Paste structure and rheological properties of lotus seed starch–glycerin monostearate complexes formed by high-pressure homogenization

Rheological properties, multiscale structure, and in vitro digestibility of a maize starch-konjac glucomannan-bamboo leaf flavonoid complex modified by dynamic high-pressure microfluidization

The effects of dynamic high-pressure microfluidization (DHPM) treatment on the rheological properties, multiscale structure and in vitro digestibility of complex of maize starch (MS), konjac glucomannan (KGM), and bamboo leaf flavonoids (BLFs) were investigated. Compared with MS, the MS-KGM-BLF complex exhibited reduced viscosity and crystallinity, along with increased lamellar thickness to 10.26 nm. MS-KGM-BLF complex had lower viscosity after DHPM treatment. The highest ordered structure and crystallinity were observed at 50 MPa, with the α value increasing from 3.40 to 3.59 and the d value decreasing from 10.26 to 9.81 nm. However, higher DHPM pressures resulted in a decrease in the α value and an increase in the d value. The highest gelatinization enthalpy and resistant starch content were achieved at 100 MPa DHPM, while the fractal structure shifted from surface fractal to mass fractal at 150 MPa. This study presents an innovative method for enhancing the properties of MS.

Effects of fatty acids and glycerides on the structure, cooking quality, and in vitro starch digestibility of extruded buckwheat noodles

This study aimed to explore the effects of various lipids on the structure, cooking quality, and in vitro starch digestibility of extruded buckwheat noodles (EBNs) with and without 20% high-amylose corn starch (HACS). Fourier transform infrared spectroscopy, differential scanning calorimetry, and X-ray diffraction revealed that lauric acid bound more strongly to starch than did stearic acid and oleic acid, and the binding capacity of fatty acids with starch was stronger than that of glycerides. The presence of HACS during extrusion facilitated increased formation of starch-lipid complexes. Evaluations of cooking quality and digestion characteristics showed that EBNs containing 20% HACS and 0.5% glycerol monooleate demonstrated the lowest cooking loss (7.28%), and that with 20% HACS and 0.5% oleic acid displayed the lowest predicted glycemic index (pGI) (63.54) and highest resistant starch (RS) content (51.64%). However, excessive starch-lipid complexes were detrimental to EBNs cooking quality and the resistance of starch to digestive enzymes because of the damage to the continuity of the starch gel network. This study establishes a fundamental basis for the development of EBNs with superior cooking quality and a relatively lower GI.

Structural characteristics and emulsifying properties of linear dextrin/eicosapentaenoic acid composites: Effect of the degree of polymerization

This work aimed at building functional emulsions based on the linear dextrins (LDs) emulsion system. The gradient polyethylene glycol (PEG) precipitaion method was used to fractionate LDs into fractions with different degrees of polymerization (DP). A package, and co-precipitation procedure of LDs, and eicosapentaenoic acid (EPA) was used to fabricate LDs-EPA composites. The gas chromatograph, Fourier transform infrared spectroscopy, X-ray diffraction and differential scanning calorimetry analyses affirmed the formation of the LDs-EPA composites. The sizes of these composites were 38.55 nm, 59.14 nm to 80.62 nm, respectively, and they had good amphiphilicity. Compared with LDs, these LDs-EPA composites stabilized Pickering emulsion had higher stability and antioxidant capacity. Their emulsifying ability was positively correlated with the DP values of LDs. Furthermore, the oxidation stability results showed that LDsF10-EPA emulsion had the lowest lipid hydroperoxide (LHs) content, malondioxide (MDA) content and hexal concentration, which were 138.75 mmol kg-1 oil, 15.50 mmol kg-1 oil and 3.83 μmol kg-1 oil, respectively. The study provided a new idea and application values for the application of LDs in emulsion.

Extrusion as pretreatment for complexation of high-amylose starch with glycerin monostearin: Dependence on the guest molecule

Low-moisture extrusion (LME) can modify starch structures and enrich their functionality. These LME-made starches may efficiently form inclusion complexes (ICs) with hydrophobic guest molecules, which is profoundly impacted by the guest molecule concentration. In this work, the influence of glycerin monostearin (GMS) concentration on the structure and in vitro digestibility of pre-extruded starch-GMS complexes was investigated. The results showed that LME pretreatment increased the complex index of high-amylose starch with GMS by 13 %. The appropriate GMS concentrations produced ICs with high crystallinity and excellent thermostability. The presence of IC retarded amylose retrogradation and dominated bound water in starches. In addition, highly crystallized ICs were resistant to enzymolysis and had a higher proportion of resistant starch. The acquired knowledge would provide a better understanding of the LME-modified starch and GMS concentration-regulated IC formation.

The influence of cooperative fermentation on the structure, crystallinity, and rheological properties of buckwheat starch

The effects of co-fermentation of yeast and Lactiplantibacillus plantarum 104 on buckwheat starch physical properties were investigated by various analytical techniques. To investigate the regulations of starch modification during fermentation and to provide a foundation for improving the performance of modified properties of buckwheat starch food. The pasting properties were decreased by co-fermentation also resulted in a reduction in the relative crystallinity. Scanning electron microscopy (SEM) demonstrated that more holes and a relatively rough granule surface were seen in the co-fermentation group. Fourier transform-infrared spectroscopy (FT-IR) results suggested that co-fermentation fermentation decreased the degree of short-range order (DO) and degree of t1he double helix (DD). The results demonstrated that co-fermentation altered these properties more rapidly than spontaneous fermentation. In conclusion, Lactiplantibacillus plantarum 104 could be used for buckwheat fermentation to improve food quality.

Preparation, structure, and in-vitro hypoglycemic potential of debranched millet starch-fatty acid composite resistant starch

Currently, the preparation methods and basic physicochemical properties of starch-FA complexes have been widely studied; however, no in-depth research on the regulatory mechanism of the digestive properties of debranched starch-unsaturated FA complexes has been conducted. Therefore, six fatty acids with different carbon chains and different degrees of unsaturation were complexed with de-branched millet starch in this research, using the microwave method. Microwave millet starch-linoleic acid complex (MPS-LOA) had the highest resistant starch (RS) content, and the structure and physicochemical properties of MPS-LOA were determined using various molecular techniques. The results indicate that MPS-LOA had a resistant starch (RS) content of 40.35% and the most notable fluorescence. The characteristic UV peaks of MPS-LOA were blue-shifted, and new IR peaks appeared. The crystalline structure changed to V-type crystals, the crystallinity increased, and the molecular weight decreased. The enthalpy and coagulability of MPS-LOA increased, and the swelling force decreased. Additionally, MPS-LOA showed enhanced α-glucosidase and α-amylase inhibition, and in-vitro hydrolysis kinetics analysis of MPS-LOA showed a hydrolysis index of 53.8 and an extended glycemic index (eGI)I of 54.6, indicating a low eGI food suitable for consumption by people with type II diabetes. These results provide a theoretical basis for the preparation of amylopectin- and starch-based foods with an anti-enzyme structure and a low glycemic index (GI).

Effect of improved extrusion cooking technology (IECT) on structure, physical properties and in vitro digestibility of starch

Extrusion can modify the structure and physical properties of starch, while the extent of improved extrusion cooking technology (IECT) affects the starch with high moisture content and different crystal types remaining unclear. Therefore, the influence of IECT at different screw speeds on the structure, physical properties and in vitro digestibility of corn (A-type), potato (B-type) and pea (C-type) starches with high moisture content (42 %) was explored. Results indicated that IECT treatment caused similar variations on structure, physical properties, and in vitro digestibility of the 3 types of starches. The contents of slowly digestible starch (SDS) and resistant starch (RS) decreased by IECT treatment, accompanied by a reduction of crystallinity, enthalpy of gelatinization, gelatinization temperature and viscosity, while the content of rapidly digestible starch (RDS) and the ratio of bound water increased. And the changes in in vitro digestibility of starch were closely related to the damage to starch structure caused by IECT. Furthermore, most of starch granules were in the agglomeration stage by appropriate IECT treatment, which induced the exposure of a great quantity of enzyme binding sites to enhance the in vitro digestibility.

Facile solid-phase synthesis of starch-fatty acid complexes via mechanical activation for stabilizing curcumin-loaded Pickering emulsions

Starch-fatty acid complexes used as emulsifiers have caught great attention because of their renewability and excellent emulsifying property, the development of a simple and efficient synthesis method for the fabrication of starch-fatty acid complexes is still greatly challenging. Herein, the rice starch-fatty acid complexes (NRS-FA) were successfully prepared by mechanical activation method using different long chain fatty acids (myristic acid, palmitic acid, and stearic acid) and native rice starch (NRS) as the raw materials. The results showed that the prepared NRS-FA with a V-shaped crystalline structure exhibited a higher digestion resistance than NRS. Moreover, when the chain length of fatty acids increased from 14 to 18 carbons, the contact angle of the complexes was much closer to 90°, and the average particle size was smaller, deriving the better emulsifying property of NRS-FA18 complexes, which were suitable to be used as an emulsifier to stabilize curcumin-loaded Pickering emulsions. The results of storage stability and in vitro digestion showed that the curcumin retention could reach 79.4 % after 28 days of storage and 80.8 % of curcumin was retained in the system after simulated gastric digestion, showing good encapsulation and delivery performance of prepared Pickering emulsions, which attributed to the enhancement of the coverage of particles at the oil-water interface.

Physicochemical properties and molecular structure of lotus seed starch

Current understanding of physicochemical properties of lotus seed starch (LS) is scarce partly due to its largely unknown molecular structure. This study compared the physicochemical and molecular characteristics of LSs of a wide collection to those of conventional starches (potato (PS) and maize starches (MS)). Variations were found in the chemical composition, physicochemical properties, and molecular structure of LSs. Amylose content and weight-based ratio of short to long chains of amylopectin (APS:APL) were principal factors affecting the physicochemical properties of LSs from different origins. Compared with PS and MS, LSs had higher gelatinization temperatures, lower amylose leaching, and faster retrogradation. These unique properties of LSs were related to their molecular structure and chemical composition. LSs had higher amylose contents than PS and MS as evaluated by various methods. A majority of amylose chains in LS were longer than those in MS but were shorter than those in PS. The APS:APL of LSs were higher than that of MS but lower than that of PS. The results provided a structural basis for understanding the properties of LS and suggested that this unconventional starch may be complementary to conventional starches for industrial applications.

Structure, thermal stability, and in vitro digestibility of rice starch-protein hydrolysate complexes prepared using different hydrothermal treatments

In this study, rice starch-protein hydrolysate (WPH-S) complexes with high resistant starch (RS) content were prepared by heat-moisture treatment (HMT) and annealing (ANN). The effects of different hydrothermal treatments on the structure and thermal stability of the WPH-S complexes and their relationship with starch digestibility were further discussed. The results showed that RS contents of ANN-WPH-S complexes (35.09-40.26 g/100 g) were higher than that of HMT-WPH-S complexes (24.15-38.74 g/100 g). Under hydrothermal treatments, WPH decreased the hydrolysis kinetic constant (k) of starch form 4.07 × 10^-2-4.63 × 10^-2 min^-1 to 3.29 × 10^-2-3.67 × 10^-2 min^-1. HMT and ANN promoted hydrogen bonding between WPH and starch molecules, thus increasing the molecular size of starch. In addition, the shear stability of WPH-S mixture was improved with the hysteresis loop area decreased after HMT/ANN treatments, resulting in a more stable structure. Most importantly, the hydrothermal treatment made the scatterers of WPH-S complexes denser and the surface smoother. Especially after ANN treatment, the WPH₆₀-S complex formed a denser aggregate structure, which hindered the in vitro digestion of starch to a certain extent. These results enrich our understanding of the regulation of starch digestion by protein hydrolysates under different hydrothermal treatments and have guiding significance for the development of foods with a low glycemic index.

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.

Effect of Ionic and Non-Ionic Surfactants on the Pasting Characteristics and Digestive Properties of Regular and Frozen Starch for Oral Delivery

Starch is an ideal wall material for controlled release in oral delivery systems due to its non-allergic properties, availability, and cheap price. However, because of its poor mechanical behavior and high water permeability, it is necessary to modify the amphiphilic nature of starch. Surfactants are essential components to emulsify the lyophobic food ingredients. However, the interaction of starch with emulsifiers and how they affect the pasting behavior and digestion of starch are not well understood. In this paper, surfactants, such as non-ionic Tween (TW) and ionic sodium fatty acid (NaFA), with varying hydrophobic carbon chain lengths, were selected as model amphiphiles to investigate the structural, pasting, rheological properties and in vitro digestibility of regular and frozen starch samples. The results showed that, in most cases, the addition of TW reduced the viscosity of starch. However, saturated medium-chain NaFA increased the starch viscosity and rheological modulus greatly. Both surfactants inhibited starch digestion. This paper presents a comparative investigation on the effect of ionic and non-ionic surfactant on the structure and properties of corn starch, and therefore the information is useful for structural-based formulation with starch for developing colloidal delivery systems. It is also helpful for developing functional food with controllable digestion properties.

Structure-digestibility relationships in the effect of fucoidan on A- and B-wheat starch

Fucoidans (FC) have a variety of biological activities, and it can also affect the functionality and nutritional characteristics of starch-based food products. However, there are few studies on the structural and digestive properties of starch - fucoidans blends. The effect of FC at different concentrations (0, 0.6 %, 0.8 %, 1.0 %, w/v) on the structural properties and digestibility properties of A-type wheat starch (AS) and B-type wheat starch (BS) subjected to autoclave treatment were investigated. The results show that compared with native wheat starch, AS with FC displayed higher crystallinity as well as the structural ordering, but the crystallinity and degree of order of BS with FC decreased, which was proposed due to AS interact with FC in crystalline region but BS reacts with FC in the amorphous region. With the interaction of FC with AS and BS, granules compactness of AS and BS were enhanced. The addition of FC delayed digestion in vitro of AS and BS, the rapidly digestible starch content was obviously lower than native one, and the proportion of slowly digestible starch raise markedly. This study might broaden the recognition of wheat starch with different proportion of AS and BS, and provide a theoretical basis for the potential utilization of FC in carbohydrate based food industry.

Synergistic effect of extrusion and polyphenol molecular interaction on the short/long-term retrogradation properties of chestnut starch

The retrogradation properties of starch are closely related to the processing quality of starch-based foods. In this study, the synergistic effects of extrusion and the presence of polyphenols on the water distribution, rheological properties and short-term (1 day)/long-term (21 day) retrogradation of chestnut starch paste were investigated. Post extrusion complexation with catechins (CC)/proanthocyanidins (PC), the short- and long-term retrogradation were both inhibited and the anti-retrogradation rates (AR) during 1 and 21 days were as high as 100% and 44.17-69.30%, respectively. Owing to the destruction of starch chains by extrusion and interaction between starch and polyphenol molecules, the approach, entanglement and aggregation tendencies of starch molecules were all inhibited, which decreased the relative crystallinity (RC), flow resistance and storage modulus of starch paste and also increased the water-holding capacity. The starch retrogradation was thus suppressed. These results are beneficial for the development of starch-based products with high quality and lower retrogradation rate.

Modifying the rheological properties, in vitro digestion, and structure of rice starch by extrusion assisted addition with bamboo shoot dietary fiber

This paper investigated the effect of extrusion treatment on the rheological properties, in vitro digestibility, and multi-structure of starch with or without bamboo shoot dietary fiber (BSDF). The viscoelasticity and thixotropy decreased after extrusion treatment, however, they increased after BSDF addition, and decreased with increasing BSDF content. The starch granules became smooth and formed big lumps after extrusion treatment. The dense lumps became loose after the addition of BSDF. Extrusion treatment changed the movement and arrangement of starch chains and thus the relative crystallinity and branching degree decreased by 92.6% and 40.9%, respectively. The disruption of starch further increased rapid digestion starch (RDS) content by 10%. The decreased disruption of starch granules and increased entanglement between BSDF and starch decreased the RDS content. The addition of BSDF is a novelty method to enhance the nutritional properties and control the physicochemical properties of extruded starchy foods.

In vitro digestion and structural properties of rice starch modified by high methoxyl pectin and dynamic high-pressure microfluidization

The rheological, structural properties and in vitro digestibility of starch with high methoxyl pectin (HMP) and further modified by dynamic high-pressure microfluidization (DHPM) were investigated. The viscosity and elasticity increased on addition of HMP and were more pronouncedly affected by 10% HMP. However, after DHPM treatment, the viscosity and elasticity decreased with increasing DHPM pressure. After 100 MPa DHPM treatment, the ordered and crystalline structures were further increased compared with starch-HMP mixtures. A compact and dense surface of starch paste was formed under 100 MPa DHPM and 10% HMP treatment, thus significantly slowing down the digestibility. In contrast, the crystalline and semicrystalline structure of starch were disrupted by intense shear force under 200 MPa DHPM. This study provides theoretical information regarding starch-HMP interaction and improves their functional and physicochemical properties through a promising strategy for better applications in food formulation.

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.

Combination treatment of bamboo shoot dietary fiber and dynamic high-pressure microfluidization on rice starch: Influence on physicochemical, structural, and in vitro digestion properties

The physicochemical, structural properties and digestibility of rice starch treated by bamboo shoot dietary fiber (BSDF) combined with dynamic high-pressure microfluidization (DHPM) were investigated. Compared with starch modified by BSDF alone, the combination treatment decreased the pasting viscosity and viscoelasticity of starch. Furthermore, the pasting viscosity and viscoelasticity showed an increase from 50 to 100 MPa and then decreased after increasing the pressure to 150 and 200 MPa. The enthalpy of gelatinization and relative crystallinity of starch treated by BSDF and 100 MPa DHPM significantly increased by 17% and 63%, respectively. Scanning electron microscopy images demonstrated that flaky BSDF coated on starch granules to form a protective layer. As a result, the fractions of resistant starch increased and the starch hydrolysis extent and rate decreased under 100 MPa DHPM. This study highlights an innovative and promising strategy for improving the properties of starch and facilitating its utilization.

Acute Effects of Three Cooked Non-Cereal Starchy Foods on Postprandial Glycemic Responses and in Vitro Carbohydrate Digestion in Comparison with Whole Grains: A Randomized Trial

Plant origin, processing, and domestic preparation may affect the postprandial glycemic response (PGR) of starchy foods. The objective of this study was to examine the possibility of integrating domestically cooked non-cereal starchy foods commonly consumed in Northeast Asia into glycemic management diet, and compare their glycemic characteristics with those of waxy and non-waxy whole grains and starchy beans. In a randomized crossover trial, ten healthy subjects consumed dried lily bulb (LB), lotus seed (LS), adlay (AD), waxy black rice (BR), millet (MI), and adzuki bean (AB), pre-soaked and each cooked for two time durations. Acute PGR tests and in vitro carbohydrate digestion were carried out for each test food. Both the LS and AB meals achieved low glycemic index (GI 21⁻51), while the other starchy foods failed to show significant difference with rice (GI 83⁻109). The hydrolysis indexes of LS and AB were 37.7%⁻61.1%, significantly lower than other test foods. The in vitro tests indicated that pre-soaking resulted in high rapidly digestible starch (RDS) and low resistant starch (RS). Careful choice of whole grain materials, minimized pre-soaking, and moderate cooking may be critical factors for successful postprandial glycemic management for diabetic and pre-diabetic.

Physicochemical Properties and Digestion of Lotus Seed Starch under High-Pressure Homogenization

Lotus seed starch (LS), dispersed (3%, w/v) in deionized water was homogenized (0–180 MPa) with high-pressure homogenization (HPH) for 15 min. The effects of HPH treatment on the physicochemical properties of the starch system were investigated. The properties were affected by HPH to various extents, depending on the pressure. These influences can be explained by the destruction of the crystalline and amorphous regions of pressurized LS. The short-range order of LS was reduced by HPH and starch structure C-type was transformed into B-type, exhibiting lower transition temperatures and enthalpy. The LS absorbed a great deal of water under HPH and rapidly swelled, resulting in increased swelling power, solubility and size distribution. It then showed “broken porcelain-like” morphology with reduced pasting properties. Digestion of pressurized LS complex investigated by a dynamic in vitro rat stomach–duodenum model showed higher digestion efficiency and the residues exhibited gradual damage in morphology.