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Field experiments were conducted to evaluate the morphology, granule size, fine structure, thermal properties, and pasting properties of starch from a waxy (139) and a non-waxy (297) varieties of proso millet grown in Yulin (YY) and Yangling (YL). Compared with the starches from the two varieties grown in YY, the starches from the two varieties grown in YL exhibited higher relative crystallinities, 1045/1022 cm -1 ratio, and amounts of amylopectin long branch chains (AP L ) but lower 1022/995 cm -1 ratio, amounts of amylopectin short branch chains (APs), and APs/AP L ratios. Starches from YL also synthesized long branch-chain amylopectin to enhance intermolecular interactions and form a stable granular structure, which resulted in increased starch gelatinization temperature, enhanced shear resistance, and reduced setback viscosity. Starch from the waxy (139) variety has good application prospects in the food industry because of its high gelatinization temperature and light transmittance and low setback value, which can be ascribed to its extremely low amylose content, polydispersity index, high molecular weight, and dispersed molecular density. It may serve as a reference for applying proso millet starches in the food industry and developing breeding programs to improve starch quality., Competing Interests: Declaration of competing interest There are no conflicts of interest regarding this paper., (Copyright © 2023. Published by Elsevier B.V.)

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., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Resistant starch (RS) is widely used in the food industry because of its ability to regulate and protect the small intestine, but their distinct effects on the structural and functional properties of waxy and non-waxy proso millet starches are not completely understood. The crystalline structure and physicochemical properties of waxy and non-waxy proso millets' starch samples were analyzed after heat-moisture treatment (HMT). The analysis revealed significant differences between the RS of waxy and non-waxy proso millets. The crystal type of proso millets' starch changed from type A to type B + V. The relative crystallinity of the RS of waxy proso millet was better than that of non-waxy proso millet. The gelatinization temperature and thermal stability of RS significantly increased, and the pasting temperature (PTM) of the RS of waxy proso millet was the highest. The water solubility and swelling power of the RS in proso millet decreased, and the viscoelasticity improved. The correlation between the short-range ordered structure of RS and Δ H , and gelatinization properties has a stronger correlation. This study provides practical information for improving the nutritional benefits of waxy and non-waxy proso millet in food applications.

Variation in salt content and in pH are common in starch-based foods and can affect starch properties and final product texture. Fifteen accessions of proso millet starch with diverse amylose content were selected to investigate single factor and interaction effects of pH and NaCl on thermal, pasting, and textural properties. Pasting properties and gelatinization temperatures were markedly altered by salt addition. Changes in pH only had substantial effects on ΔH, but other properties were generally stable under different pH conditions. From two-way ANOVA, interactive effects of salt and pH were found to affect ΔH. The response of starch of different genotypes in terms of thermal and pasting properties differed under the same pH and salinity conditions. The reason is likely that ions in the starch-water system performed the roles of both reducing water activity and building of hydrogen bonds, which will have opposite effects on starch gelatinization., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

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., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Nitrogen has a critical influence on the yield and quality of proso millet. However, the exact impact of nitrogen on the cooking quality of proso millet is not clear. In this study, the cooking quality and starch properties of two proso millet varieties (waxy‐Shaanxi millet [wSM] variety and non‐waxy‐Shaanxi millet [nSM] variety) were compared and analyzed under nitrogen fertilizer treatment (N150, 150 kg/hm2) and a control group without nitrogen application (N0, 0 kg/hm2). Compared with the N0 group, the N150 treatment significantly increased protein content, amylose levels, and total yield. Employing rapid visco analyser and differential scanning calorimetry analyses, we observed that under the N150 treatment, the peak viscosity and breakdown viscosity of proso millet powder were diminished, while the setback viscosity and enthalpy values (ΔH) increased. In addition, nitrogen treatment increased the solids content in the obtained rice soup and significantly hardened the texture of the rice. At the same time, we noticed that the absorption capacity of starch in water and oil was enhanced. These results showed that nitrogen fertilizer had significant effects on the cooking quality and starch properties of proso millet. [ABSTRACT FROM AUTHOR]

In this study, we isolated starches from non-traditional sources, including quinoa, lentil, arrowhead, gorgon fruit, sorghum, chickpea, proso millet, and purple potato and investigated their morphology, physicochemical, and functional properties. Significant differences in starch particle morphology, swelling power, solubility, syneresis, crystalline pattern, and pasting viscosity were observed among the starches from these non-traditional sources. Further, all these isolated starches had unique properties because of their characteristic distinct granules when seen under scanning electron microscopy (SEM). The amylose content of the isolated starches shown significant difference (P < 0.05), and the values ranged between 11.46 % and 37.61 %. Results demonstrated that the isolated starches contained between 79.82 % to 86.56 % starch, indicating that the isolated starches had high purity. X-ray diffraction (XRD) patterns of starches isolated from sorghum, proso millet, quinoa, purple potato, and gorgon fruit presented A-type diffraction pattern; while lentil seeds, arrowhead, and chickpea starches presented C-type diffraction pattern. Overall, these results will promote the development of products based on starch isolated from non-traditional starches.

The effects of electron beam irradiation (EBI) on the cooking quality and volatile aroma components of proso millet were studied. The EBI doses of 2, 4, and 6 KGy were used to treat proso millet. The results showed that the hardness and chewiness of irradiated millet samples decreased, whereas the soluble solid content increased, making them more suitable ingredients in soft and sticky congee. The L * and a* values of the millet decreased and increased, respectively. The starch content, pasting characteristics, pH, and color values were slightly affected at dose of 2 kGy. Volatile compounds were less negatively affected in samples treated with 2 kGy irradiation than those treated with other irradiation doses. The irradiation dose of 2 KGy was favorable for retaining cooking quality, eating quality, and volatile compounds, making it a suitable irradiation dose for proso millet. [Display omitted] • The EBI treatment of proso millet made the soluble solid more soluble. • The hardness and chewiness of proso millet after EBI treatment were decreased. • The EBI treatment of 2 KGy had less effect on the quality of proso millet. • The EBI treatment of 2 KGy had the least negative effect on the volatile compounds. [ABSTRACT FROM AUTHOR]

In this study, proso millet starch was isolated and subjected to treatment with ultra-high pressure (UHP), cold plasma (CP), or their combination to modify its functional properties. The changes in structural, physicochemical, and digestive properties of proso millet starch after these treatments were investigated. The proso millet native starch granules showed irregular and polygonal shapes with a smooth surface. Treatments with CP or UHP at low pressures did not change the morphological properties or crystalline structure type of proso millet starch granules, while the treatment with UHP at 600 MPa and CP resulted in a complete gelatinization of starch. Also, UHP treatment at high pressure, followed by CP treatment, destroyed the partial crystalline region and reduced the short-range order of proso millet starch. Besides, a combination of UHP and CP treatment promoted the depolymerization of long chains in proso millet starch. Moreover, the combined treatments could enhance the resistance to high temperature and shearing and improve the pasting stability of starch. Furthermore, the combined treatment could increase the slowly digestible starch content. Therefore, the combination of UHP and CP treatment can be suggested for modifying the functional properties of proso millet starch and promoting its industrial applications. • The native proso millet starch showed A-type crystalline structure. • Starch completely gelatinized after treatment at pressure level of 600 MPa and CP. • The treatment with CP increasd the resistant starch content of UHP- treated starch. • The combination of UHP and CP treatments is effective for starch modification. [ABSTRACT FROM AUTHOR]

Recent findings suggest that optimal application of nitrogen fertilizers can effectively improve the quality of proso millet (PM). Here, we aimed to investigate the pathways associated with starch synthesis and metabolism to elucidate the effect and molecular mechanisms of nitrogen fertilization in starch synthesis and properties in waxy and non-waxy PM varieties using transcriptomic techniques. Co-expression network analysis revealed that the regulation of starch synthesis and quality in PM by nitrogen fertilizer mainly occurred in the S2 and S3 stages during grain filling. Nitrogen fertilization inhibited glycolysis/gluconeogenesis and starch biosynthesis in grains, but increased starch degradation to maltose and dextrin and then to glucose. Moreover, nitrogen fertilization increased starch accumulation by upregulating the expression of SuS and malZ genes, thereby increasing the total starch content in grains. In contrast, nitrogen fertilization suppressed the expression of GBSS gene and decreased amylose content in PM grains, resulting in a relatively higher crystallinity, light transmittance, and breakdown viscosity in the two PM varieties. Overall, these results provided transcriptomics insights into the molecular mechanisms by which nitrogen fertilization regulates starch quality in PM, identified key genes that associated with the starch properties, and provided new insights into the quality cultivation of PM. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract 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. Highlights • 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. [ABSTRACT FROM AUTHOR]

Proso millet starch suspensions (30%, W/V) are subjected to UHP treatment at 150, 300, 450, and 600 MPa for 15 min in order to produce a modified starch for food applications. Besides, the UHP‐gelatinized starch gels are stored at room temperature for 192 h and the recrystallization characteristics are investigated during the storage time. The gelatinization extent of starch is increased with the increase in pressure level and the starch is fully gelatinized at 600 MPa. The XRD patterns show that the UHP at 600 MPa converted the A‐type crystals to the B‐type. The DSC data reveal an increase in gelatinization temperatures and a decrease in gelatinization enthalpy after treatment at 150–450 MPa. Pasting property analysis shows that trough and final viscosity, pasting temperature and peak time are increased; however, peak and breakdown viscosity are decreased with the increase in pressure level up to 600 MPa. UHP treatment resulted in a higher swelling capacity and solubility at a relatively low temperature. XRD and DSC are also used to monitor retrogradation through the growth of diffraction peaks of the recrystallized starch and the increase in the melting enthalpy. The extent of retrogradation is plotted as a function of the storage time. [ABSTRACT FROM AUTHOR]

The aim of this study was to characterize modified proso millet ( Panicum miliaceum ) starch in order to explore its prospect as an ingredient for food applications. The current study determined the effect of hydrothermal modification (HTM) at 30 g/100 g moisture level and acid modification (AM) with HCl on extracted proso millet starch physicochemical and functional properties. Amylose content reduces with AM while HTM showed negligible effect. HTM starch had higher water binding capacity (WBC) whereas AM starch showed reduction in WBC. Additionally, the solubility and swelling power of HTM starch decreased with increase in temperature, and in AM starch solubility increased sharply but swelling power increases at 80 °C but significantly (P < 0.05) reduces at 90 °C. HTM caused increase in gelatinization temperature with a mean value of 87.17 °C compared to 78.61 °C in native starch. AM reduced onset (69.71 °C) and gelatinization temperature (77.26 °C), and it increased the range (26.56 °C) significantly (P < 0.05) with no effect on ΔH G . Pasting profiles of native proso millet starch changed significantly (P < 0.05) upon modifications and reduction in peak viscosity was observed in both modifications. AM reduced the holding strength, final viscosity, setback and breakdown whereas HTM reduced only breakdown and no change was observed in other parameters. [ABSTRACT FROM AUTHOR]

The entire USDA-ARS maintained collection of 650 accessions of proso millet ( Panicum miliaceum L.) was evaluated for the presence of accessions with waxy (amylose-free) endosperm starch. Six accessions, five of which derived from mainland China, were identified. Segregation ratios for waxy endosperm were evaluated in F2 and F3 populations derived from crosses between two waxy accessions, PI 436625 (Lung Shu 16) and PI 436626 (Lung Shu 18), and several wild-type accessions. The waxy trait was found to be under the control of duplicate recessive alleles at two loci, herein designated wx-1 and wx-2. Wild-type alleles at these loci were designated Wx-1 and Wx-2. Iodine-binding revealed a mean grain-starch amylose concentration of 3.5% in waxy lines and 25.3% in wild-type proso. Expression of the granule-bound starch synthase (waxy protein) in waxy lines was reduced to approximately one-tenth that of wild-type accessions. The waxy accessions identified now are available for the introgression of this trait into breeding lines adapted to the Great Plains of North America. [ABSTRACT FROM AUTHOR]