Nutritional and Rheological Properties of Sorghum

Sorghum (Sorghum vulgare): an ancient grain, a novel choice for a healthy gluten-free diet

Celiac disease (CD) is an autoimmune disease related to gluten consumption. To date, the only effective therapy that can reverse symptoms and prevent complications is the gluten-free diet (GFD), which is challenging to maintain and has potential health risks. Identifying foods that can help diversify the GFD and that best match the nutritional needs of people with CD may improve the health and quality of life of celiac patients. This review, conducted through a non-systematic search of the available literature, aims to gather the most recent research on nutritional issues in CD and GFD. Moreover, it highlights how sorghum characteristics could provide health benefits to CD patients that counteract the nutritional problems due to CD and the nutritional consequences of GFD acceptance. Sorghum contains a wide variety of bioactive compounds, such as flavones and tannins, that have shown anti-inflammatory activity in preclinical studies. They can also regulate blood sugar levels and lower cholesterol to reduce the effects of common chronic diseases such as metabolic and cardiovascular diseases. Because it is gluten-free, its use in making foods for celiac patients is increasing, especially in the United States. In conclusion, sorghum is a fascinating grain with nutritional properties and health benefits for supplementing GFD. However, only one study confirms the short-term safety of sorghum inclusion in the GFD, and further long-term studies with a large sample are needed.

Nutritional Traits, Pasting Properties and Antioxidant Profile of Selected Genotypes of Sorghum, Oat and Maize Eligible for Gluten-Free Products

The technological and nutritional traits of food-grade sorghum hybrids, hulled/naked oat varieties and maize genotypes of different colors were studied for novel and healthier gluten-free foods. Oat genotypes showed the highest protein content, followed by maize and sorghum. The total starch and the total dietary fiber content were quite similar among the three species. Great variation was found in the amylose content, and the highest was in sorghum (27.12%), followed by oat 16.71% and maize 10.59%. Regarding the pasting profile, the rank of Peak Viscosity was sorghum (742.8 Brabender Unit, BU), followed by maize (729.3 BU) and oat (685.9 BU). Oat and sorghum genotypes had similar average breakdown (407.7 and 419.9 BU, respectively) and setback (690.7 and 682.1 BU, respectively), whereas maize showed lower values for both parameters (384.1 BU and 616.2 BU, respectively). The total antioxidant capacity, only in maize, significantly correlated with total flavonoid, phenolic and proanthocyanidin contents, indicating that all the measured compounds contributed to antioxidant capacity. The study indicated the importance of sounding out the nutritional and technological characteristics of gluten-free cereals in order to select suitable cultivars to be processed in different gluten-free foods with better and healthier quality.

Genetic variability among lowland sorghum accessions collected from southern Ethiopia for grain quality traits

The study was carried out to assess the nature and magnitude of genetic variability for grain quality traits in lowland sorghum accessions. Understanding genetic diversity and trait association is crucial to designing an effective breeding plan to develop nutrient-rich varieties. Two hundred twenty-five accessions were evaluated using a simple lattice design with two replications at Weioto. Prepared samples per replication were scanned by mixing the grains and repacking the sample cup after each scan. Analysis of grain quality traits revealed significant (P ≥ 0.01) differences among the genotypes indicating a good chance for genetic improvement. Genotypic means of nutritional content showed that amylose (Am) content ranged from 19.11 to 20.80%, ash value ranged from 0.37 to 3.14%, starch content ranged from 42.29 to 72.77%, and protein (pr) in dry basis ranged from 2.62 to 10.45%. Similarly, iron (Fe) ranged from 1.38 to 73.21 ppm, zinc (Zn) ranged from 16.8 to 66.02 ppm, and tannin content ranged between -0.08 and 9105.21%. Broad-sense heritability (h2b) of all grain quality attributes such as amylose; ash; starch; moisture; iron; zinc; protein, and tannin was in the range of 13-92%. Principal component analysis showed the first three principal components with an eigenvalue equal to or greater than unity adequately explain the variation in the data. Significant positive genetic correlations (P < 0.001) with amylase, starch, iron, and zinc, while tannin had a weak association with grain yield. This result declares/signifies/a good prospect of southern Ethiopia lowland sorghum accessions for genetic improvement in grain yield and quality traits.

Effect of sorghum pre-processing (roasting and germination) on the replacement level and quality of sorghum-wheat bread: bread characteristics, digestibility, consumer acceptability and microbiological analysis

Abstract

The present study was focused on the replacement of refined wheat flour (RWF) by control (CS) and processed sorghum flour [germinated (GS) and roasted (RS)] on the properties of flour/batter/dough (particle size, XRD, pasting, dynamic rheology, farinograph) and bread (physical, textural, digestibility, microbiological and sensory). Prominent variations adhered with sorghum processing, but decreasing patterns occurred for flour-water absorption, dough stability times, storage modulus, peak/final/breakdown viscosities, bread-moisture content, specific volume, porosity, and lightness. Flour's pasting temperature, dough development time, breadbulk density, hardness, gumminess, and bitterness increased. Composite flours mainly had weak nature compared to RWF. The baking loss was lower for 10-30% CS and GS incorporation than RS. Composite bread had higher in-vitro protein and starch digestibility (CS > GS > RS) than RWF. Three days storage life with acceptable quality scores was obtained for bread with CS and GS up to 20% and RS up to 30% incorporation.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05810-3.

Exploiting Indian landraces to develop biofortified grain sorghum with high protein and minerals

Sorghum (Sorghum bicolor L. Moench) is the staple cereal and is the primary source of protein for millions of people in Asia and sub-Saharan Africa. Sorghum grain value has been increasing in tropical countries including India owing to its gluten-free nature, anti-oxidant properties and low glycemic index. However, the nutrient composition of modern cultivars is declining thus necessitating genetic biofortification of sorghum to combat malnutrition and improve nutritional balance in the human diet. Keeping this in view, efforts were made to utilize valuable alleles, associated with nutrient composition, that might have been left behind in the varietal development in sorghum. The study aimed to determine the genetic improvement for nine nutritional and quality parameters (crude protein, in vitro protein digestibility (IVPD), total iron (Fe), total zinc (Zn), bioavailable Fe (%), bioavailable Zn (%), total phenolics, tannins and antioxidant activity) in the grains of 19 sorghum genotypes (high yield, drought and grain mold tolerant) developed from 11 superior India's landraces. After selection and advancement made from 2017 to 2022 through single seed descent method, the improvement in the nine nutritional and quality parameters was assessed. Significant variation was observed for all the nine parameters among the landraces and the genotypes. Sorghum genotypes PYPS 2 and PYPS 13 recorded the highest crude protein (13.21 and 12.80% respectively) and IVPD (18.68 and 19.56% respectively). Majority of the sorghum genotypes recorded high Fe (14.21-28.41 mg/100 g) and Zn (4.81-8.16 mg/100 g). High phenolics and antioxidant activity were recorded in sorghum genotypes PYPS 18 (85.65 mg/g gallic acid equivalents) and PYPS 19 (89.78%) respectively. Selections through SSD method revealed highest improvement in genotype PYPS 10 for crude protein (32.25%), total phenolics (18.48%) and antioxidant activity (15.43%). High improvements in genotypes PYPS 12 (23.50%), PYPS 3 (26.79%), PYPS 15 (21.18%) were recorded for total Fe, available Fe and high tannins, respectively. The study demonstrated that landraces could be effectively utilized as a potential, low-cost and eco-friendly approach in sorghum genetic biofortification to improved sorghum productivity and nutritional supply in semi-arid tropics.

Characterization of bioprocessed white and red sorghum flours: Anti-nutritional and bioactive compounds, functional properties, molecular, and morphological features

In the current investigation, white and red sorghum grains were exposed to bioprocessing techniques, such as soaking, germination, fermentation, and dual processing (both germination and fermentation). Germination and fermentation resulted in improved bioactive profile attributing to better antioxidant activity, whereas a reduction in antinutrient components was observed. On the other hand, soaking had decreased phenolic components and anti-nutritional factors attributing to their leaching in the soaking water. A significant change in the functional properties and color profile was also observed on bioprocessing. It also caused alterations in the morphological structure of the starch-protein matrix and molecular interactions of certain functional groups that reveal the synthesis of certain new bioactive compounds in the flour. The alterations in the bioprocessed flours occurred due to the structural breakdown attributing to the activity of hydrolytic enzymes that were activated during the processing treatments. Bioprocessing was also responsible for the degradation of the starch granules and unfolding of the protein matrix, thus altering the in vitro nutrient digestibility of the flours. Principal component analysis was used to authenticate the differences between different treatments and observations recorded. These bioprocessed flours could be potential ingredients for several valorized cereal products.

Exploring the possibilities of some selected flour blends for the development of bakery products: Comparison with some physicochemical and functional properties of wheat flour

This study explored the possibilities of some selected flour blends vis-a-vis the physicochemical and functional properties of wheat flour. Ten flour blends from potato starch, cassava, maize and soybean flours and wheat flour were made and evaluated for physicochemical, functional and anti-nutritional properties. The range of proximate values were for moisture (3.76%-6.67%), protein (4.33-8.96%), ash (1.35-1.96%), fat (3.37-4.88%), fibre (1.22-1.89%) and carbohydrate (78.35-84.94%), whereas wheat flour had moisture (9.45%), protein (11.31%), ash (2.54%), fat (3.78%), fibre (1.31%) and carbohydrate (73.90%). Cyanogenic glucoside, saponion and tannin contents increased with increase substitution of cassava and soybean flours. Pasting temperatures of flour blends ranged from 69.03 °C to 78.83 °C, while wheat flour had 78.05 °C. Peak, hot paste, breakdown, setback and cold paste viscosities were 1514-2822, 1036-1597, 487-1225, 580-884 and 1616-2461 cp in flour blends compared to 2361, 1360, 1001, 1079 and 2439 cp of wheat flour. Substitutions with soy flour decreased the peak, hot paste, breakdown and cold paste viscosities but increased the pasting temperatures. L*, a* and b* values ranged from 78.56 to 87.65, -0.34 to 0.71 and 10. 95 to 13.50 in flour blends while the wheat flour varied significantly at 2361.00, 1360.00 and 1001.00. The nutritional and pasting properties of some of flour blends were closely related to wheat flour and may be used for bakery requirements.

Honey Bees Prefer Pollen Substitutes Rich in Protein Content Located at Short Distance from the Apiary

The availability of floral resources is crucial for honey bee colonies because it allows them to obtain protein from pollen and carbohydrates from nectar; typically, they consume these nutrients in the form of bee bread, which has undergone fermentation. However, the intensification of agriculture, urbanization, changes to the topography, and harsh environmental conditions are currently impacting foraging sites due to habitat loss and scarcity of food resources. Thus, this study aimed to assess honey bee preference for various pollen substitute diet compositions. Bee colonies perform poorly because of specific environmental problems, which ultimately result in pollen scarcity. Pollen substitutes located at various distance from the bee hive were also investigated in addition to determining the preferences of honey bees for various pollen substitute diets. The local honey bee (Apis mellifera jemenitica) colonies and different diets (four main treatments, namely, chickpea flour, maize flour, sorghum flour, wheat flour; each flour was further mixed with cinnamon powder, turmeric powder, flour only, flour mixed with both cinnamon and turmeric powder) were used. Bee pollen was used as a control. The best performing pollen substitutes were further placed at 10, 25, and 50 m distances from the apiary. Maximum bee visits were observed on bee pollen (210 ± 25.96) followed by chickpea flour only (205 ± 19.32). However, there was variability in the bee visits to the different diets (F (16,34) = 17.91; p < 0.01). In addition, a significant difference in diet consumption was observed in control (576 ± 58.85 g) followed by chickpea flour only (463.33 ± 42.84 g), compared to rest of the diets (F (16,34) = 29.75; p < 0.01). Similarly, foraging efforts differed significantly (p < 0.01) at the observed time of 7-8 A.M., 11-12 A.M., and 4-5 P.M. at the distance of 10, 25, and 50 m away from the apiary. Honey bees preferred to visit the food source that was closest to the hive. This study should be very helpful for beekeepers in supplementing their bee colonies when there is a shortage or unavailability of pollens, and it is much better to keep the food source near the apiary. Future research needs to highlight the effect of these diets on bee health and colony development.

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.

Genome-wide screening of lectin putative genes from Sorghum bicolor L., distribution in QTLs and a probable implications of lectins in abiotic stress tolerance

BACKGROUND

Sorghum bicolor is one of the most important crops worldwide with the potential to provide resilience when other economic staples might fail against the continuous environmental changes. Many physiological, developmental and tolerance traits in plants are either controlled or influenced by lectins; carbohydrate binding proteins. Hence, we aimed at providing a comprehensive in silico account on sorghum's lectins and study their possible implication on various desired agronomical traits.

RESULTS

We have searched sorghum's genome from grain and sweet types for lectins putative genes that encode proteins with domains capable of differentially binding carbohydrate moieties and trigger various physiological responses. Of the 12 known plant lectin families, 8 were identified regarding their domain architectures, evolutionary relationships, physiochemical characteristics, and gene expansion mechanisms, and they were thoroughly addressed. Variations between grain and sweet sorghum lectin homologs in term of the presence/absence of certain other joint domains like dirigent and nucleotide-binding adaptor shared by APAF-1, R-proteins, and CED-4 (NB-ARC) indicate a possible neofunctionalization. Lectin sequences were found to be preferentially overrepresented in certain quantitative trait loci (QTLs) related to various traits under several subcategories such as cold, drought, salinity, panicle/grain composition, and leaf morphology. The co-localization and distribution of lectins among multiple QTLs provide insights into the pleiotropic effects that could be played by one lectin gene in numerous traits.

CONCLUSION

Our study offers a first-time inclusive details on sorghum lectins and their possible role in conferring tolerance against abiotic stresses and other economically important traits that can be informative for future functional analysis and breeding studies.

Proximate Composition, Antidiabetic and Hypolipidemic Activity of Bread Produced from Wheat-Sorghum Base Supplemented with Mung Bean Malt and Carrot Flour

Diabetes is a group of disorders of carbohydrate metabolism characterized by a high level of glucose in urine. Evidence supports the use of whole-grain foods, vegetables, and fruits, and foods with a low glycemic index in the management of diabetes. Ten (10) blends of wheat-sorghum flour supplemented with mung bean malt and carrot flour were used for bread production and evaluated for proximate composition. Three bread samples with protein contents of 18% or higher were tested for antidiabetic and hypolipidemic effects on alloxan-induced diabetic rats. Bread samples containing 30% mung bean malt and 5% carrot flour had the highest protein (22.88%), ash (2.41%), and fiber (3.60%) contents that differed significantly (P < .05) from other composite breads and control (100% wheat bread). The reduction in fasting blood sugar level was observed to be greater in the rat groups fed experimental samples than in the control. Bread samples with the highest content of mung bean malt (30%) and carrot flour (5%) were more effective in the reduction of fasting blood glucose, triglyceride, and serum cholesterol levels than other formulations. When rats fed experimental diets were compared with controls, they had lower serum cholesterol (137.67, 150.67, and 154.67 mg/dL), lower low-density lipoprotein (LDL; 68.46, 84.96, and 84.20 mg/dL), higher very LDL (11.86, 20.20, and 22.18 mg/dL), and higher high-density lipoprotein (54.67, 45.67, and 48.33 mg/dL). The results suggest that the bread modified with mung bean malt and carrot flour possesses antidiabetic and hypolipidemic effects. Approval Reference Number: FVM-UNN-IACUC-2021-1182.

Characterization of Sorghum Processed through Dry Heat Treatment and Milling

Sorghum grain nutritional quality can be enhanced by applying dry heat treatments. The purpose of this study was to investigate the effects of dry heat treatment at two temperatures (121 and 14 °C) with three fractionation factors (S fraction < 200 μm, M fraction 200–250 μm and, L fraction > 300 μm) on sorghum flour chemical and functional properties, to optimize processes by means of a desirability function, and to characterize the optimal products. Treatment temperature negatively affected oil- and water-absorption capacity, protein and moisture contents, while the opposite trend was obtained for hydration capacity, swelling power, emulsifying properties, fat, ash, and carbohydrate content. Sorghum flour fractions positively influenced the hydration and water-retention capacities, emulsifying properties, and protein and carbohydrate content, while oil absorption, swelling power, fat, ash, and moisture were negatively affected. The optimal processing determined for each fraction was heat treatment at 121.00 °C for S fraction, 132.11 °C for M, and 139.47 °C for L. Optimal product characterization revealed that the color, bioactive properties, and protein and starch structures of the optimal samples had changed after heat treatment, depending on the fraction. These findings could be helpful for the cereal industry, since sorghum flour could be an alternative for conventional crops for the development of new products, such as snacks, baked goods, and pasta.

Sorghum-Phosphate Solubilizers Interactions: Crop Nutrition, Biotic Stress Alleviation, and Yield Optimization

Sweet sorghum [Sorghum bicolor (L.) Moench] is a highly productive, gluten-free cereal crop plant that can be used as an alternative energy resource, human food, and livestock feed or for biofuel-ethanol production. Phosphate fertilization is a common practice to optimize sorghum yield but because of high cost, environmental hazards, and soil fertility reduction, the use of chemical P fertilizer is discouraged. Due to this, the impetus to search for an inexpensive and eco-friendly microbiome as an alternative to chemical P biofertilizer has been increased. Microbial formulations, especially phosphate solubilizing microbiome (PSM) either alone or in synergism with other rhizobacteria, modify the soil nutrient pool and augment the growth, P nutrition, and yield of sorghum. The use of PSM in sorghum disease management reduces the dependence on pesticides employed to control the phytopathogens damage. The role of PSM in the sorghum cultivation system is, however, relatively unresearched. In this manuscript, the diversity and the strategies adopted by PSM to expedite sorghum yield are reviewed, including the nutritional importance of sorghum in human health and the mechanism of P solubilization by PSM. Also, the impact of solo or composite inoculations of biological enhancers (PSM) with nitrogen fixers or arbuscular mycorrhizal fungi is explained. The approaches employed by PSM to control sorghum phytopathogens are highlighted. The simultaneous bio-enhancing and biocontrol activity of the PS microbiome provides better options for the replacement of chemical P fertilizers and pesticide application in sustainable sorghum production practices.

Improving abiotic stress tolerance in sorghum: focus on the nutrient transporters and marker-assisted breeding

Identification of molecular markers and characterization of nutrient transporters could help to improve the tolerance under abiotic and low nutrient stresses in sorghum ensuring higher yield to conserve food security Sorghum is an important cereal crop delivering food and energy security in the semi-arid tropics of the world. Adverse climatic conditions induced by global warming and low input agriculture system in developing countries demand for the improvement of sorghum to tolerate various abiotic stresses. In this review, we discuss the application of marker-assisted breeding and nutrient transporter characterization studies targeted towards improving the tolerance of sorghum under drought, salinity, cold, low phosphate and nitrogen stresses. Family members of some nutrient transporters such as nitrate transporter (NRT), phosphate transporter (PHT) and sulphate transporter (SULTR) were identified and characterized for improving the low nutrient stress tolerance in sorghum. Several quantitative trait loci (QTL) were identified for drought, salinity and cold stresses with an intention to enhance the tolerance of sorghum under these stresses. A very few QTL and nutrient transporters have been identified and validated under low nitrogen and phosphorus stresses compared to those under drought, salinity and cold stresses. Marker-assisted breeding and nutrient transporter characterization have not yet been attempted in sorghum under other macro- and micro-nutrient stresses. We hope this review will raise awareness among plant breeders, scientists and biotechnologists about the importance of sorghum and need to conduct the studies on marker-assisted breeding and nutrient transporter under low nutrient stresses to improve the sorghum production.

Effect of Tempering Conditions on White Sorghum Milling, Flour, and Bread Properties

The effects of room temperature water, hot water, and steam tempering methods were investigated on sorghum kernel physical properties, milling, flour, and bread-making properties. Overall tempering condition and tempering moisture content were found to have a significant effect on the physical properties. Milling properties were evaluated using a laboratory-scale roller milling flowsheet consisting of four break rolls and eight reduction rolls. Room temperature tempering (18% moisture for 24 h) led to better separation of bran and endosperm without negatively impacting flour quality characteristics i.e., particle size distribution, flour yield, protein, ash, damaged starch, and moisture content. Bread produced from the flour obtained from milling sorghum kernels tempered with room temperature water (18% m.c for 24 h) and hot water (16% m.c at 60 °C for 18 h) displayed better bread-making properties i.e., high firmness, resilience, volume index, higher number of cells, and thinner cell walls when compared to other tempering conditions. Room temperature water tempering treatment (18% m.c for 24 h) could be a better pretreatment process for milling white sorghum kernels without negatively impacting the flour and bread-making quality characteristics.

Integrating Omics and Gene Editing Tools for Rapid Improvement of Traditional Food Plants for Diversified and Sustainable Food Security

Indigenous communities across the globe, especially in rural areas, consume locally available plants known as Traditional Food Plants (TFPs) for their nutritional and health-related needs. Recent research shows that many TFPs are highly nutritious as they contain health beneficial metabolites, vitamins, mineral elements and other nutrients. Excessive reliance on the mainstream staple crops has its own disadvantages. Traditional food plants are nowadays considered important crops of the future and can act as supplementary foods for the burgeoning global population. They can also act as emergency foods in situations such as COVID-19 and in times of other pandemics. The current situation necessitates locally available alternative nutritious TFPs for sustainable food production. To increase the cultivation or improve the traits in TFPs, it is essential to understand the molecular basis of the genes that regulate some important traits such as nutritional components and resilience to biotic and abiotic stresses. The integrated use of modern omics and gene editing technologies provide great opportunities to better understand the genetic and molecular basis of superior nutrient content, climate-resilient traits and adaptation to local agroclimatic zones. Recently, realizing the importance and benefits of TFPs, scientists have shown interest in the prospection and sequencing of TFPs for their improvements, cultivation and mainstreaming. Integrated omics such as genomics, transcriptomics, proteomics, metabolomics and ionomics are successfully used in plants and have provided a comprehensive understanding of gene-protein-metabolite networks. Combined use of omics and editing tools has led to successful editing of beneficial traits in several TFPs. This suggests that there is ample scope for improvement of TFPs for sustainable food production. In this article, we highlight the importance, scope and progress towards improvement of TFPs for valuable traits by integrated use of omics and gene editing techniques.

Chemical and Physical Characterization of Sorghum Milling Fractions and Sorghum Whole Meal Flours Obtained via Stone or Roller Milling

Due to climate change sorghum might gain widespread in the Western countries, as the grain is adapted to hot climate. Additionally sorghum contains a notable amount of health-promoting nutrients. However, Western countries do not have a long history of sorghum consumption, and thus little experience in processing it. Milling systems in these areas were mostly developed for wheat or rye milling. In the present work, the effectiveness of sorghum milling when using a stone and a roller milling system (pilot scale) was investigated as well as its impact on the chemical and physical properties of the obtained flour fractions and whole-grain flours. Results showed that both milling systems could be successfully adapted to producing chemically and physically distinct flour and bran fractions from the small sorghum kernels. Fractions with increased bran material that contained higher amounts of ash, protein, fat, total dietary fiber, and total phenolic content but less starch, showed enhanced water absorption indices and water solubility indices. Interestingly, no significant difference was found in the ash and fat content of the different fractions obtained from stone milling. Overall, the study provided information on the production and composition of distinct flour fractions, which offer a wider range of future food applications.

Sprouting of Sorghum (Sorghum bicolor [L.] Moench): Effect of Drying Treatment on Protein and Starch Features

The nutritional and physicochemical properties of sorghum proteins and starch make the use of this cereal for food production challenging. Sprouting is a cost-effective technology to improve the nutritional and functional profile of grains. Two drying treatments were used after sorghum sprouting to investigate whether the drying phase could improve the protein and starch functionalities. Results showed that the drying treatment at lower temperature/longer time (40 °C for 12 h) extended the enzymatic activity that started during sprouting compared to the one performed at higher temperature/shorter time (50 °C for 6 h). An increased protein hydrolysis and water- and oil-holding capacity were found in the flour obtained by the former treatment. Higher protein matrix hydrolysis caused high exposure of starch to enzymes, thus increasing its digestibility, while worsening the technological functionality. Overall, modulating drying conditions could represent a further way, in addition to sprouting, to improve sorghum flour’s nutritional profile.

Combined effects of hydroxypropylation and alcoholic alkaline treatment on structural, functional and rheological characteristics of sorghum and corn starches

This study describes the effects of hydroxypropylation (HP) on sorghum and corn cold water soluble (CWS) starches prepared via alcoholic alkaline treatment (AAT). Propylene oxide (5% and 12% on starch weight basis) was used to modify both sorghum and corn starches. SEM analysis revealed that HP modification prior to AAT altered the granular morphology of native CWS starches. The characteristic peaks at 2980.28 cm^-1 and 2979.87 cm^-1 indicated the presence of hydroxypropyl groups and the complete loss of the granular order for HS12-CWS (hydroxypropylated sorghum CWS starch treated with 12% propylene oxide based on dry starch weight) and HC12-CWS (hydroxypropylated corn CWS starch treated with 12% propylene oxide based on dry starch weight) starches. Increase in swelling power and water binding capacity of HP modified CWS starches was observed. However, Percent transmittance was significantly reduced due to fragmented water-soluble granules. HP-modified CWS starch gels exhibited a more rigid gel network. Broader linear viscoelastic range suggesting greater stability and well dispersed behavior of HP-CWS starches. High G' values of HP-CWS starches were due to the ordered and elastic gel network that resisted deformation. Furthermore, all HP-CWS starches exhibited higher shear and thermal resistance compared to unmodified CWS starches.

Sorghum Pasta and Noodles: Technological and Nutritional Aspects

Sorghum is a major cereal crop with various agronomic advantages, contains health-promoting compounds and is gluten-free. There is a growing tendency to use sorghum in pasta and noodle formulations, which are among the most widely consumed products in the world, but its potential benefits in human diet are not being fully exploited. Here we review research carried out during the past few years on the use of sorghum as the main ingredient or as an additive in pasta and noodles, highlighting its properties and production technology. Pasta and noodles can be produced with 5 to 100% of sorghum at laboratory, pilot or industrial scale with suitable cooking and textural quality coupled with distinctive sensory attributes. Cooking loss shows minimum values of 0.85 and 1.9 g/100 g for pasta and noodles, respectively, and high water absorption (up to 345 g/100 g). The interesting nutritional profile of the products generally includes up to 45% resistant starch (RS) and phenolic compound content with high antioxidant activity. In addition, tannins decrease starch digestibility 15-20%, producing low glycemic index (GI) products (below 65). This is especially important for celiac people, offering them the alternative of gluten-free sorghum pasta and noodles.

Efficacy of compositing with snail meat powder on protein nutritional quality of sorghum-wheat buns using a rat bioassay

BACKGROUND

Protein energy malnutrition (PEM) is an important health burden in most developing countries mainly in sub-Saharan Africa, where it contributes to high rates of child morbidity and mortality. This study evaluated the efficacy of compositing with snail meat powder (SMP) on protein nutritional quality of sorghum-wheat buns using a rat bioassay. Nine diets -seven isonitrogenous diets, based on six variations of buns and a reference diet made using skimmed milk powder, in addition to the basal diet meant to estimate the endogenous nitrogen excretion and a 16% protein rehabilitation diet - were fed to male weanling albino rats. Protein efficiency ratio (PER), and food efficiency ratio (FER), net protein retention ratio (NPRR), apparent protein digestibility (APD), and true protein digestibility (TPD), protein digestibility corrected amino acid score (PDCAAS), and digestible indispensable amino acid score (DIAAS) indices of protein quality were determined.

RESULTS

Fortification with SMP significantly (P < 0.05) enhanced PER from 0.21% to 2.70%, FER from 0.02% to 0.27%, APD from 81.17% to 88.28%, and TPD from 87.48% to 95.38%. PDCAAS and DIAAS increased from 45% to 78% and 44% to 69% respectively in unfortified buns to buns fortified with 25% SMP.

CONCLUSION

Complementary diets fortified with SMP promote growth and rehabilitate emaciated rats, whereas unfortified diet did not support weight gain. Thus, supplementation of buns with SMP might enhance a faster recovery in children affected by PEM. © 2020 Society of Chemical Industry.

African Sorghum-Based Fermented Foods: Past, Current and Future Prospects

Sorghum (Sorghum bicolor) is a well-known drought and climate resistant crop with vast food use for the inhabitants of Africa and other developing countries. The importance of this crop is well reflected in its embedded benefits and use as a staple food, with fermentation playing a significant role in transforming this crop into an edible form. Although the majority of these fermented food products evolve from ethnic groups and rural communities, industrialization and the application of improved food processing techniques have led to the commercial success and viability of derived products. While some of these sorghum-based fermented food products still continue to bask in this success, much more still needs to be done to further explore evolving techniques, technologies and processes. The addition of other affordable nutrient sources in sorghum-based fermented foods is equally important, as this will effectively augment the intake of a nutritionally balanced product.

Proximate and antioxidant activities of bio-preserved ogi flour with garlic and ginger

Background: Ogi from locally available cereals remains a relatively affordable complementary food in West Africa, but has a tendency to spoil due it high moisture content. This study explored effects of garlic and ginger as biopreservatives in ogi flour. Methods:Ogi flour was prepared from sorghum and quality protein maize grains with different concentrations of garlic and ginger powder (2 and 4% w/w) by fermentation technique. These samples were stored for 16 weeks during which the total titratable acidity, pH, proximate composition, mineral content and total antioxidant activities were determined. Results: The proximate compositions of bio-preserved ogi samples were relatively stable throughout storage. The addition of garlic and ginger slightly increased the ash (0.04%), crude protein and mineral contents (mg/ 100g) of the samples.  Magnesium (10.85-13.13 and 5.17-9.72); zinc (1.37-1.78 and 7.01-8.50), manganese (1.30-1.71 and 0.45-0.86) and iron (1.53-1.77 and 0.68-2.77) contents increased on addition (of garlic and ginger) to maize ogi and sorghum ogi flours respectively. The free radical scavenging activity; total phenolic and flavonoid contents increased correspondingly with the antioxidants activity. Conclusion: Although not well known to ogi consumer, the bio-preserved ogi flours showed better nutritional values and have potential as a health food.

Proximate and antioxidant activities of bio-preserved ogi flour with garlic and ginger

Background: Ogi from locally available cereals remains a relatively affordable complementary food in West Africa, but has a tendency to spoil due it high moisture content. This study explored effects of garlic and ginger as biopreservatives in ogi flour. Methods:Ogi flour was prepared from sorghum and quality protein maize grains with different concentrations of garlic and ginger powder (2 and 4% w/w) by fermentation technique. These samples were stored for 16 weeks during which the total titratable acidity, pH, proximate composition, mineral content and total antioxidant activities were determined. Results: The proximate compositions of bio-preserved ogi samples were relatively stable throughout storage. The addition of garlic and ginger slightly increased the ash (0.04%), crude protein and mineral contents (mg/ 100g) of the samples.  Magnesium (10.85-13.13 and 5.17-9.72); zinc (1.37-1.78 and 7.01-8.50), manganese (1.30-1.71 and 0.45-0.86) and iron (1.53-1.77 and 0.68-2.77) contents increased on addition (of garlic and ginger) to maize ogi and sorghum ogi flours respectively. The free radical scavenging activity; total phenolic and flavonoid contents increased correspondingly with the antioxidants activity. Conclusion: Although not well known to ogi consumer, the bio-preserved ogi flours showed better nutritional values and have potential as a health food.

Variation in energy sorghum hybrid TX08001 biomass composition and lignin chemistry during development under irrigated and non-irrigated field conditions

This study was conducted to document the extent and basis of compositional variation of shoot biomass of the energy Sorghum bicolor hybrid TX08001 during development under field conditions. TX08001 is capable of accumulating ~40 Mg/ha of dry biomass under good growing conditions and this genotype allocates ~80% of its shoot biomass to stems. After 150 days of growth TX08001 stems had a fresh/dry weight ratio of ~3:1 and soluble biomass accounted for ~30% of stem biomass. A panel of diverse energy sorghum genotypes varied ~6-fold in the ratio of stem structural to soluble biomass after 150 days of growth. Near-infrared spectroscopic analysis (NIRS) showed that TX08001 leaves accumulated higher levels of protein, water extractives and ash compared to stems, which have higher sugar, cellulose, and lignin contents. TX08001 stem sucrose content varied during development, whereas the composition of TX08001 stem cell walls, which consisted of ~45–49% cellulose, ~27–30% xylan, and ~15–18% lignin, remained constant after 90 days post emergence until the end of the growing season (180 days). TX08001 and Della stem syringyl (S)/guaiacyl (G) (0.53–0.58) and ferulic acid (FA)/para-coumaric acid (pCA) ratios were similar whereas ratios of pCA/(S+G) differed between these genotypes. Additionally, an analysis of irrigated versus non-irrigated TX08001 revealed that non-irrigated hybrids exhibited a 50% reduction in total cell wall biomass, an ~2-fold increase in stem sugars, and an ~25% increase in water extractives relative to irrigated hybrids. This study provides a baseline of information to help guide further optimization of energy sorghum composition for various end-uses.

Storage influence on the functional, sensory and keeping quality of quality protein maize flour

Apart from nutritional values functional and sensory properties affect the behavior of food system and its acceptability for consumption during storage. Hence keeping quality of maize flour (HQPM-7) with and without lime treatment(control) was studied in terms of functional (bulk density, pH, swelling capacity, water and oil absorption capacity, least gelation concentration, peroxide value), sensory (appearance, color, taste, texture, mouth feel and overall acceptability) and rolling parameters (water absorption by flour, rolling quality, diameter after baking ) for a period of 6 months under room temperature (25 ± 5 °C) in two types of packages viz, LDPE cover (P) and plastic box (B). Physical parameters such as length, breadth and thickness (11.26-10.52 mm, 9.67-9.14 mm, & 4.72-3.95 mm) were reduced in lime treated grains compared to control. Significant increase (p ≤ 0.05) in ash content of lime treated flour (1.67 ± 0.01 g) was observed compared to control (1.5 ± 0.02 g). Calcium content of lime treated maize flour increased significantly (p ≤ 0.05) from 48 to 136 mg. There is a significant reduction in functional properties of flour after 3 and 2 months irrespective in polyethylene cover and plastic box. The properties like rolling quality, diameter after baking and water uptake by the flour were reduced significantly (p ≤ 0.05) after 4 months of storage in treated and after 1 month in control samples. Sensory scores of roti (dry pan cake) decreased significantly after 3 months of storage with an overall acceptability score of 4.0 and 3.4. In control samples mean taste (3.6), mouth feel (3.8) as well as OAA scores (3.8) decreased after second month. Hence lime treated maize flour with added nutritional benefits is suitable for making rotis of good palatability and can be stored in LDPE covers up to 3 months.

Effect of roasting on rheological and functional properties of sorghum flour

In this study, the effect of grain moisture content (12–20%), temperature (140–180 ℃), and time (5–15 min) of roasting on the quality attributes of sorghum grain was studied. The response functions were rheological attributes of powder flowability, color, water absorption capacity, and sensory acceptability. These response functions could be correlated ( r ≥ 0.91, p ≤ 0.01) with the independent variables by second order polynomials. Higher temperature and longer roasting time had a detrimental effect on color and sensory acceptability of product. An increase in moisture content of grain induced lower cohesion characteristics in the flour as evidenced by less energy for compression. Raw sorghum flour exhibited highest peak viscosity of 297 BU compared to only 32–71 BU for roasted samples. Roasted sorghum flour exhibited less shear-thinning phenomenon compared to raw sample, and was more stable towards retrogradation. Optimum condition for maximum sensory acceptability was achieved with a grain moisture content of 16–20% and temperature 161–179 ℃ for 12 min of roasting.