The understanding of the protein structure-function relationship is very important to the study of protein chemistry. In this research, the physicochemical, functional, and structural properties of ...the storage protein fractions from two defatted proso millet cultivars (Dawn and Plateau) were determined and reported. The results show that protein recovery efficiency of 53.5% and 60.1% was recorded for Dawn and Plateau, respectively. The average denaturation temperature of all fractions was about 82.1 ± 3.5 °C. Surface hydrophobicity values for Dawn fractions were 11781, 10594, 316, and 2225 for albumin, globulin, and glutelin, respectively and 3415, 2865, 353, and 456 for Plateau fractions, respectively. Most of the protein fractions showed the highest solubility at pH 9 and lowest solubilities at pH ≤ 7 with solubility range from 5.7 to 100%. Emulsifying activity index (EAI) of less than 0.25 m2/g was recorded for most fractions, while the highest emulsion stability index (ESI) recorded was about 60 min. Prolamin fractions showed three major peptide bands of 11, 14, and 24 kDa while glutelin fraction revealed only a major band of 15 kDa and several minor bands of 11, 22, 24, 78, 209 kDa. No differences in the electrophoresis pattern were observed for the fraction with or without a reducing agent.
Extraction and characterization of proso millet protein fractions. Display omitted
•Prolamin is the major protein fraction in proso millet and with least solubility.•Albumin and globulin showed a higher S0 to prolamin and glutelin protein fractions.•EAI was highest in albumin fraction while ESI was highest in prolamin fraction.•FC and FS is highest in glutelin fraction but lowest in prolamin fraction.•Major polypeptide bands in prolamin are 11, 14 and 24 kDa; 15 kDa for glutelin.
As part of ongoing efforts to promote millet as a double crop for the American Midwest, four Minnesota-grown proso millet varieties were selected for fresh gluten-free pasta production and compared ...to commercially available fresh gluten-free and wheat pasta. Raw and cooked pasta were analyzed for starch and protein content, color, and carotenoids. Cooked pasta was assessed for cooking quality, in-vitro starch and protein digestibility, and sensory quality. Millet pasta contained less rapidly digestible starch than commercial gluten-free pasta; however, millet and commercial gluten-free pasta had lower protein digestibility than wheat pasta. Sensory panelists detected more graininess and starchiness in millet samples than in commercial pasta. Millet varieties differed in amylose content and prolamin profile, and both factors influenced pasta properties. Pasta with more amylose and high-molecular weight prolamins had lower cooking loss and lower stickiness scores. Higher amylose contents also corresponded to higher firmness and chewiness among millet pasta samples. The millet sample with the lowest amylose and prolamin content yielded pasta of the lowest quality. Results indicated that select proso millet varieties may be suitable for fresh pasta, yet quality improvement is warranted by recipe or processing optimizations.
•Both amylose content and prolamin profile influenced millet pasta properties.•High amylose and high-molecular weight prolamins caused low leaching and low pasta stickiness.•High amylose content corresponded to high firmness and chewiness.•The millet sample with the lowest amylose and prolamin content yielded pasta of the lowest quality.
Drought is one of the environmental stressors that limits plant growth, production, and is a great threat to the rising population and security throughout the globe. In the present work, we aimed to ...check the impact of drought stress given at different days interval drought (DID) on proso millet and its tolerance capability. The pot culture experiment was conducted and drought stress was given at 3 DID, 5 DID, and 7 DID respectively, and sampling was done on 15, 30, and 60 DAS, and unstressed plants were irrigated regularly. Drought stress results in decreased protein contents in both the roots and shoots of P. miliaceum on all sampling days. However, with increasing drought intensity and duration there was a tremendous increase in amino acids, and proline contents as well. Therefore, increasing osmolytes like proline with an increased drought period proves the role of proline in stress tolerance of proso millet and helps it to survive by maintaining osmotic potential, water influx, and detoxifying ROS. Thus, proso millet can be cultivated in drought-prone areas, and used for the breeding program.
This study investigated the composition and properties of four colors of proso millet husks and brans. The brans had the highest crude protein, crude fat, and starch content, whereas the husks had ...the highest crude fiber level. The husks had greater water holding capacity, oil holding capacity, swelling capacity, glucose absorption capacity, TPC, TFC, and antioxidant capacity than the brans. TPC and TFC were significantly associated with the color values of husks and brans. The varieties of phenolic chemical compounds and content extracted from black and white proso millet husks and brans varied considerably. Twenty-six, twenty-four, twenty-four, and nineteen phenolics were identified in black and white proso millet husks and brans. The husks and brans with varied colors differed in physicochemical characteristics to assess their food and non-food application potential.
•Physicochemical properties and phenolics of proso millet husk and bran were compared.•The color of proso millet husk and bran showed variations in the nutrition contents.•The nutraceutical components are distributed unevenly among the husks and brans.•The phenolic compound composition varied among different color samples.
Profile of phenolic compounds and antioxidant activity of proso millets were studied. Twelve phenolic derivatives were identified in the free extract, including N′-caffeoyl-N″-feruloylspermidine, N′, ...N″-dicaffeoylspermidine and N-(p-coumaroyl) serotonin reported for the first time in proso millets. Fifteen phenolic acid derivatives were found in the bound fraction with p-coumaric acid and ferulic acid being the major phenolic acids, as well as four ferulic acid dimers (DFAs) detected for the first time in proso millets. The total phenolic content (TPC) of the soluble and insoluble phenolic fractions varied from 592 to 1510 mg ferulic acid equivalents (FAE)/kg dry weight (DW) and 1146–2436 mg FAE/kg DW, respectively. The total flavonoid content (TFC) of the proso millets ranged from 284 to 978 mg rutin equivalents (RE)/kg DW. DPPH, ABTS and FRAP assays were applied to determine in vitro antioxidant activities for all the phenolic extracts, and the antioxidant levels were attributed to TPCs. The diverse phenolics contributed to the antioxidant properties of proso millet, which can serve as viable functional food ingredients.
•N-(p-coumaroyl) serotonin and two hydroxycinnamic acid spermidines were identified in proso millet.•Two chlorogenic acid isomers and four ferulic acid dimers were detected.•Ferulic acid and p-coumaric acid were the major phenolic acids in bound form.•Proso millet could serve as healthy food ingredients for development of functional foods.
Proso millet flour (PMF) and starch (PMS) were subjected to heat-moisture treatment (HMT) at 25 % moisture content and 110 °C for 4 h. The effects of HMT on physicochemical and structural properties ...and in vitro digestibility of PMF and PMS were analyzed. After HMT, SEM showed aggregation and damage to the surface of starch granules, while CLSM showed proteins wrapped around the granules. The amylopectin chain length distribution (CLD) remained unchanged in PMF and PMS after HMT, indicating intact covalent bonds between glucose units. HMT decreased the swelling power, solubility, viscosity of the paste, and gelatinization enthalpy and increased the pasting temperature and gelatinization temperature of PMF and PMS. HMT changed the XRD pattern of PMF from A to A + V type starches, whereas that of PMS remained unchanged. FTIR study showed an increase in the degree of short-range molecular order of PMF and PMS after HMT. In vitro digestibility evaluation showed that the rapidly (RDS) and slowly digestible starch (SDS) contents of PMF and PMS increased, whereas the resistant starch (RS) content decreased after HMT. HMT flour and starch have suitable properties for use in a wide range of food products, from canned to frozen, as well as non-food products.
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•Heat-moisture treatment (HMT) affected properties of proso millet flour and starch.•HMT decreased swelling power, solubility, paste viscosity, and gelatinization enthalpy.•HMT increased pasting and gelatinization temperatures and short-range molecular order.•HMT had no effect on the amylopectin chain length distribution of flour and starch.•HMT increased RDS and SDS content and decreased RS content of flour and starch.
Proso millet (PM) is a gluten-free cereal grain with potential to be used in gluten-free product development. However, research on improving the rheological properties of PM dough is limited. In the ...present study, rheological and color characteristics of PM dough (37% moisture) were compared with the behavior of wheat dough. Three hydrocolloids guar gum (GG), xanthan gum (XG) and sodium alginate (SA) at concentrations of 0%, 1% and 2% were added to improve the physical properties of PM dough. The textural properties of PM dough developed pasta with hydrocolloids were also studied. Wheat dough presented a much higher apparent viscosity and elastic modulus than PM dough. Both the apparent viscosity and elasticity were increased by all three hydrocolloids, with 2% XG presenting the most pronounced improvement in elasticity. Generally, the capacity of hydrocolloids to improve the PM dough follow the order XG > GG > SA. The addition of hydrocolloids showed no significant impact on the color of PM dough. GG and XG showed an improvement in the network strength of PM pasta, while SA did not contribute to textural enhancement.
•Proso millet (PM) was utilized as the sole ingredient to produce gluten-free pasta.•The rheology of PM dough was improved by sodium alginate (SA), guar gum (GG) and xanthan gum (XG).•XG and GG improved the texture of PM pasta while SA had no contribution.•Hydrocolloids did not significantly affect the color of proso millet dough.
Proso millet, a high-quality fermentation material used for Chinese yellow wine production, can produce special flavored substances; however, its role in improving the flavor and altering microbial ...communities of light-flavored Baijiu during fermentation remain unknown. Thus, we aimed to investigate the effect of proso millet on improving the flavor of light-flavored Baijiu and altering microbial communities during different fermentation stages.
The dynamic changes in the microbial communities and flavor of proso millet (50%) + sorghum (50%) mixed fermentation samples were analyzed through intermittent sampling on days 7, 14, 21, and 28 of the fermentation process. Microbial high-throughput sequencing and the analysis of flavor characteristics were conducted through 16S DNA/ ITS amplicon sequencing and gas chromatography (multi-capillary column)-ion mobility spectrometry, respectively.
Proso millet significantly changed the core flavor compound composition of traditional light-flavored Baijiu from ethyl acetate, ethyl hexanoate, ethyl hexanoate dimer, ethyl butanoate, ethyl lactate, and butyl acetate to oct-2-ene, 2-butanol, propyl propanoate, 2-pentenal, and 4-methylpentanal. The amplicon sequencing analysis revealed that the alpha diversity parameters of bacterial and fungal communities, including the Chao1, Pielou_e, Shannon, and Simpson indices, for proso millet-sorghum mixed fermentation samples were significantly higher than those for sorghum fermentation samples (
< 0.05). Of the 40 most significant microbial genera in two treatments, proso millet significantly increased the abundance of 12 bacterial and 18 fungal genera. Among the 40 most significant bacterial and fungal species, 23 bacterial species belonged to the
genus, whereas the 30 primary fungal species belonged to 28 different genera. The analysis of the relationship between microbial changes and the main flavor compounds of light-flavored Baijiu showed that bacteria from the
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genera and fungi from the
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genera significantly inhibited the synthesis of ethyl hexanoate, ethyl butanoate, ethyl lactate ethyl lactate, and butyl acetate but increased the synthesis of ethyl acetate (
< 0.05). Moreover, these microbes exhibited a significantly greater abundance in proso millet-sorghum mixed fermentation samples than in sorghum samples. The synthesis of special flavored compounds in proso millet Baijiu was significantly positively correlated with the presence of fungi from the
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genera but negative correlated with the presence of bacteria from the
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genera. Regarding ethanol content, the low alcohol content of Fenjiu may be due to the significantly high abundance of fungi from the
genus and bacteria from the
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genera during fermentation. In summary, proso millet significantly altered the flavor of light-flavored Baijiu by inducing the formation of a special microbial community; however, it did not increase alcohol concentration.
This study lays the foundation for future research on Baijiu fermentation. Additionally, the study findings may help improve the production efficiency and elevate the quality and flavor of the final product.
•95 proso millet accessions were characterized for starch physicochemical properties.•Wide variation in starch quality traits were observed in proso millet.•Inter-relationships among starch quality ...traits were analyzed.
In this study, 95 accessions of proso millet (Panicum miliaceum L.) were characterized for starch physicochemical properties, including apparent amylose content (AAC), gel textural properties, Rapid Visco Analyzer (RVA) pasting viscosity properties, thermal and retrogradation properties. Based on genotypic data, the genetic diversity and inter-relationship of these starch traits were analyzed. Diverse starch quality was found, for example, AAC ranged from 0 to 32.3%, gelatinization temperature (GT) varied from 71.5 to 79.0 ℃, and RVA profile showed distinct patterns among proso millet of different AAC types. Interestingly, high AAC proso millet usually had GT lower than that of low AAC proso millet, which is different from the findings in rice starch. Many starch traits were significantly correlated and most of the 18 tested traits could be classified as either AAC-related traits or GT-related traits. In summary, the information presented here will be useful for further development of proso millet products.
Niandoubao is a famous fermented proso millet food in northeast China. To investigate the composition and drivers of Niandoubao sourdough microbiota, high-throughput sequencing (HTS) combined with ...culture-dependent method was used to analyze the bacterial and fungal diversity of 28 spontaneous waxy proso millet sourdoughs (WPMSDs). The 537 isolates were identified by plate culture. HTS identified 271 bacterial and 233 fungal species. The 5 genera of Lactobacillales and 6 genera of Saccharomycetales were the dominant fermentation population. Based on beta diversity, the 22 mature sourdoughs were clustered into 5 bacterial clusters or 9 fungal clusters, and each cluster of sourdoughs had unique biomarker. According to ANOSIM and PERMANOVA analyses, microbial interaction exhibited the key driver for community composition (R > 0.91); flour and water played a fundamental role in bacterial composition (R > 0.66); pH, TTA and fermentation time exhibited specific effects on a few species (R < 0.51). Considering the features of growth, antimicrobial and synergistic fermentation, Lactobacillus curvatus, Candida sake and Wickerhamyces anomalus exhibited the best potential as a WPMSD starter. Altogether, the results provide insights into the diversity and drivers of type I WPMSDs microbiota, and important reference for the starter selection and quality improvement of Niandoubao in the future.
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•Bacterial and fungal compositions of 28 spontaneous WMPSDs were identified.•5 genera of Lactobacillales and 6 genera of Saccharomycetales are the dominant population.•Microbial interactions are the key driver of community composition.•Lb. curvatus, C. sake and W. anomalus exhibit the best potential as WPMSDs starter.•It has important reference value for starter selection and quality improvement of Niandoubao.
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