Tocochromanols and carotenoids in sorghum (Sorghum bicolor L.): Diversity and stability to the heat treatment

Grain yellowness is an effective predictor of carotenoid content in global sorghum populations

Identification of high carotenoid germplasm is crucial to assist breeders in provitamin-A biofortification of sorghum (Sorghum bicolor [L.] Moench). High-performance liquid chromatography is the gold standard for carotenoid quantification, however, it is not feasible for large scale phenotyping due to its high cost and low throughput. In this study, we tested the feasibility of using grain color as a high-throughput method of carotenoid biofortification breeding. We hypothesized that visual, color-based selection can be an effective strategy to identify high-carotenoid accessions. Yellow grain had significantly higher carotenoid content than red, brown, and white grain. The degree of yellowness could distinguish the presence or absence of carotenoids, but could not distinguish carotenoid concentrations within yellow-only accessions. The degree of luminosity of the grain, however, was able to better predict carotenoid concentrations within yellow-only accessions. Genome-wide association studies identified significant marker-trait associations for qualitative and quantitative grain color traits and carotenoid concentrations near carotenoid pathway genes-ZEP, PDS, CYP97A, NCED, CCD, and LycE-three of which were common between grain color and carotenoid traits. These findings suggest that using grain color as a method for screening germplasm may be an effective high-throughput selection tool for prebreeding and early-stage breeding in carotenoid biofortification.

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.

Physical-Chemical and Nutritional Characterization of Somali Laxoox Flatbread and Comparison with Yemeni Lahoh Flatbread

The physical-chemical and nutritional characteristics of Somali laxoox and Yemeni lahoh flatbreads have not been studied to date, nor have their possible similarities been investigated. Fieldwork was carried out in Somaliland (northwest Somalia), at nine different households, to collect Somali and Yemeni flatbreads. The nutritional characteristics (12.47-15.94 g/100 g proteins, 2.47-4.11 g/100 g lipids) and the total phenolic compounds (5.02-7.11 mg gallic acid equivalents/g on dry matter) were influenced by the natural variability of manual food preparation, as well as variability in the recipes used. All the breads had a porous structure. Cell density varied from 22.4 to 57.4 cells/cm2 in the Somali flatbreads, reaching 145 cells/cm2 in the Yemeni flatbreads. Higher amounts of refined flour increased the pale color of the breads. The principal component analysis highlighted differences between Yemeni and Somali flatbreads, pointing out a certain variability within the latter, with two samples forming a separate subgroup.

Characterization of grain carotenoids in global sorghum germplasm to guide genomics-assisted breeding strategies

BACKGROUND

Crop biofortification is a successful strategy to ameliorate Vitamin A deficiency. Sorghum is a good candidate for vitamin A biofortification, as it is a staple food in regions with high prevalence of vitamin A deficiency. β-carotene-the main provitamin A carotenoid-is below the target concentration in sorghum grain, therefore biofortification breeding is required. Previous studies found evidence that sorghum carotenoid variation is oligogenic, suggesting that marker-assisted selection can be an appropriate biofortification method. However, we hypothesize that sorghum carotenoids have both oligogenic and polygenic components of variation. Genomics-assisted breeding could accelerate breeding efforts, but there exists knowledge gaps in the genetics underlying carotenoid variation, as well as appropriate germplasm to serve as donors.

RESULTS

In this study, we characterized carotenoids in 446 accessions from the sorghum association panel and carotenoid panel using high-performance liquid chromatography, finding high carotenoid accessions not previously identified. Genome-wide association studies conducted with 345 accessions, confirmed that zeaxanthin epoxidase is a major gene underlying variation for not only zeaxanthin, but also lutein and β-carotene. High carotenoid lines were found to have limited genetic diversity, and originated predominantly from only one country. Potential novel genetic diversity for carotenoid content was identified through genomic predictions in 2,495 accessions of unexplored germplasm. Oligogenic variation of carotenoids was confirmed, as well as evidence for polygenic variation, suggesting both marker-assisted selection and genomic selection can facilitate breeding efforts.

CONCLUSIONS

Sorghum vitamin A biofortification could be beneficial for millions of people who rely on it as a dietary staple. Carotenoid content in sorghum is low, but high heritability suggests that increasing concentrations through breeding is possible. Low genetic diversity among high carotenoid lines might be the main limitation for breeding efforts, therefore further germplasm characterization is needed to assess the feasibility of biofortification breeding. Based on germplasm here evaluated, most countries' germplasm lacks high carotenoid alleles, thus pre-breeding will be needed. A SNP marker within the zeaxanthin epoxidase gene was identified as a good candidate for use in marker-assisted selection. Due to the oligogenic and polygenic variation of sorghum grain carotenoids, both marker-assisted selection and genomic selection can be employed to accelerate breeding efforts.

Biofortification to avoid malnutrition in humans in a changing climate: Enhancing micronutrient bioavailability in seed, tuber, and storage roots

Malnutrition results in enormous socio-economic costs to the individual, their community, and the nation's economy. The evidence suggests an overall negative impact of climate change on the agricultural productivity and nutritional quality of food crops. Producing more food with better nutritional quality, which is feasible, should be prioritized in crop improvement programs. Biofortification refers to developing micronutrient -dense cultivars through crossbreeding or genetic engineering. This review provides updates on nutrient acquisition, transport, and storage in plant organs; the cross-talk between macro- and micronutrients transport and signaling; nutrient profiling and spatial and temporal distribution; the putative and functionally characterized genes/single-nucleotide polymorphisms associated with Fe, Zn, and β-carotene; and global efforts to breed nutrient-dense crops and map adoption of such crops globally. This article also includes an overview on the bioavailability, bioaccessibility, and bioactivity of nutrients as well as the molecular basis of nutrient transport and absorption in human. Over 400 minerals (Fe, Zn) and provitamin A-rich cultivars have been released in the Global South. Approximately 4.6 million households currently cultivate Zn-rich rice and wheat, while ~3 million households in sub-Saharan Africa and Latin America benefit from Fe-rich beans, and 2.6 million people in sub-Saharan Africa and Brazil eat provitamin A-rich cassava. Furthermore, nutrient profiles can be improved through genetic engineering in an agronomically acceptable genetic background. The development of "Golden Rice" and provitamin A-rich dessert bananas and subsequent transfer of this trait into locally adapted cultivars are evident, with no significant change in nutritional profile, except for the trait incorporated. A greater understanding of nutrient transport and absorption may lead to the development of diet therapy for the betterment of human health.

The Effect of Chia Seed Extracts against Complete Freund’s Adjuvant-Induced Rheumatoid Arthritis in Rats

Background and Objectives. It is known that the oxidation of chia seeds is minimal or absent, due to the presence of bioactive compounds, having a great potential in the foods and pharmacological industry. This investigation was done to estimate the nutrition values and anti-oxidant activity of chia seed extracts. Materials and Methods. The protective effects of chia seed extract against complete Freund’s adjuvant (CFA) rheumatoid arthritis in rats were investigated with 100, 200, 300, and 400 ppm/kg BW rat/day chia seeds aqueous extract for 4 weeks. Results. The results obtained revealed that chia seed extract contained high proportions of protein and total dietary fiber values of 21.35% and 27.24%, respectively. Moreover, the results reported that the mineral contents were the greatest in phosphorous, potassium, magnesium, calcium, and sodium (450.09, 410.46, 245.22, 218.69, and 120.34 mg/100 g, respectively). Meanwhile, iron, zinc, and copper were the lowest in chia seeds (9.26, 4.67, and 3.66 mg/100 g, respectively). Besides, vitamins C and E reported 1.65 and 0.82 mg/100 g, respectively. Chia seed extracts were effective in vitro for the bioactive components such as phenolics, flavonoids, and anti-oxidant activities. The biomarkers of complete blood picture, lipid profile, anti-oxidant enzymes, TNF-α, and IL-10 had been improved. Histopathological examination of the rat knee confirmed health amelioration, revealing that chia seed extract consumption can lower pathological changes in injured rheumatoid arthritis rats. Conclusion. It could be seen that the chia seed extracts alleviated the harmful effect of rheumatoid arthritis CFA-induced rats.

Does Plant Breeding for Antioxidant-Rich Foods Have an Impact on Human Health?

Given the general beneficial effects of antioxidants-rich foods on human health and disease prevention, there is a continuous interest in plant secondary metabolites conferring attractive colors to fruits and grains and responsible, together with others, for nutraceutical properties. Cereals and Solanaceae are important components of the human diet, thus, they are the main targets for functional food development by exploitation of genetic resources and metabolic engineering. In this review, we focus on the impact of antioxidants-rich cereal and Solanaceae derived foods on human health by analyzing natural biodiversity and biotechnological strategies aiming at increasing the antioxidant level of grains and fruits, the impact of agronomic practices and food processing on antioxidant properties combined with a focus on the current state of pre-clinical and clinical studies. Despite the strong evidence in in vitro and animal studies supporting the beneficial effects of antioxidants-rich diets in preventing diseases, clinical studies are still not sufficient to prove the impact of antioxidant rich cereal and Solanaceae derived foods on human

A review of extrusion-modified underutilized cereal flour: chemical composition, functionality, and its modulation on starchy food quality

Compared with three major cereals, underutilized cereals (UCs) are those with less use but having abundant bioactive components and better functionalities after proper processing. As a productive and energy-efficient technology, extrusion has been used for UC modification to improve its technological and nutritional quality. Extrusion could induce structural and quantitative changes in chemical components of UC flour, the degree of which is affected by extrusion intensity. Based on the predominant component (starch), functionalities of extruded underutilized cereal flour (EUCF) and potential mechanisms are reviewed. Considering bioactive compounds, it also summarizes the physiological functions of EUCF. EUCF incorporation could modulate the dough rheological behavior and starchy foods quality. Controlling extrusion intensity or incorporation level of EUCF is vital to achieve sensory-appealing and nutritious products. This paper gives comprehensive information of EUCF to promote its utilization in novel staple foods.

Bioactive Compounds and Biological Activities of Sorghum Grains

Sorghum is the fifth most commonly used cereal worldwide and is a rich source of many bioactive compounds. We summarized phenolic compounds and carotenoids, vitamin E, amines, and phytosterols in sorghum grains. Recently, with the development of detection technology, new bioactive compounds such as formononetin, glycitein, and ononin have been detected. In addition, multiple in vitro and in vivo studies have shown that sorghum grains have extensive bio-logical activities, such as antioxidative, anticancer, antidiabetic, antiinflammatory, and antiobesity properties. Finally, with the establishment of sorghum phenolic compounds database, the bound phenolics and their biological activities and the mechanisms of biological activities of sorghum bioactive compounds using clinical trials may be researched.

Stability of B vitamins, vitamin E, xanthophylls and flavonoids during germination and maceration of sorghum (Sorghum bicolor L.)

The impact of maceration and germination on the concentration of bioactive compounds still needs to be evaluated. The stability of B complex vitamins (thiamine, riboflavin, pyridoxine), vitamin E (α, β, γ, δ tocopherols and tocotrienols), xanthophylls (lutein and zeaxanthin) and flavonoids (3-deoxyanthocyanidins-3-DXAs, flavones and flavanones) was evaluated in sorghum grains subjected to maceration and germination, using High Performance Liquid Chromatography. Maceration and germination reduced thiamine and pyridoxine concentrations (retentions ranging from 3.8 to 50.2%). Riboflavin and Vitamin E concentrations were not affected by maceration. Germination increased riboflavin and reduced vitamin E. 3-DXAs were sensitive to maceration and germination (retentions of 69.6% and 69.9%, respectively). Flavones contents decreased with germination. Our results indicate that, after germination and/or maceration, sorghum had important nutritional and functional value. Thus, its intake, mainly in macerated forms, should be encouraged, since concentrations of riboflavin, vitamin E and flavones were not altered during this processing.

Comparison of blue discoloration in radish root among different varieties and blue pigment stability analysis

The internal blue discoloration of radish root after harvest is a physiological phenomenon that decreases the radish quality. Internal blue discoloration in the roots of 16 varieties of Chinese radish along with the stability of blue pigment under different light, pH, and temperature conditions were investigated. Among the varieties LB05-244 and LB05-240 displayed the greatest degrees of discoloration, while the Piton and Dense radishes exhibited the lowest degrees of discoloration. The light and pH conditions along with the storage temperature affected the pigment stability. The degradation of blue pigment occurred faster under blue light than under green, red, and white light and darkness. Blue pigment degraded fastest at pH values of 13 and 1. The blue pigments in radish exhibited thermal instability, with complete degradation occurring in 5 or 10 min at 90 or 100 °C, respectively. In conclusion, variety affected the discoloration. The pigment exhibited light, pH and thermal instability.

Advancing provitamin A biofortification in sorghum: Genome-wide association studies of grain carotenoids in global germplasm

Vitamin A deficiency is one of the most prevalent nutritional deficiencies worldwide. Sorghum [Sorghum bicolor L. (Moench)] is a major cereal crop consumed by millions of people in regions with high vitamin A deficiency. We quantified carotenoid concentrations in a diverse sorghum panel using high-performance liquid chromatography and conducted a genome-wide association study (GWAS) of grain carotenoids to identify genes underlying carotenoid variation. There was moderate variation for β-carotene (00.8 μg g^-1 ), lutein (0.3-9.4 μg g^-1 ), and zeaxanthin (0.2-9.1 μg g^-1 ), but β-cryptoxanthin and α-carotene were nearly undetectable. Genotype had the largest effect size, at 81% for zeaxanthin, 62% for β-carotene, and 53% for lutein. Using multiple models, GWAS identified several significant associations between carotenoids and single nucleotide polymorphisms (SNPs), some of which colocalized with known carotenoid genes that have not been previously implicated in carotenoid variation. Several of the candidate genes identified have also been identified in maize (Zea mays L.) and Arabidopsis (Arabidopsis thaliana) carotenoid GWAS studies. Notably, an SNP inside the putative ortholog of maize zeaxanthin epoxidase (ZEP) had the most significant association with zeaxanthin and with the ratio between lutein and zeaxanthin, suggesting that ZEP is a major gene controlling sorghum carotenoid variation. Overall findings suggest there is oligogenic inheritance for sorghum carotenoids and suitable variation for marker-assisted selection. The high carotenoid germplasm and significant associations identified in this study can be used in biofortification efforts to improve the nutritional quality of sorghum.

Carotenoids in Cereal Food Crops: Composition and Retention throughout Grain Storage and Food Processing

Carotenoids are C40 isoprenoids synthesized by plants, as well as some bacteria, fungi and algae, that have been reported to be responsible for a number of benefits conferred on human health. The inability of animals and humans to synthesize de novo these compounds is the reason why they must be introduced from dietary sources. In cereal grains, carotenoids are important phytochemicals responsible for the characteristic yellow colour of the endosperm, which confers nutritional and aesthetic quality to cereal-based products. Cereals are staple foods for a large portion of the world population, and the biofortification of cereal grains with carotenoids may represent a simple way to prevent many human diseases and disorders. Unfortunately, evidence exists that the storage and processing of cereal grains into food products may negatively impact their carotenoid content; so, this loss should be taken into consideration when analysing the potential health benefits of the cereal-based products. Focusing on the recent updates, this review summarizes the chemical composition of the carotenoids in the grains of staple cereals, including wheat, maize, rice and sorghum, the main factors that affect their carotenoid content during storage and processing and the most fruitful strategies used improve the grain carotenoid content and limit the carotenoid post-harvest losses.

Gluten-Free Alternative Grains: Nutritional Evaluation and Bioactive Compounds

Interest in gluten-free grains is increasing, together with major incidences of celiac disease in the last years. Since to date, knowledge of the nutritional and bioactive compounds profile of alternative gluten-free grains is limited, we evaluated the content of water-soluble (thiamine and riboflavin) and liposoluble vitamins, such as carotenoids and tocols (tocopherols and tocotrienols), of gluten-free minor cereals and also of pseudocereals. The analysed samples showed a high content of bioactive compounds; in particular, amaranth, cañihua and quinoa are good sources of vitamin E, while millet, sorghum and teff (Eragrostis tef, or William’s Lovegrass) are good sources of thiamine. Moreover, millet provides a fair amount of carotenoids, and in particular of lutein. These data can provide more information on bioactive compounds in gluten-free grains. The use of these grains can improve the nutritional quality of gluten-free cereal-based products, and could avoid the monotony of the celiac diet.

Triacylglycerol, fatty acid, and phytochemical profiles in a new red sorghum variety (Ji Liang No. 1) and its antioxidant and anti-inflammatory properties

In this study, a new red sorghum variety (Ji Liang No. 1) was investigated for its triacylglycerol (TAG) and fatty acid profiles, carotenoid and tocopherol compositions, total phenolic, total flavonoid and phenolic acid contents, and antioxidant and anti-inflammatory properties. A total of 17 TAGs were identified in the red sorghum oil. Linoleic and oleic acids were the primary fatty acids, contributing more than 80% of the total fatty acids. β-Carotene was the primary carotenoid at a level of 26.14 μg/g. α-, γ-, and δ-tocopherols were at levels of 0.19, 4.08, and 0.10 μg/g, respectively. Moreover, acetone-water (60:40, v/v) extract of the red sorghum exhibited the greatest total phenolic content of 2.77 mg GAE/g and total flavonoid content of 5.44 mg RE/g. The extract had scavenging capacities against DPPH, ABTS +, and peroxyl radicals and suppressed LPS stimulated IL-1β, IL-6, and COX-2 mRNA expressions in a dose-dependent manner. Ferulic, p-coumaric, isoferulic, and p-hydroxybenzoic acids were found in the red sorghum, with ferulic acid as the predominant phenolic acid and mostly in an insoluble bound form. These data indicated a potential utilization of the red sorghum in health-promoting functional food or supplemental products.

Evaluation of the health benefits of consumption of extruded tannin sorghum with unfermented probiotic milk in individuals with chronic kidney disease

This study investigated the chemical and nutritional composition of breakfast cereal based on whole sorghum, and the effect of its association with unfermented probiotic milk on the inflammation and oxidative stress of individuals with chronic kidney disease. Extruded sorghum breakfast meal presented higher carbohydrate concentration (approximately 71%), followed by protein (approximately 11%) and lipid (approximately 0.4%). When compared to extruded maize breakfast meal, it presented higher percentage of dietary fiber (p < 0.05), and higher content of phenolic compounds and tannin, consequently higher antioxidant activity (p < 0.05). Extruded sorghum breakfast cereal combined with unfermented probiotic milk decreased the C-reactive protein (p < 0.05) and malondialdehyde (p < 0.05) serum levels and increased the total antioxidant capacity and superoxide dismutase (p < 0.05) in patients with chronic kidney disease. Therefore, the extruded sorghum, source of tannin, anthocyanin, and dietary fiber, when consumed with unfermented probiotic milk alleviates the inflammation and oxidative stress in patients with chronic kidney disease.

Alternative grains in nutrition

Many people suffer from gluten sensitivity or gluten intolerance. They have to avoid or limit their gluten intake. Sorghum and millet are gluten-free cereals, wherefore persons with gluten sensitivity or gluten intolerance could consume them. Moreover, they have a lot of positive effects due to their phenolic compounds as phenol acid or flavonoid. Antioxidant activity in sorghum is especially high in comparison with other cereals. Our aim was to compare literature data about the chemical compositions of sorghum and millet with other grains.

Comparing sorghum and wheat whole grain breakfast cereals: Sensorial acceptance and bioactive compound content

The sensory acceptance and the content of bioactive compounds of whole-sorghum and whole-wheat breakfast cereals were compared. Sensory acceptance was assessed using the Food Action RatingScale. 3-Deoxyanthocyanidins, flavones and flavanones were determined by high-performance liquid chromatography (HPLC) with diode array detection, and vitamin E by HPLC with fluorescence detection. Total phenolics and antioxidant activity were determined by spectrophotometry. The sorghum breakfast cereal had better sensory acceptance (70.6%) than wheat breakfast cereal (41.18%). Sorghum had higher 3-deoxyanthocyanidin content (100% higher), total phenolic compounds (98.2% higher) and antioxidant activity (87.9% higher) than wheat breakfast cereal. Flavones and flavanones were not detected in both breakfast cereals. Total vitamin E content was 78.6% higher in wheat than in sorghum breakfast cereal. Thus, consumption of whole sorghum breakfast cereal should be encouraged, since it had good sensory acceptance and is a source of bioactive compounds that can promote benefits to human health.

Mauritia flexuosa L. protects against deficits in memory acquisition and oxidative stress in rat hippocampus induced by methylmercury exposure

OBJECTIVE

Methylmercury (MeHg) is the most toxic form of mercury that can affect humans through the food chain by bioaccumulation. Human organism is capable of triggering visual and cognitive disorders, neurodegeneration, as well as increased production of reactive species of O2 and depletion of natural anti-oxidant agents. In this context, Mauritia flexuosa L., a fruit rich in compounds with anti-oxidant properties, emerged as an important strategy to prevent the MeHg damages. So, this work has aimed to elucidate the protective effect of Mauritia flexuosa L. on the damage caused by the exposure of rats to MeHg.

METHODS

In order to evaluate the effect of MeHg on rat aversive memory acquisition and panic-like behavior, we have used elevated T-maze apparatus and after behavioral test, the hippocampus was removed to perfom lipid peroxidation.

RESULTS

Our results demonstrated that the exposure to MeHg caused deficits in inhibitory avoidance acquisition (aversive conditioning) and in the learning process, and increased levels of lipid peroxidation in hippocampus tissue. However, the pretreatment with feed enriched with Mauritia flexuosa L. showed a protective effect against cognitive deficits caused by MeHg and also prevented the occurrence of cytoplasmic membrane damage induced by lipid peroxidation in the hippocampal region.

DISCUSSION

Therefore, this study suggests that Mauritia flexuosa L. represents an important strategy to prevent neurocytotoxics and behavioral effects of MeHg.

Exploiting Nutritional Value of Staple Foods in the World's Semi-Arid Areas: Risks, Benefits, Challenges and Opportunities of Sorghum

Sorghum (Sorghum bicolor (L.) Moench) is a drought-resistant crop and an important food resource in terms of nutritional as well as social-economic values, especially in semi-arid environments. Cultivar selection and processing methods have been observed to impact on composition and functional and nutritional value of sorghum. Amino acid imbalance, cyanogenic glycosides, endogenous anti-nutrients, mycotoxins and toxic elements are among factors impairing its nutritional value. This paper reviews possible approaches (varieties selection, production practices, cooking processes) to improve the benefits-to-risks balance of sorghum meal, to mitigate the risk of deficiencies and/or imbalances and to improve effects on human nutrition. Opportunity for avoiding dietary diversification in high sorghum consumers is also discussed, e.g., tryptophan and niacin deficits potentially related to pellagra, or unavailability of proteins and divalent cations (e.g., Fe, Zn) due to the antinutrient activity of phytic acid and tannins. As potential candidate for production investments, the role of sorghum in preserving biological diversity is also considered.