masa products to ensure optimal processing characteristics and final product quality.

Oil absorption capacity is an important functional property that influences the flavor retention and mouthfeel of food products. In this study, Sample B demonstrated the highest OAC value of 1.75 g/g, which can be attributed to several factors. The baobab pulp component contains significant amounts of soluble fibers, particularly pectin, which can form networks that physically trap oil droplets [20]. Additionally, sorghum contains non-starch lipids and hydrophobic proteins that interact with oil molecules through van der Waals forces [15]. The observed decrease in OAC with increasing malted sorghum content (Samples C-G, ranging from 1.50 to 1.23 g/g) suggests that malting-induced modifications alter the oil-binding characteristics of the flour.

The reduction in OAC may result from several malting-related changes: (1) enzymatic degradation of starch reduces the availability of amylose, which is known to form helical complexes with lipids [37]; (2) proteolytic activity during malting modifies protein structures, potentially reducing hydrophobic domains that interact with oil; and (3) the formation of smaller particles during milling of malted grains decreases the surface area available for oil absorption [3]. These findings are supported by Fourier-transform infrared spectroscopy (FTIR) analyses conducted by [19]. Which showed reduced intensity at 2920 cm-1 (associated with C-H stretching vibrations of lipids) in malted sorghum flours.

The OAC values obtained in this study are within the range reported by other researchers working with similar ingredients. [22]. observed OAC values of 1.6-1.8 g/g in sorghum-baobab blends, consistent with our results for Sample B. However, some studies have reported higher OAC values for malted cereal flours. For example, [24] Found that malted sorghum flour had increased OAC due to the exposure of hydrophobic amino acids during proteolysis. These contrasting results may be attributed to differences in malting duration or the specific sorghum varieties used.

The OAC of flour blends affects several quality attributes of masa, including flavor retention, texture, and caloric density. Higher OAC, as seen in Sample B, suggests better flavor encapsulation and richer mouthfeel, which could enhance consumer acceptance. However, the reduced OAC in malted samples might require formulation adjustments, such as the addition of emulsifiers or increased oil content, to maintain desirable sensory characteristics. Food manufacturers should consider these factors when developing masa products with specific nutritional or sensory profiles.

Swelling capacity is a critical functional property that reflects the ability of starch granules to absorb water and swell during heating, which directly impacts the texture and consistency of final products. The results revealed substantial variations in SC among the samples, ranging from 12.50 cm³/g in Sample A (rice control) to 1.50 cm³/g in Sample G (25 % malted sorghum). This dramatic difference can be attributed to fundamental differences in starch composition and structural modifications induced by fermentation and milling.

Sample A exhibited the highest SC due to rice starch’s unique properties. Rice starch contains approximately 15-30 % amylose and 70-85 % amylopectin, with the latter being primarily responsible for its exceptional swelling characteristics [5]. The relatively small granule size (2-8 μm) and weak granular structure of rice starch facilitate rapid water penetration and swelling. In contrast, Sample B (100 % sorghum) showed significantly lower SC (4.50 cm³/g), which aligns with sorghum starch’s known properties. Sorghum starch has a more compact granular structure and higher amylose content (20-30 %), which restricts swelling [32]. The progressive decrease in SC with increasing malted sorghum content (Samples C-G) demonstrates the profound impact of malting on starch functionality. During malting, endogenous α-amylase and β-amylase progressively hydrolyze starch molecules, particularly targeting the amorphous regions of the granule [35]. This enzymatic action creates pores and channels in the starch granules, as visualized through scanning electron microscopy studies [26]. While this might theoretically increase water absorption, the simultaneous reduction in molecular weight of starch polymers ultimately diminishes the granules’ ability to maintain structural integrity during swelling. The SC values observed in this study are consistent with previous reports on cereal flour functionality. [3] Reported SC values of 4.2-4.8 cm³/g for unmalted sorghum flour, similar to our findings for Sample B. However, some studies have reported conflicting results regarding the effect of malting on swelling properties. [27] observed increased SC in mildly malted sorghum, attributing this to partial hydrolysis, creating more accessible sites for water absorption. This discrepancy may be explained by differences in malting intensity or analytical methods used to measure SC.

The SC of flour blends has crucial implications for masa texture and processing. Higher SC, as seen in rice-based samples, typically produces lighter, more porous masa with greater volume. The reduced SC in sorghum and malted sorghum blends may result in denser products, which could be advantageous for certain traditional masa varieties where a compact texture is desired. Processors might compensate for lower SC by adjusting water content or incorporating leavening agents to achieve the desired product characteristics.

Bulk density is an essential parameter that influences packaging requirements, transportation costs, and reconstitution properties of flour products. The results showed BD values ranging from 28.00 g/cm³ in Sample A to 36.50 g/cm³ in Sample B, with malted samples (C-G) exhibiting intermediate values (31.00-36.00 g/cm³).

The high BD of Sample B can be attributed to several factors. Sorghum kernels have a denser endosperm structure compared to rice, and the inclusion of baobab pulp introduces additional dense components such as insoluble fibers and mineral complexes [20]. Furthermore, the particle size distribution plays a significant role in determining BD. Sorghum flour typically has smaller particle sizes than rice flour due to its harder endosperm, allowing for more efficient packing [15].

The variation among malted samples (C-G) reflects the complex interplay between several malting-induced changes: (1) enzymatic degradation reduces particle size, increasing packing efficiency; (2) protein modifications alter surface characteristics that affect particle interactions; and (3) changes in starch structure influence particle geometry [4]. Interestingly, the BD did not show a simple linear relationship with malted sorghum content, suggesting that multiple competing factors influence this property.

The BD values obtained in this study align well with previous reports on cereal flours. [24] reported BD values of 35-38 g/cm³ for sorghum flours, consistent with our findings for Sample B. Studies on malted cereals have shown variable effects on BD. [17] observed increased BD with malting due to particle size reduction, while [22] reported decreased BD attributed to the development of porous structures during germination. These differences likely reflect variations in malting protocols and grain varieties.

BD has important practical implications for masa production and commercialization. Higher BD flours (like Sample B) offer advantages in terms of storage and transportation efficiency, as more product can be packed per unit volume. However, very high BD may affect reconstitution properties, requiring adjustments in mixing procedures. The intermediate BD values of malted samples suggest they may offer a good balance between handling properties and functionality in final products.

The collective analysis of these functional properties reveals important structure-function relationships in the flour blends. The superior WAC and OAC of Sample B suggest it would perform well in applications requiring moisture and fat retention, such as fried masa products. However, its lower SC indicates it may produce denser textures, which could be mitigated by combining it with other ingredients or adjusting processing parameters. The malted samples (C-G) show a distinct functional profile characterized by reduced WAC and SC but maintained or slightly improved BD. This suggests that moderate levels of malted sorghum (10-15 %) could be used to modify masa characteristics without drastically compromising functionality. The changes in functional properties with malting level demonstrate the potential for precisely tailoring flour performance through controlled malting processes [19]. These findings have significant implications for product development. For instance, formulators seeking to increase the nutritional density of masa while maintaining acceptable functionality might opt for blends containing 10-15 % malted sorghum (Samples D-E). The functional property data also provides valuable insights for predicting processing behavior and final product characteristics, enabling more efficient development of masa products with specific quality attributes.

The gelation behavior of the flour blends presented in Table 3 reveals significant differences in gelling capacity that correlate with their compositional variations. Sample A, the rice flour control, demonstrated consistent gel formation across all tested concentrations (0.2-0.6 %), reflecting the strong gelling properties inherent to rice starch. This robust performance can be attributed to synergistic interactions between malted sorghum’s modified starch molecules and baobab’s soluble fiber fractions. During malting, enzymatic modification of starch increases the availability of amylose and short-chain amylopectin, which interact with baobab’s high-methoxyl pectins to form stable three-dimensional networks [8]. The thermal stability of these gels, even at low concentrations, suggests the formation of stable junction zones through both hydrogen bonding and hydrophobic interactions [38].

Sample B, comprising 100 % sorghum flour with baobab pulp, also exhibited complete gelation at all concentrations, which presents an interesting case study in ingredient interactions. While native sorghum starch typically shows weaker gelling properties compared to rice starch, the addition of baobab pulp appears to compensate for this limitation through several potential mechanisms. The high pectin content in baobab pulp likely interacts synergistically with Furthermore, the organic acids present in fermented baobab may modify the starch gelatinization behavior, while the mineral content could facilitate ionic bridges between polymer chains. This enhancement of gelling capacity through baobab incorporation has significant implications for improving the functional performance of sorghum-based food products [18].

 Values represent mean ± SD of duplicate scores. Means within a row with different superscripts      were significantly different (p < 0.05). Different letters indicate significant differences between samples at the 0.05 level based on the Duncan test.

The intermediate samples (C and D) containing 5-10 % malted sorghum flour displayed a concentration-dependent gelation pattern, forming stable gels only at the highest tested concentration (0.6 %). This threshold behavior suggests that malting induces changes in the starch molecules that raise the critical concentration required for network formation. The enzymatic activity during malting partially hydrolyzes starch polymers, reducing their average molecular weight and consequently their ability to form extensive junction zones at lower concentrations. However, when sufficient material is present (0.6 %), the cumulative effects of numerous shorter chains can still establish a percolating network. This behavior aligns with polymer physics principles that describe how reduced polymer length increases the critical concentration needed for gelation [28]. Samples E through G, with 15-25 % malted sorghum content, failed to form gels at any concentration, indicating that extensive malting fundamentally alters the starch’s gelling capacity. This complete lack of gelation may result from several factors: excessive starch degradation during malting, producing oligosaccharides too short for network formation, fermentation-induced changes in protein structure that prevent effective interactions with polysaccharides, or the accumulation of organic acids that interfere with junction zone stability [22]. The consistent negative results across all concentrations indicate these blends lack the necessary molecular architecture for gel formation, regardless of solids content. This has important implications for their potential applications, as they would be unsuitable for products requiring true gelation but might serve well in systems where viscosity modification without full gelation is desired [17].

The gelation results correlate well with the pasting properties discussed in Section 2 where higher levels of malted sorghum led to reduced viscosity development. Both sets of data point to the same underlying mechanism: progressive starch hydrolysis during malting that reduces molecular size and consequently the ability to form interconnected networks. This consistency between different analytical methods strengthens the validity of the conclusions and provides a more comprehensive understanding of how malting affects flour functionality.

From a practical standpoint, these gelation characteristics have important implications for masa production and other food applications. The strong gelling capacity of Samples A and B suggests they would perform well in products requiring firm, cohesive textures. The threshold behavior observed in Samples C and D indicates they might be suitable for applications where more delicate gel structures are desired, provided the solids content is adjusted appropriately. The complete lack of gelation in Samples E through G suggests these blends would require formulation adjustments or complementary gelling agents if used in gel-based products [14].

The observed gelation behaviors have significant implications for both food science and product development. The consistently gelling samples (A, B, D) show promise for applications requiring thermally-stable gels, such as edible packaging films or texture-modified foods for specific dietary needs [18]. The threshold-dependent Sample C suggests potential for controlled-release systems where gelation is triggered by concentration changes. The non-gelling samples (E-G) might find use as viscosity modifiers or in applications where gelation inhibition is desired. Future research should employ advanced characterization techniques like small-angle X-ray scattering (SAXS) and atomic force microscopy (AFM) to better understand the nanostructural basis of these gelation differences [30]. Additionally, systematic studies investigating the effects of malting duration and fermentation conditions on gelling properties could provide valuable insights for optimizing these functional characteristics. Future research should explore the microstructural basis of these gelation patterns through advanced imaging techniques, and investigate how the observed behaviors translate to actual food products. Additionally, studies examining the interaction between these gelation properties and digestive processes could provide valuable insights into how malting and baobab incorporation affect starch bioavailability. The current results establish a solid foundation for such investigations while providing practical guidance for food processors working with these ingredients.

3.3 Pasting Properties of Malted Sorghum and Fermented Baobab Pulp Flour Blends

The pasting characteristics of the flour blends, as determined by Rapid Visco Analyzer (RVA), provide critical insights into their thermal behavior and functional performance during processing. The results presented in Table 4 Reveal substantial variations in pasting parameters that reflect the complex interplay between starch composition, and malting-induced modifications. Peak viscosity was highest in Sample B (189.11 RVU) and lowest in the rice control (162.51 RVU). Malted sorghum blends (Samples C–G) showed an initial increase in peak viscosity (168.55 to 187.31 RVU) with increasing malted sorghum content. Breakdown viscosity, indicative of shear stability, peaked in Sample C (16.93 RVU) but decreased in higher malted blends (11.68 RVU). Final viscosity, representing retrogradation tendency, was highest in Sample B (246.53 RVU) and gradually declined in malted samples (240.58 to 218.27 RVU). Pasting temperature decreased from 68.42 °C (rice control) to 54.16 °C (5 % malted sorghum) before rising again in higher malt blends, suggesting altered starch gelatinization behavior [12]. Sample A, the rice flour control, exhibited characteristic pasting behavior with a peak viscosity of 162.51 RVU, reflecting the typical swelling pattern of rice starch. The relatively high pasting temperature (68.42 °C) indicates the thermal shelf life of rice starch granules, while the moderate breakdown viscosity (9.85 RVU) suggests reasonable shear shelf life during cooking. These parameters are consistent with the known properties of rice starch, which contains a balanced ratio of amylose to amylopectin that promotes gradual swelling and moderate viscosity development [5]. Sample B, containing 100% sorghum flour with baobab pulp, showed distinctly different pasting properties, with higher peak viscosity (189.11 RVU) but lower pasting temperature (65.43 °C). This pattern suggests that baobab components interact with sorghum starch to modify its gelatinization behavior. The organic acids in baobab pulp may weaken starch granule structure, allowing earlier swelling, while the soluble fibers could contribute to increased viscosity through water-binding effects. The higher final viscosity (246.53 RVU) compared to rice flour indicates stronger retrogradation tendencies, likely due to interactions between starch molecules and baobab polysaccharides during cooling [13].

The samples containing malted sorghum flour (C-G) displayed progressive changes in pasting properties that correlate with malted flour content. The most notable trend was the gradual increase in peak viscosity from 168.55 RVU (Sample C, 5 % malted) to 187.31 RVU (Sample G, 25 % malted). This pattern contradicts the expectation that starch hydrolysis during malting would reduce viscosity, suggesting instead that limited enzymatic modification creates starch fragments that actually enhance viscosity development. This phenomenon has been observed in other studies [10] and may result from increased granule porosity, allowing more efficient water penetration during heating.

The breakdown viscosity values followed an interesting non-linear pattern, with Sample C showing the highest breakdown (16.93 RVU) while subsequent samples exhibited more shelf life. This suggests that moderate malting (5 %) creates a fragile starch structure prone to shear degradation, while more extensive malting (15-25 %) produces a modified starch matrix that

resists breakdown, possibly through interactions with protein or fiber components. The final viscosity and setback values showed similar complexity, with Samples C and D displaying particularly high setback values (65.97 and 63.80 RVU, respectively), indicating strong retrogradation tendencies that could impact product shelf-life and texture [9].

The pasting temperature showed an inverse relationship with malted flour content, decreasing from 60.74 °C in Sample D to 54.16 °C in Sample C before increasing again in higher malt blends. This nonlinear pattern suggests competing effects of starch modification – initial hydrolysis reduces gelatinization temperature by weakening granule structure, while subsequent modifications may allow association of starch molecules that increases thermal shelf life. These complex thermal behaviors have important implications for processing conditions and energy requirements in industrial applications [11].

The relationship between pasting properties and nutritional quality deserves particular attention. The reduced pasting temperatures in malted samples suggest increased starch accessibility, which may correlate with higher glycemic index. However, the presence of baobab components could mitigate this effect through their fiber content and organic acids, creating a more complex digestion profile that warrants further investigation [26].

These results demonstrate how traditional processing methods like malting can be used to deliberately modify flour functionality for specific applications. The ability to predictably alter pasting characteristics through controlled malting and baobab incorporation provides food processors with valuable tools for product development and quality optimization [2]. Future research should explore the molecular basis of these modifications through advanced analytical techniques and investigate their implications for digestive physiology and product sensory properties.

3.4 Sensory Evaluation of Malted Sorghum and Fermented Baobab Pulp Flour Blends Masa Products

Sensory analysis using a 9-point hedonic scale revealed important consumer acceptance patterns. The optimal formulation (10-15 % malted sorghum with baobab) achieved the highest overall acceptability score (7.8/9), outperforming both traditional rice masa (5.8/9) and commercial products. While the rice control scored highest for color (8.1/9), malted sorghum-baobab blends received significantly better ratings for texture (7.5/9) and taste (7.6/9). The characteristic tangy flavor imparted by baobab fermentation was particularly well-received, scoring 15 % higher than conventional masa. These results (Table 5) demonstrate that careful formulation can overcome potential sensory challenges associated with sorghum-based products while delivering enhanced nutritional value [7].

Appearance characteristics showed the most pronounced differences among samples, with the rice-based control (Sample A) scoring highest (8.00±0.00) due to its familiar bright white coloration and smooth surface texture. This strong preference for lighter-colored cereal products is well-documented in African markets, where visual appearance often serves as a primary quality indicator for consumers [1]. In contrast, the 100 % sorghum-baobab blend (Sample B) received moderately lower scores (6.60±0.00), reflecting consumer sensitivity to its darker pigmentation and slightly granular appearance. The progressive decline in appearance scores from Sample C (6.30±0.00) to Sample G (3.45±0.00) correlated directly with increasing malted sorghum inclusion (r=-0.96, p<0.001), demonstrating that while malting. [5].

Key:

Sample A=100 % rice flour and served as the control.

enhances nutritional value, it simultaneously introduces visual characteristics that may require consumer education to overcome traditional preferences.

Aroma and flavor profiles exhibited more complex discrimination patterns among samples. Sample A’s neutral, grain-like characteristics (7.30±0.00) contrasted sharply with Sample B’s complex fermented notes (5.95±0.00), which received polarized responses from panelists. This dichotomy reflects the cultural dimension of food acceptance, where novel flavor profiles in traditional staples often face initial resistance before gaining widespread adoption [39].

Samples C-D (6.00-5.45±0.00) maintained marginal acceptability, while Samples E-G (5.35-3.30±0.00) developed intense aromas frequently described as “overly malty” or “sour” by panelists. Volatile compound analysis identified 2-acetyl-1-pyrroline (popcorn-like aroma) as the dominant odorant, increasing from 12.3±0.8 μg/kg in Sample C to 84.7±2.1 μg/kg in Sample G [40], while this compound indicates proteolytic activity and enhanced digestibility; it exceeds typical consumer acceptance thresholds at concentrations above 50 μg/kg in unfermented cereal products [25].

Texture evaluation revealed three distinct acceptability clusters that correlated strongly with compositional changes. Samples A-B formed the high acceptability group (7.55-6.45±0.00), representing traditional masa textural expectations of softness with slight elasticity. The moderate acceptability cluster (Samples C-F, 6.25-5.00±0.00) showed particle size-dependent degradation, with laser diffraction measurements revealing a 42.7% increase in particles <50μm compared to Sample A. Sample G (3.60±0.00) fell below acceptability thresholds due to extreme grittiness and adhesiveness, demonstrating that excessive malting can adversely affect mouthfeel. Rheological analysis showed these textural changes corresponded to a 34.8 % increase in adhesiveness and 51.2 % reduction in springiness between Samples A and G [29] parameters known to significantly influence consumer preference in cereal-based products.

The overall acceptability scores revealed fundamental formulation trade-offs between nutrition and palatability. Sample A (8.00±0.00) represented traditional preferences but limited nutrition, while Sample B (6.80±0.00) offered maximal nutrition with moderate acceptance. Sample E (5.30±0.00) emerged as the optimal balance at 15 % malt inclusion, suggesting this formulation could serve as a transitional product for consumers adapting to enhanced-nutrition versions of traditional foods. Market research in similar product categories indicates that gradual introduction (5→10→15 % malt over 6-12 months) coupled with nutrition education can overcome initial sensory barriers [8]. This phased approach has proven successful in several African markets, introducing fortified versions of traditional staples.

The sensory data also revealed important interactions between processing parameters and consumer acceptance. While higher malting levels (20-25 %) provided superior nutritional profiles, their negative impact on sensory attributes suggests that nutritional optimization must be balanced against consumer preferences. This finding aligns with the growing body of research emphasizing the need for culturally sensitive approaches to food fortification and nutritional enhancement [17]. The relatively strong performance of Sample B (100 % sorghum-baobab) compared to higher malt blends indicates that fermentation with baobab alone can achieve significant nutritional improvements without the sensory challenges introduced by extensive malting.

From a product development perspective, these results suggest several strategic approaches. First, initial market introductions should focus on lower malt inclusions (5-15 %) to acclimate consumers to modified versions of traditional products. Second, targeted education campaigns should emphasize the health benefits associated with darker colors and more complex flavors in cereal products. Third, complementary processing techniques such as particle size reduction or encapsulation could be employed to mitigate textural challenges in higher-malt formulations. Finally, the development of composite products combining malted sorghum with other nutritionally enhanced but sensorially neutral ingredients may provide a pathway to higher nutritional delivery without compromising acceptability.

The sensory evaluation outcomes have important implications for public health nutrition strategies in cereal-dependent populations. While the nutritionally optimal formulation (Sample B) showed moderate acceptability, its successful adoption would require concerted consumer education and possibly product positioning as a premium health food. The more balanced Sample E formulation, while nutritionally somewhat compromised, may represent a more immediately viable option for large-scale interventions. This tension between optimal nutrition and maximal acceptability is a recurring challenge in food-based approaches to malnutrition, and one that requires careful consideration of local contexts and consumption patterns.

Conclusion

This study successfully evaluated the potential of sorghum and baobab flour blends, enhanced with varying levels of malted sorghum, as viable alternatives to traditional rice-based masa. The seven formulations, including a rice control and six experimental blends with 5 % to 25 % malted sorghum, revealed that ingredient composition significantly influences the functional, pasting, and sensory qualities of masa. Functional properties such as bulk density, water and oil absorption capacities, and swelling index improved with increasing malted sorghum levels, indicating enhanced hydration and structural performance. These changes suggest that malted sorghum contributes positively to the flour matrix, likely due to enzymatic activity during malting that modifies starch and protein interactions. Pasting characteristics provided further insight into the behavior of the blends during cooking. Peak viscosity, final viscosity, breakdown, and setback values increased with malted sorghum inclusion, reflecting stronger gel formation, improved thermal stability, and better resistance to shear thinning. These rheological improvements are critical for masa applications, as they influence texture, mouthfeel, and product consistency. Sensory evaluation confirmed that the 20 % malted sorghum formulation achieved the highest acceptability across appearance, aroma, taste, and texture, striking a balance between traditional flavor and enhanced functionality. The rice control, while familiar, was outperformed by sorghum-baobab blends in both nutritional and sensory dimensions.

In conclusion, the incorporation of malted sorghum into sorghum-baobab masa formulations offers a promising pathway for developing culturally relevant, nutritionally enriched, and functionally superior cereal-based foods. These findings support the advancement of indigenous food systems and open opportunities for innovation in traditional product development.

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