Sorghum Grain: From Genotype, Nutrition, and Phenolic Profile to Its Health Benefits and Food Applications

Genetics of sorghum: grain quality, molecular aspects, and drought responses

MAIN CONCLUSION

Sorghum kernel composition is a crucial characteristic that determines its functional qualities. The total protein content of sorghum grain increases under drought stress, but starch, protein digestibility, and micronutrient contents decrease. Sorghum (Sorghum bicolor L.) is a staple source of starch, protein, and micronutrients in Ethiopia, where it is a key ingredient in local foods like injera and traditional beverages such as tela and areke. It has adapted remarkably to the diverse climatic conditions and soils of both highland and lowland regions. However, grain quality is influenced by climate change, drought stress, and genotype-environment interactions. Under drought conditions, sorghum shows reduced starch content, protein digestibility, and micronutrient levels, as well as increased kernel hardness and total protein content. The genetic and geographic diversity of sorghum makes it an adaptable crop, essential for breeding and diversity studies. Genome-wide association studies (GWAS) have emerged as essential tools for identifying candidate genes linked to key traits, thereby advancing genetic improvement initiatives, particularly for Ethiopian sorghum landraces. Advances in genotyping techniques, particularly genotyping-by-sequencing (GBS) and association mapping, have facilitated the identification of quantitative trait loci (QTL) associated with grain quality, enhancing breeding efficiency and the development of resilient, high-quality sorghum varieties. This review explored the genetic and phenotypic diversity of sorghum, focusing on grain quality traits, molecular mechanisms, and responses to drought stress.

Dynamic Metabolomic Changes in the Phenolic Compound Profile and Antioxidant Activity in Developmental Sorghum Grains

Phenolic compounds (PC) were analyzed by UHPLC-ESI-QTOF-MSE in two sorghum genotypes, harvested in two growing seasons (GS) at five distinct days after flowering (DAF) to evaluate how genotype/GS influences the PC synthesis and antioxidant capacity during grain growth. Total phenolic contents were strongly correlated with antioxidant capacity (r > 0.9, p < 0.05). Globally, 97 PC were annotated, including 20 PC found irrespective of the grain developmental stage and genotype/GS. The phenolic profile clearly differs between stages: phenolic acids were the most abundant class in early stages (50%), and flavonoid accumulation becomes predominant in late ones (3/5 of total ion abundance). Dimeric and trimeric tannins were identified even in 10DAF grains. Chemometry revealed great PC variability between genotypes (27%) and important biomarkers of GS differentiation (e.g., ferulic acid). This work can input open databases of PC and paves the way to understand biosynthetic pathways of PC in sorghum and future sorghum selection.

Sorghum starch review: Structural properties, interactions with proteins and polyphenols, and modification of physicochemical properties

Sorghum, a gluten-free carbohydrate source with high antioxidants and resistant starch, contains anti-nutrients like phytic acid, tannin, and kafirin. Interactions with starch and proteins result in polyphenol-starch, starch-kafirin, and tannin-protein complexes. These interactions yield responses such as V-type amylose inclusion complexes, increased hydrophobic residues, and enzyme resistance, reducing nutrient availability and elevating resistant starch levels. Factors influencing these interactions include starch composition, structure, and Chain Length Distribution (CLD). Starch structure is impacted by enzymes like ADP-glucose pyrophosphorylase, starch synthases, and debranching enzymes, leading to varied chain lengths and distributions. CLD differences significantly affect crystallinity and physicochemical properties of sorghum starch. Despite its potential, the minimal utilization of sorghum starch in food is attributed to anti-nutrient interactions. Various modification approaches, either direct or indirect, offer diverse physicochemical changes with distinct advantages and disadvantages, presenting opportunities to enhance sorghum starch applications in the food industry.

Sorghum grain as a bio-template: emerging, cost-effective, and metal-free synthesis of C-doped g-C3N4 for photo-degradation of antibiotic, bisphenol A (BPA), and phenol under solar light irradiation

Due to the industry's rapid growth, the presence of organic pollutants, especially antibiotics, in water and wastewater resources is the main concern for wildlife and human health. Therefore, these days, a significant challenge is developing an efficient, sustainable, and eco-friendly photocatalyst. Natural biological models have numerous advantages compared to artificial model materials. Biological models with unique multi-level structures and morphology can be used to create porous bio-templates to produce hierarchical materials. So, in this work, for the first time, this was achieved by using sorghum grain seeds as a bio-template (natural waste material) and urea as a precursor, through a simple and environmentally friendly method. We believed that natural waste materials with high carbon atom content could be used as both a carbon doping agent and a bio-template, thus improving the physical and optical properties of the resulting materials. In comparison to previous studies on the synthesis of C-doped g-C3N4, our work offers a greener and more cost-effective approach to synthesis, while also reducing waste material. We succeeded in the photo-degradation of a series of organic pollutants such as phenol, bisphenol A (BPA), and amoxicillin (AMX) in an aqueous solution under solar light illumination.

Current and potential future uses of sorghum to increase nutrient density for human foods

This review attempts to set forth the current uses and benefits of sorghum ingredients (sorghum syrup, grain, and flour) and implications for future potential uses of sorghum for human consumption. Additionally, this review aims to direct future innovation, research, and development for this grain in all forms, with a particular focus on increasing the nutritional quality of food for human onsumption. Sorghum is an ancient grain that has been underutilized in terms of its nutrient and antioxidant density and functional properties. Sorghum syrup is a sweetener that has a complex flavor profile lending a harmonious balance of sweet and savory in product formulations and provides a lower glycemic index and a higher antioxidant content compared to other commonly used sweeteners. Sorghum syrup has great potential uses within the beverage category, specifically coffee, as a clean-label sweetener with a complex flavor profile. Currently, with growing interest in gluten-free alcohol, specialty brews, and sorghum's shorter growing season compared to barley and wheat, sorghum grain is being used more frequently in alcohol and no- and low-alcohol beverage production. Additionally, sorghum grain is being utilized in products as a non-wheat, nutrient-dense baking grain that has a glycemic index lower than wheat, is high in resistant starch, and contains significantly more antioxidants. Other potential applications for sorghum ingredients include a non-synthetic food dye and a sustainable and biodegradable alternative to plastic films and coatings for foods. Sorghum should be considered an ingredient in product formulation, especially in light of its ability to withstand drought and high temperatures seen in global warming.

Gastrointestinal Health Benefits of Sorghum Phenolics

Sorghum is considered a promising food security crop and remarkable rich source of bioactive components including phenolic acids, flavonoids, and tannins. Sorghum phenolics exhibited numerous protective effects against multiple chronic diseases. However, there is no review of the effects of sorghum phenolics on gastrointestinal (GI) health. Specifically, recent studies have highly suggested that sorghum phenolics can maintain gastrointestinal homeostasis and enhance microbial diversity and richness. Furthermore, sorghum phenolics showed GI anticancer effects in both in vitro and in vivo studies against colorectal and esophageal cancers. Treatment of GI related human cancer cell lines stimulated apoptosis and suppressed proliferation. Sorghum intake and extracts treatments reduced intestinal oxidative stress and inflammatory mediators in human and in vivo studies. In addition, understanding the role and mechanisms underlying gastrointestinal health benefits of sorghum phenolics is crucial to determine treatment strategies of different GI diseases.

Effect of electro-stimulated Bacillus subtilis and Lactobacillus casei on ensiling quality, anti-nutrients, and bacterial community of mulberry leaf silage

BACKGROUND

There are few studies on the effects of electrically stimulated bacteria on anti-nutritional factors and microbial communities in mulberry leaf silage. This study aimed to examine the impact of the combined use of electrically stimulated Bacillus subtilis (EB) and Lactobacillus casei (LC) on the quality and degradation of anti-nutritional factors in mulberry leaf silage.

RESULTS

The results revealed that the synergistic effect of EB and LC significantly enhanced the nutritional value of mulberry leaves, as evidenced by the promotion of lactic acid synthesis, the reduction of anti-nutritional factors, and the augmentation of lactic acid bacteria following a 60-day silage period. Moreover, the EB + LC co-inoculation resulted in the highest quality of mulberry leaf silage, with the degradation rates of tannin and phytic acid at 38.8% and 47.1%, respectively. The combination of EB + LC also enhanced lactic acid content, along with significant reductions in ammonia nitrogen (NH3-N), soluble protein, and non-protein nitrogen (NPN) (P < 0.05). Spearman correlation analysis showed that Lactobacillus in the silage was significantly positively correlated with crude protein (CP) and lactic acid, while negatively correlated with water-soluble carbohydrates, pH and NPN (P < 0.05). In contrast, Weissella was significantly negatively correlated with CP and lactic acid.

CONCLUSION

This study represents a pioneering application of electro-stimulation in the field of feed silage, offering a scientifically substantiated approach to degrading anti-nutritional factors in mulberry leaves for livestock feeding. © 2024 Society of Chemical Industry.

Effect of In Vitro Gastrointestinal Digestion on the Polyphenol Bioaccessibility and Bioavailability of Processed Sorghum (Sorghum bicolor L. Moench)

Sorghum is a significant source of polyphenols, whose content, antioxidant properties and bioaccessibility may be modulated by digestion. Studies have reported sorghum polyphenol changes after simulated digestion. However, the effects of simulated digestion on processed, pigmented sorghum are unknown. This study investigated the bioaccessibility and bioavailability of black (BlackSs and BlackSb), red (RedBa1, RedBu1, RedBa2, RedBu2) and white (WhiteLi2 and White Li2) sorghum samples using a Caco-2 in vitro model. Ultra high performance liquid chromatography-online 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (UHPLC-online ABTS)-and quadrupole time-of-flight liquid chromatography mass spectra (QTOF LC-MS) facilitated the identification of digested and transported compounds. Simulated digestion showed increased bioaccessibility and total phenolic content (TPC) for BlackSs by 2-fold. BlackSs and BlackSb exhibited high antioxidant capacities, with variations dependent on processing in other varieties. Kaempferol-3-O-xyloside exhibited a 4-fold increase in TPC following digestion of processed BlackSs and BlackSb but was absent in the others. BlackSs, BlackSb, and RedBu1 revealed twelve bioaccessible and Caco-2 transported compounds not previously reported in sorghum, including trans-pinostilbene, tryptophan and maackin a. This study demonstrates that in vitro digestion increases the bioaccessiblity of sorghum polyphenols through the process of cellular biotransformation, possibly improving transport and bioactivity in vivo.

Harnessing the nutritional profile and health benefits of millets: a solution to global food security problems

India is dealing with both nutritional and agricultural issues. The maximum area of agricultural land with irrigation capabilities has been largely utilized, while the amount of dry land is expanding. The influence is distinct on farmer's livelihoods and earnings, which ultimately affects nutritional security. In order to attain nutritional security and the goal of SDG (Sustainable Development Goals), millets are sustainable solutions, with respect to high nutritional content, bioactive and medicinal properties, and climate resilience. The nutrient profile of millet includes 60%-70% carbohydrate content, 3.5%-5.2% fat, and 7.52%-12.1% protein sources. A wide spectrum of amino acids, including cysteine, isoleucine, arginine, leucine, tryptophan, lysine, histidine, methionine, tyrosine, phenylalanine, threonine, and valine are generally present in millets. Mineral content in millets includes calcium, phosphorus, potassium, sodium, and magnesium. Additionally, millets are an excellent source of bioactive molecules such as polyphenol, phenolic acid, flavonoids, active peptides, and soluble fiber, which have a wide range of therapeutic applications, including the prevention of free radical damage, diabetes, anti-microbial, anti- biofilm, and anti-cancer effects. This review will focus on the nutritional profile and health benefits of millet considering the present-day food security problems.

Tracking the changes and bioaccessibility of phenolic compounds of sorghum grains (Sorghum bicolor (L.) Moench) upon germination and seedling growth by UHPLC-QTOF-MS/MS

In this study, phenolic profile/content was analyzed by high-resolution untargeted metabolomics after short germination (72 h) and seedling growth (144 h), using three sorghum genotypes varying in tannin content (IS 29569, Macia and IS 30400). In vitro antioxidant capacity and phenolic bioaccessibility were determined by microplate-based and INFOGEST methods, respectively. A total of 58 % annotated compounds were found in all genotypes; and phenolic acids and flavonoids represent more than 80 % of sorghum total abundance. PCA analysis showed higher phenolic variability in germination times (72 %) than genotypes (51 %). Germination reduced total ion abundance (-7 %) and free:bound phenolic compounds ratio (2.4-1.1), but antioxidant capacity remained constant. These results indicate the cell matrix-phenolic decomplexation, with the free compounds were quickly consumed after radicle emergence. Germination increased phenolic bioaccessibility (mainly in oral phase) but reduces flavonoids contents in gastric/intestinal digestion steps. This work can stimulate seed germination as a viable option for sorghum-based foods development, with improved nutritional and bioactive properties.

A review of appropriate mechanisation systems for sustainable traditional grain production by smallholder farmers in sub-Saharan Africa with particular reference to Zimbabwe

Climate change and variability is affecting the production of maize, a staple food in Zimbabwe, leading to the advocacy for production of traditional grains (sorghum, pearl millet and finger millet) as complementary crops for food and nutrition security; mainly because of their drought tolerance. Adoption of traditional grains as a climate change adaptation strategy is, however, limited by lack of appropriate field mechanisation technologies, inter alia. The specific objective of this review was to examine the field mechanisation technologies being used in different farming systems across the globe for their appropriateness in smallholder traditional grain production systems in developing countries, using Zimbabwe as an example, and focusing on the prevailing technical, socio-economic and environmental factors which influence sustainable adoption. The review was conducted by searching ScienceDirect, Researchgate, JSTOR, Springer, AGORA and Google Scholar databases for mechanisation strategies, policies, machinery and equipment used in cereal production systems across the globe. The review revealed that the mechanisation of traditional grain production operations is lagging behind that of other cereals and that there is need to work on developing appropriate mechanisation systems for smallholder farmers in developing countries. Various farm power options were analysed and the use of two-wheel tractors under service-provision was identified as the most suitable option. Conservation agriculture-based direct seeders and use of mowers or bio-pesticides are the best-suited technologies for crop establishment and weed control, respectively. In terms of harvesting, no available equipment can be recommended for smallholder use as yet. Further research is required to optimize the practical application of mowers and bio-pesticides as well as develop scale-based direct seeders and harvesting equipment. Policy issues were identified and recommendations for improvement made. The findings of the current study can be adapted by other sub-Sahara Africa countries where farming systems, priorities and challenges are similar to that of Zimbabwe.

Unveiling the potential of African fermented cereal-based beverages: Probiotics, functional drinks, health benefits and bioactive components

Traditionally, dairy products have been the primary medium for delivering probiotics to humans. However, despite their numerous health benefits, such as nutrient supply and prevention and treatment of certain diseases, there are limitations to their use in many regions, including Africa. These limitations arise from allergens, lactose intolerance, hypercholesterolemia effects, the need for vegetarian options, cultural food taboos against milk, and religious beliefs. As a result, research efforts worldwide have focused on probiotics with health benefits. To address this issue, an integrative approach has been adopted, consolidating ideas and concepts from various studies. Researchers have explored different food matrices to determine their potential as probiotic carriers, specifically emphasizing cereals and cereal products. Studies have revealed that traditional African fermented cereal-based beverages show promise as probiotic carriers due to the presence of probiotic organisms involved in the fermentation process. This presents an opportunity to utilize African cereal beverages to deliver. This review paper provides comprehensive information on probiotics, including their sources, types, health benefits, and delivery vehicles. Specifically, it highlights the challenges and prospects for developing and consuming cereal-based probiotics in Africa. This opens up new avenues for providing probiotic benefits to a broader African population and contributes to the advancement of probiotic research and development in the region.

Physiological potential of different Sorghum bicolor varieties depending on their bioactive characteristics and antioxidant potential as well as different extraction methods

A comprehensive study of sorghum bran and flour was performed to explore the secondary metabolite profiles of differently coloured genotypes and to evaluate the variability in the antioxidant properties based on differences in polarity and solubility. This research included one red variety and one white variety. Among the samples, the red variety contained significantly greater amounts of secondary metabolites than did the white variety, with total polyphenol contents of 808.04 ± 63.89 mg.100 g-1 and 81.56 ± 3.87 mg.100 g-1, respectively. High-molecular-weight condensed tannin-type flavonoid extracts with high antioxidant activity were obtained by using relatively low-polarity acetone-water solvents, which was reflected by the measured antioxidant values. Among the methods used, the electron-donating Trolox equivalent antioxidant assay provided the highest antioxidant capacity, with values ranging from 118.5 to 182.6 μmol g-1 in the case of the red variety, in accordance with the electron donor properties of condensed tannins. Key secondary metabolites were identified using MS techniques and quantified using HPLC. Catechin and procyanidin B1 were found in the red variety at concentrations of 3.20 and 96.11 mg.100 g-1, respectively, while the concentrations in the white variety were under the limit of detection. All four tocopherols were found in sorghum, with the red variety containing a higher amount than the white variety, but the vitamin B complex concentrations were higher in the white variety. Overall, the red sorghum variety proved to be a better source of secondary metabolites with potential health benefits and could be used as a nutrient-rich food source.

Impact of Processing on the Phenolic Content and Antioxidant Activity of Sorghum bicolor L. Moench

Sorghum, a cereal grain rich in nutrients, is a major source of phenolic compounds that can be altered by different processes, thereby modulating their phenolic content and antioxidant properties. Previous studies have characterised phenolic compounds from pigmented and non-pigmented varieties. However, the impact of processing via the cooking and fermentation of these varieties remains unknown. Wholegrain flour samples of Liberty (WhiteLi1 and WhiteLi2), Bazley (RedBa1 and RedBa2), Buster (RedBu1 and RedBu2), Shawaya black (BlackSb), and Shawaya short black 1 (BlackSs) were cooked, fermented, or both then extracted using acidified acetone. The polyphenol profiles were analysed using a UHPLC-Online ABTS and QTOF LC-MS system. The results demonstrated that combining the fermentation and cooking of the BlackSs and BlackSb varieties led to a significant increase (p < 0.05) in total phenolic content (TPC) and antioxidant activities, as determined through DPPH, FRAP, and ABTS assays. The 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity of WhiteLi1, BlackSb, RedBu2, and BlackSs increased by 46%, 32%, 25%, and 10%, respectively, post fermentation and cooking. Conversely, fermentation only or cooking generally resulted in lower phenolic content and antioxidant levels than when samples were fully processed compared to raw. Notably, most of the detected antioxidant peaks (53 phenolic compounds) were only detected in fermented and cooked black and red pericarp varieties. The phenolic compounds with the highest antioxidant activities in pigmented sorghum included 3-aminobenzoic acid, 4-acetylburtyic acid, malic acid, caffeic acid, and luteolin derivative. Furthermore, the growing location of Bellata, NSW, showed more detectable phenolic compounds following processing compared to Croppa Creek, NSW. This study demonstrates that sorghum processing releases previously inaccessible polyphenols, making them available for human consumption and potentially providing added health-promoting properties.

Effect of water content on gelatinization functionality of flour from sprouted sorghum

Sorghum starch granules are encapsulated in a rigid protein matrix that prevents the granules from fully swelling and gelatinizing. Sprouting and subsequent drying treatment can affect the gelatinization properties of sorghum starch. This study aimed to evaluate the gelatinization properties of flours from unsprouted (US) and sprouted (S50, S40) sorghum dried at 50 °C (6h) and 40 °C (12h), respectively. Swelling power (Sp), thermal properties (DSC) and 1H molecular mobility and dynamics were evaluated at different water contents (38-91%). Sp increased with increasing water content, with S40 showing the lowest values, probably due to prolonged amylase activity and thus starch breakdown. Sprouting increased gelatinization temperatures; however, these differences disappeared for high water contents (82 and 91%). From a molecular point of view, sprouted samples showed a decrease in protons associated to the rigid protein matrix and starch structures. 1H CPMG results showed the presence of 4 populations at 38% water content. The evolution of the more mobile population with increasing water content supported the assignment of more mobile water fraction to this population. Sprouting decreased the mobility of populations in unheated samples, suggesting an increase in molecular bonds between flour biopolymers and water. After heating, however, increased molecular mobility in S40 indicated the formation of a weaker network between starch, protein, and water at the molecular level. These results suggest that post-sprouting drying treatment influences sorghum gelatinization, with potential modulation by water content. This study contributes to understanding the application of sprouted sorghum in foods with different moisture content.

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.

Advances in the novel and green-assisted techniques for extraction of bioactive compounds from millets: A comprehensive review

Millets are rich in nutritional and bioactive compounds, including polyphenols and flavonoids, and have the potential to combat malnutrition and various diseases. However, extracting these bioactive compounds can be challenging, as conventional methods are energy-intensive and can lead to thermal degradation. Green-assisted techniques have emerged as promising methods for sustainable and efficient extraction. This review explores recent trends in employing green-assisted techniques for extracting bioactive compounds from millets, and potential applications in the food and pharmaceutical industries. The objective is to evaluate and comprehend the parameters involved in different extraction methods, including energy efficiency, extraction yield, and the preservation of compound quality. The potential synergies achieved by integrating multiple extraction methods, and optimizing extraction efficiency for millet applications are also discussed. Among several, Ultrasound and Microwave-assisted extraction stand out for their rapidity, although there is a need for further research in the context of minor millets. Enzyme-assisted extraction, with its low energy input and ability to handle complex matrices, holds significant potential. Pulsed electric field-assisted extraction, despite being a non-thermal approach, requires further optimization for millet-specific applications, are few highlights. The review emphasizes the importance of considering specific compound characteristics, extraction efficiency, purity requirements, and operational costs when selecting an ideal technique. Ongoing research aims to optimize novel extraction processes for millets and their byproducts, offering promising applications in the development of millet-based nutraceutical food products. Therefore, the current study benefits researchers and industries to advance extraction research and develop efficient, sustainable, and scalable techniques to extract bioactive compounds from millets.

Production of cost-competitive bioethanol and value-added co-products from distillers' grains: Techno-economic evaluation and environmental impact analysis

Here, Baijiu distillers' grains (BDGs) were employed in biorefinery development to generate value-added co-products and bioethanol. Through ethyl acetate extraction at a 1:6 solid-liquid ratio for 10 h, significant results were achieved, including 100 % lactic acid and 92 % phenolics recovery. The remaining BDGs also achieved 99 % glucan recovery and 81 % glucan-to-glucose conversion. Simultaneous saccharification and fermentation of remaining BDGs at 30 % loading resulted in 78.5 g bioethanol/L with a yield of 94 %. The minimum selling price of bioethanol varies from $0.149-$0.836/kg, contingent on the co-product market prices. The biorefinery processing of one ton of BDGs caused a 60 % reduction in greenhouse gas emissions compared to that of the traditional production of 88 kg corn-lactic acid, 70 kg antioxidant phenolics, 234 kg soybean protein, and 225 kg corn-bioethanol, along with emissions from BDG landfilling. The biorefinery demonstrated a synergistic model of cost-effective bioethanol production and low-carbon emission BDGs treatment.

Interactions between proteins and phenolics: effects of food processing on the content and digestibility of phenolic compounds

Phenolic compounds have recently become one of the most interesting topics in different research areas, especially in food science and nutrition due to their health-promoting effects. Phenolic compounds are found together with macronutrients and micronutrients in foods and within several food systems. The coexistence of phenolics and other food components can lead to their interaction resulting in complex formation. This review article aims to cover the effects of thermal and non-thermal processing techniques on the protein-phenolic interaction especially focusing on the content and digestibility of phenolics by discussing recently published research articles. It is clear that the processing conditions and individual properties of phenolics and proteins are the most effective factors in the final content and intestinal fates of phenolic compounds. Besides, thermal and non-thermal treatments, such as high-pressure processing, pulsed electric field, cold plasma, ultrasonication, and fermentation may induce alterations  in those interactions. Still, new investigations are required for different food processing treatments by using a wide range of food products to enlighten new functional and healthier food product design, to provide the optimized processing conditions of foods for obtaining better quality, higher nutritional properties, and health benefits. © 2024 Society of Chemical Industry.

Bio-functional and prebiotics properties of products based on whole grain sorghum fermented with lactic acid bacteria

BACKGROUND

Products fermented with lactic acid bacteria based on whole grain flours of red or white sorghum (Sorghum bicolor (L.) Moench) added with malted sorghum flour, or with skim milk (SM) were developed. Composition, protein amino acid profile, total acidity, pH, prebiotic potential, and bio-functional properties after simulation of gastrointestinal digestion were evaluated.

RESULTS

In all cases, a pH of 4.5 was obtained in approximately 4.5 h. The products added with SM presented higher acidity. Products made only with sorghum presented higher total dietary fiber, but lower protein content than products with added SM, the last ones having higher lysine content. All products exhibited prebiotic potential, white sorghum being a better ingredient to promote the growth of probiotic bacteria. The addition of malted sorghum or SM significantly increased the bio-functional properties of the products: the sorghum fermented products added with SM presented the highest antioxidant (ABTS•+ inhibition, 4.7 ± 0.2 mM Trolox), antihypertensive (Angiotensin converting enzyme-I inhibition, 57.3 ± 0.5%) and antidiabetogenic (dipeptidyl-peptidase IV inhibition, 31.3 ± 2.1%) activities, while the products added with malted sorghum presented the highest antioxidant (reducing power, 1.6 ± 0.1 mg ascorbic acid equivalent/mL) and antidiabetogenic (α-amylase inhibition, 38.1 ± 0.9%) activities.

CONCLUSION

The fermented whole grain sorghum-based products could be commercially exploited by the food industry to expand the offer of the three high-growth markets: gluten-free products, plant-based products (products without SM), and functional foods. © 2023 Society of Chemical Industry.

Optimisation of multigrain seera from sorghum, green gram and finger millet: effect of ingredients on functional, structural and thermal properties

Seera, is a traditional Indian fermented food, has high carbohydrate and reducing sugar content, however, lacks functional components like antioxidant properties. The present study aims to optimize and evaluate the multigrain seera with added values. The optimization of seera was made using mixture design, with green gram (X1, 15-30%), sorghum (X2, 15-25%) and finger millet (X3, 5-10%) as independent variables. The responses checked were total phenolic content (Y1), protein content (Y2) and overall acceptability (Y3). The optimum run with green gram (25.58%), sorghum (15%) and finger millet (9.41%) resulted in TPC (1.2 ± 0.12 mg GAE/g), protein content (11.40 ± 0.10 g) with overall acceptability (8.32 ± 0.30). The optimized multigrain seera depicted higher fibre (4.23 ± 0.08%), ash (1.90 ± 1.1%) and protein (11.40 ± 0.10%) than the control seera. The rheological properties of seera depicted shear thinning and elastic behaviour. Texture profile analysis showed that cohesiveness (0.415 ± 0.01) increased significantly (along with decreased springiness (0.251). Morphology of seera showed broken and deformed starch granules with few cracks due to fermentation phenomena that leads to superficial corrosion.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05854-5.

Exploring the Impacts of Sorghum (Sorghum bicolor L. Moench) Germination on the Flour's Nutritional, Chemical, Bioactive, and Technological Properties

Germination is a natural, simple, and economical process used to improve the quality of nutritional and technological grains. In this study, native and sprouted sorghum flours were characterized regarding their technological properties (particle size distribution, water, and oil absorption capacity, swelling power and solubility, microscopy of starch granules, and pasting and thermal properties). Nutritional and phytochemical characterization profiles, including free sugars, fatty acids, organic acids, tocopherols, and phenolic compounds, were explored through chromatographic methods. The antioxidant, anti-inflammatory, and cytotoxic activities of the respective hydroethanolic extracts were also evaluated. The results showed that the germination process caused significant changes in the flour composition and properties, causing reduced gelatinization temperature and retarded starch retrogradation; an increased content of free sugars and total organic acids; and a decreased content of tocopherols and phenolic compounds. In terms of bioactivity, the sprouted sorghum flour extract showed better lipid-peroxidation-inhibition capacity and none of the extracts revealed hepatotoxicity or nephrotoxicity, which are important results for the validation of the use of the flours for food purposes. Germination is an efficient and alternative method for grain modification that gives improved technological properties without chemical modification or genetic engineering.

Bioconversion of cellulose and hemicellulose in corn cob into L-lactic acid and xylo-oligosaccharides

With the banning of antibiotic chemical feed additives, multi-functional bioactive feed additives have been extensively sought after by the feed industry. In this study, low-cost and renewable corn cobs were treated with liquid hot water and converted into bioactive xylo-oligosaccharides and L-lactic acid after enzymatic hydrolysis, strain activation, and fermentation under mild conditions, which achieved a full utilization of cellulose and hemicellulose in corn cobs. Simultaneous saccharification fermentation after strain activation with enzymatic hydrolysate delivered the highest conversion rate of glucose to L-lactic acid (93.00 %) and yielded 17.38 g/L L-lactic acid and 2.68 g/L xylo-oligosaccharides. On this basis, batch-feeding fermentation resulted in a 78.03 % conversion rate of glucose to L-lactic acid, 18.99 g/L L-lactic acid, and 2.84 g/L xylo-oligosaccharides. This work not only provided a green and clean bioconversion strategy to produce multi-functional feed additives but can also boost the full utilization of renewable and cheap biomass resources.

Potential roles of cereal bioactive compounds in the prevention and treatment of type 2 diabetes: A review of the current knowledge

Diabetes is one of the most common non-communicable diseases in both developed and underdeveloped countries with a 9.3% prevalence. Unhealthy diets and sedentary lifestyles are among the most common reasons for type 2 diabetes mellitus (T2DM). Diet plays a crucial role in both the etiology and treatment of T2DM. There are several recommendations regarding the carbohydrate intake of patients with T2DM. One of them is about reducing the total carbohydrate intake and/or changing the type of carbohydrate to reduce the glycaemic index. Cereals are good sources of carbohydrates in the diet with a significant amount of soluble and non-soluble fiber content. Apart from fiber, it has been shown that the bioactive compounds present in cereals such as proteins, phenolic compounds, carotenoids, and tocols have beneficial impacts in the prevention and treatment of T2DM. Moreover, cereal by-products especially the by-products of milling processes, which are bran and germ, have been reported to have anti-diabetic activities mainly because of their fiber and polyphenols content. Considering the potential functions of cereals in patients with T2DM, this review focuses on the roles of cereal bioactive compounds in the prevention and treatment of type 2 diabetes.

Sorghum: A Multipurpose Crop

Sorghum (Sorghum bicolor L.) is one of the top five cereal crops in the world in terms of production and planting area and is widely grown in areas with severe abiotic stresses such as drought and saline-alkali land due to its excellent stress resistance. Moreover, sorghum is a rare multipurpose crop that can be classified into grain sorghum, energy sorghum, and silage sorghum according to its domestication direction and utilization traits, endowing it with broad breeding and economic value. In this review, we mainly discuss the latest research progress and regulatory genes of agronomic traits of sorghum as a grain, energy, and silage crop, as well as the future improvement direction of multipurpose sorghum. We also emphasize the feasibility of cultivating multipurpose sorghum through genetic engineering methods by exploring potential targets using wild sorghum germplasm and genetic resources, as well as genomic resources.

Effect of Flour Particle Size on the Glycemic Index of Muffins Made from Whole Sorghum, Whole Corn, Brown Rice, Whole Wheat, or Refined Wheat Flours

The unique properties of sorghum are increasingly being studied for potential health benefits, with one area of emphasis being the impact of sorghum consumption on mitigating type 2 diabetes. The glycemic index (GI) of muffins made from whole grain sorghum flour ground to three different particle sizes (fine, intermediate, coarse) was tested on eight healthy volunteers (ages 18-40) and compared to the glycemic index of whole grain corn, wheat, and rice flours produced using a similar product formula. Sorghum flour ground through a 0.5 mm screen ("fine") had an overall similar particle size to that of the brown rice flour ground using a 0.5 mm screen. The range of GI values was 32 to 56, with only the GI of intermediate milled sorghum flour being lower than that of corn, rice, or wheat (p < 0.05). The lowest glycemic index (32 +/- 17) was found when using sorghum flour with an intermediate particle size (167 +/- 4 μm). Muffins made using brown rice had the next lowest glycemic index at 37 +/- 17. All GI values calculated had large standard deviations, which is common for these types of studies. These results can assist in the product development process to advance the quality of healthy, gluten-free sorghum-based foods for consumers. Further research should investigate if these results can be duplicated and the possible reason for the lower GI of intermediate particle size sorghum flour.

Effect of High-Hydrostatic-Pressure Treatment on the Physicochemical Properties of Kafirin

The kafirin derived from Jin Nuo 3 sorghum underwent a high-hydrostatic-pressure (HHP) treatment of 100, 300, and 600 MPa for 10 min to investigate alterations in its physicochemical attributes. The findings exhibited a reduction in protein solubility, declining from 83% to 62%, consequent to the application of the HHP treatment. However, this treatment did not lead to subunit-specific aggregation. The absorption intensity of UV light diminished, and the peak fluorescence absorption wavelength exhibited a shift from 342 nm to 344 nm, indicating an increased polarity within the amino acid microenvironment. In an aqueous solution, the specific surface area expanded from 294.2 m2/kg to 304.5 m2/kg, while the average particle-size value in a 70% ethanol solution rose to 26.3 nm. Conversely, the zeta-potential value decreased from 3.4 mV to 1.3 mV, suggesting a propensity for aggregation in ethanol solutions. A notable rise in the intermolecular β-sheet content to 21.06% was observed, along with a shift in the peak denaturation temperature from 76.33 °C to 86.33 °C. Additionally, the content of disulfide bonds increased to 14.5 μmol/g. Collectively, the application of the HHP treatment not only enhanced the thermal stability but also induced a more ordered secondary structure within the kafirin.

Assessment of yield performances for grain sorghum varieties by AMMI and GGE biplot analyses

Grain sorghum is an exceptional source of dietary nutrition with outstanding economic values. Breeding of grain sorghum can be slowed down by the occurrence of genotype × environment interactions (GEI) causing biased estimation of yield performance in multi-environments and therefore complicates direct phenotypic selection of superior genotypes. Multi-environment trials by randomized complete block design with three replications were performed on 13 newly developed grain sorghum varieties at seven test locations across China for two years. Additive main effects and multiplicative interaction (AMMI) and genotype + genotype × environment (GGE) biplot models were adopted to uncover GEI patterns and effectively identify high-yielding genotypes with stable performance across environments. Yield (YLD), plant height (PH), days to maturity (DTM), thousand seed weight (TSW), and panicle length (PL) were measured. Statistical analysis showed that target traits were influenced by significant GEI effects (p < 0.001), that broad-sense heritability estimates for these traits varied from 0.40 to 0.94 within the medium to high range, that AMMI and GGE biplot models captured more than 66.3% of total variance suggesting sufficient applicability of both analytic models, and that two genotypes, G3 (Liaoza No.52) and G10 (Jinza 110), were identified as the superior varieties while one genotype, G11 (Jinza 111), was the locally adapted variety. G3 was the most stable variety with highest yielding potential and G10 was second to G3 in average yield and stability whereas G11 had best adaptation only in one test location. We recommend G3 and G10 for the production in Shenyang, Chaoyang, Jinzhou, Jinzhong, Yulin, and Pingliang, while G11 for Yili.

Characteristics of Highland Barley-Wheat Composite Flour and Its Effect on the Properties of Coating Batter and Deep-Fried Meat

Highland barley flour-based coating batter has rarely been reported, although highland barley flour is promising due to its high β-glucan and amylose content. In this study, highland barley flour was used to substitute 40% to 80% of wheat flour to form a highland barely-wheat composite flour used in the coating batter. The characteristics of the highland barley-wheat composite flour and its effect on the properties of coating batter and deep-fried meat were analyzed. Results showed that the composite flour significantly improved water holding capacity, oil absorbing capacity, and water solubility index. In contrast, no significant change was observed in the water absorption index or swelling power. The incorporation of highland barley flour significantly changed the pasting properties of the composite flour. Compared with the wheat flour, the viscosity and the pickup of the coating batter made with composite flour increased from 4905 Pa·s and 0.53% to more than 12,252 Pa·s and 0.63%, respectively, and its water mobility decreased. These changes were closely related to the substitution rate of highland barley flour. The composite flour significantly increased the moisture content from 27.73% to more than 33.03% and decreased the oil content of the crust from 19.15% to lower than 16.44%, respectively. It decreased L* and increased a* of the crust and decreased the hardness, adhesiveness, and springiness of the deep-fried meat. A spongy inner structure with a flatter surface was formed in all composite flour-based crusts, and the substitution rate influenced the flatness of the crust. Thus, highland barley flour could be used for batter preparation with partial substitution, enhancing the quality of deep-fried meat and acting as an oil barrier-forming ingredient for fried batter foods.

Adult Ossabaw Pigs Prefer Fermented Sorghum Tea over Isocaloric Sweetened Water

Ossabaw pigs (n = 11; 5-gilts, 6-barrows; age 15.6 ± 0.62 SD months) were exposed to a three-choice preference maze to evaluate preference for fermented sorghum teas (FSTs). After conditioning, pigs were exposed, in four sessions, to choices of white FST, sumac FST, and roasted sumac-FST. Then, pigs were exposed, in three sessions, to choices of deionized H2O (-control; avoidance), isocaloric control (+control; deionized H2O and sucrose), and blended FST (3Tea) (equal portions: white, sumac, and roasted sumac). When tea type was evaluated, no clear preference behaviors for tea type were observed (p > 0.10). When the 3Tea and controls were evaluated, pigs consumed minimal control (p < 0.01;18.0 ± 2.21% SEM), and they consumed great but similar volumes of +control and 3Tea (96.6 and 99.0 ± 2.21% SEM, respectively). Likewise, head-in-bowl duration was the least for -control, but 3Tea was the greatest (p < 0.01; 5.6 and 31.9 ± 1.87% SEM, respectively). Head-in-bowl duration for +control was less than 3Tea (p < 0.01; 27.6 vs. 31.9 ± 1.87% SEM). Exploration duration was the greatest in the area with the -control (p < 0.01; 7.1 ± 1.45% SEM), but 3Tea and +control exploration were not different from each other (1.4 and 3.0 ± 1.45% SEM, respectively). Regardless of tea type, adult pigs show preference for FST, even over +control. Adult pigs likely prefer the complexity of flavors, rather than the sweetness alone.

A genome‑wide approach to the systematic and comprehensive analysis of LIM gene family in sorghum (Sorghum bicolor L.)

The LIM domain-containing proteins are dominantly found in plants and play a significant role in various biological processes such as gene transcription as well as actin cytoskeletal organization. Nevertheless, genome-wide identification as well as functional analysis of the LIM gene family have not yet been reported in the economically important plant sorghum (Sorghum bicolor L.). Therefore, we conducted an in silico identification and characterization of LIM genes in S. bicolor genome using integrated bioinformatics approaches. Based on phylogenetic tree analysis and conserved domain, we identified five LIM genes in S. bicolor (SbLIM) genome corresponding to Arabidopsis LIM (AtLIM) genes. The conserved domain, motif as well as gene structure analyses of the SbLIM gene family showed the similarity within the SbLIM and AtLIM members. The gene ontology (GO) enrichment study revealed that the candidate LIM genes are directly involved in cytoskeletal organization and various other important biological as well as molecular pathways. Some important families of regulating transcription factors such as ERF, MYB, WRKY, NAC, bZIP, C2H2, Dof, and G2-like were detected by analyzing their interaction network with identified SbLIM genes. The cis-acting regulatory elements related to predicted SbLIM genes were identified as responsive to light, hormones, stress, and other functions. The present study will provide valuable useful information about LIM genes in sorghum which would pave the way for the future study of functional pathways of candidate SbLIM genes as well as their regulatory factors in wet-lab experiments.

Sorghum (Sorghum bicolor L. Moench) Gluten-Free Bread: The Effect of Milling Conditions on the Technological Properties and In Vitro Bioaccessibility of Polyphenols and Minerals

The absence of gluten proteins in sorghum allows for the production of baked goods that are suitable for celiacs. Previous studies have shown that the milling process affects the performance of sorghum flour in baked products, especially those that are gluten-free (GF). This study aimed to explore the effects of mill type (impact and roller) on flour properties and GF bread quality by assessing the technological quality, antioxidant activity, and mineral content of the bread. All particle populations of flour obtained via both millings presented a bimodal distribution, and the volume mean diameter (D 4,3) ranged from 431.6 µm to 561.6 µm. The partially refined milled flour obtained via polishing and impact milling produced bread with a soft crumb, fewer but larger alveoli in the crumb, and a structure that did not collapse during baking, showing the best performance in bread quality. In the in vitro bread digestibility assay, the total polyphenol content and antioxidant activity decreased during the digestion steps. High mineral (Cu, Fe, Mn, and Zn) contents were also found in a portion of the bread (120 g) made with whole sorghum flour; however, their potential bioavailability was reduced in the presence of a higher amount of bran.

Exploring the potentials of sorghum genotypes: a comprehensive study on nutritional qualities, functional metabolites, and antioxidant capacities

Introduction

Sorghum, long regarded as one of the most underutilized crops, has received attention in recent years. As a result, conducting multidisciplinary studies on the potential and health benefits of sorghum resources is vital if they are to be fully exploited. In this study, the nutritional contents, functional metabolites, and antioxidant capacities of 23 sorghum breeding lines and three popular cultivars were assessed.

Materials and method

All of the sorghum genotypes were grown under the same conditions, and mature seeds were hand-harvested. The metabolite contents and antioxidant capacities of sorghum seeds were assessed using standard protocols. Fatty acids were quantified using a gas chromatography-flame ionization detector, whereas flavonoids and 3-deoxyanthocyanidins were analyzed using a liquid chromatography-tandem mass spectrometry method. The data were analyzed using both univariate and multivariate statistical approaches.

Results and discussion

Total protein (9.05-14.61%), total fat (2.99-6.91%), crude fiber (0.71-2.62%), dietary fiber (6.72-16.27%), total phenolic (0.92-10.38 mg GAE/g), and total tannin (0.68-434.22 mg CE/g) contents varied significantly across the sorghum genotypes (p < 0.05). Antioxidant capacity, measured using three assays, also differed significantly. Five fatty acids, including palmitic, stearic, oleic, linoleic, and linolenic acids, were found in all the sorghum genotypes with statistically different contents (p < 0.05). Furthermore, the majority of the sorghum genotypes contained four 3-deoxyanthocyanidins, including luteolinidin, apigeninidin, 5-methoxyluteolinidin, and 7-methoxyapigeninidin, as well as two dominant flavonoids, luteolin and apigenin. Compared to the cultivars, some breeding lines had significantly high levels of metabolites and antioxidant activities. On the other hand, statistical analysis showed that total tannin, total phenolic, and antioxidant capacities varied significantly across white, yellow, and orange genotypes. Principal component analysis was used to differentiate the sorghum genotypes based on seed color and antioxidant index levels. Pearson's correlation analysis revealed strong links between biosynthetically related metabolites and those with synergistic antioxidant properties.

Conclusion

This research demonstrated the diversity of the sorghum resources investigated. Those genotypes with high levels of nutritional components, functional metabolites, and antioxidant activities could be used for consumption and breeding programs.

Chemical Composition, Antioxidant Potential, and Nutritional Evaluation of Cultivated Sorghum Grains: A Combined Experimental, Theoretical, and Multivariate Analysis

Sorghum grain (Sorghum bicolor L. Moench) is a gluten-free cereal with excellent nutritional value and is a good source of antioxidants, including polyphenols, as well as minerals with proven health benefits. Herein, the phenolic composition, elemental profile, and antioxidant activity of sixteen food-grade sorghum grains (S1-S16) grown under agroecological conditions in Serbia were determined. Nine phenolic compounds characteristic of sorghum grains, such as luteolinidin, 5-methoxyluteolinidin, luteolidin derivative, luteolidin glucoside, apigeninidin, 7-methoxyapigeninidin, apigeninidin glucoside, and cyanidin derivative, were quantified. The antioxidant potential of the analyzed sorghum grains was evaluated by UV/Vis (DPPH, ABTS, and FRAP) and Electron Paramagnetic Resonance spectroscopy (hydroxyl and ascorbyl radical scavenging assays). The content of macro- and microelements was determined by Inductively Coupled Plasma Optical Emission spectroscopy. Theoretical daily intakes of selected major and trace elements were assessed and compared with the Recommended Daily Allowance or Adequate Intake. Sample S8 had the highest amount of phenolic compounds, while S4, S6, and S8 exhibited the strongest antioxidative potential. The sorghum studied could completely satisfy the daily needs of macro- (K, Mg, and P) and microelements (Se, Zn, Fe). Pattern recognition techniques confirmed the discrimination of samples based on phenolic profile and elemental analysis and recognized the main markers responsible for differences between the investigated samples. The reaction between hydroxyl radicals and luteolinidin/apigeninidin was investigated by Density Functional Theory and thermodynamically preferred mechanism was determined.

Sorghum Flour Features Related to Dry Heat Treatment and Milling

Heat treatment of sorghum kernels has the potential to improve their nutritional properties. The goal of this study was to assess the impact of dry heat treatment at two temperatures (121 and 140 °C) and grain fractionation, on the chemical and functional properties of red sorghum flour with three different particle sizes (small, medium, and large), for process optimization. The results showed that the treatment temperature had a positive effect on the water absorption capacity, as well as the fat, ash, moisture and carbohydrate content, whereas the opposite tendency was obtained for oil absorption capacity, swelling power, emulsion activity and protein and fiber content. Sorghum flour particle size had a positive impact on water absorption capacity, emulsion activity and protein, carbohydrate and fiber content, while oil absorption capacity, swelling power and fat, ash and moisture content were adversely affected. The optimization process showed that at the treatment temperature at 133 °C, an increase in fat, ash, fiber and carbohydrate content was experienced in the optimal fraction dimension of red sorghum grains. Moreover, the antioxidant performance showed that this fraction produced the best reducing capability when water was used as an extraction solvent. Starch digestibility revealed a 22.81% rise in resistant starch, while the thermal properties showed that gelatinization enthalpy was 1.90 times higher compared to the control sample. These findings may be helpful for researchers and the food industry in developing various functional foods or gluten-free bakery products.

A comprehensive review on functional beverages from cereal grains-characterization of nutraceutical potential, processing technologies and product types

Due to growing consumer interest in fitness and wellbeing, foods and beverages with therapeutic and functional qualities are in higher demand. In addition to being significant staple crops and major providers of nutrition and energy, cereals are rich in bioactive phytochemicals with health benefits. Cereal grains offer a lot of promise for processing into functional beverages since these include a wide variety of bioactive phytochemicals such as phenolic compounds, carotenoids, dietary fibres, phytosterols, tocols, gamma-oryzanol, and phytic acid. Despite the fact that a wide variety of beverages made from cereal grains are produced globally, they have received very little technological and scientific attention. The beverages confer replacements for milk made from cereal grains, roasted cereal grain teas and fermented non-alcoholic cereal grain drinks. This review emphasizes on the three primary kinds of functional beverages made from cereal grains. Further, the potential applications and directions for the future related to these beverages are discussed with elaborated processing methods, health benefits and product attributes. Cereal grain-based beverages may represent a promising new class of healthy functional beverages in our daily lives as the food industry gets more diverse.

Estimated dietary intake of polyphenols from cereal foods and associated lifestyle and demographic factors in the Melbourne Collaborative Cohort Study

Cereal foods are consumed globally and are important sources of polyphenols with potential health benefits, yet dietary intakes are unclear. We aimed to calculate the dietary intakes of polyphenols from cereal foods in the Melbourne Collaborative Cohort Study (MCCS), and describe intakes by demographic and lifestyle factors. We estimated intakes of alkylresorcinols, lignans and phenolic acids in n = 39,892 eligible MCCS participants, using baseline dietary data (1990-1994) from a 121-item FFQ containing 17 cereal foods, matched to a polyphenol database developed from published literature and Phenol-Explorer Database. Intakes were estimated within groups according to lifestyle and demographic factors. The median (25th-75th percentile) intake of total polyphenols from cereal foods was 86.9 mg/day (51.4-155.8). The most consumed compounds were phenolic acids, with a median intake of 67.1 mg (39.5-118.8), followed by alkylresorcinols of 19.7 mg (10.8-34.6). Lignans made the smallest contribution of 0.50 mg (0.13-0.87). Higher polyphenol intakes were associated with higher relative socio-economic advantage and prudent lifestyles, including lower body mass index (BMI), non-smoking and higher physical activity scores. The findings based on polyphenol data specifically matched to the FFQ provide new information on intakes of cereal polyphenols, and how they might vary according to lifestyle and demographic factors.

Conversion of hydroxycinnamic acids by Furfurilactobacillus milii in sorghum fermentations: Impact on profile of phenolic compounds in sorghum and on ecological fitness of Ff. milii

The conversion of phenolic compounds by lactobacilli in food fermentations contributes to food quality. The metabolism of phenolics by lactobacilli has been elucidated in the past years but information on the contribution of specific enzymes in food fermentations remains scarce. This study aimed to address this gap by disruption of genes coding for the hydroxycimmanic acid reductase Par1, the hydroxycinnamic acid decarboxylase Pad, the hydrocinnamic esterase EstR, and strains with disruption of all three genes in Furfurilactobacillus milii FUA3583. The conversion of phenolics by Ff. milii and its isogenic mutants in sorghum fermentations was studied by LC-UV and LC-UV-MS/MS analyses. Ff. milii FUA3583 converted hydroxycinnamic acids predominantly with Par1. Vinylphenols were detected only in mutants lacking par1. A phenotype for the estR defective mutant was not identified. The formation of pyrano-3-deoxyanthocyanidins was observed only after fermentation with strains expressing Pad. Specifically, formation of these compounds was low with Ff. milii FUA3583, substantially increased in the Par1 mutant and abolished in all mutants with disrupted pad. Competition experiments with Ff. milii FUA3583 and its isogenic mutants demonstrated that expression of one of the two metabolic pathways for hydroxycinnamic acids increases the ecological fitness of the strain. Disruption of EstR in a Δpar1Δpar2Δpad background improved ecological fitness, indirectly demonstrating a phenotype of the esterase in Ff. milii. The documentation of the functionality of genes coding for conversion of hydroxycinnamic acids may support the selection of starter cultures for improved quality of fermented cereal products.

Functional genomic effects of indels using Bayesian genome-phenome wide association studies in sorghum

High-throughput genomic and phenomic data have enhanced the ability to detect genotype-to-phenotype associations that can resolve broad pleiotropic effects of mutations on plant phenotypes. As the scale of genotyping and phenotyping has advanced, rigorous methodologies have been developed to accommodate larger datasets and maintain statistical precision. However, determining the functional effects of associated genes/loci is expensive and limited due to the complexity associated with cloning and subsequent characterization. Here, we utilized phenomic imputation of a multi-year, multi-environment dataset using PHENIX which imputes missing data using kinship and correlated traits, and we screened insertions and deletions (InDels) from the recently whole-genome sequenced Sorghum Association Panel for putative loss-of-function effects. Candidate loci from genome-wide association results were screened for potential loss of function using a Bayesian Genome-Phenome Wide Association Study (BGPWAS) model across both functionally characterized and uncharacterized loci. Our approach is designed to facilitate in silico validation of associations beyond traditional candidate gene and literature-search approaches and to facilitate the identification of putative variants for functional analysis and reduce the incidence of false-positive candidates in current functional validation methods. Using this Bayesian GPWAS model, we identified associations for previously characterized genes with known loss-of-function alleles, specific genes falling within known quantitative trait loci, and genes without any previous genome-wide associations while additionally detecting putative pleiotropic effects. In particular, we were able to identify the major tannin haplotypes at the Tan1 locus and effects of InDels on the protein folding. Depending on the haplotype present, heterodimer formation with Tan2 was significantly affected. We also identified major effect InDels in Dw2 and Ma1, where proteins were truncated due to frameshift mutations that resulted in early stop codons. These truncated proteins also lost most of their functional domains, suggesting that these indels likely result in loss of function. Here, we show that the Bayesian GPWAS model is able to identify loss-of-function alleles that can have significant effects upon protein structure and folding as well as multimer formation. Our approach to characterize loss-of-function mutations and their functional repercussions will facilitate precision genomics and breeding by identifying key targets for gene editing and trait integration.

Detoxification of Aflatoxins in Fermented Cereal Gruel (Ogi) by Probiotic Lactic Acid Bacteria and Yeasts with Differences in Amino Acid Profiles

Toxigenic members of Aspergillus flavus contaminate cereal grains, resulting in contamination by aflatoxin, a food safety hazard that causes hepatocellular carcinoma. This study identified probiotic strains as aflatoxin detoxifiers and investigated the changes to the grain amino acid concentrations during fermentation with probiotics in the presence of either A. flavus La 3228 (an aflatoxigenic strain) or A. flavus La 3279 (an atoxigenic strain). Generally, higher concentrations (p < 0.05) of amino acids were detected in the presence of toxigenic A. flavus La 3228 compared to the atoxigenic A. flavus La 3279. Compared to the control, 13/17 amino acids had elevated (p < 0.05) concentrations in the presence of the toxigenic A. flavus compared to the control, whereas in systems with the atoxigenic A. flavus 13/17 amino acids had similar (p > 0.05) concentrations to the control. There were interspecies and intraspecies differences in specific amino acid elevations or reductions among selected LAB and yeasts, respectively. Aflatoxins B1 and B2 were detoxified by Limosilactobacillus fermentum W310 (86% and 75%, respectively), Lactiplantibacillus plantarum M26 (62% and 63%, respectively), Candida tropicalis MY115 (60% and 77%, respectively), and Candida tropicalis YY25, (60% and 31%, respectively). Probiotics were useful detoxifiers; however, the extent of decontamination was species- and strain-dependent. Higher deviations in amino acid concentrations in the presence of toxigenic La 3228 compared to atoxigenic La 3279 suggests that the detoxifiers did not act by decreasing the metabolic activity of the toxigenic strain.

Extraction, Identification and Antioxidant Activity of 3-Deoxyanthocyanidins from Sorghum bicolor L. Moench Cultivated in China

3-deoxyanthocyanidins (3-DAs) are typical flavonoids found in sorghum bran, and they have received much attention in recent years owing to their bioactivities. To further enhance the resource utilization of sorghums cultivated in China, three brewing sorghum cultivars (Liaoza-48, Liaonuo-11, and Liaonian-3) commonly used in China were selected as raw materials for the construction of an extraction technology system for 3-DAs and the clarification of their structures and bioactivities. Based on single-factor experiments and response surface analysis, the optimized system for the extraction of 3-DAs from sorghum grains was as follows: a hydrochloric acid-methanol solution (1:100, v/v) was the extraction solvent, the solid-liquid ratio was 1:20 (g/mL), the extraction time was 130 min, and the temperature was 40 °C. This extraction system was simple and feasible. High performance liquid chromatography analysis suggested that the main monomeric compounds of the extracted 3-DAs were Apigeninidin (AE) and Luteolinidin (LE). Among the three selected sorghum grains, Liaoza-48 had the highest amount of AE (329.64 μg/g) and LE (97.18 μg/g). Antioxidant experiments indicated that the 3-DAs extracted from Liaoza-48 showed higher free-radical scavenging activities for DPPH, ABTS+, and hydroxyl radicals than those extracted from Liaonuo-11 and Liaonian-3. These results provide basic data and technical support for the high-value and comprehensive utilization of sorghums in China.

Host Determinants of Fungal Species Composition and Symptom Manifestation in the Sorghum Grain Mold Disease Complex

Sorghum grain mold (SGM) is an important multifungal disease complex affecting sorghum (Sorghum bicolor) production systems worldwide. SGM-affected sorghum grain can be contaminated with potent fumonisin mycotoxins produced by Fusarium verticillioides, a prevalent SGM-associated taxon. Historically, efforts to improve resistance to SGM have achieved only limited success. Classical approaches to evaluating SGM resistance are based solely on disease severity, which offers little insight regarding the distinct symptom manifestations within the disease complex. In this study, three novel phenotypes were developed to facilitate assessment of SGM symptom manifestation. A sorghum diversity panel composed of 390 accessions was inoculated with endogenous strains of F. verticillioides and evaluated for these phenotypes, as well as for the conventional panicle grain mold severity rating phenotype, in South Carolina, U.S.A., in 2017 and 2019. Distributions of phenotype values were examined, broad-sense heritability was estimated, and relationships to botanical race were explored. A typology of SGM symptom manifestations was developed to classify accessions using principal component analysis and k-means clustering, constituting a novel option for basing breeding decisions on SGM outcomes more nuanced than disease severity. Genome-wide association studies were performed using SGM trait data, resulting in the identification of 19 significant single nucleotide polymorphisms in linkage disequilibrium with a total of 86 gene models. Our findings provide a basis of exploratory evidence regarding the genetic architecture of SGM symptom manifestation and indicate that traits other than disease severity could be tractable targets for SGM resistance breeding.

Formulation of a Synergistic Enzyme Cocktail for Controlled Degradation of Sorghum Grain Pericarp

Sorghum is one of the major grains produced worldwide for food and fodder, owing to its nutritional profile advantages. However, the utilisation of whole grain sorghum as an ingredient in conventional food formulations is limited due to its poor digestibility, which requires the removal of the outer fibrous layers. Grain breakage and loss of essential nutrients also disadvantage traditional milling practices. Using carbohydrate degrading enzymes to hydrolyse the grain pericarp is a novel approach to biopolishing, where selective degradation of the pericarp layers occurs without adversely affecting the nutrient profile. A collective synergism of enzymes has been proven to cause effective hydrolysis compared to individual enzymes due to the complex presence of non-starch polysaccharides in the grain's outer layers, which comprise a variety of sugars that show specific degradation with respect to each enzyme. The present study aimed to formulate such an enzyme cocktail with xylanase, cellulase, and pectinase in different proportions for hydrolysing sorghum grain pericarp by determining the yield of specific sugars in the pericarp extract after a certain period of incubation. The results showed that the xylanase enzyme has a major effect on the grain bran composition compared to cellulase and pectinase; however, a synergistic mixture yielded more hydrolysed sugars and anti-nutrients in the extract compared to each of the enzymes individually. The results were confirmed by morphological and crystallinity studies of the soaked grain. Compared to conventional water-soaked samples, grains soaked in a cocktail with 66.7% xylanase, 16.7% cellulase, and 16.7% pectinase had visibly thinner and more degraded fibre layers.

Sorghum in foods: Functionality and potential in innovative products

Sorghum grain is a staple food for about 500 million people in 30 countries in Africa and Asia. Despite this contribution to global food production, most of the world's sorghum grain, and nearly all in Western countries, is used as animal feed. A combination of the increasingly important ability of sorghum crops to resist heat and drought, the limited history of the use of sorghum in Western foods, and the excellent functional properties of sorghum grain in healthy diets, suggests a greater focus on the development of new sorghum-based foods. An understanding of the structural and functional properties of sorghum grain to develop processes for production of new sorghum-based foods is required. In this review, we discuss the potential of sorghum in new food products, including sorghum grain composition, the functional properties of sorghum in foods, processing of sorghum-based products, the digestibility of sorghum protein and starch compared to other grains, and the health benefits of sorghum. In the potential for sorghum as a major ingredient in new foods, we suggest that the gluten-free status of sorghum is of relatively minor importance compared to the functionality of the slowly digested starch and the health benefits of the phenolic compounds present.

Comparative assessment of nutritional and functional properties of different sorghum genotypes for ensuring nutritional security in dryland agro-ecosystem

The cultivation of unique sorghum (resistant to abiotic stresses and re-recognized as healthy food) has attracted interest as an environmentally friendly minor cereal and may be a solution to food and nutritional security. However, information about how the use of selected sorghum grains affects nutritive values and its functional properties from sorghum flours is still lacking. To address this question, we selected six sorghum varieties (i.e., JinZa 34, LiaoZa 19, JinNuo 3, JiZa 127, JiNiang 2, and JiaXian) for the comprehensive analysis of the relationship among nutritional compositions, energy value contributions, and functional properties of sorghum grains. Results showed that Carr's index (CI) and angle of repose (AR) of all sorghum flours indicated good flow and compressibility properties in terms of micrometric parameters. All sorghums were considered free of tannin. Based on the scatterplot analysis, the proportions of energy contributions due to protein, fat, and carbohydrate (CHO), were highly positively correlated with protein, fat, and CHO, respectively. The significantly different flours of six sorghum varieties resulted in different functional properties. The amylose content showed a highly negative association with light transmittance and water and oil absorption capacities. In addition, amylose had a highly positive relationship with water solubility (WS) and swelling power (SP). JinNuo 3 had the highest nutritional compositions [proximate, mineral, anti-nutritional values, and amino acid (AA) profiles] and functional properties indicating that it could be used as a brewing liquor. Our findings will provide a new opportunity to cultivate sorghum as an environment friendly minor cereal crop in dryland agro-ecosystems of arid and semi-arid regions of northern China for nutritional security, agriculture processing, and non-food industry in the future.

Metabolomics Reveals Nutritional Diversity among Six Coarse Cereals and Antioxidant Activity Analysis of Grain Sorghum and Sweet Sorghum

Coarse cereals are rich in dietary fiber, B vitamins, minerals, secondary metabolites, and other bioactive components, which exert numerous health benefits. To better understand the diversity of metabolites in different coarse cereals, we performed widely targeted metabolic profiling analyses of six popular coarse cereals, millet, coix, buckwheat, quinoa, oat, and grain sorghum, of which 768 metabolites are identified. Moreover, quinoa and buckwheat showed significantly different metabolomic profiles compared with other coarse cereals. Analysis of the accumulation patterns of common nutritional metabolites among six coarse cereals, we found that the accumulation of carbohydrates follows a conserved pattern in the six coarse cereals, while those of amino acids, vitamins, flavonoids, and lipids were complementary. Furthermore, the species-specific metabolites in each coarse cereal were identified, and the neighbor-joining tree for the six coarse cereals was constructed based on the metabolome data. Since sorghum contains more species-specific metabolites and occupies a unique position on the neighbor-joining tree, the metabolite differences between grain sorghum 654 and sweet sorghum LTR108 were finally compared specifically, revealing that LTR108 contained more flavonoids and had higher antioxidant activity than 654. Our work supports an overview understanding of nutrient value in different coarse cereals, which provides the metabolomic evidence for the healthy diet. Additionally, the superior antioxidant activity of sweet sorghum provides clues for its targeted uses.

Limiting silicon supply alters lignin content and structures of sorghum seedling cell walls

Sorghum has been recognized as a promising energy crop. The composition and structure of lignin in the cell wall are important factors that affect the quality of plant biomass as a bioenergy feedstock. Silicon (Si) supply may affect the lignin content and structure, as both Si and lignin are possibly involved in plant mechanical strength. However, our understanding regarding the interaction between Si and lignin in sorghum is limited. Therefore, in this study, we analyzed the lignin in the cell walls of sorghum seedlings cultured hydroponically with or without Si supplementation. Limiting the Si supply significantly increased the thioglycolic acid lignin content and thioacidolysis-derived syringyl/guaiacyl monomer ratio. At least part of the modification may be attributable to the change in gene expression, as suggested by the upregulation of phenylpropanoid biosynthesis-related genes under -Si conditions. The cell walls of the -Si plants had a higher mechanical strength and calorific value than those of the +Si plants. These results provide some insights into the enhancement of the value of sorghum biomass as a feedstock for energy production by limiting Si uptake.

Sorghum Association Panel whole-genome sequencing establishes cornerstone resource for dissecting genomic diversity

Association mapping panels represent foundational resources for understanding the genetic basis of phenotypic diversity and serve to advance plant breeding by exploring genetic variation across diverse accessions. We report the whole-genome sequencing (WGS) of 400 sorghum (Sorghum bicolor (L.) Moench) accessions from the Sorghum Association Panel (SAP) at an average coverage of 38× (25-72×), enabling the development of a high-density genomic marker set of 43 983 694 variants including single-nucleotide polymorphisms (approximately 38 million), insertions/deletions (indels) (approximately 5 million), and copy number variants (CNVs) (approximately 170 000). We observe slightly more deletions among indels and a much higher prevalence of deletions among CNVs compared to insertions. This new marker set enabled the identification of several novel putative genomic associations for plant height and tannin content, which were not identified when using previous lower-density marker sets. WGS identified and scored variants in 5-kb bins where available genotyping-by-sequencing (GBS) data captured no variants, with half of all bins in the genome falling into this category. The predictive ability of genomic best unbiased linear predictor (GBLUP) models was increased by an average of 30% by using WGS markers rather than GBS markers. We identified 18 selection peaks across subpopulations that formed due to evolutionary divergence during domestication, and we found six F_st peaks resulting from comparisons between converted lines and breeding lines within the SAP that were distinct from the peaks associated with historic selection. This population has served and continues to serve as a significant public resource for sorghum research and demonstrates the value of improving upon existing genomic resources.