Properties of lotus seed starch-glycerin monostearin V-complexes after long-term retrogradation

Microwave-mediated formation of lotus-seed starch-palmitic acid complexes and their multi-scale structural changes

Recent studies have revealed that starch-lipid complexation can significantly impact gut health via the formation of V-type resistant starch. This study used varying microwave (MW) power levels (600, 700, 800, 900, 1000 W) to prepare V-type lotus-seed starch (LS)-palmitic acid (PA) complexes and investigates their multi-scale structural and thermal properties. The results indicate that MWs promote hydrophobic LS-PA complexation to form a B + V6II-type crystalline structure, with the V-type complexation rate found to positively correlate with MW power. Specifically, a higher MW power is more conducive to guiding the evolution of the disordered structure in the complex system back to the ordered arrangement and enhancing the crystallinity and stability of the system. The evolution of this V-type crystallization process peaks at an MW power of 1000 W MW to afford a complexing index of 55.409 %. Further thermal-property analyses reveal that the V-type complexed starch is mainly arranged as highly thermally stable accumulated single-helix structures that dissociate at 100-105 °C. These findings provide valuable data for regulating V-type complex formation through MW treatment and establish a theoretical foundation for precisely designing healthy starch-based foods.

Structural and physicochemical properties of debranched lotus seed starch treated with high hydrostatic pressure

Lotus seeds represent a significant economic crop and are abundant in starch. To further enhance their application value, this study investigates the structural characteristics of lotus seed starch (LS) under the combined influence of pullulanase and high hydrostatic pressure (HHP). Pullulanase increased amylose content from 39.80 % to 72.26 %, and HHP increased amylose content further. LS crystals changed from C-type to B-type, and the ordered structure of LS was destroyed by enzymatic hydrolysis, and amylose single helix and partial double helix structure were formed. At low concentration, lotus seed amylose single helix tends to form amylose double helix structure with itself. At high concentrations, they tend to aggregate, forming a network structure with large surface area and loose order. HHP destroys the double helix structure of amylose, resulting in the decrease of starch crystallinity. These findings provide new insights into improving the processing properties and application range of lotus seed starch.

Debranched rice starch with highly enriched B1 chains enhanced the encapsulation of aroma molecules

Three debranched rice starch (DBS) with varying chain lengths were isolated in the hydrolysate solution-to-ethanol ratio of 1:3, 1:1.5, and 1:0, which were named as DBS1:3, DBS1:1.5, and DBS1:0, respectively. Three C8 aroma molecules with distinct functional groups, namely 1-octanol, 1-octen-3-ol, and γ-octalactone, were selected as the research objects. DBS1:1.5 exhibited a narrow chain length distribution and the content of B1 chains with degree of polymerization 13-24 was 58.77 %. The inclusion rates of DBS1:1.5 with the aforementioned aroma molecules ranged from 42.30 % to 68.09 %, which were higher than those of DBS1:0 (8.72 %-12.16 %) and DBS1:3 (24.26 %-48.24 %). Additionally, DBS1:1.5-aroma complexes showed high crystallinity, short-range order, and thermal stability. DBS1:0-aroma and DBS1:3-aroma complexes possessed a hybrid crystal structure combining B-type and V-type arrangements, characterized by low short-range order and thermal stability. The mechanism by which aroma molecules affected their interaction with starch was associated with their structure and hydrophobicity. High hydrophobicity and linear structure facilitated the interaction of 1-octanol with starch, thereby enhancing its encapsulation effect. Contrastingly, the low hydrophobicity and large size of the lactone ring attenuated the interaction between γ-octalactone and DBS. This research held significant implications for improving aroma quality in starch-based food processing.

Esterified starches enhance short-term satiety in mice via structural and physicochemical alterations

Starch is the main carbohydrate in the human diet, of which resistant starch (RS) has positive effects on satiety. This study examined the impact of esterified starch with varying degrees of substitution on short-term satiety in mice. Three forms of esterified starch were investigated: phosphorylated starch (SP), acetylated starch (SA), and octenylsuccinic acid starch (OSA). The findings showed that esterified starch increased the RS content by altering the short-range ordered structure. Additionally, esterification modification increased chewiness and viscosity, thereby delaying gastric emptying. Esterified starch stabilized the postprandial blood glucose concentration and increased the secretion of GLP-1 in mice, thereby generating short-term satiety effects, particularly in the SP-8%, SA-8%, and OSA-3% groups. The short-range ordered structure of starch significantly affects the 4-hour intake of mice. The phosphorylation modification exhibited the highest content of RS and the most pronounced effect in reducing postprandial fluctuations in blood glucose concentration, whereas the acetylation modification resulted in the highest increase in GLP-1 concentration. This study lays a theoretical foundation for the production and application of high-satiety foods.

Identification of the function of a key gene NnHCT1 in lignin synthesis in petioles of Nelumbo nucifera

Leaf petiole or stem strength is an important agronomic trait affecting the growth of underground organs as a channel for material exchange and plays a vital role in the quality and yield of crops and vegetables. There are two different types of petioles in lotus, floating leaf petioles and vertical leaf petioles; however, the internal difference mechanism between these petioles is unclear. In this study, we investigated the differences between the initial vertical leaf petioles and the initial floating leaf petioles based on RNA sequencing (RNA-seq), and >2858 differentially expressed genes were annotated. These genes were chiefly enriched in phenylpropanoid biosynthesis, which is the source of the lignin and cellulose in petioles and stems. Lignin biology-related gene NnHCT1 was identified, and subsequent biological function validation demonstrated that the transient overexpression of NnHCT1 significantly increased the lignin and cellulose contents in lotus petioles and tobacco leaves. In contrast, silencing NnHCT1 through virus-induced gene silencing significantly reduced petiole lignin synthesis. Additionally, differentially up-regulated MYB family transcription factors were identified using RNA-seq. Yeast-one-hybrid and dual-luciferase reporter assays demonstrated that MYB4 could bind to the NnHCT1 promoter and up-regulate NnHCT1 expression. These findings demonstrate the significant potential of NnHCT1 to enhance lignin synthesis, thereby improving stem or petiole resistance to stunting and explaining the need for the study of differential petiole relationships in plants.

Synergistic impact of ultrasound-high pressure homogenization on the formation, structural properties, and slow digestion of the starch-phenolic acid complex

The modification of starch digestibility can be achieved through the formation of complexes with polyphenols. We studied the combined impacts of ultrasound and high-pressure homogenization (UT-HPH) on the structure and in vitro digestibility of rice starch-chlorogenic acid complexes. The development of V-type complexes was supported by our findings, which also showed that synergistic UT-HPH therapy exhibited the highest absorbance value for the complexing index (0.882). Significant alterations in digestibility were also observed in the complexes, with the content of RDS decreasing from 49.27% to 27.06%, the content of slowly SDS increasing from 25.69% to 35.35%, and the percentage of RS increasing from 25.05% to 37.59%. Furthermore, a high positive correlation was found by applying the Pearson correlation coefficient in our research between RS, weight, PSD, and CI. This study presents a sustainable processing approach for utilizing chlorogenic acid in starch-rich food systems.

The role of C18 fatty acids in improving the digestion and retrogradation properties of highland barley starch

In this study, five C18 fatty acids (FA) with different numbers of double bonds and configurations including stearic acid (SA), oleic acid (OA), elaidic acid (EA), linoleic acid (LA), and α-linolenic acid (ALA), were selected to prepare highland barely starch (HBS)-FA complexes to modulate digestibility and elaborate the underlying mechanism. The results showed that HBS-SA had the highest complex index (34.18 %), relative crystallinity (17.62 %) and single helix content (25.78 %). Furthermore, the HBS-C18 FA complexes were formed by EA (C18 FA with monounsaturated bonds) that had the highest R1047/1022 (1.0509) and lowest full width at half-maximum (FWHM, 20.85), suggesting good short-range ordered structure. Moreover, all C18 FAs could form two kinds of V-type complexes with HBS, which can be confirmed by the results of CLSM and DSC measurements, and all of them showed significantly lower digestibility. HBS-EA possessed the highest resistant starch content (20.17 %), while HBS-SA had the highest slowly digestible starch content (26.61 %). In addition, the inhibition of HBS retrogradation by fatty acid addition was further proven, where HBS-SA gel firmness (37.80 g) and aging enthalpy value were the lowest, indicating the most effective. Overall, compounding with fatty acids, especially SA, could be used as a novel way to make functional foods based on HBS.

Effect of dynamic high-pressure treatments on the multi-level structure of starch macromolecule and their techno-functional properties: A review

Over the past decades, dynamic high-pressure treatment (DHPT) executed by high-pressure homogenization (HPH) or microfluidization (DHPM) technology has received humongous research attention for starch macromolecule modification. However, the studies on starch multi-level structure alterations by DHPT have received inadequate attention. Furthermore, no review comprehensively covers all aspects of DHPT, explicitly addressing the combined effects of both technologies (HPH or DHPM) on starch's structural and functional characteristics. Hence, this review focused on recent advancements concerning the influences of DHPT on the starch multi-level structure and techno-functional properties. Intense mechanical actions induced by DHPT, such as high shear and impact forces, hydrodynamic cavitation, instantaneous pressure drops, and turbulence, altered the multi-level structure of starch for a short duration. The DHPT reduces the starch molecular weight and degree of branching, destroys short-range ordered and long-range crystalline structure, and degrades lamellar structure, resulting in partial gelatinization of starch granules. These structural changes influenced their techno-functional properties like swelling power and solubility, freeze-thaw stability, emulsifying properties, retrogradation rate, thermal properties, rheological and pasting, and digestibility. Processing conditions such as pressure level, the number of passes, inlet temperature, chamber geometry used, starch types, and their concentration may influence the above changes. Moreover, dynamic high-pressure treatment could form starch-fatty acids/polyphenol complexes. Finally, we discuss the food system applications of DHPT-treated starches and flours, and some limitations.

Synergistic effect of enzymatic pre-treatment and amylose-lipid complex construction on the physicochemical properties of maize starch

In this study, the effects of maltogenic amylase (MAA) pre-treatment and starch-fatty acid complex construction on the physicochemical properties of maize starch (MAS) were investigated. The average chain length of MAA-modified MAS was found to decrease from 18.15 to 14.92. Moreover, MAA pre-treatment of starch induced the formation of a V-type complex. This behaviour was demonstrated by the higher diffraction intensity, enzymatic resistance and short-range ordering of the samples pre-treated with MAA compared with unmodified samples. X-ray diffraction and rheological analysis revealed that the re-crystallisation peak intensities and storage modulus of MAA-MAS-lauric acid (LA)/stearic acid (SA) complexes were lower than those of MAA-starches, MAS-LA/SA complexes and control. The rate of starch re-crystallisation was effectively decreased by the combination of MAA pre-treatment and V-type complex construction. The anti-retrogradation (long-term) characteristics of the tested samples were in the following order: MAA-MAS-LA/SA complexes > MAA-starches > MAS-LA/SA complexes > control.

Bionanocomposite Based on Cassava Waste Starch, Locust Bean Galactomannan, and Cassava Waste Cellulose Nanofibers

Natural polysaccharides are among the renewable sources with great potential for replacing petroleum-derived chemicals as precursors to produce biodegradable films. This study aimed to prepare biopolymeric films using starch extracted from the periderm and cortex of cassava roots (waste from cassava root processing), locust bean galactomannan, and cellulose nanofibers also obtained from cassava waste. The films were prepared by casting, and their physicochemical, mechanical, and biodegradability properties were evaluated. The content of cellulose nanofibers varied from 0.5 to 2.5%. Although the addition of cellulose nanofibers did not alter the mechanical properties of the films, it significantly enhanced the vapor barrier of the films (0.055 g mm/m2 h kPa-2.5% nanofibers) and their respective stabilities in aqueous acidic and alkaline media. All prepared films were biodegradable, with complete degradation occurring within five days. The prepared films were deemed promising alternatives for minimizing environmental impacts caused by the disposal of petroleum-derived materials.

Flexible control of bigel microstructure for enhanced stability and flavor release during oral consumption

Edible delivery systems such as emulsions and gels that possess flexible oral flavor sensation and comprehensive stability under freeze-thaw processing are highly demanded in the frozen food industry. Bigels were fabricated via emulsification of stearic acid based oleogel with konjac glucomannan (KGM)-gelatin (G) based binary hydrogel. By varing the KGM/G mass ratio (γ) and oleogel/hydrogel volume ratio (φ) of bigels, modulation over the micromorphology, tribology, flavor sensation and cheese stick imitating capacity were achieved. Notably, as φ increased from O4:W6 to O5:W5, the microstructural transformation from oleogel-in-hydrogel to bicontinuous morphology emerged as a remarkable feature. The influence of γ was evident in bicontinuous bigels, significantly enhancing water holding capacity (WHC) by 3.38-fold as γ transitioned from 1KGM:5G to 6KGM:5G during freeze-thaw cycles. φ and γ both played pivotal roles in altering the microstructure and rheological properties of the bigels, enabling customizable release of bioactive components and flavor perception. Oleogel-in-hydrogel bigels effectively prevented bioactive compound leakage during freeze-thaw conditions, while bicontinuous bigels demonstrated sustained flavor release during oral mastication. Release behaviors were dual-controlled by φ and γ, reducing oil-soluble flavor release with increased φ and lowering hydrophilic volatile release with elevated γ. Moreover, bigel-based cheese sticks showcased lower viscosity, higher creep recovery rates, and enhanced mouthfeel during minimal oral chewing, suggesting their potential in mimicking the properties of commercial counterparts. These findings extend insights into bigel design for tailored flavor release and bioactive preservation in food products.

Structure and physicochemical properties of low digestible Euryale ferox Salisb. seed starch

BACKGROUND

Euryale ferox Salisb. is widely grown in China and Southeast Asia as a grain crop and medicinal plant. The composition, morphology, structure, physicochemical properties, thermal properties, and in vitro digestibility of North Euryale ferox seeds starch (NEFS), hybrid Euryale ferox seeds starch (HEFS), and South Euryale ferox seeds starch (SEFS) were studied.

RESULT

Of the varieties that were studied, the amylose content of NEFS (23.03%) was the highest. Starch granules of each variety were smooth, sharp, small, and had an average diameter of 2 μm. All three varieties were A-type crystals with crystallinity ranging from 26.42% to 28.17%. The degree of double helix and the short-range order ranged from 1.9006 to 2.5324 and 1.4294 to 1.6006, respectively. The high proportion of C1 region in NEFS (17.74%) and HEFS (17.66%) were found. Thermodynamic properties in North Euryale ferox seeds included the highest onset temperature (T_o ) (71.43 °C), peak temperature (T_p ) (76.60 °C), conclusion temperature (T_c ) (82.77 °C), enthalpy of gelatinization (ΔH) (12.64 J g^-1 ), and peak viscosity (1514 mPa·s). All three varieties maintained a low level of in vitro digestibility, with the highest resistant starch (RS) content (29.57%), the lowest rapidly digestible starch (RDS) content (27.07%), and the slowest hydrolysis kinetic constant (0.0303) in NEFS.

CONCLUSION

The results revealed that the low digestibility of NEFS was attributable to compact granules, high crystallinity, high degree of order, and strong thermal stability. These digestive, physicochemical, and thermodynamic properties provide information for the future application of Euryale ferox seed starch in the food industry. © 2022 Society of Chemical Industry.

Ultrasonication-mediated formation of V-type lotus seed starch for subsequent complexation with butyric acid

V-type starches comprise single helical structures that can be complexed with other small hydrophobic molecules. The development of the subtypes of these assembled V-conformations is dependent on the helical state of the amylose chains during complexation, which is influenced by the pretreatment employed. In this work, the effect of preultrasonication on the structure and in vitro digestibility of preformed V-type lotus seed starch (VLS) and its potential for complexing with butyric acid (BA), was investigated. The results showed that ultrasound pretreatment did not affect the crystallographic pattern of the V₆-type VLS. The optimal ultrasonic intensities increased the crystallinity and molecular ordering of the VLSs. With an increase in the preultrasonication power, the pores on the VLS gel surface decreased in size and were more densely distributed. The VLSs formed at 360 W were less vulnerable to digestive enzymes than their untreated counterparts. Additionally, their highly porous structures could accommodate numerous BA molecules, and thus generated inclusion complexes via hydrophobic interactions. These findings would provide valuable insights into the ultrasonication-mediated formation of VLSs and suggest their potential application as carriers for the delivery of BA molecules to the gut.

Influence of ultrasonic-microwave power on the structure and in vitro digestibility of lotus seed starch-glycerin monostearin complexes after retrogradation

The digestibility of starches with high amylose content can be modulated by the complexation with lipids, which is largely influenced by physical modification methods. In the current work, the impact of ultrasound-microwavre synergistic treatment on the structure and in vitro digestibility of lotus seed starch-glycerin monostearin complexes (LS-GMSc) after retrogradation were investigated. Results showed that 400 W of ultrasound treatment combined with microwave was more conducive to the formation of LS-GMSc, which increased the microcrystalline region and ordering degree of starch. However, excessively high ultrasound intensity weakened V-type diffraction and promoted amylose recrystallization. Investigation of the micromorphology and thermal properties revealed that the existence of V-complexes retarded starch retrogradation, and this effect was significantly enhanced after appropriate ultrasound (400 W) treatment. The digestion showed that 400 W of ultrasound treatment improved the digestive resistance of starch complexes and increased the content of resistant starch. These results are significant to the theoretical foundation and functional application of V-type complexes on anti-gelling and anti-digestion.

Production of buckwheat starch-myristic acid complexes and effect of reaction conditions on the physicochemical properties, X-ray pattern and FT-IR spectra

In this study, the effect of reaction parameters on complex index (CI%) value of complexes formed between buckwheat starch (BS) and myristic acid (MA) was investigated. The temperature (60-90 °C) and MA to BS ratio (0.1-0.8 mmoL/g) were determined as the most effective parameters and their effect on CI% was evaluated using response surface methodology. The MA to BS ratio, temperature, and interaction between them had an influence on CI%. The CI% of BS-MA complexes increased with increasing MA ratio until a certain level of MA. Principal component analysis (PCA) was used for correlation analysis between parameters. Swelling power and paste clarity of BS decreased with complex formation while syneresis increased. Peak and final viscosity values of the BS-MA complexes were significantly lower than those of BS. FT-IR revealed the complex formation led to change in starch structure. The XRD confirmed the BS-MA complex formation but the BS-MA produced using 0.1 mmoL/g at 60 °C was not detected by XRD due to having low crystallinity, and expectedly, the lowest relative crystallinity value was achieved with this sample among complex samples. All results showed that the buckwheat might be an alternative starch source for starch-lipid complex formation.

Effects of freeze-thaw treatment and pullulanase debranching on the structural properties and digestibility of lotus seed starch-glycerin monostearin complexes

The effects of multiple cycles of freeze-thaw treatment, combined with pullulanase debranching, on the structural properties and digestibility of lotus seed starch-glycerin monostearin complexes were investigated. The formation and melting of ice crystals during freeze-thaw treatment disrupted the crystalline structure of the starch granules, creating pores which facilitated access of pullulanase to the interior of the granules. Pullulanase debranching increased the free amylose content of the starch, which promoted the formation of starch-lipid complexes, which, in turn, increased the proportion of resistant starch and the overall resistance of the starch to digestive enzyme action. These effects increased with the number of freeze-thaw cycles, because more cycles increased both the disruption of the granule structure and the extent of pullulanase debranching. These findings provide a basis for the preparation of functional foods with low glycemic indices, which have strong potential for management of type II diabetes.

The impact of various exogenous type starch on the structural properties and dispersion stability of autoclaved lotus seed starch

In order to investigate the effects of exogenous V-type starch on the structural properties and dispersion stability of lotus seed starch after autoclave treatment, the crystal structure, molecular structure, and dispersion stability were analyzed and discussed, as well as compared with exogenous A-type and B-type starches. Analysis of structural properties indicated that the addition of different crystal nuclei led the crystallization of disordered helices to a specific direction. The B- and V-type starch addition increased the crystallinities of starch and enhanced the ordered arrangement of disordered helices, whereas A-type starch had no significant positive influence on the stability of starch system. The microstructure observation showed that A- and B-type starch addition led to a rough and porous morphology of starch particles; the presence of V-type starch retarded the agglomeration and retrogradation of starch after autoclaving. Analysis of contact angle and dispersion stability revealed that the addition of various exogenous starch increased the contact angle of starch particles in different extent, suggesting the enhancement of hydrophobicity. But B-type starch addition resulted in the poor dispersion stability compared to A-type starch, instead V-type starch addition improved the dispersion stability of starch in aqueous solution, allowing the particles to stay dispersed for 141.12 ± 6.52 min. These results provided a theoretical basis for the effects of exogenous type starch on original starch properties, and revealed the potential of V-type starch as dispersion stabilizer.