Foxtail millet: Properties, processing, health benefits, and uses

The importance of starch chain-length distribution for in vitro digestion of ungelatinized and retrograded foxtail millet starch

The digestibility of ungelatinized, short-term retrograded and long-term retrograded starch from foxtail millet was investigated and correlated with starch chain length distributions (CLDs). Some variations in starch CLDs of different varieties were obtained. Huangjingu and Zhonggu 9 had higher average chain lengths of debranched starch and lower average chain length ratios of amylopectin and amylose than Dajinmiao and Jigu 168. Compared to ungelatinized starch, retrogradation significantly increased the estimated glycemic index (eGI), whereas significantly decreased the resistant starch (RS). In contrast, long-term retrograded starches have lower eGI (93.33-97.37) and higher RS (8.04-14.55%) than short-term retrograded starch. PCA and correlation analysis showed that amylopectin with higher amounts of long chains and longer long chains contributed to reduced digestibility in ungelatinized starch. Both amylose and amylopectin CLDs were important for the digestibility of retrograded starch. This study helps a better understanding of the interaction of starch CLDs and digestibility during retrogradation.

Experimental and drying kinetics study on millet particles by a pulsating fluidized bed dryer

This research studies experimentally the drying of foxtail millet in a pulsation-assisted fluidized bed. The effects of temperature and pulsating flow frequency on millet drying are examined. The experiments are conducted at temperatures of 40 °C, 50 °C, and 60 °C for three pulsating frequencies of 0.5, 1, and 2.5 Hz and continuous flow. The best result is obtained for drying with a frequency of 1 Hz. It shows that the pulsating flow is more effective at 50 °C as compared to other temperatures. Four reliable semi-empirical models are used for predicting the moisture reduction during drying process. Among the fitted dynamic models, the model that has the maximum correlation coefficient (R 2 ) and minimum sum of squares of error (SSE) and root mean squared error (RMSE) and well able to predict the behavior of millet drying in the whole process was chosen.

Effects of Lactobacillus plantarum fermentation on the structure, physicochemical properties, and digestibility of foxtail millet starches

This study investigated the effects of Lactobacillus plantarum fermentation on the structural, physicochemical, and digestive properties of foxtail millet starches. The fermented starch granules formed a structure with honeycomb-like dents, uneven pores, and reduced particle size. As the fermentation time extended, the amylose content of waxy (0.88 %) and non-waxy (33.71 %) foxtail millet starches decreased to the minimum value at 24 h (0.59 % and 29.19 %, respectively), and then increased to 0.85 % and 31.87 % at 72 h, respectively. Both native and fermented foxtail millet starches exhibited an A-type crystal structure. Compared with native samples, the fermented samples performed enhanced proportion of short-branched chain, crystallinity, and short-range ordered degree. After fermentation for 24 h, the solubility, adsorption capacity, and pasting viscosity of foxtail millet starches improved, whereas the swelling power, pasting temperature, breakdown, setback, and degree of retrogradation reduced. Additionally, fermentation increased the transition temperatures, enthalpy, and digestibility. Overall, Lactobacillus plantarum fermentation is considered a competent choice to regulate the characteristics of foxtail millet starch.

High Overexpression of SiAAP9 Leads to Growth Inhibition and Protein Ectopic Localization in Transgenic Arabidopsis

Amino acid permeases (AAPs) transporters are crucial for the long-distance transport of amino acids in plants, from source to sink. While Arabidopsis and rice have been extensively studied, research on foxtail millet is limited. This study identified two transcripts of SiAAP9, both of which were induced by NO3- and showed similar expression patterns. The overexpression of SiAAP9L and SiAAP9S in Arabidopsis inhibited plant growth and seed size, although SiAAP9 was found to transport more amino acids into seeds. Furthermore, SiAAP9-OX transgenic Arabidopsis showed increased tolerance to high concentrations of glutamate (Glu) and histidine (His). The high overexpression level of SiAAP9 suggested its protein was not only located on the plasma membrane but potentially on other organelles, as well. Interestingly, sequence deletion reduced SiAAP9's sensitivity to Brefeldin A (BFA), and SiAAP9 had ectopic localization on the endoplasmic reticulum (ER). Protoplast amino acid uptake experiments indicated that SiAAP9 enhanced Glu transport into foxtail millet cells. Overall, the two transcripts of SiAAP9 have similar functions, but SiAAP9L shows a higher colocalization with BFA compartments compared to SiAAP9S. Our research identifies a potential candidate gene for enhancing the nutritional quality of foxtail millet through breeding.

Identification, molecular evolution, codon bias, and expansion analysis of NLP transcription factor family in foxtail millet (Setaria italica L.) and closely related crops

The NODULE-INCEPTION-like protein (NLP) family is a plant-specific transcription factor (TF) family involved in nitrate transport and assimilation in plants, which are essential for improving plant nitrogen use efficiency. Currently, the molecular nature and evolutionary trajectory of NLP genes in the C4 model crop foxtail millet are unknown. Therefore, we performed a comprehensive analysis of NLP and molecular evolution in foxtail millet by scanning the genomes of foxtail millet and representative species of the plant kingdom. We identified seven NLP genes in the foxtail millet genome, all of which are individually and separately distributed on different chromosomes. They were not structurally identical to each other and were mainly expressed on root tissues. We unearthed two key genes (Si5G004100.1 and Si6G248300.1) with a variety of excellent characteristics. Regarding its molecular evolution, we found that NLP genes in Gramineae mainly underwent dispersed duplication, but maize NLP genes were mainly generated via WGD events. Other factors such as base mutations and natural selection have combined to promote the evolution of NLP genes. Intriguingly, the family in plants showed a gradual expansion during evolution with more duplications than losses, contrary to most gene families. In conclusion, this study advances the use of NLP genetic resources and the understanding of molecular evolution in cereals.

Polyphenols from whole millet grain (Setaria italica) alleviate glucose and lipid homeostasis in diet-induced obese mice by increasing endogenous GLP-1

BACKGROUND

Foxtail millet (Setaria italica) is a whole millet grain that has been considered for improving the disorder of glucose and lipid metabolism. The purpose of the work is to explore the extraction and enrichment of polyphenols from foxtail millets which can regulate the disorder of glucose and lipid metabolism by increasing endogenous GLP-1 (glucagon-like peptide-1).

RESULTS

The optimum ultrasound-assisted extraction (UAE) of foxtail millet polyphenols (FMPs) was as follows: 70 °C and 400 W and 70% ethanol concentration, further purification using macroporous resin. In vitro, the FMP eluent of 60% ethanol (FMP-60) has the best effect in promoting GLP-1 secretion from L cells among the different active components of FMP. Millet polyphenols (MPs) were obtained from finishing foxtail millet with the bran removed by the same extraction and purification method. Compared with MP-60, FMP-60 mainly included eight active phenolic constituents and contained more ferulic acid, p-coumaric acid, 2-hydroxycinnamic acid, and coniferaldehyde. After gavage treatment of diet-induced obese (DIO) mice with FMP-60, FMP-60 promoted endogenous GLP-1 secretion in mice and ameliorated disorders of glucolipid metabolism in DIO mice.

CONCLUSION

FMP-60 could improve glucose homeostasis and ameliorates metabolic disease by promoting the endogenous GLP-1 level and preventing weight gain in DIO mice. © 2023 Society of Chemical Industry.

Starch chain-length distributions determine cooked foxtail millet texture and starch physicochemical properties

Starch chain-length distributions play an important role in controlling cereal product texture and starch physicochemical properties. Cooked foxtail millet texture and starch physicochemical properties were investigated and correlated with starch chain-length distributions in eight foxtail millet varieties. The average chain lengths of amylopectin and amylose were in the range of DP 24-25 and DP 878-1128, respectively. The percentage of short amylopectin chains (Ap1) was negatively correlated with hardness but positively correlated with adhesiveness and cohesion. Conversely, the amount of amylose intermediate chains was positively correlated with hardness but negatively correlated with adhesiveness and cohesion. Additionally, the amount of amylose long chains was negatively correlated with adhesiveness and chewiness. The relative crystallinity (RC) of starch decreased with reductions in the length of amylopectin short chains in foxtail millet. Pasting properties were mainly influenced by the relative length of amylopectin side chains and the percentage of long amylopectin branches (Ap2). Longer amylopectin long chains resulted in lower gelatinization temperature and enthalpy (ΔH). The amount of starch branched chains had important effects on the gelatinization temperature range (ΔT). These results can provide guidance for breeders and food scientists in the selection of foxtail millet with improved quality properties.

Comparison of dehulling efficiency and grain nutritional parameters of two cultivated barnyard millet species (Echinochloa spp.)

Due to increased awareness regarding the health-promoting profile of millets, inclination towards their consumption has increased considerably. In the Himalayan region of India, cultivars of the two species of barnyard millet, namely Indian (Echinochloa frumentacea) and Japanese barnyard millet (E. esculenta), are grown. To compare the dehulled grain recovery, grain physical parameters, nutritional profile and antioxidant activity, an experiment was carried out at ICAR-VPKAS, Almora, Uttarakhand hills for two years using released and popular cultivars of Indian barnyard millet (VL 207 and VL 172) and Japanese barnyard millet (PRJ-1). The results indicated that the whole grain yield of Japanese barnyard millet cultivar PRJ-1 was significantly higher than Indian Barnyard millet cultivars VL 172 and VL 207; however, the dehulled grain recovery was considerably higher in VL 172 and VL 207 than PRJ-1. Similarly, the physical grain parameters were significantly higher in PRJ-1, but most dehulled grain parameters were at par in cultivars of both species. The nutritional estimation of dehulled grains of both species did not show remarkable differences for most traits. Still, crude fibre, Mn, and Zn were high in PRJ-1, while total digestible nutrients and phosphorous were high in VL 172 and VL 207. Dehulled grains exhibited much more crude protein, ash, minerals, and total digestible nutrients, but the husk accumulated significantly higher crude fibre and total polyphenols.

Analysis of genetic diversity and population structure of Magnaporthe grisea, the causal agent of foxtail millet blast using microsatellites

Foxtail millet blast caused by Magnaporthe grisea is becoming a severe problem in foxtail millet growing regions of India. The genetic diversity and population structure of foxtail millet infecting M. grisea is crucial for developing effective management strategies, such as breeding blast-resistant cultivars. We analyzed thirty-two M. grisea isolates from ten foxtail millet-growing districts in Tamil Nadu, India for genetic diversity using twenty-nine microsatellite or simple sequence repeat (SSR) markers. A total of 103 alleles were identified with a mean of 3.55 alleles/locus. Gene diversity ranged from 0.170 to 0.717, while major allelic frequencies ranged from 0.344 to 0.906. The polymorphism information content (PIC) ranged from 0.155 to 0.680, with a mean value of 0.465. Population structure analysis of the genomic data sets revealed two major populations (SP1 and SP2) with different levels of ancestral admixture among the 32 blast isolates. Phylogenetic analysis classified the isolates into three major clusters. Analysis of molecular variance (AMOVA) showed high genetic variation among individuals and less among populations. Principal Coordinate Analysis (PCoA) revealed 27.16% genetic variation among populations. The present study provides the first report on the genetic diversity and population structure of the foxtail millet-infecting M. grisea population in Tamil Nadu, which could be useful for the development of blast-resistant foxtail millet cultivars.

Valorization of millet agro-residues for bioenergy production through pyrolysis: Recent inroads, technological bottlenecks, possible remedies, and future directions

Millets are receiving increasing attention, lately, in view of their preeminent agronomic traits, nutritional significance, and renewed emphasis on highlighting their health benefits through national and international programs. As a consequence, a variety of millets are being cultivated in different parts of the world resulting in significant amount of millet agro-residues. Present study comprehends critical analysis of reported investigations on pyrolysis of different millet agro-residues encompassing (i) physico-chemical characterization (ii) kinetics and thermodynamic parameters (iii) reactors employed and (iv) relationship between the reaction conditions and characteristics of millets-derived biochar and its prospective applications. Based on the analysis of reported investigations, specific research gaps have been figured out. Finally, future directions for leveraging the energy potential of millet agro-residues are also discussed. The analysis elucidated is expected to be useful for the researchers for making further inroads pertaining to sustainable utilization of millet agro-residues in tandem with other commonly employed agro-residues.

From Foxtail Millet Husk (Waste) to Bioactive Phenolic Extracts Using Deep Eutectic Solvent Extraction and Evaluation of Antioxidant, Acetylcholinesterase, and α-Glucosidase Inhibitory Activities

Foxtail millet husk (FMH) is generally removed and discarded during the first step of millet processing. This study aimed to optimize a method using deep eutectic solvents (DESs) combined with ultrasonic-assisted extraction (UAE) to extract phenols from FMH and to identify the phenolic compositions and evaluate the biological activities. The optimized DES comprised L-lactic acid and glycol with a 1:2 molar ratio by taking the total flavonoid content (TFC) and total phenolic content (TPC) as targets. The extraction parameters were optimized to maximize TFC and TPC, using the following settings: liquid-to-solid ratio of 25 mL/g, DES with water content of 15%, extraction time of 41 min and temperature of 51 °C, and ultrasonic power at 304 W. The optimized UAE-DES, which produced significantly higher TPC, TFC, antioxidant activity, α-glucosidase, and acetylcholinesterase inhibitory activities compared to conventional solvent extraction. Through UPLC–MS, 12 phenolic compounds were identified, with 1-O-p-coumaroylglycerol, apigenin-C-pentosyl-C-hexoside, and 1-O-feruloyl-3-O-p-coumaroylglycerol being the main phenolic components. 1-O-feruloyl-3-O-p-coumaroylglycerol and 3,7-dimethylquercetin were identified first in foxtail millet. Our results indicated that FMH could be exploited by UAE-DES extraction as a useful source of naturally derived antioxidants, along with acetylcholinesterase and α-glucosidase inhibitory activities.

Large-scale metabolome analysis reveals dynamic changes of metabolites during foxtail millet grain filling

Compared with traditional staple crops, foxtail millet grain is rich in nutrition and beneficial to human health. Foxtail millet is also tolerance to various abiotic stresses, including drought, making it a good plant for growing in barren land. The study on the composition of metabolites and its dynamics changes during grain development is helpful to understand the process of foxtail millet grain formation. In our study, metabolic and transcriptional analysis were used to uncover the metabolic processes that could influence grain filling in foxtail millet. A total of 2104 known metabolites, belonging to 14 categories, were identified during grain filling. Functional analysis of DAMs and DEGs revealed a stage-specific metabolic properties in foxtail millet grain filling. Some important metabolic processes, such as flavonoid biosynthesis, glutathione metabolism, linoleic acid metabolism, starch and sucrose metabolism and valine, leucine and isoleucine biosynthesis were co-mapped for DEGs and DAMs. Thus, we constructed a gene-metabolite regulatory network of these metabolic pathways to explain their potential functions during grain filling. Our study showed the important metabolic processes during grain filling and focused on the dynamic changes of related metabolites and genes at different stages, which provided a reference for us to better understand and improve foxtail millet grain development and yield.

Health-Promoting Potential of Millet: A Review

Being a key source of animal food, millet production has been sharply increasing over the last few years in order to cope with the dietary requirements of the ever-increasing world population. It is a splendid source of essential nutrients such as protein, carbohydrates, fat, minerals, vitamins, and also some other bioactive compounds that eventually help through multiple biological activities, including antioxidant, anti-hyperglycemic, anti-cholesterol, anti-hypertensive, anthropometric effects and regulation of gut microbiota composition. These bioactive compounds, nutrients, and functions of cereal grains can be affected by processing techniques such as decortication, soaking, malting, milling, fermentation, etc. This study discusses the nutritional and functional properties of millet-incorporated foods and their impact on health, based on around 150 articles between 2015 and 2022 from the Web of Science, Google Scholar, Food and Agriculture Organization of the United Nations (FAO), Breeding Bid Survey (BBS), and FoodData Central (USDA) databases. Analyzing literature reviews, it is evident that the incorporation of millet and its constituents into foodstuffs could be useful against undernourishment and several other health diseases. Additionally, this review provides crucial information about the beneficial features of millet, which can serve as a benchmark of guidelines for industry, consumers, researchers, and nutritionists.

Foxtail millet [Setaria italica (L.) P. Beauv.] grown under nitrogen deficiency exhibits a lower folate contents

Foxtail millet [Setaria italica (L.) P. Beauv.], as a rich source of folates, has been cultivated on arid infertile lands, for which N deficiency is one of the major issues. Growing environments might have a significant influence on cereal folate levels. However, little is known whether N deficiency modulates cereal folate levels. In order to obtain enriched folate foxtail millet production in nutrient-poor soil, we conducted a study investigating the content of folate derivatives of 29 diverse foxtail millet cultivars under two N regimes (0 and 150 kg N ha^-1) for 2 years to explore folate potential grown under low N. The contents of total folate and most derivatives were reduced by N deficiency. The effect on total folate content caused by N was stronger than cultivar genotype did. Folate content of enriched folate cultivars was prone to be reduced by N deficiency. Structural equation models (SEMs) revealed that N fertilization had a positive indirect effect on grain folate content through influencing plant N and K accumulation. Collectively, the results indicate much more attention should be paid to N management when foxtail millet is cultivated in infertile soil, to improve foxtail millet folate contents.

Nutrient Composition of Germinated Foxtail Millet Flour Treated with Mixed Salt Solution and Slightly Acidic Electrolyzed Water

Germination of millet can improve its consumption quality, optimize its nutritional composition, and promote the accumulation of functional components such as γ-aminobutyric acid (GABA). In the present study, foxtail millet was germinated with tap water, a mixed salt solution of 7.5 mmol/L NaCl and 15 mmol/L CaCl₂, and slightly acidic electrolyzed water (SAEW) with three available chlorine concentrations (ACCs; 10.92, 20.25, and 30.35 mg/L). The effects of the salt solution and SAEW on the germination of foxtail millet and the GABA, crude protein, and amino acid composition of the germinated millet flour were analyzed. The results showed that the salt solution and SAEW treatments promoted the growth of millet sprouts, contributed to the accumulation of GABA in germinated millet flour, and optimized the protein and amino acid composition. The GABA content of germinated foxtail millet flour treated with salt solution for 60 h (336.52 mg/100 g) was 29.5 times higher than that of ungerminated millet flour. In conclusion, the highest GABA content and amino acid scores of germinated millet flour obtained by germination treatment with salt solution at 25 °C and 86% humidity for 60 h were more acceptable for human nutritional requirements.

Total Protein Content, Amino Acid Composition and Eating-Quality Evaluation of Foxtail Millet (Setaria italica (L.) P. Beauv)

Foxtail millet has attracted substantial attention in recent years because of its excellent properties as a cereal crop with high nutritional value. Although the cultivation area of foxtail millet keeps growing, the fundamental research into the nutritional and eating qualities of foxtail millet germplasm collections is limited. In this study, we performed a survey of protein content, amino acid composition and eating quality among a germplasm collection of foxtail millet accessions grown in different environments. Our results revealed 21 accessions with stable protein content under different environments. The correlation analysis further revealed that the protein content of the grains was affected by environmental and genotypic interactions. The further amino acid composition analyses suggested that higher protein content accessions have a better essential amino acid index, providing more nutritional value for human beings and animal feedstock. Moreover, the flavor-related amino acid content and other eating-quality trait analyses were also performed. The subordinative analysis suggested that B331 could be the best accession with high protein content and superior eating quality. Taken together, this study provides essential nutritional and eating-quality data on our germplasm collection of foxtail millets, and provides a core genetic resource from which to breed elite foxtail millet varieties in the future.

Protective Effect of Foxtail Millet Protein Hydrolysate on Ethanol and Pyloric Ligation-Induced Gastric Ulcers in Mice

Foxtail millet has been traditionally considered to possess gastroprotective effects, but studies evaluating its use as a treatment for gastric ulcers are lacking. Here, we assessed the antiulcer effects of foxtail millet protein hydrolysate (FPH) and explored its mechanism by using blocking agents. In a mouse model of ethanol-induced gastric ulcers, pretreatment with FPH reduced the ulcerative lesion index, downregulated the expression of inflammatory cytokines in the gastric tissue, increased the activity of antioxidant enzymes, and improved the oxidative status. FPH increased constitutive the activity of nitric oxide synthase (cNOS), NO levels, and mucin expression in gastric mucosa, and inhibited the activation of the ET-1/PI3K/Akt pathway. In a mouse model of pyloric ligation-induced gastric ulcers, FPH inhibited gastric acid secretion and decreased the activity of gastric protease. Pretreatment of mice with the sulfhydryl blocker NEM and the NO synthesis inhibitor L-NAME abolished the gastroprotective effect of FPH, but not the KATP channel blocker glibenclamide and the PGE2 synthesis blocker indomethacin. Among the peptides identified in FPH, 10 peptides were predicted to have regulatory effects on the gastric mucosa, and the key sequences were GP and PG. The results confirmed the gastroprotective effect of FPH and revealed that its mechanism was through the regulation of gastric mucosal mucus and NO synthesis. This study supports the health effects of a millet-enriched diet and provides a basis for millet protein as a functional food to improve gastric ulcers and its related oxidative stress.

Genetic characterization of hull color using BSR-Seq and genome re-sequencing approaches in foxtail millet

Hull color of foxtail millet is an important indicator of certain nutritional quality parameters. An F_2:6 recombinant inbred line (RIL) population developed by crossing a yellow-hulled cultivar Yugu 5 and a brown-hulled cultivar Jigu 31 was used to determine the genetic control of the hull color trait. This population segregated for yellow and brown hull colors in a ratio of 2:1, indicating that hull color is regulated by multiple genetic loci. A bulk segregant analysis-RNA sequencing (BSR-Seq) approach performed using the RNA bulks from 30 lines with brown and yellow hull colors each identified three genomic regions on chromosomes 1 (4,570,517-10,698,955 bp), 2 (40,301,380-46,168,003 bp), and 3 (44,469,860-50,532,757 bp). A new QTL for brown hull color of Jigu 31, QHC.czas1, was detected between bin markers Block43 and Block697 on chromosome 1 with the genetic linkage map constructed by re-sequencing a subset of the 147 RILs. This QTL explained a high level of phenotypic variation ranging from 28.0% to 47.0%. The corresponding genomic region of this QTL in the foxtail millet reference genome overlapped with that detected on chromosome 1 by the BSR-Seq analysis. Nineteen genes associated with biosynthesis of anthocyanin were annotated in this genomic region. Gene Si1g06530 encoding a SANT/Myb domain protein was highly expressed in developing panicles and seeds, which warrants further verification as the candidate gene for the brown color hull of Jigu 31. Moreover, several annotated genes for biosynthesis of anthocyanin were identified in the genomic regions of chromosomes 2 and 3.

Physical, functional, nutritional and antioxidant properties of foxtail millet in Bangladesh

The nutritional and phytochemical content of foxtail millet (Cetaria italica) makes it a viable food grain. In this study, we looked at foxtail millet in Bangladesh and analyzed its nutritional value, functional and physical characteristics. In addition, methanol, ethanol, and acetone: water: acetic acid (70: 29.50: 0.50) extracts of foxtail millet flour (FMF) were analyzed for their antioxidant properties (total phenolic and flavonoid content, total antioxidant capacity, ferric reducing antioxidant power (FRAP) assay, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity). According to this study, foxtail millet has favorable physiological and functional properties. FMF had protein at 11.65 ± 0.45 g/100 g, fat at 3.48 ± 0.04 g/100 g, carbohydrates at 75.33 ± 0.53 g/100 g, and crude fiber at 2.21 ± 0.03 g/100 g. Calcium was found at 47 ± 0.48 mg/100 g, iron at 4.59 ± 0.14 mg/100 g, potassium at 393 ± 15.87, sodium at 27.4 ± 1.21, magnesium at 45.40 ± 2.22, manganese at 0.71 ± 0.02, copper at 0.58 ± 0.04 and zinc at 2.30 ± 0.18 mg/100 g. The total flavonoid content (TFC) of the methanolic extract (68.26 ± 1.51 mg quercetin equivalents (QE)/100 g) was significantly (p < 0.05) higher than the extract of acetone: water: acetic acid. Total antioxidant capacity (TAC) (169.40 ± 3.45 mg ascorbic acid equivalents (AAE)/100 g) and total phenolic content (TPC) (51.35 ± 1.35 mg gallic acid equivalents (GAE)/100 g) of the methanolic extracts were significantly (p < 0.05) higher than others. The ascending order of DPPH free radical scavenging activity of FMF extract is as follows: acetone: acetic acid: water < ethanol < methanol. In the ferric reducing antioxidant power (FRAP) test, the reducing power of FMF extracts increased with the rise in sample concentration. Foxtail millet has potential as a functional food that could influence rural residents' diets and health.

Effect of Mechanical Grinding on the Physicochemical, Structural, and Functional Properties of Foxtail Millet (Setaria italica (L.) P. Beauv) Bran Powder

This study investigated the functional, physicochemical, and structural characteristics of foxtail millet bran powder with different particle sizes. The morphological analysis revealed that the surface roughness declined in conjunction with the particle sizes of the millet bran powder. The Fourier-transform infrared (FTIR) spectra showed that none of the samples generated any additional chemical functional groups. A decrease in the particle sizes of the millet bran powder increased their dissemination and surface areas, as well as the bulk density, tap density, water-holding capacity (WHC), angle of repose (θ) and angle of slide (α), and peak temperature, while the oil holding capacity (OHC) and crystallinity index (CI) value declined. Moreover, fine millet bran powder (54.7 μm) exhibited a higher protein, fat, soluble dietary fiber (SDF), total phenolic content, and antioxidant capacity than its coarse counterpart.

Integrative genomics analysis of the ever-shrinking pectin methylesterase (PME) gene family in foxtail millet (Setaria italica)

Pectin methylesterase (PME) plays a vital role in the growth and development of plants. Their genes can be classified into two types, with Type-1 having an extra domain, PMEI. PME genes in foxtail millet (Setaria italica L.) have not been identified, and their sequence features and evolution have not been explored. Here, we identified 41 foxtail millet PME genes. Decoding the pro-region, containing the PMEI domain, revealed its more active nature than the DNA encoding PME domain, easier to be lost to produce Type-2 PME genes. We inferred that the active nature of the pro-region could be related to its harbouring more repetitive DNA sequences. Further, we revealed that though whole-genome duplication and tandem duplication contributed to producing new copies of PME genes, phylogenetic analysis provided clear evidence of ever-shrinking gene family size in foxtail millet and the other grasses in the past 100 million years. Phylogenetic analysis also supports the existence of two gene groups, Group I and Group II, with genes in Group II being more conservative. Our research contributes to understanding how DNA sequence structure affects the functional innovation and evolution of PME genes.

Transcriptome Analysis Reveals Molecular Mechanisms under Salt Stress in Leaves of Foxtail Millet (Setaria italica L.)

Foxtail millet (Setaria italica L.) is an important cereal for managing future water scarcity and ensuring food security, due to its strong drought and salt stress resistance owing to its developed root system. However, the molecular responses of foxtail millet leaves to salt stress are largely unknown. In this study, seeds of 104 foxtail millet accessions were subjected to 0.17 mol·L^-1 NaCl stress during germination, and various germination-related parameters were analyzed to derive 5 salt-sensitive accessions and 13 salt-tolerant accessions. Hong Gu 2000 and Pu Huang Yu were the most salt-tolerant and salt-sensitive accessions, respectively. To determine the mechanism of the salt stress response, transcriptomic differences between the control and salt-treated groups were investigated. We obtained 2019 and 736 differentially expressed genes under salt stress in the salt-sensitive and salt-tolerant accessions, respectively. The transcription factor families bHLH, WRKY, AP2/ERF, and MYB-MYC were found to play critical roles in foxtail millet's response to salt stress. Additionally, the down-regulation of ribosomal protein-related genes causes stunted growth in the salt-sensitive accessions. The salt-tolerant accession alleviates salt stress by increasing energy production. Our findings provide novel insights into the molecular mechanism of foxtail millet's response to salt stress.

Investigations on Functional and Thermo-Mechanical Properties of Gluten Free Cereal and Pseudocereal Flours

Seven commercial gluten-free (rice, oat, sorghum, foxtail millet, amaranth, quinoa, and buckwheat) flours were investigated in this study from the point of view of thermo-mechanical properties and solvent retention capacity (SRC). Each flour was used to prepare doughs with specific water absorption (WA) to get a consistency of 1.1 Nm (WA1) and doughs with WA2 levels higher than 85% to ensure a sufficient amount of water in the system for allowing the hydration of all components of the flours. Different correlations were established between proteins, ash, pentosans, damaged starch, and amylose contents on the one hand, and the capacity of the flour samples to retain different solvents such as sucrose, sodium carbonate and CaCl₂ on the other hand. Although no significant correlation was found between the protein content of the flours and lactic acid-SRC, the mechanical weakening of the protein was significantly correlated with lactic acid-SRC for both tested WA levels. The doughs with WA1 had higher starch gelatinization and hot gel stability values compared to the corresponding dough systems with a higher water amount. Moreover, lower starch retrogradation and setback torques were obtained in the case of the dough prepared with higher amounts of water.

Orphan Crops: A Best Fit for Dietary Enrichment and Diversification in Highly Deteriorated Marginal Environments

Orphan crops are indigenous and invariably grown by small and marginal farmers under subsistence farming systems. These crops, which are common and widely accepted by local farmers, are highly rich in nutritional profile, good for medicinal purposes, and well adapted to suboptimal growing conditions. However, these crops have suffered neglect and abandonment from the scientific community because of very low or no investments in research and genetic improvement. A plausible reason for this is that these crops are not traded internationally at a rate comparable to that of the major food crops such as wheat, rice, and maize. Furthermore, marginal environments have poor soils and are characterized by extreme weather conditions such as heat, erratic rainfall, water deficit, and soil and water salinity, among others. With more frequent extreme climatic events and continued land degradation, orphan crops are beginning to receive renewed attention as alternative crops for dietary diversification in marginal environments and, by extension, across the globe. Increased awareness of good health is also a major contributor to the revived attention accorded to orphan crops. Thus, the introduction, evaluation, and adaptation of outstanding varieties of orphan crops for dietary diversification will contribute not only to sustained food production but also to improved nutrition in marginal environments. In this review article, the concept of orphan crops vis-à-vis marginality and food and nutritional security is defined for a few orphan crops. We also examined recent advances in research involving orphan crops and the potential of these crops for dietary diversification within the context of harsh marginal environments. Recent advances in genomics coupled with molecular breeding will play a pivotal role in improving the genetic potential of orphan crops and help in developing sustainable food systems. We concluded by presenting a potential roadmap to future research engagement and a policy framework with recommendations aimed at facilitating and enhancing the adoption and sustainable production of orphan crops under agriculturally marginal conditions.

Protective effects of bioactive peptides in foxtail millet protein hydrolysates against experimental colitis in mice

It is of great significance to develop a dietary intervention strategy to prevent inflammatory bowel disease (IBD). A millet-rich diet can ameliorate IBD, but the active ingredients and mechanisms remain to be studied. Our results showed that the oral administration of foxtail millet protein hydrolysates (FMPH) reduced the disease activity index (DAI) score and improved the colon symptoms of dextran sulfate sodium (DSS)-induced colitis mice. FMPH reduced the serum LPS level, increased intestinal ZO-1 and occludin expression, inhibited NF-κB phosphorylation, and reduced the levels of TNF-α and IL-6. Further, FMPH inhibited Th17 cell differentiation, and inhibited inflammasome activation and IL-1β expression through the NLRP3/ASC/caspase-1 pathway. The results on Caco-2 cells confirmed the role of FMPH on tight junction and inflammasomes activation. A total of 2620 peptides were identified in FMPH by UPLC-MS/MS, of which 22 peptides were predicted as potential biopeptides, and the key sequences were LPF, ANP, PY, YW, and IPP. This study supports the effect of a diet rich in millet on the improvement of IBD and provides a scientific basis for the use of millet protein as a functional food to improve intestinal inflammation.

Effect of Different Processing Methods on the Millet Polyphenols and Their Anti-diabetic Potential

Interest in polyphenols has grown due to their beneficial effect on diabetes attenuation. Millets are ancient crops that are rich in polyphenols and used for both food and feed. They are grown worldwide and are adapted to production under dry, hot conditions. The polyphenols found in millets have anti-diabetic properties. However, millet is usually consumed after being processed by heating, germination, fermentation, and other processing methods, which may alter polyphenol content and thus affect their anti-diabetic potential. This mini-review profiles the effects of different processing methods on millet polyphenols and how changes in millet polyphenols affect the hypoglycemic effect of millet. Future studies are needed to compare the anti-diabetes potential of millet polyphenols before and after processing and to explore ways to minimize polyphenol losses and thus maintain their hypoglycemic effect in final products.

Modern Processing of Indian Millets: A Perspective on Changes in Nutritional Properties

Globally, billions of people are experiencing food insecurity and malnutrition. The United Nations has set a global target to end hunger by 2030, but we are far from reaching it. Over the decade, climate change, population growth and economic slowdown have impacted food security. Many countries are facing the challenge of both undernutrition and over nutrition. Thus, there is a need to transform the food system to achieve food and nutrition security. One of the ways to reach closer to our goal is to provide an affordable healthy and nutritious diet to all. Millets, the nutri-cereals, have the potential to play a crucial role in the fight against food insecurity and malnutrition. Nutri-cereals are an abundant source of essential macro- and micronutrients, carbohydrates, protein, dietary fiber, lipids, and phytochemicals. The nutrient content and digestibility of millets are significantly influenced by the processing techniques. This review article highlights the nutritional characteristics and processing of Indian millets, viz. foxtail, kodo, proso, little, and pearl millets. It also envisages the effect of traditional and modern processing techniques on millet’s nutritional properties. An extensive literature review was conducted using the research and review articles related to processing techniques of millets such as fermentation, germination, dehulling, extrusion, cooking, puffing, popping, malting, milling, etc. Germination and fermentation showed a positive improvement in the overall nutritional characteristics of millets, whereas excessive dehulling, polishing, and milling resulted in reduction of the dietary fiber and micronutrients. Understanding the changes happening in the nutrient value of millets due to processing can help the food industry, researchers, and consumers select a suitable processing technique to optimize the nutrient value, increase the bioavailability of nutrients, and help combat food and nutrition security.

Anti-nutrient & bioactive profile, in vitro nutrient digestibility, techno-functionality, molecular and structural interactions of foxtail millet (Setaria italica L.) as influenced by biological processing techniques

The present investigation aimed at assessing the impact of biological processing techniques on bio-and techno-functional characteristics of foxtail millet (Setaria italica L.). Grains were exposed to soaking, germination, fermentation and combination of aforesaid treatments and significant variation (p < 0.05) in anti-nutritional factors, in vitro starch and protein digestibility, bioactive constituents and associated antioxidant potential was noted. Bioprocessed flours were characterized by altered functional properties due to hydrolytic action of activated enzymes. ATR-FTIR spectra and X-ray diffraction patterns revealed structural variation in macromolecular arrangement, synthesis of bioactive compounds in bioprocessed flours and slight reduction in the crystallinity of starch molecules. Bioprocessed flours exhibited degraded protein matrix; however, only fermentation and combination treatments caused hydrolysis of granular starch. Principal component analysis was employed to validate the differences in processing treatments and observations. The results are suggestive that bioprocessed flours could serve as potential ingredients with improved techno-and bio-functionality in valorized cereal products.

Gluten-Free Cereal Products and Beverages: A Review of Their Health Benefits in the Last Five Years

In the past decades, food products and beverages made from gluten-free cereals were initially created for certain groups of people who experience gluten-related disorders such as wheat allergies, gluten ataxia, non-celiac gluten sensitivity, and the most well-known, celiac disease. Nowadays, the consumption of gluten-free products is not only restricted to targeted groups, but it has become a food trend for normal consumers, especially in countries such as the UK, the US, and some European countries, who believe that consuming a gluten-free product is a healthier choice compared to normal gluten-containing products. However, some research studies have disapproved of this claim because the currently available gluten-free products in the market are generally known to be lower in proteins, vitamins, and minerals and to contain higher lipids, sugar, and salt compared to their gluten-containing counterparts. The use of other gluten-free cereals such as sorghum, millet, and teff as well as pseudo cereals such as buckwheat and quinoa has gained significant interest in research in terms of their various potential health benefits. Hence, this review highlights the potential health benefits of some gluten-free cereals and pseudo cereals apart from corn and rice in the last decade. The potential health benefits of gluten-free products such as bread, pasta, crackers, and cookies and the health benefits of some other non-alcoholic beverages made from gluten-free cereals and pseudo cereals are reported.

Improvement of small seed for big nutritional feed

Exploding global population, rapid urbanization, salinization of soils, decreasing arable land availability, groundwater resources, and dynamic climatic conditions pose impending damage to our food security by reducing the grain quality and quantity. This issue is further compounded in arid and semi-arid regions due to the shortage of irrigation water and erratic rainfalls. Millets are gluten (a family of proteins)-free and cultivated all over the globe for human consumption, fuel, feed, and fodder. They provide nutritional security for the under- and malnourished. With the deployment of strategies like foliar spray, traditional/marker-assisted breeding, identification of candidate genes for the translocation of important minerals, and genome-editing technologies, it is now tenable to biofortify important millets. Since the bioavailability of iron and zinc has been proven in human trials, the challenge is to make such grains accessible. This review encompasses nutritional benefits, progress made, challenges being encountered, and prospects of enriching millet crops with essential minerals.

Eco-geographic patterns of child malnutrition in India and its association with cereal cultivation: An analysis using demographic health survey and agriculture datasets

Background: High prevalence of maternal malnutrition, low birth-weight and child malnutrition in India contribute substantially to the global malnutrition burden. Rural India has disproportionately higher levels of child malnutrition. Stunting and wasting are the primary determinants of child malnutrition and their district-level distribution shows clustering in different geographies and regions. Cereals, particularly millets, constitute the bulk of protein intake among the poor, especially in rural areas in India where high prevalence of wasting persists. Methods: The last round of National Family Health Survey (NFHS4) has disaggregated data by district, enabling a more fine-scale characterisation of the prevalence of markers of malnutrition. We used data from NFHS4 and agricultural statistics datasets to analyse relationship of prevalence of malnutrition at the district level and area under cereal cultivation. We analysed malnutrition through data on under-5 stunting and wasting by district.  Results: Stunting and wasting patterns across districts show a distinct geographical and age distribution; districts with higher wasting showed relatively higher prevalence before six months of age. Wasting prevalence at district level was associated with higher cultivation of millets, with a stronger association seen for jowar and other millets (Kodo millet, little millet, proso millet, barnyard millet and foxtail millet). District level stunting was associated with higher district level cultivation of all crops (except other millets). The analysis was limited by lack of fine-scale data on prevalence of low birth-weight and type of cereal consumed. Conclusions: Better cereal cultivation and consumption data will be needed to confirm causal pathways contributing to potential ecogeographic patterns. The cultivation of other millets has a strong association with prevalence of wasting. State-of-the-art studies that improve our understanding of bio-availability of amino acids and other nutrients from the prevalent dietary matrices of rural poor communities will be needed to confirm causal pathways contributing to potential eco-geographic patterns.

Structural and Film-Forming Properties of Millet Starches: A Comparative Study

Millets are an underutilized and important drought-resistant crop, which are mainly used for animal feed. The major constituent in millet is starch (70%); millet starch represents an alternative source of starches like maize, rice, potato, etc. This encouraged us to isolate and characterize the starches from different millet sources and to evaluate the application of these starches in edible film preparation. In the present study, the physicochemical, morphological, and film-forming characteristics of millet starches were studied. The amylose content, swelling power, and solubility of millet starches ranged from 11.01% to 16.61%, 14.43 to 18.83 g/g, and 15.2% to 25.9%, respectively. Significant differences (p < 0.05) were found with different pasting parameters, and the highest peak (2985 cP), breakdown (1618 cP), and final viscosity (3665 cP) were observed for barnyard, proso, and finger millet starch, respectively. Little millet starch achieved the highest pasting temperature. All starches showed A-type crystalline patterns, and relative crystallinity was observed at levels of 24.73% to 32.62%, with proso millet starch achieving the highest value. The light transmittance of starches varied from 3.3% to 5.2%, with proso millet starch showing the highest transparency. Significant differences (p < 0.05) were observed in the water solubility, thickness, opacity and mechanical characteristics of films. The results of the present study facilitate a better assessment of the functional characteristics of millet starches for their possible applications in the preparation of starch films.

Effects of Different Amylose Contents of Foxtail Millet Flour Varieties on Textural Properties of Chinese Steamed Bread

In order to improve the nutritional value and quality of steamed bread, and promote the industrial development of the whole-grain food industry, a texture analyzer was used to study the effects of cultivars of whole foxtail millet flour (WFMF) on the texture of Chinese steamed bread (CSB). Orthogonal partial least squares discriminant analysis (OPLS-DA) was also conducted. The addition of different cultivars of WFMF significantly altered the height–diameter ratio, specific volume, hardness, cohesiveness, gumminess, and chewiness of CSB (p < 0.05). Large amounts of foxtail millet flour significantly increased the hardness, gumminess and chewiness of the bread (p < 0.05), and the bread height–diameter ratio, specific volume, cohesiveness and springiness significantly decreased (p < 0.05). We screened sensory evaluation, chewiness, specific volume, and hardness as the signature differences in the quality components according to the variable influence on the projection (VIP) values. OPLS-DA could distinguish the addition levels of different samples.

Foxtail Millet Improves Blood Glucose Metabolism in Diabetic Rats through PI3K/AKT and NF-κB Signaling Pathways Mediated by Gut Microbiota

Foxtail millet (FM) is receiving ongoing increased attention due to its beneficial health effects, including the hypoglycemic effect. However, the underlying mechanisms of the hypoglycemic effect have been underexplored. In the present study, the hypoglycemic effect of FM supplementation was confirmed again in high-fat diet and streptozotocin-induced diabetic rats with significantly decreased fasting glucose (FG), glycated serum protein, and areas under the glucose tolerance test (p < 0.05). We employed 16S rRNA and liver RNA sequencing technologies to identify the target gut microbes and signaling pathways involved in the hypoglycemic effect of FM supplementation. The results showed that FM supplementation significantly increased the relative abundance of Lactobacillus and Ruminococcus_2, which were significantly negatively correlated with FG and 2-h glucose. FM supplementation significantly reversed the trends of gene expression in diabetic rats. Specifically, FM supplementation inhibited gluconeogenesis, stimulated glycolysis, and restored fatty acid synthesis through activation of the PI3K/AKT signaling pathway. FM also reduced inflammation through inhibition of the NF-κB signaling pathway. Spearman’s correlation analysis indicated a complicated set of interdependencies among the gut microbiota, signaling pathways, and metabolic parameters. Collectively, the above results suggest that the hypoglycemic effect of FM was at least partially mediated by the increased relative abundance of Lactobacillus, activation of the PI3K/AKT signaling pathway, and inhibition of the NF-κB signaling pathway.

Transcriptome analysis reveals the mechanism associated with dynamic changes in fatty acid and phytosterol content in foxtail millet (Setaria italica) during seed development

Foxtail millet (Setaria italica) is an excellent source of beneficial natural fatty acids and phytosterols. However, the mechanisms underlying the dynamic changes of fatty acids and phytosterols during seed development are unknown. In this study, a comprehensive dynamic change analysis of the bioactive compounds during seed development was conducted in two cultivars with different crude fat content (high-fat, JG 35 [5.40%]; and low-fat, JG 39 [2.90%]). GC-FID/MS analysis showed that the proportion of unsaturated fatty acids (UFAs) were higher than the saturated fatty acids (SFAs). UFA content first increased, then decreased during seed development, while SFA content showed the opposite trend. Oil contents continuously increased with seed development, especially at the S2 stage. Phytosterol contents initially increased, then decreased with seed development. Transcriptome analysis revealed that 152 genes were associated with fatty acid metabolism and phytosterol biosynthesis, of which 46 and 62 were related to UFA and phytosterol biosynthesis, respectively. Furthermore, the key genes involved in fatty acid synthesis (ACCase and FATA/B), triacylglycerol biosynthesis (LACS, GPAT, and DGAT), and phytosterols synthesis (CAS1, STM1, EGR6, and DWF1) were overexpressed. This led to maximum UFA, oil, and phytosterol accumulation in JG 35 at the S2 stage. This study reveals the mechanism behind the dynamic changes of fatty acid and phytosterol contents in foxtail millet during seed development.