Exploring Scientific Validation of Millets in Contemporary Healthcare: A Traditional Food Supplement

Millets, small-seeded grasses, are gaining interest for their nutrition and health benefits. This abstract provides a comprehensive overview of millets' pharmacological activities, highlighting their rich bioactive compounds. These compounds, including phenolic compounds, flavonoids, and dietary fibers, contribute to antioxidant effects, safeguarding against chronic diseases. Millets also possess anti-inflammatory properties, potentially alleviating conditions, like arthritis and asthma. They show anti-carcinogenic potential, possibly preventing various cancers' development through mechanisms, like apoptosis induction and inhibiting tumor growth. Moreover, millets offer hypolipidemic and hypoglycemic effects, beneficial for managing conditions, such as dyslipidemia and diabetes. Their high dietary fiber and resistant starch content regulate blood lipids and glucose, reducing the cardiovascular risk. Additionally, millets act as antimicrobials, inhibiting pathogens and serving as natural alternatives to synthetic antimicrobials. They exhibit immunomodulatory effects, enhancing immune function and response. Overall, millets' pharmacological properties, including antioxidant, antiinflammatory, anti-carcinogenic, hypolipidemic, hypoglycemic, antimicrobial, and immunomodulatory traits, position them as functional foods with varied health benefits. Further research can integrate millets into preventive and therapeutic approaches for diverse diseases.

Sorghum Flour and Sorghum Flour Enriched Bread: Characterizations, Challenges, and Potential Improvements

A Sorghum flour (SF) is a leading and prominent food source for humans in African countries. Recently extensive studies have been conducted on Sorghum bread (SB) or sorghum composite bread (SCB), covering various aspects. However, there are many technical challenges in the formation of SF and sorghum composite flour (SCF) that impact the quality of the bread and fail to meet the consumer's desires and expectations. This review primarily focuses on the characteristics of SF, SCF, SB, and SCB, with discussions encompassing the rheological and morphological properties of the dough, improvement strategies, and bread quality. Moreover, a comprehensive analysis has been conducted to investigate the behavior of SF and SCF along with a discussion of the challenges affecting bread quality and the strategies applied for improvement. The significant demand for nutrients-rich and gluten-free bread indicates that sorghum will become one of the most vital crops worldwide. However, further comprehensive research is highly demanded and necessary for an in-depth understanding of the key features of SF and the resulting bread quality. Such understanding is vital to optimize the utilization of sorghum grain in large-scale bread production.

Sorghum Flour Application in Bread: Technological Challenges and Opportunities

Sorghum has a long history of use in the production of different types of bread. This review paper discusses different types of bread and factors that affect the physicochemical, technological, rheological, sensorial, and nutritional properties of different types of sorghum bread. The main types of bread are unleavened (roti and tortilla), flatbread with a pre-ferment (injera and kisra), gluten-free and sorghum bread with wheat. The quality of sorghum flour, dough, and bread can be improved by the addition of different ingredients and using novel and traditional methods. Furthermore, extrusion, high-pressure treatment, heat treatment, and ozonation, in combination with techniques such as fermentation, have been reported for increasing sorghum functionality.

In situ thermal modification of kafirin using infrared radiations and microwaves

BACKGROUND

Kafirin is a prolamin protein located in the corneous endosperm of sorghum. The conventional thermal processing of kafirin reduces its solubility, which limits its utilization in the food industry. Therefore, the study was aimed to investigate the effect of in situ thermal modification of kafirin using two different electromagnetic thermal treatments, namely infrared (IR) and microwave (MW) radiation, on the physicochemical, structural, thermal, and antioxidant properties.

RESULTS

The results demonstrated that both the thermal modifications improved yield, purity, and solubility of the kafirin with a decrease in hydrophobicity. However, IR-treated samples showed higher solubility (910.67 g kg^-1 ) and lower hydrophobicity (387.67). The IR modifications also improved the ratio of α helix/β sheets to a great extent. The alterations in the disulfide content were concomitant with the improvement in the thermal stability of kafirin. Sodium dodecyl sulfate polyacrylamide gel electrophoresis showed variations in the band intensities of β- and γ-kafirin, indicating alterations in the kafirin subunits. Morphological examination of kafirin revealed surface withering and agglomeration. Notably, IR treatment improved the antioxidant activity more efficiently (from 32.11% to 74.05%).

CONCLUSION

Although both the IR and MW treatments modified kafirin, the effect seemed to be more pronounced in IR modification. The IR-modified kafirin had better solubility and lesser hydrophobicity than MW-modified kafirin. The physicochemical and structural changes induced by IR treatment improved the biological activity of kafirin, in terms of antioxidant activity. Therefore, it was concluded that the in situ IR modification of kafirin can alter its characteristic properties, improving its potential as a food ingredient. © 2021 Society of Chemical Industry.

Vibrational and fluorescence spectroscopy to study gluten and zein interactions in complex dough systems

The volume-spanning network formed by gluten during breadmaking is crucial in the production of high-quality bakery products. Zein proteins are also capable of forming a protein network under specific conditions. Vibrational (Fourier transform infrared spectroscopy (FTIR) and Raman scattering) and fluorescence spectroscopy are powerful, non-invasive techniques capable of assessing protein structures and interactions. The main objective of this project was to explore the suitability of these techniques to study zein and gluten structures and interactions in complex dough systems. The dough samples were prepared by mixing 20 w/w% of protein (with different proportions of zein and gluten) and 80 w/w% of corn starch. The tyrosine (Tyr) fluorescence emission peak (λ_exc = 280 nm) was still present even in those zein-gluten samples containing the highest gluten concentration and lowest zein concentration. This suggests that the Tyr moieties (stemming from zein) are not in close proximity to tryptophan (Trp) of gluten and their fluorescence is not quenched efficiently. Raman scattering results also showed the presence of different Tyr residues, exposed and buried, as well as different conformations of disulfide bridges, in zein and gluten samples. Based on the results from spectroscopic measurements and scanning electron microscopy (SEM), two distinct network structures composed of gluten and zein were identified in the mixed dough systems. The present work illustrates how complementary vibrational (Raman scattering and FTIR) and fluorescence spectroscopy methods can be combined to non-invasively assess protein structure and interactions in a complex food matrix.

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Exploration of non-invasive techniques to study proteins in complex food systems.

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Complementary information obtained on protein structure at several length scales.

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Zein dough viscoelasticity relates to the formation of beta-sheet rich fibrils.

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Gluten and zein form two distinct network structures in dough making.

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Zein inclusion increases water availability for gluten in gluten-zein dough.

Characteristics of white, yellow, purple corn accessions: phenolic profile, textural, rheological properties and muffin making potential

Physicochemical, antioxidant, phenolic profile and muffin-making properties of white, yellow and purple corn accessions were evaluated. HPLC analysis revealed the presence of ferulic acid, quercetin, sinapic acid, gallic acid and protocatechuic acid in different corn accessions. Ferulic acid was the major phenolic acid present in all accessions. Total phenolic content (TPC), DPPH and ABTS inhibition ranged from 903 to 1843 µg GAE/g, 0.73-0.89 and 3.81-4.92 µM trolox/mg, respectively. Purple accessions had higher TPC than yellow and white accessions. Pasting profiles of different accessions revealed high thermal stability indicated by low breakdown viscosity. Muffin-making properties were determined as batter rheology and muffin specific volume, texture and sensory analysis. Storage modulus (G') and loss modulus (G″) of batters for white colored exhibited the highest while yellow colored had the lowest value. Firmness and TPC of muffins ranged from 3.1 to 5.9 N and 811-1406 µg GAE/g, respectively. Muffin cohesiveness and chewiness were correlated positively, whereas firmness was negatively related to paste viscosities. Antioxidant activity was correlated to phenolic content of the muffins. Sensory analysis revealed that muffins prepared from yellow corn accession (IC447648) were highly acceptable, while those made from purple corn (IC447644) were not liked much.

Optimisation and Evaluation of the Effect of Bambara Groundnut Addition on the Nutritional Quality and Functional Properties of Amaranth Grain-Based Composite Flour

Nutritional quality and functional properties of composite flour consisting amaranth grain, bambara groundnut, carrot and rice bran flours were evaluated. The dependent variables were optimized using optimal mixture model of response surface methodology. Amaranth grain flour (70 – 80.75%), bambara groundnut flour (15-25%), carrot flour (2-5%) and rice bran (2-10%) were the independent variables. From the results, very high protein content (about 40%) was obtained when the bambara content inclusion was 25%. Bambara groundnut flour inclusion up to 15% also resulted in high protein contents (≤ 37%). Supplementation of the composite flour with high carrot flour content (up to 10%) also enhanced the protein content when the bambara groundnut content was low. High carrot flour inclusion had the highest positive effect on the crude fibre content (3.7-3.9%) followed by rice bran and bambara groundnut flours in that order. Bambara groundnut had highest positive effect on the ash content; followed by carrot and rice flours. While amaranth grain, carrot and rice bran significantly (p≤0.05) affect the proximate and functional compositions, bambara groundnut had the highest and best effect on the proximate, functional, mineral properties as well as the amino acid profile of the composite flour.

Physicochemical and Rheological Properties of Optimised Cocoyam-Based Composite Flour Comprising Cassava Starch

Composite flour comprising cocoyam (Colocassia esculenta), bambara groundnut and cassava starch was produced. The proximate and minerals compositions and functional properties were optimized using optimal mixture design of response surface methodology. The antinutritional, pasting and farinograph analyses of the optimum blends were evaluated. Bambara groundnut improved protein, fibre, ash and minerals contents; cassava starch improved swelling capacity, least gelation and pasting characteristics. The optimum blends CBC1 (70% cocoyam flour, 18.33% bambara groundnut flour, 11.67% cassava starch) and CBC2 (69.17% cocoyam flour, 16.67% bambara groundnut flour, 14.17% cassava starch). were comparable to wheat–based flour samples (60% wheat, 30% cocoyam, 10% bambara groundnut flours) and (72% wheat, 19% cocoyam, 9% bambara groundnut flours) in terms of pasting and farinograph analyses.

Production and evaluation of breakfast cereals from blends of acha and fermented soybean paste (okara)

Breakfast cereals was formulated from blends of acha and fermented okara (soybean residue). Acha grains were cleaned, winnowed, washed, dried (at 50 °C for 4 h) and milled into flour. Okara was processed from soybean seed through the stepwise procedure of cleaning, soaking, washing, milling and sieving. The residue was divided into five portions, fermented differently for 0, 12, 24, 36, and 48 h and then dried at 50 °C for 6 h. Acha flour (UFAC) was milled and blended at 50, 60, 70, 80, 90, 100 % ratio with milled okara flour. Functional properties (bulk density, water absorption capacity, swelling capacity, wettability, viscosity and particle size distribution, microbial load, and proximate composition were carried out on the individual flour samples. The blended flours were conditioned, partially heat treated (for 10 min), aged (4 °C for 6 h), cut, toasted (120 °C for 1 h), cooled and packaged. The different toasted breakfast cereals, TBFC, were subjected to sensory evaluation, proximate composition, micronutrient composition (vitamin A, B1, B2, B3, calcium, iron, phosphorus, and zinc) and microbial analyses (mould count and total viable count). The proximate composition of the unfermented okara (UFOK) and fermented okara (FEOK 1, 2, 3, and 4 fermented at 12, 24, 36, 48 h respectively) flour samples showed that fermentation increased moisture from 4.71 ± 0.06 to 6.11 ± 0.05, crude fibre from 36.62 ± 0.01 to 46.18 ± 0.55, and carbohydrate from 2.50 ± 0.18 to 2.71 ± 0.34 contents. There was a decrease in the fat content from 16.29 ± 0.04 to 13.27 ± 0.22, ash from 1.41 ± 0.17 to 6.36 ± 0.17 and crude protein from 30.32 ± 0.21 to 33.53 ± 0.11 contents. From the sensory evaluation, the result showed that 70:30 acha-unfermented okara TBFC, FEOK 1D 60:40 acha-12 h FEOK TBFC, 70:30 acha-24 h FEOK TBFC, 50:50 acha-36 h FEOK TBFC, and 70:30 acha-48 h FEOK TBFC had the best overall acceptability for the different fermentation times. The functional properties, proximate and sensory evaluation were the basis for selection of the best products which were UFAC (control), UFOK C (70:30 acha UFOK TBFC) and FEOK 4C (70:30 acha 48 h FEOK TBFC) which were further subjected to proximate, micronutrient, and microbial analyses. There was an increase in the protein, fat, ash, crude fibre content whereas the moisture and carbohydrate contents decreased. A considerable decrease was found in vitamin A and B1 contents of the products, whereas vitamin B2 and B3 increased. Also the mineral contents of all the products were improved as indicated in the increase in ash content.

Antioxidant, functional and rheological properties of optimized composite flour, consisting wheat and amaranth seed, brewers' spent grain and apple pomace

Consumer's interest in functional food has continued to increase due to its potential health benefits. This study therefore is aimed at developing a functional wheat based flour comprising, amaranth (Amaranthus hypochondriacus) seed, brewers' spent grain and apple pomace. The statistical analyses were carried out using response surface methodology (RSM). For the experimental design, the composite flour components were the variables while the proximate and mineral compositions were the responses. After the statistical optimisation process, the best three blends were chosen for further analyses; determination of antioxidant, functional and rheological properties. From the results, the best blends were Runs 11, 13 and 19, with percentages composition of wheat, amaranth seed, brewers, spent grain and apple pomace of 65 %, 30 %, 2 %, 3 %; 60.43 %, 29.68 %, 4.1 %, 5.79 % and 81.94 %, 6.75 %, 3.39 %, 7.92 % respectively. The ANOVA, R(2) and R(2) adjusted values for the proximate and mineral compositions showed that the composite flours were statistically satisfactory. The results also indicated that the antioxidant, functional and rheological properties of the three best blends showed good and acceptable nutritional and rheological properties. Composite flours with acceptable and excellent nutritional composition, functional properties and rheological behaviour can be obtained from composite blends consisting wheat, amaranth seed, brewers, spent grain and apple pomace flours.

Antioxidant properties and consumer acceptability of pearl millet – tiger nut biscuits

Purpose

– This paper aims to focus on the antioxidant properties and consumer acceptability of biscuits produced from pearl millet (PM)–tiger nut (TN) composite blends, with the aim of encouraging the use of these under-utilised food crops in producing value-added products with nutraceutical potential.

Design/methodology/approach

– PM grains and TN seeds were processed into flour and blended at ratios: 15:85 (A), 20:80 (B), 25:75 (C), 30:70 (D), 35:65 (E), 40:60 (F), 45:55 (G), of PM to TN using response surface methodology. The antioxidant properties of the biscuits produced from the flour blends were determined using standard methods, and data obtained were subjected to analysis of variance (ANOVA); differences of means were separated using Duncan multiple range test. The biscuits were subjected to sensory evaluation using 50 untrained panellist and results statistically analysed.

Findings

– The total phenolic content (TPC-mg/GAE) of PM–TN flour blends ranged from 2.65-4.95 (A-G), with an average TPC of 3.85. In PM–TN biscuits, total phenolic values ranged from 1.20-3.42 (A-G), with an average of 2.39. The 2,2′-azino-bis(3-ethyl benzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activities (μmolTEAC/g) of PM–TN flour blends ranged from 26.7-36.4 (A-G), and the values for biscuits ranged from 28.5-38.6 (A-G). There was a highly significant correlation, r = 0.811(p < 0.001) and r = 0.913 (p < 0.001) between phenolic content and antioxidant activity for flour and biscuit, respectively. The effect of in vitro digestion of biscuits on the antioxidant assays viz-a-viz: TPC and ABTS radical scavenging activities were also investigated. The order of phenolic release was enzymic > aqueous > ethanolic digest for TPC, while for ABTS, the order of release was enzymic > ethanolic > aqueous. The highest values for antioxidant properties were found in the simulated in vitro enzyme digested biscuits. Consumer acceptability revealed that the overall acceptability scores of the biscuits were not significantly different except for biscuit sample G.

Originality/value

– The paper has demonstrated the antioxidant potentials and consumer acceptability of PM–TN biscuits. It also shows the effect of in vitro digestion on the antioxidant activities of the biscuit and its potential health benefit, as a source of antioxidant.

Functionality of alternative protein in gluten-free product development

Celiac disease is an immune-mediated disease triggered in genetically susceptible individuals by ingested gluten from wheat, rye, barley, and other closely related cereal grains. The current treatment for celiac disease is life-long adherence to a strict gluten-exclusion diet. The replacement of gluten presents a significant technological challenge, as it is an essential structure-building protein, which is necessary for formulating high-quality baked goods. A major limitation in the production of gluten-free products is the lack of protein functionality in non-wheat cereals. Additionally, commercial gluten-free mixes usually contain only carbohydrates, which may significantly limit the amount of protein in the diet. In the recent past, various approaches are attempted to incorporate protein-based ingredients and to modify the functional properties for gluten-free product development. This review aims to the highlight functionality of the alternative protein-based ingredients, which can be utilized for gluten-free product development both functionally as well as nutritionally.

Effect of brown rice flour fortification on the quality of wheat-based dough and flat bread

The objective of present study was to investigate the impact of Brown Rice flour (BR) incorporation, at three different levels of 5, 10 and 15 % to the Wheat Flour (WF) preparations on rheological properties of wheat-based dough and quality of wheat-based flat bread. The BR flour incorporation mainly affected the chemical properties of flours, the rheological characteristics of dough and, quality and shelf life of bread. The protein-related properties of flours principally experienced reduction; however, the ash content had an increase, along with BR flour incorporation. The rheological properties of dough were affected considerably by BR flour substitution, wherein the sample containing 5 % BR flour was closest to BR flour-free dough (control). Regarding the yielded bread, BR flour addition affirmatively affected sensorial properties and firmness quality evaluation, wherein the bread made from dough with composite flour fortified with 5 % BR flour was scored the best. The findings from instrumental firmness quality assessment were confirmed as the bread containing 5 % BR flour remained softer and demanded lowest force to be compressed over the storage period. Overall, results showed that adding BR flour up to 5 % can be used in baking of flat bread since it meets the required criteria.

Interaction of maize zein with wheat gluten in composite dough and bread as determined by confocal laser scanning microscopy

Protein body-free maize zein, when mixed at 35 degrees C (above its glass transition temperature range), significantly (p < 0.01) improved the rheological and leavening properties of sorghum-wheat composite flour dough, resulting in improved loaf volume. Confocal laser scanning microscopy was used to observe the structure of zein fibrils and the interaction between zein and gluten proteins in the composite dough and bread systems. Autofluorescence and immunolocalization techniques were used to locate gluten and zein, respectively. Optical sections were collected every 0.4 microm through the samples and digitally processed to produce reconstructed three-dimensional images. Results showed that zein fibrils form an outer layer that intermittently coats the gluten networks, thereby strengthening them. This type of microstructure is able to withstand the pressure exerted by gas cell expansion during yeast fermentation to increase loaf volume.