Tartary Buckwheat Starch Research Articles

Physicochemical, structural, digestive properties, and interaction mechanism of Tartary buckwheat starch-Rutin-calcium hydroxide complex

Tartary buckwheat is rich in starch and rutin, with Ca(OH)2 often used to improve the quality of buckwheat-extruded noodles. This study investigated the properties of a system combining tartary buckwheat starch (TBS), fixed Ca(OH)2 (0.6 %), and varying rutin addition (R, 2–10 %) to understand their interactions. Rutin addition in the presence of Ca(OH)2 significantly affected the structural and physicochemical properties of TBS in a dose-dependent manner. Microscopy showed that rutin particles precipitated on the gel walls of the TBS-R-Ca complexes at high rutin doses, more noticeably without Ca(OH)2. Rutin decreased gelatinization viscosity, whereas Ca(OH)2 alleviated this reduction in viscosity and gel structure. Ca(OH)2 and 2 % rutin significantly reduced the gelatinization and retrogradation enthalpies, relative crystallinity, short-range order degree, and TBS digestion rate. 1H NMR spectroscopy revealed interaction sites between rutin and TBS. Molecular dynamics results indicated that rutin and TBS can form effective hydrogen bonds and hydrophobic interactions, with Ca(OH)2 helping to maintain system stability.

Variation Analysis of Starch Properties in Tartary Buckwheat and Construction of Near-Infrared Models for Rapid Non-Destructive Detection.

Due to the requirements for quality testing and breeding Tartary buckwheat (Fagopyrum tartaricum Gaerth), it is necessary to find a method for the rapid detection of starch content in Tartary buckwheat. To obtain samples with a continuously distributed chemical value, stable Tartary buckwheat recombinant inbred lines were used. After scanning the near-infrared spectra of whole grains, we employed conventional methods to analyze the contents of Tartary buckwheat. The results showed that the contents of total starch, amylose, amylopectin, and resistant starch were 532.1-741.5 mg/g, 176.8-280.2 mg/g, 318.8-497.0 mg/g, and 45.1-105.2 mg/g, respectively. The prediction model for the different starch contents in Tartary buckwheat was established using near-infrared spectroscopy (NIRS) in combination with chemometrics. The Kennard-Stone algorithm was used to split the training set and the test set. Six different methods were used to preprocess the spectra in the wavenumber range of 4000-12,000 cm-1. The Competitive Adaptive Reweighted Sampling algorithm was then used to extract the characteristic spectra, and the prediction model was built using the partial least squares method. Through a comprehensive analysis of each parameter of the model, the best model for the prediction of each nutrient was determined. The correlation coefficient of calibration (Rc) and the correlation coefficient of prediction (Rp) of the best models for total starch and amylose were greater than 0.95, and the Rc and Rp of the best models for amylopectin and resistant starch were also greater than 0.93. The results showed that the NIRS-based prediction model fulfilled the requirement for the rapid determination of Tartary buckwheat starch, thus providing an effective technical approach for the rapid and non-destructive testing of starch content in the food science and agricultural industry.

Effect of ethanol addition on the physicochemical, structural and in vitro digestive properties of Tartary buckwheat starch-quercetin/rutin complexes

The effects of ethanol on the physicochemical, structural and in vitro digestive properties of Tartary buckwheat starch-quercetin/rutin complexes (e-TBSQ and e-TBSR) were investigated. Ethanol restricted the gelatinization of Tartary buckwheat starch (TBS), which resulted an increase in ∆H, G' and G" as well as a decrease in apparent viscosity of e-TBSQ and e-TBSR. The particle size, scanning electron microscopy and X-ray diffraction results showed that ethanol influenced the morphological structure of TBS granules and the starch crystalline structure in e-TBSQ and e-TBSR changed from B-type to V-type when the ethanol concentration was 25%. Saturation transfer difference-nuclear magnetic resonance results revealed that ethanol weakened the binding ability of quercetin/rutin to TBS in e-TBSQ and e-TBSR, leading to a change in the binding site on the quercetin structural unit. The residual ungelatinized TBS granules in e-TBSQ and e-TBSR induced a high slowly digestible starch content, and thus displayed a “resistant-to-digestion”.

Potential relation between starch granule-associated proteins and retrogradation properties of buckwheat starch

To elucidate the effect of starch granule-associated proteins (SGAPs) on retrogradation properties of buckwheat starch, the retrogradation properties of Tartary buckwheat starch (TBS) and common buckwheat starch (CBS) before and after removal of SGAPs were systematically investigated, with wheat starch (WS) as reference. A significant decrease in gel strength of starches and density of starch aggregates were observed after removing SGAPs. The results were in line with the changes in retrogradation enthalpy of starches and short-range ordered structure of starch aggregates. After removing SGAPs, the retrogradation enthalpy of TBS decreased from 4.16 J/g to 3.74 J/g, CBS decreased from 4.05 J/g to 3.35 J/g and WS decreased from 3.27 J/g to 2.81 J/g, respectively. Taken together the results of LF-NMR, FTIR and rheological analysis, it can be concluded that SGAPs could promote the hydrogen bond interactions between starch molecules by competitively binding with water molecules, enhancing the rearrangement of starch molecules and forming a more ordered structure. Overall, the study suggested that the presence of SGAPs could enhanced the interaction between starch molecules chains, thus accelerated the retrogradation process. The research results provide more information about SGAPs in buckwheat starch and support further study for manipulation of starch properties.

Analysis of genotype-by-environment effects on starch content in 281 Tartary buckwheat varieties and evaluation of the physicochemical properties of two elite varieties

Tartary buckwheat (TB) starch is a low-glycaemic-index food source. Analysis of genotype-by-environment effects on starch content is needed to improve high-quality TB production. However, an accurate and high-throughput evaluation method for starch content is a bottleneck for the analysis of genotype-by-environment effects on starch content. In the current study, a rapid and non-destructive method for detecting starch was developed based on near-infrared reflectance (NIR) spectroscopy. Overall, 281 varieties were planted in three environments for 2 years and measured. The coefficient of correlation between the laboratory-determined and NIR model-predicted starch content values was 0.9577. The average starch content of TB varieties had higher variants among the three environments. The genotype-by-environment interaction analysis showed the significant impact of environmental factors on TB starch content. Of them, two varieties (Ft155 and Ft184) with stable and relatively high starch contents (733.43 and 689.16 mg/g) were identified. The amylose content, structure character, thermal properties and pasting character revealed that these physicochemical properties of TB starch were distinct from those of potato and rice. Moreover, Ft155 was more difficult to gelatinise, and Ft184 has desired high-starch-quality cooking properties. These assessments provide robust nutritional quality evaluation approaches and food processing materials.

Tartary Buckwheat Starch Modified with Octenyl Succinic Anhydride for Stabilization of Pickering Nanoemulsions.

In this study, Tartary buckwheat starch was modified to different degrees of substitution (DS) with octenyl succinate anhydride (OS-TBS) in order to explore its potential for stabilizing Pickering nanoemulsions. OS-TBS was prepared by reacting Tartary buckwheat starch with 3, 5 or 7% (w/v) octenyl succinate in an alkaline aqueous solution at pH 8.5. Fourier-transform infrared spectroscopy gave peaks at 1726 cm-1 (C=O) and 1573 cm-1 (RCOO-), indicating the formation of OS-TBS. We further studied the physicochemical properties of the modified starch as well as its emulsification capacity. As the DS with octenyl succinate anhydride increased, the amylose content and gelatinization temperature of the OS-TBS decreased, while its solubility increased. In contrast to the original Tartary buckwheat starch, OS-TBS showed higher surface hydrophobicity, and its particles were more uniform in size and its emulsification stability was better. Higher DS with octenyl succinate led to better emulsification. OS-TBS efficiently stabilized O/W Pickering nanoemulsions and the average particle size of the emulsion was maintained at 300-400 nm for nanodroplets. Taken together, these results suggest that OS-TBS might serve as an excellent stabilizer for nanoscale Pickering emulsions. This study may suggest and expand the use of Tartary buckwheat starch in nanoscale Pickering emulsions in various industrial processes.

Effect of Calcium Hydroxide on Physicochemical and In Vitro Digestibility Properties of Tartary Buckwheat Starch-Rutin Complex Prepared by Pre-Gelatinization and Co-Gelatinization Methods

This study examined the effect of calcium hydroxide (Ca(OH)2, 0.6%, w/w) on structural, physicochemical and in vitro digestibility properties of the complexed system of Tartary buckwheat starch (TBS) and rutin (10%, w/w). The pre-gelatinization and co-gelatinization methods were also compared. SEM results showed that the presence of Ca(OH)2 promoted the connection and further strengthened the pore wall of the three-dimensional network structure of the gelatinized and retrograded TBS-rutin complex, indicating the complex possessed a more stable structure with the presence of Ca(OH)2, which were also confirmed by the results of textural analysis and TGA. Additionally, Ca(OH)2 reduced relative crystallinity (RC), degree of order (DO) and enthalpy, inhibiting their increase during storage, thereby retarding the regeneration of the TBS-rutin complex. A higher storage modulus (G') value was observed in the complexes when Ca(OH)2 was added. Results of in vitro digestion revealed that Ca(OH)2 retarded the hydrolysis of the complex, resulting in an increase in values in slow-digestible starch and resistant starch (RS). Compared with pre-gelatinization, the complex process prepared with the co-gelatinization method presented lower RC, DO, enthalpy, and higher RS. The present work indicates the potential beneficial effect of Ca(OH)2 during the preparation of starch-polyphenol complex and would be helpful to reveal the mechanism of Ca(OH)2 on improving the quality of rutin riched Tartary buckwheat products.

Effect of environment and variety on the physicochemical properties of Tartary buckwheat starch.

Starch is a major nutrient in the human diet and has been widely used as an ingredient in many food and non-food applications. However, the research on the quality characteristics of Tartary buckwheat is lagging behind, and there is a lack of high-quality special varieties, which makes it difficult to become a popular food. The physicochemical properties of Tartary buckwheat starch may be affected by different environments and varieties, and the stability of planted varieties in different regions is also an important issue in current research. The average amylose content and pasting properties of Dingxi Tartary buckwheat were lower, while the solubility, transparency, relative crystallinity and gelatinization enthalpy were higher compared with the other two regions, and there were significant differences between different varieties. All samples showed typical A-type structure, and the starch short-range order structure changed slightly. Amylose content, solubility, transparency, granule size distribution, pasting properties and thermal properties were significantly affected by environment and variety. When choosing high-quality special varieties and products for processing, it contributes to select different buckwheat varieties and planting areas based on various objectives by understanding the effects of environment and varieties on the physicochemical properties of Tartary buckwheat starch. In this study, the four varieties planted in Dingxi and the two varieties in Zhaojue were easy to digest, and the differences of pasting properties and thermal properties are helpful to improve the application of Tartary buckwheat starch in the food industry. © 2023 Society of Chemical Industry.

Effects of quercetin and Ca(OH)2 addition on gelatinization and retrogradation properties of Tartary buckwheat starch

In this study, effects of separate and synergistic addition with quercetin (Q) and Ca(OH)2 (named TBSQ, TBSCa, and TBSQCa) on gelatinization and retrogradation characteristics of Tartary buckwheat starch (TBS) were investigated. Swelling power, solubility, and paste viscosity of TBSQCa were higher than TBSQ, and lower than TBSCa, indicating that Ca(OH)2 alleviated the restriction of quercetin on TBS gelatinization, that was also confirmed by images at nanometer scale from atomic force microscope. Retrograded TBSQ, TBSCa, and TBSQCa presented lower enthalpy, relative crystallinity, and degree of order than TBS, manifesting retrogradation of TBS can be delayed by quercetin and Ca(OH)2. Morphology of SEM and texture analysis revealed that the Ca2+, Ca(OH)+, and alkaline conditions promoted the interaction among starch, quercetin and Ca(OH)2, eliminated the influence of quercetin as a rigid filler on starch, and formed higher strength gel in TBSQCa. These findings proclaimed effective action of Ca(OH)2 in quercetin-rich starch-based foods.

Effect of autoclave-cooling cycles combined pullulanase on the physicochemical and structural properties of resistant starch from black Tartary buckwheat.

A starch-rich portion is produced as a by-product of black Tartary buckwheat processing. The effect of enzymatic combined with autoclaving-cooling cycles (one, two, or three times) on the physicochemical and structural properties of black Tartary buckwheat type 3 resistant starch (BRS) was evaluated. The autoclaving-cooling cycles enhanced solubility and reduced swelling, with the BRS content increasing from 14.12% to 25.18%. The high crystallinity of the BRS reflected a high molecular order. However, increasing the number of autoclaving-cooling cycles did not result in higher BRS content. The highest BRS yield in the autoclaved starch samples was 25.18% after double-autoclaving-cooling cycles. Furthermore, the autoclaving-cooling cycles altered the crystalline structure of black Tartary buckwheat, and the subsequent crystallinity changed from 36.33% to 42.05% to 38.27%. Fourier-transform infrared spectroscopy shows that the number of cycles results in more efficient double-helical packing within the crystalline lamella. Principal component analysis showed that the autoclaving-cooling cycle treatment leads to significant changes in the molecular structure of resistant starch (RS). These results indicated that autoclaving-cooling cycles might be a feasible way for producing RS from black Tartary buckwheat starch with better structural stability to expand their application range.

Exploring the underlying mechanisms on starch restricted swelling-induced reduction in digestion rate of buckwheat noodles

To elucidate the slower digestion rate of buckwheat starch in noodles-matrix, the digestion kinetics of Tartary (TBN) and common (CBN) buckwheat starch reconstituted noodles as well as wheat starch reconstituted noodles (WSN) were compared using a simulated oral-gastric-intestinal in vitro digestion. The swelling degree of starch in cooked noodles can be expressed by quantitative analysis of microstructure. The digestion rate of WSN was 2.3–2.9 times higher as compared to CBN and TBN. The swelling degree of starch in CBN and TBN was restricted due to their denser structure, which led to the reduction of the contact area between starch molecules and amylase. Additionally, the stronger water retention ability and higher cohesiveness of CBN and TBN could hinder the water migration, and ultimately affect the accessibility of enzymes. These results demonstrated that the restricted swelling of starch in CBN and TBN during cooking was the important reason for their slower digestibility.

Electron beam irradiation as a physical modification method to deform the properties and structures of Tartary buckwheat starch: A perspective of granule and crystal

Electron beam irradiation (EBI) was widely used in industry and known as a kind of novel physical modification methods to improve the processing characteristics of starch. It had significant influence on particle properties and crystal structure of Tartary buckwheat starch. The gradually deepened yellow degree and totally higher △E were observed after EBI treatment, with a dose correlated a* and b* values. More than that, amylose content and thermal stability decreased significantly with improved particle size values as well as wrinkles, holes and depression on the surface. C–H stretching vibration and CO carbonyl functional groups were generated and a reduced crystallinity in all ranges (short, intermediate and long) were observed, attributed to the partial deformation of amylose double helices and intertwist of amylopectin external chains in a way. These results indicated that EBI treatment had an obvious impacts on the particle properties and crystal structure.

A metabolomics study of the intervention effect of Tartary buckwheat on hyperlipidemia mice.

Tartary buckwheat can improve hyperlipidemia and affect the changes of metabolic pathways to the body. In this study, we use LC/MS to obtain metabolic fingerprints of plasma samples collected from control (LFD), high-fat diet (HFD), Tartary buckwheat protein (BWP), and Tartary buckwheat starch (BWS). Using the metabolic network database, through OPLS-DA, the potential biomarkers and pathways of BWP and BWS intervention in hyperlipidemia mice are initially determined. The results showed that there are 30 metabolites in total, among which linoleic acid, glycerol, phosphatidyl, ethanolamine, and galactose ceramide are the most important differentially expressed metabolites in BWP and BWS plasma samples. These metabolites are involved in eight metabolic pathways, such as linoleic acid metabolism, arachidonic acid metabolism. Tartary buckwheat can alleviate the symptoms of hyperlipidemia in mice by affecting the above-mentioned metabolic pathways. This research has a profound impact on the development of nutritious foods of buckwheat. PRACTICAL APPLICATIONS: Tartary buckwheat, also known as wild buckwheat, is a typical embodiment homology of medicine and food. We have clarified that the protein and starch extracted from tartary buckwheat have the function of reducing blood lipids. It is expected to be applied to functional food materials in the health food market. Also, the effects of tartary buckwheat protein and starch in improving metabolic pathways can be generally applied as a physiological active compound of functional food supplements.

Insights into the reasons for lower digestibility of buckwheat-based foods: The structure-physical properties of starch aggregates

To elucidate the lower digestibility of buckwheat starch-based foods, tartary buckwheat starch (TBS) and common buckwheat starch (CBS) were treated by different hydrothermal temperatures, cooling, lyophilization and micronization, and wheat starch (WS) used as reference. The in vitro digestibility, thermodynamic properties, particle-size distribution and texture of starches were measured. According to the structural evolution of starch during the processing, the reasons behind a lower digestibility of buckwheat starch were investigated. At hydrothermal of 25 °C, a significantly higher digestion rate was observed for TBS and CBS as compared to WS, due to smaller granule size of buckwheat starches (BS). At 65 °C, the digestion rate of BS was lower than that of WS, because the more intact crystalline structure was retained in BS due to its higher gelatinization temperature. At 100 °C, in the initial phase, CBS (38.70%) and TBS (53.13%) displayed a lower digestible fraction compared to WS (59.12%), probably as BS had a higher tendency of aggregation during gelatinization-cooling process, thus the BS are more difficult to be micronized. Overall, the formation of denser aggregates during gelatinization-cooling process was proposed to illustrate the relatively lower digestibility of BS.

High-voltage and short-time dielectric barrier discharge plasma treatment affects structural and digestive properties of Tartary buckwheat starch

To systematically explore the effects of high-voltage and short-time (HV-ST) dielectric barrier discharge (DBD) plasma treatment on Tartary buckwheat starch (TBS), TBS was treated at 15 and 20 kV for 20 and 40 s. Compared to native starch, more corrosions and holes were observed on the surfaces of plasma-modified TBS observed by SEM. Increased crystallinity and short-range structure order in plasma-modified TBS were determined using XRD and FT-IR respectively, while the average chain length and amylose content decreased, with lowest values (13.5 and 6.9%) in sample 20–40. Meanwhile, the solubility and paste clarity of plasma-modified TBS increased, whereas the viscosities decreased, enhancing in vitro digestibility with highest value (79.5%) in sample 20–40. These changes of TBS properties positively correlated with the treatment voltage and time length. Therefore, HV-ST DBD plasma treatment served as an effective tool for altering the properties of TBS. It is favorable for the applications of starch ingredients with low viscosity and high paste clarity, as well as accelerating starch hydrolyzation processes, such as brewing and food fermentation.

Effect of high hydrostatic pressure treatment on the formation and in vitro digestion of Tartary buckwheat starch/flavonoid complexes

Tartary buckwheat is rich in flavonoids and starch, and the interaction between these two components affects the structural and digestive properties of the food product. In this study, we analyze the effects of thermal gelatinization (GT), ultrasonic treatment (UT), and high hydrostatic pressure treatment (HHP) on the compounding degree of starch and flavonoids in Tartary buckwheat and on the properties of the starch/flavonoid complex system (HBS-BF). Based on scanning electron microscope (SEM) and X-ray diffraction (XRD) analyses, the surface of HBS-BF becomes rough after GT or UT, and many small cavities appear. Comparatively, HHP treatment is less damaging to HBS-BF. Moreover, HHP maintains the original A-type crystal morphology of buckwheat starch in HBS-BF, whereas GT and UT change to V-type. Repeated HHP further improves the crystallinity and digestion resistance of HBS-BF. According to the recorded Fourier transform infrared (FT-IR) spectra, HBS-BF by different methods does not exhibit new covalent bonds.Practical application: The results reported herein promote the application of Tartary buckwheat starch and flavonoids in the food industry by providing a theoretical basis for the development of starch anti-digestion mechanisms and the preparation of resistant starch.

Modified Tartary buckwheat (Fagopyrum tataricum Gaertn.) starch by gaseous ozone: Structural, physicochemical and in vitro digestible properties

The present study investigated the effects of gaseous ozone treatment on the structural, physicochemical and in vitro digestible properties of Tartary buckwheat starch (TBS). The results showed that gaseous ozone treatment increased the detectable carbonyl and carboxyl groups content, improved the amylose content, and decreased pH of TBS. The granule microstructures of native TBS and ozone-treated TBS (OTBS) were characterized by SEM, CLSM and small-angle X-ray scattering (SAXS), showing that OTBS exhibited a reduced granule smoothness and integrity, lessened coloration area of FITC fluorescent as well as decreased crystalline layer and increased amorphous region. FTIR and XRD results revealed that appropriate time of gaseous ozone treatment (2.5 and 7.5 min) enhanced short-range and long-range order structure due to the increased intermolecular oxidation cross-linking, whereas over treatment (15 and 20 min) caused degradation of the starch. With the increasing treatment time, apparent viscosity increased while breakdown viscosity, setback viscosity, swelling power and solubility decreased. OTBS exhibited a higher gelatinization enthalpy (ΔH) and a better viscoelasticity after gelation (6% OTBS gel, w/w). Additionally, OTBS-2.5 and OTBS-7.5 showed a decreased rapidly digested starch (RDS) content and increased resistant starch (RS) content, indicating that the digestible properties of two oxidized starches was decreased, which provide a feasible way to develop TBS as a new modified starch source.

Influence of the Addition of Extruded Endogenous Tartary Buckwheat Starch on Processing and Quality of Gluten-Free Noodles.

Extruded starch could be used as a thickener for food processing due to its pre-gel properties. This study aimed to explore the influence of the addition of extruded endogenous Tartary buckwheat starch (ES) on the process and quality of gluten-free noodles. ES was mixed with Tartary buckwheat flour in different proportions (10–40%) to prepare the blended flour and noodles. When the content of ES was increased, the swelling power of blended flour at 90 °C had no significant changes, and the decrease in peak viscosity of blended flour was reduced. This indicated that the high-content ES could afford better thermal stability for blended flour and inhibit the swelling ability. The higher level of ES was beneficial to the formation and stabilization of dough, and the improvement of noodle tensile strength. Furthermore, there was no difference in cooking loss between noodles with 30% and 40% ES addition. The microstructure and water distribution of the noodles prepared by blended flour indicated that the gel-entrapped structure organized by the higher content ES could be closely related to the above results. In conclusion, higher ES could contribute to improving the processing properties and quality of noodles.

Physicochemical properties and in vitro digestibility of tartary buckwheat starch modified by heat moisture treatment: A comparative study

In general, modified starches provided a desirable feature so that they can be used in the food industry like food additive products. The awareness of eating healthy has become very evident. The food industry is willing to produce foods and food ingredients that not only maintain nutrition but also promote health and safety. Tartary buckwheat starch has been isolated to assess the effect of HMT on its digestibility, morphological structure, pasting, thermal and textural properties and compared with common buckwheat, sorghum, and broomcorn millet. HMT changed significantly the granular structure of native starches. The complete starch granular structure increased the size and changed into an irregular shape, with a rough surface. The modified starches exhibited higher onset and peak temperatures, while their amylose content, solubility, swelling power, gel hardness, and enthalpy of gelatinization were significantly reduced. In pasting properties, tartary buckwheat and sorghum modified starch had the highest thermal treatment stability with lower setback and breakdown viscosity. Moreover, after three hours of starch hydrolysis; Resistant (RS) starch was higher in tartary buckwheat followed by broomcorn millet and lastly sorghum. In this study, we reported that tartary buckwheat modified starch is more useful in the preparation of food with thermal stability combined with a high amount of resistant starch.

Analysis of synthesis, accumulation and physicochemical properties of Tartary buckwheat starches affected by nitrogen fertilizer

Nitrogen fertilizer is a crucial factor affecting the growth and grain quality of Tartary buckwheat. This study was to investigate the synthesis, accumulation, and physicochemical properties of Tartary buckwheat starches under four nitrogen levels (0, 90, 180, 270 kg N ha−1). The results showed that activities of four key enzymes, starch contents all first increased and then decreased with increasing nitrogen levels, and peaked at 180 kg N ha−1. All the starches showed typical A-type, while higher nitrogen levels significantly increased the relative crystallinity. The viscosities significantly decreased, onset, peak, and conclusion first decreased and then increased, while pasting temperature and gelatinization enthalpy increased with increasing nitrogen levels. Nitrogen fertilizer and year had significant effects on the synthesis, accumulation and physicochemical properties of Tartary buckwheat starch, and the nitrogen level of 180 kg N ha−1 was more suitable for planting in the northern area of the Loess Plateau.