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Vitamin D plays a significant role in the physiological functions of the human body. However, the application of vitamin D in functional foods is limited due to its sensitivity to light and oxygen. Therefore, in this study, we developed an effective method to protect vitamin D by encapsulating it in amylose. In detail, vitamin D was encapsulated by amylose inclusion complex, followed by structural characterization and evaluation of its stability and release properties. The results of X−ray diffraction, differential scanning calorimetry, and Fourier transform infrared spectroscopy showed that vitamin D was successfully encapsulated in the amylose inclusion complex, and the loading capacity was 1.96% ± 0.02%. The photostability and thermal stability of vitamin D after encapsulation was increased by 59% and 28%, respectively. In addition, in vitro simulated digestion showed that vitamin D was protected through the simulated gastric environment and can be released gradually in the simulated intestinal fluid, implying its improved bioaccessibility. Our findings provide a practical strategy for the development of functional foods based on vitamin D. [ABSTRACT FROM AUTHOR]

Amylose is well known to form inclusion complexes with various small molecules including fatty acids. In this study, we prepared amylose inclusion complexes with stearic acid derived spin probes and demonstrated the electron paramagnetic resonance (EPR) spectroscopy as an emerging tool for studying the microstructure and microenvironment of amylose-guest inclusion complex. Two spin probes, namely 5-doxyl-stearic acid (5-DSA) and 16-doxyl-stearic acid (16-DSA), were used as guest molecules in forming amylose-guest inclusion complexes. The molecular dynamics and local polarity of the spin probes and their interaction with amylose in physical mixtures and inclusion complexes were studied using EPR spectroscopy. Complexed guest spin probes could be released when the inclusion complex was dissolved dimethyl sulfoxide (DMSO) and detected by EPR. Since the inclusion complex could not be dissolved in water, the motion of spin probes was restricted in hydrated samples shown by the powder-like slow spectra. Our findings also indicated that the individual association between amylose and the two DSA molecules in forming the inclusion complexes were different. A portion of 16-DSA molecules were not tightly immobilized in the amylose helical channel, but instead were loosely entrapped in the amorphous region of the semicrystalline V 6 -type amylose. Therefore, EPR spectroscopy provides valuable information on the molecular dynamics and microenvironment of guest molecules and their interaction with amylose in inclusion complex, and can be exploited as a useful tool to study amylose-guest inclusion complex and other host-guest systems. [ABSTRACT FROM AUTHOR]

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. [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]

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]

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. [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]

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. • A variety of bioactive compounds can form inclusion complex with starch. • Methods of preparation, characterization, and guest quantification were developed. • Controlled release kinetics were evaluated by both in vitro and in vivo studies. [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]