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Newborns' eyes and brains are prone to oxidative stress. Lutein has antioxidant properties and is the main component of macular pigment essential for protecting the retina, but has low bioavailability, thereby limiting its potential as a nutritional supplement. Oil-in-water emulsions have been used as lutein delivery systems. In particular, octenylsuccinated (OS) starch is a biopolymer-derived emulsifier safe to use in infant foods, while exhibiting superior emulsifying capacity. This study determined the effects of an OS starch-stabilized lutein emulsion on lutein bioavailability in Sprague-Dawley neonatal rats. In an acute study, 10-day-old pups received a single oral dose of free lutein or lutein emulsion, with subsequent blood sampling over 24 h to analyze pharmacokinetics. The lutein emulsion group had a 2.12- and 1.91-fold higher maximum serum lutein concentration and area under the curve, respectively, compared to the free lutein group. In two daily dosing studies, oral lutein was given from postnatal day 5 to 18. Blood and tissue lutein concentrations were measured. The results indicated that the daily intake of lutein emulsion led to a higher lutein concentration in circulation and key tissues compared to free lutein. The OS starch-stabilized emulsion could be an effective and safe lutein delivery system for newborns.

Amylose, the linear component of starch, can complex with small molecules to form single helical inclusion complexes of 6, 7, or 8 glucosyl units per helical turn, known as V 6 , V 7 , and V 8 . In this study, starch-salicylic acid (SA) inclusion complexes with different amounts of residual SA were obtained. Their structural characteristics and digestibility profiles were obtained with complementary techniques and an in vitro digestion assay. Upon complexation with excess SA, V 8 type starch inclusion complex was formed. When excess SA crystals were removed, the V 8 polymorphic structure could remain, while further removing intra-helical SA converted the V 8 conformation to V 7 . Furthermore, the digestion rate of the resulted V 7 was lowered as indicated by increased resistant starch (RS) content, which could be due to its tight helical structure, whereas the two V 8 complexes were highly digestible. Such findings could have practical implications for novel food product development and nanoencapsulation technology., 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 © 2022 Elsevier Ltd. All rights reserved.)

Ethylene gas was loaded into "pre-formed" V-type starch (V 6 , V 7 and V 8 ) by molecular encapsulation, and granular cold-water-soluble starch (GCWSS) was chosen as a control. The formation, structural characteristics and morphological properties of inclusion complexes (ICs) were investigated using X-ray diffraction, scanning electron microscopy, and 13 C solid-state nuclear magnetic resonance spectroscopy. The V 6a -type starch represented the most effective structure in encapsulating ethylene gas among different "pre-formed" V-type starches. The Avrami equation was used to describe the release kinetic properties of ethylene gas from ICs under various conditions of temperatures and relative humidities (RHs). The release of ethylene from ICs conformed to diffusion-limited release mechanisms (temperature) and first-order kinetics (RH). This could be caused by the differences in starch structure and association mechanisms between ethylene and starch single helices. Accelerated ripening experiments showed that ethylene-starch ICs could ripen bananas within 5 days, suggesting that this molecular encapsulation technology can provide precise control and targeted application of ethylene gas in the ripening of vegetables and fruits., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

High internal phase emulsions (HIPEs) stabilized by debranched starch-capric acid (DBS-CA) complex nanoparticles were fabricated and their performance was evaluated. DBS-CA was prepared through enzymatic debranching and solid encapsulation methods, and displayed V-type crystalline structure. Contact angle measurements show enhanced hydrophobicity of DBS-CA compared to native starch. The DBS-CA nanoparticles have an average size of 463.77 nm and tended to be aggregating as analyzed by scanning electron microscope and dynamic light scattering particle size analysis. When used as a particulate emulsifier, DBS-CA could stabilize HIPEs with oil volume fraction as high as 80%. The HIPEs showed pH-dependent properties; good storage stability and mechanical strength were achieved within pH range from 3 to 11, especially under alkaline conditions. It was proposed that smaller particle size and higher surface charging were responsible for the more tightly connected gel structure and thus their performance. This study demonstrates a novel approach to fabricate food-grade Pickering HIPEs, which may have many promising potential applications in the food industry., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The linear component of starch, especially amylose, is capable of forming inclusion complex (IC) with various small molecules. It could significantly modify the structure and properties of starch, and it could bring beneficial effects when bioactive compounds can be encapsulated. This review discusses the formation and characterization of the starch-guest IC and focuses on the recent developments in the use of starch ICs for the encapsulation and controlled release of bioactive guest compounds. A great number of guest compounds, such as lipids, aroma compounds, pharmaceuticals, and phytochemicals, were studied for their ability to be complexed with starch and/or amylose and some of the formed ICs were evaluated for the chemical stability improvement and the guest release regulation. Starch-guest ICs has a great potential to be a delivery system, as most existing studies demonstrated the enhancement on guest retention and the possibility of controlled release., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

We aimed to develop a greener process for dry-electrospinning food-grade modified starch through the elimination of organic solvents. The rheological properties and electrospinnability of aqueous dispersions of commercial octenylsuccinylated (OS) starches with various molecular weight (Mw) were investigated, yet only nanofibers with beads or defects could be obtained from OS starch with the highest Mw, i.e., Purity Gum @ Ultra (PGU). Further improvement in the fiber morphology was achieved by adding pullulan (PUL) as a minor component in the spinning dope. Smooth, continuous, and bead-free nanofibers (147-250 nm) were obtained from the PGU-PUL dispersions. Shown on an electrospinnability map, the successful electrospinning of 12%, 15%, and 20% (w/v) aqueous PGU dispersions required a minimum addition of 6%, 5%, and 3% (w/v) of PUL, respectively. The addition of PUL contributed to establishing sufficient molecular entanglement for electrospinning. This study provides a promising green process to produce starch-based nanofibers for use in various applications, e.g., drug delivery, wound dressing, and tissue engineering., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Starch/amylose-guest inclusion complexes, a class of supramolecular host-guest assemblies, are of critical importance in the processing, preservation, digestion, nutrients/energy uptake, and health outcomes of starch-containing foods. Particularly, the formation of inclusion complex has been suggested to lower the rate and extent of enzymatic digestion of starch and starch-containing foods. Compared with rapidly digestible starch, starch inclusion complex may fall into the category of slowly digestible starch, providing sustained glucose release and maintaining glucose homeostasis. Therefore, the ability of starch-guest inclusion complex to alter the digestive behavior of energy-dense starchy foods has been of interest to many researchers and has the potential to be developed and formulated into functional foods. In this article, we provide a comprehensive and critical review on the current knowledge of the in vitro and in vivo enzymatic digestion of starch-guest inclusion complexes, by emphasizing the structure-digestibility relationship. We examine the preparation methods employed, crystalline structures obtained, and physicochemical properties characterized in previous reports, which all have implications on the digestive behavior reported on the starch-guest inclusion complexes. In addition, we give suggestions on future research to elucidate the digestive properties of starch-guest inclusion complexes and to develop functional structures based on these complexes for use in foods and nutrition.

This study was to compare the characteristics of 21 starches isolated from chestnuts produced in different regions in China, also to investigate their potential food applications. Starches were isolated from chestnuts under the Castanea mollisima Blume variety with sub-varieties of Banli, Youli, and Maoli. Several properties of the starch samples were examined, including the moisture content, amylose content, morphological characteristics, color values, light transmittance, syneresis, swelling power, water solubility index, pasting properties, FTIR characteristics, X-ray diffraction (XRD) patterns, and thermal properties. The results showed that starches isolated from Youli presented higher resistance to shear and swelling during heating, indicating more suitability for high-heat cooking. The FTIR spectra confirmed the polysaccharide nature of all the chestnut starches. The XRD patterns showed most chestnut starches were in C b -type, while only five were in C a -type. Overall, this comparative study would be relevant for the further exploration of the potential utilization of chestnut starch in both food and non-food industries., (Copyright © 2019 Elsevier B.V. All rights reserved.)

The formation of high amylose corn starch (HACS)-alkylresorcinol (AR) inclusion complexes was demonstrated using HACS and a crude AR extract from rye bran, and was confirmed by complementary characterization techniques. Inclusion complex was extracted using hot 2-propanol/water (3:1), and thirteen different AR homologs were identified in the 2-propanol/water extract. However, this extraction regime was insufficient to remove all guests from the inclusion complexes, but did result in annealing of the V-type crystallinity, yielding an endotherm with higher onset and peak temperatures and dissociation enthalpy. The remaining guest compounds were recovered by disruption of the inclusion complexes with DMSO followed by liquid-liquid extraction. A total of nine AR homologs were recovered and two saturated long alkyl chain AR homologs (C21:0 and C19:0) were obviously enriched in the complexes compared to the crude AR extract. The formation of HACS-AR inclusion complexes may have the potential to inhibit staling in baked goods., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

In the present study, we report a novel composition based on amylose (or starch) inclusion complex with an amphiphilic material as an effective encapsulation platform technology to incorporate guests of interest. Specifically, the encapsulation of β-carotene in amylose-surfactant and amylose/starch-ascorbyl palmitate (AscP) inclusion complexes was investigated. Surfactants of different hydrophilicity/lipophilicity were selected to cover a broad range of HLB values. The formation of the inclusion complexes was characterized by X-ray diffraction and differential scanning calorimetry. The ability of amylose-surfactant system to encapsulate β-carotene was dependent on the HLB value of the surfactants, instead of their ability to induce inclusion complexation. The incorporation of β-carotene hindered amylose-surfactant inclusion complex formation, whereas no significant effect was observed on structural and thermal properties of starch-AscP inclusion complex in the presence of β-carotene. The X-ray diffraction pattern of amylose-AscP-β-carotene showed that β-carotene molecules did not crystallize into a separated phase and thus were suggested to be homogeneously immobilized within the polycrystalline amylose-AscP inclusion complexes. During a storage period of six weeks at 20 and 30°C, the stability of β-carotene was improved by encapsulation in starch-AscP inclusion complexes compared with that in physical mixtures of the three components., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

In the present study, we introduce a simple method to prepare inclusion complexes by "inserting" guest molecules into preformed "empty" V-type amylose helices. Ascorbyl palmitate (AscP) was used as a model guest material to investigate the effect of solvent environment, complexation temperature, annealing and guest concentration on inclusion complex formation. High complexation temperature was not necessary for encapsulating guest molecules in amylose helices, avoiding thermal degradation of guest compounds. This method would also avoid the wasting of guest materials because uncomplexed guest can be reused. It was found in the study that intermediate ethanol and acetone concentrations (generally 40-60%, v/v) at room temperature were appropriate for the complexation between V-amylose and AscP. Annealing, i.e. heat treatment in ethanol solutions at elevated temperatures (45-70 °C), was able to significantly increase the crystallinity of V-amylose and V-starch to as high as 65% and facilitate greater complexation evidenced from higher enthalpies, probably due to more regularly arranged helical cavities in larger crystalline phase. The complexation between V-amylose and AscP was also found to be enhanced with AscP concentration, while the dissociation temperature experienced a slight decrease., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

The polymorphic structures of starch were characterized with vibrational sum frequency generation (SFG) spectroscopy. The noncentrosymmetry requirement of SFG spectroscopy allows for the detection of the ordered domains without spectral interferences from the amorphous phase and also the distinction of the symmetric elements among crystalline polymorphs. The V-type amylose was SFG-inactive due to the antiparallel packing of single helices in crystal unit cells, whereas the A- and B-type starches showed strong SFG peaks at 2904 cm(-1) and 2952-2968 cm(-1), which were assigned to CH stretching of the axial methine group in the ring and CH2 stretching of the exocyclic CH2OH side group, respectively. The CH2/CH intensity ratios of the A- and B-type starches are significantly different, indicating that the conformation of hydroxymethyl groups in these two polymorphs may be different. Cyclodextrin inclusion complexes were also analyzed as a comparison to the V-type amylose and showed that the head-to-tail and head-to-head stacking patterns of cyclodextrin molecules govern their SFG signals and peak positions. Although the molecular packing is different between V-type amylose and cyclodextrin inclusion complexes, both crystals show the annihilation of SFG signals when the functional group dipoles are arranged pointing in opposite directions.

The diameter of the starch fibers produced by electrospinning is a key parameter for most potential applications. In this study, a quantitative relationship between fiber diameter and certain electrospinning parameters, i.e. starch concentration, applied voltage, spinning distance and feed rate, was established by empirical modeling using a fractional factorial experimental design in a constrained region. Response surface methodology was employed to analyze the interactions of the electrospinning parameters and predict the direction to minimize and maximize the fiber diameters., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Starch is a promising bio-based material to replace synthetics in a number of applications. The production of starch-based fibers has been actively pursued in the patent literature. This article reviews patents on starch fiber technology, including fiber spinning from amylose, thermoplastic starch compositions, and non-thermoplastic starch compositions. Some new fiber spinning techniques, e.g. electrospinning and rotary jet spinning, employed for spinning starch fibers are also presented.

We have demonstrated a method of fabricating pure starch fibers with an average diameter in the order of micrometers. In the present study, correlation between the rheological properties of starch dispersions and the electrospinnability was attempted via the extrapolation of the critical entanglement concentration, which is the boundary between the semidilute unentangled regime and the semidilute entangled regime. Dispersions of high amylose starch containing nominally 80% amylose (Gelose 80) required 1.2-2.7 times the entanglement concentration for effective electrospinning. Besides starch concentration, molecular conformation, and shear viscosity were also of importance in determining the electrospinnability. The rheological properties and electrospinnability of different starches were studied. Hylon VII and Hylon V starches, containing nominally 70 and 50% amylose, respectively, required concentrations of 1.9 and 3.7 times their entanglement concentrations for electrospinning. Only poor fibers were obtained from mung bean starch, which contains about 35% amylose, while starches with even lower amylose contents could not be electrospun.

Abstract Electrospinning is a versatile technique to fabricate non-woven fiber mats with an average fiber diameter ranging from nanometers to micrometers. Fibers produced by electrospinning have potential application in numerous fields owing to their light weight, high surface area, and high porosity. In certain applications, anisotropic properties are desired, which may also improve mechanical strength. This study comprehensively documented the feasibility of directed fiber deposition in wet-electrospinning and offers an inexpensive setup for laboratory investigation. Aligned starch fiber mats were produced and the effects of three operational parameters, i.e., rotational speed, drum location, and coagulation bath composition, were evaluated. The alignment of starch fibers was affected by the ethanol concentration in the coagulation bath and drum rotational speed. Coherent fibers could be obtained in all trials except for the one at the lowest ethanol concentration (60% v/v) and highest rotational speed (500 rpm) when the drum was below the liquid. The tensile strength was influenced by the interaction of location and ethanol concentration, and that of rotational speed and ethanol concentration. This study set a promising example of making aligned biopolymer fiber mats and investigating fiber deposition in wet-electrospinning. Aligned starch fiber mats have potential applications in areas such as tissue engineering and as wound dressings. Graphical abstract Image 104 Highlights • A benchtop setup for making aligned wet-electrospun fiber mats was developed. • Effects of operational parameters in wet-electrospinning were evaluated. • The tensile strength of fiber mat increased with fiber alignment. [ABSTRACT FROM AUTHOR]

Abstract Electrospinning has become an increasingly attractive technique to produce micro-to nano-scale fibers from bio-based polymers, including starch. Compared to their synthetic counterparts, fibers electrospun from bio-based polymers generally have inferior mechanical strength. In the present study, we aim to enhance the mechanical strength of electrospun starch-based fibers by using nanocellulose as a reinforcing filler and cationic starch as a binding agent. The potential ionic bonding between cationic starch and anionic nanocellulose, and the hydrogen bonding as well as macromolecular entanglement between the three components, are expected to improve the compatibility of polymers and the mechanical strength of their composite fibers. Rheological properties of nanocellulose, cationic starch, and their mixtures were studied to understand their conformation and interaction in DMSO dispersions. The rheological properties of the ternary systems were studied and correlated with their electrospinnability and the tensile strength of the composite fiber mats. Our results suggested that nanocellulose-cationic starch at its percolation concentration (≈2%, w/w, of starch) has the most profound influence on fiber strength, and CS:NC ratios of 1:2 and 1:1 created improved intermolecular ionic bonding for reinforcing the fiber structure. Graphical abstract Image 1 Highlights • Tensile strength of electrospun starch fiber mats increased using nanocellulose filler and cationic starch as a binding agent. • Rheological behavior of individual, binary, and ternary biopolymer blends was evaluated to guide electrospinning process. • NC CS at its percolation concentration (≈2%, w/w, of starch) had the most influence on electrospun fiber strength. [ABSTRACT FROM AUTHOR]

Resistant starch (RS) is well known for its health beneficial effects for glycemic control and gut health. In addition to some commonly reported RS types, such as raw high amylose maize starch (HAMS), potato starch, retrograded starch, and cross-linked starch, formation of starch inclusion complexes could also contribute to an increase in RS content. In this study, V type starch inclusion complexes with two guest compounds, ascorbyl palmitate (AP) and palmitic acid (PA), were formed using the novel "empty" V type method, and hydrothermal treatments were performed to further enhance the RS contents. Complimentary X-ray diffraction (XRD) and differential scanning calorimetry (DSC) techniques were conducted to assess the crystalline structure and thermal properties of the raw and treated inclusion complexes, and simulated in vitro enzymatic digestion was performed to study the structure-digestibility relationship in the treated samples. Although the raw inclusion complex samples exhibited minimal RS contents, all the treatments retarded starch digestion by increasing RS or SDS levels. For both V 6h -AP and V 6h -PA inclusion complexes, annealing followed by long-term strong acid hydrolysis treatment (ANN-ACH) resulted in the greatest increase in RS content, followed by strong ACH treatments alone. In addition, while presenting a comparable RS level as traditional RS2, the ANN-ACH treated V 6h -AP inclusion complex retained a V type crystalline structure, indicating its great potential as a novel type of RS, i.e., RS5. The study findings could have practical implications for the design and modification of RS-containing food for the control and modulation of glycemic response. [Display omitted] • V 6h type inclusion complexes were formed with ascorbyl palmitate and palmitic acid. • V 6h -palmitic acid inclusion complex had higher thermal stability and crystallinity. • Raw starch inclusion complexes showed low resistance to digestion. • Hydrothermal treatments enhanced resistant starch levels in inclusion complexes. • Annealing followed by acid hydrolysis was most effective to retard starch digestion. [ABSTRACT FROM AUTHOR]

Abstract: We have demonstrated a method of fabricating starch fibers with an average diameter in the order of micrometers. In the present study, the formation of starch-guest inclusion complexes in the electrospun starch fibers was evaluated. Two methods were used to electrospin starch fibers with starch-guest inclusion complexes: a dope mixing method, where guest material was mixed into the starch dispersion prior to electrospinning, and a bath mixing method, where guest material was mixed into the coagulation bath into which starch dispersions were electrospun. Three selected guest compounds, palmitic acid, ascorbyl palmitate, and cetyl-trimethylammonium bromide, formed inclusion complexes with starch in the electrospun starch fibers. The presence of native lipids was not necessary to induce the inclusion complex formation. Encapsulation of these molecules in electrospun starch fibers may increase their stability during processing and storage, while providing controlled release properties. [Copyright &y& Elsevier]

Abstract: Many efforts to spin starch fibers are reported in the patent and research literature. All reported spinning methods are dependent upon addition of non-starch components, e.g. other polymers, plasticizers or cross-linkers. In the present study, we demonstrate a method of producing pure starch fibers by an electrospinning technique. This method involves choosing an appropriate solvent for native high amylose starch and spinning on a modified electrospinning setup. Resulting starch fibers have diameters in the order of microns. Coagulation solvent composition can affect the crystallinity of the starch fibers. Post-spinning treatments were employed to increase the crystallinity and cross-link the starch fibers. The novel starch fibers have potential in various applications, e.g. in the food, textile, and biomedical industries. [Copyright &y& Elsevier]

Since starch is the major energy source of the human diet, retarding starch digestion could serve as an effective way for modulating glycemic response and for the prevention and treatment of obesity. In this study, a dietary bioactive compound, ascorbyl palmitate (AP), was evaluated as a potential inhibitor in the digestion of raw, cooked, and retrograded high amylose maize starch (HAMS) and potato starch (PS). The inhibitory effect of AP was compared with that of palmitic acid (PA), without the ascorbyl group. In addition, HAMS inclusion complexes with AP and PA were formed and treated by annealing (ANN), acid hydrolysis (ACH), and the combination of both. Upon the addition of AP, the resistant starch (RS) contents in raw, cooked, and retrograded starches were increased significantly, indicating the inhibitory effect of AP against starch digestion. Although both HAMS-AP and HAMS-PA inclusion complexes exhibited minimal RS contents, all the hydrothermal treatments enhanced the RS contents in both inclusion complexes, marking their potential to serve as a new type of RS, i.e., RS5. Among the treatments, ANN followed by ACH (ANN-ACH) was most effective to retard starch digestion by increasing RS contents. The study findings could have practical implications in designing functional starch-based ingredients and increasing their nutritional value. [Display omitted] • Ascorbyl palmitate inhibited the digestion of raw, cooked, and retrograded starches. • Palmitic acid could not alter the digestibility profiles of starches. • Raw starch inclusion complexes showed low resistance to digestion. • Hydrothermal treatments enhanced resistant starch levels in inclusion complexes. • Annealing followed by acid hydrolysis was most effective to retard starch digestion. [ABSTRACT FROM AUTHOR]

Amylose-guest inclusion complexes are a type of supramolecular host-guest assembly that can provide protection for and controlled release of guest molecules. The successful and efficient complexation between amylose and guest molecules is governed by factors including: guest structure and chemistry, and process method and parameters. Here we investigated the formation, crystalline structure, and thermal stability of amylose inclusion complexes with a total of ten guest molecules differing in alkyl chain length (C10 and C16), molecular shape (linear vs. branched), and functional groups (alcohol, aldehyde, carboxylic acid, and ester). Their ability to complex with amylose was evaluated using two complexation methods (partitioning from water after heating and partitioning from a DMSO/water solution), and two annealing temperatures (60 and 90 °C). The extent of complexation differed for the two methods, likely due to guest solubility and partitioning behavior in the respective solvent systems. Annealing temperature created inclusion complexes of different structure and dissociation temperature using the water approach. Here we suggest that the so-called "Form I" and "Form II" V-type amylose inclusion complexes differ in their crystal size, crystallinity and arrangement of guest molecules in the helical cavity, rather than being amorphous or crystalline as previously reported. Chain length, molecular shape, and functional groups affected the thermal stability of the inclusion complexes. Shorter chain length, unsaturation, and short branched chains formed inclusion complexes with lower dissociation temperatures. We propose the Form II as a tail-to-tail arrangement of molecules in the helices that leaves the functional groups at the helical openings. Guest compounds that either failed to form complexes from water or formed poor complexes were able to form inclusion complexes with amylose using the DMSO approach, suggesting solubility of the guest, flexibility of the amylose chain, or the partitioning of the guest between the solvent and the helix core affected complexation. Image 1 • Most linear compounds formed inclusion complexes with amylose. • Annealing at higher temperature resulted in Form II complexes. • Form II complex showed higher stability and larger crystals. • Different complexation methods are best suited for different guest compounds. [ABSTRACT FROM AUTHOR]

Off-flavors have garnered significant attention in research due to their impact on overall flavor, which leads consumers to avoid purchasing or consuming food products with off-flavors, even if they offer health benefits. However, there has been limited research on encapsulating off-flavor compounds as a means to mask them and to improve the flavor profiles of food products. Starch, particularly its amylose component, is well-known for its ability to form inclusion complexes (ICs) with various small molecules, providing protection and controlled release of these encapsulated guest molecules. The complexation interaction between starch and guest compounds is influenced by factors such as the structure and chemistry of the guest, as well as the process method and parameters. In the present study, nine different beany off-flavor compounds, including hexanal (HAL), 3-hexanol (HOL), benzaldehyde (BAL), 1-octen-3-ol (OOL), 1-octen-3-one (ONE), 2-pentylfuran (PTF), trans -2-nonenal (NAL), trans, trans -2,4-nonadienal (NAD), and trans, trans -2,4-decadienal (DEC) were used as model off-flavors to examine their complexation ability with three types of preformed "empty" V-type high amylose maize starches (HAMS), namely V 6h , V 7 , and V 8. The successful formation of inclusion complexes was characterized using complementary techniques, including X-ray diffraction (XRD), differential scanning calorimetry (DSC), and gas chromatography-mass spectrometry (GC-MS). The results revealed that the complexation of off-flavor compounds with the starches did not significantly alter the original structures of the starches. Additionally, the IC samples prepared using the gas phase (GP) approach exhibited significantly higher encapsulation efficiency compared to the direct contact (DC) approach, as indicated by GC-MS analysis. Among the V-type starches, V 6h HAMS demonstrated the highest complexation efficiency for all selected beany off-flavor compounds when the ICs were prepared using the GP approach. This study suggests that both V 6h and V 8 starches exhibit effective scavenging abilities for beany off-flavor compounds. Further, complexation properties depend on the properties of the off-flavor compounds, the type of V starch used, and the IC preparation approach. [Display omitted] • Scavenging beany off-flavor compounds by preformed "empty" V-type starch. • Starch structure not significantly altered upon complexation. • Guest structure influenced scavenging efficiency, especially in direct contact approach. • V 6h -type starch has shown as the most effective through gas phase approach. [ABSTRACT FROM AUTHOR]

In the current study, V 6 , V 7 and V 8 amyloses were prepared, their crystalline polymorphic transitions upon hydration at different moisture conditions examined by wide-angle X-ray diffraction (XRD), and the relative degrees of crystallinity calculated. Upon the formation of V 7 or V 8 crystals, the XRD peaks shifted to lower Bragg angles as compared to V 6h due to the expansion of the amylose helices. Conditioning at 75% equilibrium relative humidity (ERH) transformed V 6a and V 7 amyloses to the V 6h pattern. Long-term vapor hydration at 100% ERH or total hydration by immersion in water transformed all V-type XRD patterns to the B-type with decreased degrees of crystallinity. Upon dehydration by ethanol wash, the relative crystallinities of all V-type amyloses were increased, while the crystalline patterns remained mostly unchanged. Such explicit study of polymorphic transitions revealed by XRD can help establish optimal conditions for the encapsulation of bioactive compounds with V-type amyloses and provide insights for novel food product developments. [Display omitted] • Four types of V amylose (V 6a , V 6h , V 7 , and V 8) subject to hydration and dehydration • Hydration at 75% equilibrium relative humidity (ERH) transformed V 6a and V 7 to V 6h • Total and long-term vapor hydration at 100% ERH transformed all V types to B type • Dehydration increased relative crystallinities of all V-type amyloses [ABSTRACT FROM AUTHOR]

The prevalence of type 2 diabetes (T2D) has become a major public health concern worldwide. Slowly digested or indigestible carbohydrates such as resistant starch (RS) are associated with a low glycemic index (GI) and the decreased risk of developing T2D. Recently, starch inclusion complexes (ICs) have raised attention due to their thermally stable structure and high RS content. In this study, starch-ascorbyl palmitate (AP) ICs were produced using two different methods with hydrothermal treatments performed, and their in vitro digestion kinetics and in vivo glycemic response in C57BL/6J mice were investigated to determine their potential as a new type of RS, i.e. , RS5. After treatments of annealing followed by acid hydrolysis (ANN-ACH), IC samples produced by both methods retained V-type crystalline structure. Either in their raw or treated conditions, V 6h -AP ICs prepared using the "empty" V-type method exhibited a more favorable hydrolysis pattern as compared to its counterpart produced by the DMSO method in terms of a lower hydrolysis rate and equilibrium concentration (C ∞) (p < 0.05). From the in vitro results, the ANN-ACH treated V 6h -AP IC exhibited an estimated GI (e GI) value of 54.83, falling within the range of low GI foods and was the lowest among all tested samples (p < 0.05). Consistent with the in vitro digestion kinetics, the in vivo results showed that mice fed with ANN-ACH V 6h -AP IC exhibited a modest glycemic response as evidenced by the lowest increase in postprandial blood glucose and AUC blood glucose (p < 0.05). In addition, the in vivo GI of the ANN-ACH V 6h -AP IC (39.53) was the lowest among all the sample treatments and was even lower than that of the RS2 comparison (56, p < 0.05), indicating its more pronounced effect in modulating the postprandial glycemic response in mice and great potential as a new RS5. [Display omitted] [ABSTRACT FROM AUTHOR]

Starch, especially its amylose component, is well-known to form inclusion complexes with a variety of small molecules such as fatty acids. The structure of the lipid guest could affect its complexation ability and other properties such as thermal stability. The present study aimed to investigate the complexation ability and the physicochemical properties of high amylose maize starch (HAMS) inclusion complexes with C18 fatty acids of various numbers and positions of double bonds, including octadecanoic (stearic, SA), (Z)-octadec-9-enoic (oleic, OA), (E)-octadec-9-enoic (elaidic, EA), (9Z,12Z)-octadeca-9,12-dienoic (linoleic, LA), (9Z,12Z,15Z)-octadeca-9,12,15-trienoic (α-linolenic, ALA), and conjugated linoleic acids (CLA). Two complexation methods were used, which are the DMSO method and the "empty" V-type method. The formation, structural characteristics, and thermal properties of inclusion complexes formed were examined by complementary techniques including differential scanning calorimetry (DSC), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. As the guest fatty acid became more unsaturated and as the number of double bonds increased, the dissociation temperatures of HAMS-fatty acid inclusion complexes formed decreased with either complexation method. The DMSO method resulted in the formation of Form I inclusion complexes only, whereas the "empty" V-type method promoted the formation of Form II inclusion complexes with higher thermal stability. In addition, ethanol concentration was found to influence the formation of inclusion complexes when using the "empty" V-type method, and intermediate concentrations were more favorable to maintain a stable and flexible amylose helical structure to form inclusion complexes with higher crystallinity and thermal stability. [Display omitted] • Starch inclusion complexes formed with C18 fatty acids of different chain configuration. • Lamellar thickness and thermal stability increased with degree of saturation. • Trans-double bonds facilitate complexation compared to cis-double bonds. • Form I & II type complex structures formed by empty helix method. • Ethanol content affected chain flexibility and thus the proportions of Form I & II. [ABSTRACT FROM AUTHOR]

Catechin is a natural phenolic compound with various bioactivities. However, it is unstable under light and heat environments. Amylose can form a single helical hydrophobic cavity to encapsulate and protect bioactive compounds. In this work, we applied amylose inclusion complexes (IC) to encapsulate a lipophilized catechin, i.e. , hexadecyl catechin (HC), to improve its photostability and thermal stability. The formation of amylose-HC IC was characterized using differential scanning calorimetry, X-ray diffraction, and Fourier transform infrared spectroscopy. The photostability and thermal stability studies showed that the retention of guest molecules in IC was 86.1% ± 5.1% and 87.4% ± 0.6%, respectively, which was significantly higher than that of the catechin, HC, and amylose-HC physical mixture groups. Moreover, the in vitro release profile of IC demonstrated a steady and complete release of catechin. The findings show the amylose encapsulation of catechin is a promising technique to preserve bioactive compounds in food. [Display omitted] • Successful lipophilization of catechin confirmed by 1H NMR and MS. • Complexation of hexadecyl catechin by amylose evidenced by DSC, XRD, and FTIR. • Inclusion complex enhanced photostability and thermal stability of catechin. • Catechin could be steadily and completely released from the inclusion complex. [ABSTRACT FROM AUTHOR]

The interactions between starch and phenolic compounds have a great impact on the physicochemical and nutritional properties of starch-containing foods. One particular form of the interaction is starch-guest inclusion complexation, which is a specific non-covalent interaction formed between starch and guest molecules. This study investigates complexation ability and enzymatic digestibility profiles of amylose and high amylose maize starch (HAMS) inclusion complexes with gallic acid (GA) and alkyl gallates of various chain lengths, including butyl (BG), octyl (OG), dodecyl (DG), hexadecyl (HG), and octadecyl (SG) gallates. The formation of inclusion complex was examined by complementary techniques including differential scanning calorimetry (DSC), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. The digestibility profiles, represented as rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS) contents, were obtained through simulated in vitro enzymatic digestion assays. The results showed that while GA, BG, and OG were not capable of forming inclusion complex with either amylose or HAMS, gallates with longer alkyl chains were able to form more stable inclusion complexes. Precipitated amylose and HAMS samples without inclusion complex formation contained the lowest RDS and highest SDS + RS, probably due to starch retrogradation. Amylose and HAMS inclusion complexes with long alkyl chain, particularly HG and SG, also possessed the lowest RDS and highest SDS + RS, but higher SDS proportions than the non-complexed starch samples. It was suggested that the inclusion complexes, especially amylose-HG and SG, and HAMS-DG, HG, and SG, might have contributed to the increase in SDS content. The water insusceptibility and high thermal stability of these inclusion complexes helped retard the starch digestion. The resistant yet steady digestion behavior of the starch-gallate inclusion complexes has significant implications in modulating glycemic response, as well as enabling a slow and sustained release of bioactive guest compounds into the gastrointestinal tract. Image 1 • Gallates with longer alkyl chains formed more stable V-type inclusion complex. • Amylose/starch-gallate inclusion complexes retarded digestion. • Slowly digestible starch (SDS) greatly increased in starch-gallate inclusion complexes. • Both precipitated starch and inclusion complexes had the lowest digestibility. [ABSTRACT FROM AUTHOR]

As phenolic compounds, alkyl gallates may inhibit the activity of digestive enzymes for starch. Furthermore, their alkyl chains may facilitate starch inclusion complexation and results in an increased resistant starch (RS) content or slowly digestible starch (SDS) content, which may further retard starch digestion. The significance of such inhibition is that the rate of starch hydrolysis into glucose is reduced, thereby preventing hyperglycemia and related metabolic diseases. This study examined the inhibitory effects on in vitro enzymatic digestion of starch by gallic acid and five alkyl gallates of varying alkyl chain lengths, i.e., butyl gallate, octyl gallate, dodecyl gallate, hexadecyl gallate, and octadecyl gallate. Raw and cooked potato starch (PS) and high-amylose maize starch (HAMS) were tested. For both types of raw starch, gallic acid and all the alkyl gallates significantly (p < 0.05) increased RS content except for octadecyl gallate. In the case of cooked starch, the RS contents were markedly decreased (p < 0.05) as compared to those in raw starch, because gelatinization caused an overall greater susceptibility to enzymatic digestion. The reduction in RS content was less in cooked HAMS than that in cooked PS, due to a higher gelatinization temperature range of HAMS. The aforementioned effect of gallates on RS content was also found for cooked PS, while cooked HAMS experienced increased RS only with gallic acid and butyl gallate. Overall, for the digestion of both starches, regardless of raw or cooked, gallic acid and alkyl gallates with shorter chains demonstrated the strongest inhibitory effects. Our findings indicate that shorter alkyl gallates are effective in inhibiting enzymatic digestion of starch and therefore may have potential in modulating glycemic response. Image 1 • Gallates reduced digestibility of potato (PS) and high amylose maize starch (HAMS). • Resistant starch increased in the presence of gallic acid and alkyl gallates. • Inhibition on starch digestion decreased with increasing alkyl chain length. • Digestibility of PS more affected than HAMS by cooking. • Gallates may form inclusion complex with cooked HAMS that resisted digestion. [ABSTRACT FROM AUTHOR]

Flavoring ingredients are often the most expensive ingredients in food formulations, and their stability and release behavior are significant factors for quality and acceptability of food products. Among flavoring compounds, aroma compounds draw a lot of attention in research, as their volatile nature makes their release difficult to control. In the present study, we employed pre-formed V-type starches to molecularly encapsulate an aroma compound, i.e., menthol. We examined high amylose maize starch of six different V-type crystalline structures (containing 6, 7 and 8 glucose units per helical turn), namely V 6 , V 7 , and V 8 -types, to encapsulate menthol and thus, to control the release behavior. Rehydration of V 6a at a relative humidity of 0.75 lead to its conversion to V 6h (V h), while rehydration had only minor influence on the XRD patterns of anhydrous forms of V 7 and V 8. Successful inclusion complexation was characterized by X-ray diffraction (XRD), differential scanning calorimetry (DSC), and gas chromatography-mass spectrometry (GC-MS). Upon complexation with menthol, the XRD pattern of V 6h shifted to V 7 , whereas all other V-subtypes retained their original crystalline structures. An endotherm with peak temperature at ca. 118 °C appeared after inclusion complexation, corresponding to the dissociation of starch-menthol inclusion complexes. Endothermic enthalpy, with the exclusion of V 6a , and GC-MS quantification agreed that the total menthol content in inclusion complexes followed the order of V 6h > V 6a > V 7a > "V 7h " > V 8a > "V 8h ", with the helices initially of the V 6h -type being the most effective in encapsulating menthol molecules. The controlled release characteristics of the encapsulated aroma compound were investigated in the presence and absence of pancreatic α-amylase. The presence of amylase increased both the release rate and the amount of menthol released within 2 h. The release rates were different among samples made from different subtypes, due to their different association mechanisms with menthol, including physical adsorption on the surface of starch or in the amorphous phase, inter-helical entrapment, and intra-helical inclusion complexation. The Higuchi model was fitted to understand the release kinetics and showed that the constant Y for menthol release from different V-type ICs followed the order of "V 8h " > V 8a > "V 7h " > V 6a > V 7a > V 6h. Image 10937 • Starch-menthol inclusion complexes prepared using starch of different V-types. • Successful inclusion complexation characterized by XRD, DSC, and GC-MS. • Total menthol content followed the order of V 6h > V 6a > V 7a > V 7h > V 8a > V 8h. • V 6h -type was the most effective in encapsulating menthol molecules. [ABSTRACT FROM AUTHOR]