Lipophilization and amylose inclusion complexation enhance the stability and release of catechin

Simple Method for Preparing Starch Inclusion Complexes with Enhanced Amylolysis Resistance and Antioxidant Properties

Slow-digesting starch with bioactive functionality has been attracting much interest with the increasing incidence of type-2 diabetes and other diet-related illnesses. The present study demonstrates a simple method for preparing a starch inclusion complex with reduced enzymic digestion and enhanced antioxidant activities using debranched pea starch (PS) and 10-gingerol (10G). Enzymically debranched starch complexed more 10G and formed more structurally ordered starch-10G complexes compared to PS that had not been debranched. Debranching for 6 h resulted in starch with better complexing ability for 10G than starches debranched for longer times. The debranched starch-10G complexes had higher antioxidant activities and a much slower in vitro enzymic digestion profile (rate and hydrolysis extent) than the 10G complex prepared with starch that was not debranched. Our study demonstrates that debranched pea starch-10G complexes with slow-digesting and antioxidant properties are likely to be of interest for developing ingredients for healthier food choices.

Novel Type of Slowly Digested Starch Complex with Antioxidant Properties

With the increasing number of diabetic patients in the world, there is an urgent requirement to reduce the incidence of diabetes. It is considered that a viable prophylactic treatment for type 2 diabetes mellitus is to reduce starch digestibility and oxidative stress. In this study, a novel type of slowly digested starch [pea starch (PS)-gingerol complex] was fabricated to evaluate its in vitro enzymatic digestibility and antioxidant activities. Theoretical and experimental analyses showed that PS can encapsulate gingerols with long alkyl chains to form starch-gingerol complexes, which are further stacked into a mixture of V6- and V7-crystallites. These complexes, in particular the PS-10-gingerol complex, showed high resistance to amylolysis and good antioxidant activities. This study demonstrates that these novel starch-gingerol complexes have the potential to deliver antioxidants encapsulated in starch with slow-digesting properties and reduce oxidative stress. Moreover, this new type of slowly digested starch with antioxidant properties showed great potential in the prevention of type 2 diabetes.

Improved accelerated stability of starch-chia oil fatty acid inclusion complexes formed under mild reaction conditions

The starch inclusion complexation of sensitive compounds requires the use of conditions that minimize their degradation. This research work is aimed at investigating the effect of an alkaline complexation method employing mild reaction conditions on the physicochemical properties and accelerated stability of inclusion complexes of high amylose corn starch with omega-3 and omega-6 fatty acids. Hydrolyzed chia seed oil, rich in α-linolenic and linoleic fatty acids, was used as guest material and was incorporated at two ratios (10 and 20 % w/w hydrolysate/starch). Under the reaction conditions assessed, it were successfully formed V-type inclusion complexes with a high content of omega-3 and omega-6 (3.9-6 %). The initial hydrolysate concentration did not have a significant effect on the structural (crystallinity, short-range order) and thermal (dissociation temperature, melting enthalpy) properties. The method studied allowed the formation of complexes with an enhanced accelerated oxidative stability, compared to those formed using thermal treatment. The complexes formed using mild conditions with 20 % hydrolysate content had the highest oxidative stability, showing an omega-3 and omega-6 retention >90 % after 6 h of storage at 90 °C, an enhanced stability under thermogravimetric analysis, and flattened Rancimat curves, suggesting an appropriate preliminary behavior as potential carriers of bioactive fatty acids.

Insights into formation and stability mechanism of V7-type short amylose-resveratrol complex using molecular dynamics simulation and molecular docking

Pre-formed V-type amylose as a kind of wall material has been reported to carry polyphenols, while the interaction mechanism between V-type amylose and polyphenol is still elusive. In this work, the formation and stability mechanism of a V7-type short amylose-resveratrol complex was investigated via isothermal titration calorimetry, molecular dynamics, and molecular docking. The results presented that two stoichiometric ratios of resveratrol to short amylose were calculated to 0.120 and 0.800, and the corresponding main driving force was hydrogen bonding and hydrophobic interaction, respectively. The folding and unfolding conformation of V7-type short amylose chains appeared alternately during the simulation. Resveratrol tended to be bound in the short amylose helix between 40 ns and 80 ns to form a more stable complex. Hydrogen bonds between resveratrol molecule and O6 at the 22nd glucose molecule/O2 at the 24th glucose molecules and hydrophobic interaction between resveratrol molecule and glucose molecules (19th, 20th, 21st and 23rd) could be found.

Effect of milling on in vitro Digestion-Induced release and bioaccessibility of active compounds in rice

To investigate the impact of milling on the active components in rice, this study examined the stability of phenols, vitamin B1 (VB1), and alpha-aminobutyric acid (α-GABA) during cooking and digestion of rice and their distribution in digestive juices and residue by adjusting the degree of milling (DOM). The findings revealed that milling exacerbated the instability of γ-GABA during cooking and VB1 during digestion. Their total losses peaked at 19.76% and 39.53% as DOM respectively reached 6.07% and 8.06%. In vitro digestion combined with release mathematical models demonstrated the impact of milling on their bioaccessibility. This effect increased the small intestinal bioaccessibility of phenols and γ-GABA, whilst reducing that of VB1. This was attributed to milling-induced pre-gastric full release of VB1, which amplifies its intestinal susceptibility and induces its re-entry into digestive residues. In conclusion, this study recommends keeping DOM below 6.07% to optimize the bioaccessibility of these active compounds.

Experimental and Molecular Docking Studies on Enzyme-Driven Biohybrid-Inspired Micromotors Based on Amylose-b-(PEG-co-PBA) Inclusion Complexes

Amylose is a linear polysaccharide with a unique ability to form helical inclusion complexes with the appropriate guest components. Numerous studies have been conducted on encapsulation of bioactive compounds for various applications. In the biomedical field, biohybrid micro/nanomotors (MNMs) have emerged as innovative candidates due to their excellent biocompatible and biodegradable properties. This study was inspired by the biohybrid- and enzymatic-propelled MNMs and explored the potential of amylose inclusion complexes (ICs) in creating these MNMs. The study developed a new type of micromotor made from (PEG-co-PBA)-b-amylose. Nanoprecipitation, dimethyl sulfoxide (DMSO), and ultrasound-treated methods were employed to create spherical, thick crystalline, and rod-bacterial-like morphologies, respectively. Candida antarctica lipase B (CALB) was used as the catalytic fuel to induce the motion by the enzymatic degradation of ester linkages in the polymeric segment. Optical microscopy was utilized to observe the motion of the motors following incubation with enzyme concentrations of 5, 10, and 20% (w/w). The results demonstrated that the velocity of the motors increased proportionally with the percentage of added enzyme. Additionally, a comprehensive molecular docking evaluation with PyRx software provided insight into the interaction of the CALB enzyme with polymeric moieties and demonstrated a good affinity between the enzyme and polymer in the binding site. This study provides novel insight into the design and development of enzymatically driven polymeric micromotors and nanomotors.

Developing biopolymer-stabilized emulsions for improved stability and bioaccessibility of lutein

Lutein is essential for infant visual and cognitive development but has low stability and solubility. This study aimed to enhance the stability and bioaccessibility of lutein using oil-in-water emulsions stabilized with biopolymers. Commercially available octenylsuccinylated (OS) starches, including capsule TA® (CTA), HI-CAP®100 (HC), and Purity Gum® 2000 (PG), along with gum Arabic (GA) variants Ticaloid acacia Max® (TAM), TICAmulsion® 3020 (TM), and pre-hydrate gum Arabic (PHGA), were chosen as emulsifiers. By screening the effect of biopolymer concentration and oil volume fraction (Φ), emulsions stabilized with CTA, HC, or TM at 20% and 30% (w/v) concentration and 70% Φ exhibited a gel-like structure and were selected for further assessments. After a week at 25 °C, emulsions stabilized by CTA and HC showed no significant change in droplet size, while TM emulsion exhibited a 1.58-fold increase. At 45 °C, all emulsions exhibited increase in droplet size. Lutein retention is higher in CTA emulsions at both storage temperatures than free lutein. In vitro bioaccessibility of all lutein emulsions was higher than that of free lutein. These findings highlight the superior stability and bioaccessibility of the lutein emulsion stabilized by OS starch, positioning it as a promising carrier to broaden lutein applications in infant foods.

The Iodine/Iodide/Starch Supramolecular Complex

The nature of the blue color in the iodine-starch reaction (or, in most cases, iodine-iodide-starch reaction, i.e., I2 as well as I- are typically present) has for decades elicited debate. The intensity of the color suggests a clear charge-transfer nature of the band at ~600 nm, and there is consensus regarding the fact that the hydrophobic interior of the amylose helix is the location where iodine binds. Three types of possible sources of charge transfer have been proposed: (1) chains of neutral I2 molecules, (2) chains of poly-iodine anions (complicated by the complex speciation of the I2-I- mixture), or (3) mixtures of I2 molecules and iodide or polyiodide anions. An extended literature review of the topic is provided here. According to the most recent data, the best candidate for the "blue complex" is an I2-I5--I2 unit, which is expected to occur in a repetitive manner inside the amylose helix.

Effect of high pressure homogenization on the interaction between corn starch and cyanidin-3-O-glucoside

The effects of high pressure homogenization (HPH) at different pressures (50, 100, 150 and 200 MPa) and temperatures (4, 20, 40, 60 and 80 °C) on the interaction between corn starch (CS) and cyanidin-3-O-glucoside (C3G) were investigated. Based on analyses of zeta potential, attenuated total reflection-flourier transformed infrared spectroscopy and binding rate after adding shielding agents, the main interaction force changed from electrostatic interaction to hydrogen bonds. In comparison, the interaction between CS and C3G exhibited greater strength at low temperatures and pressures. Especially, 4 °C/50 MPa HPH caused the most significant enhancement in binding rate and binding amount, from 9.56 % to 25.16 % and 0.96 μg/mg CS to 2.52 μg/mg CS, respectively. At this condition, the specific surface area of CS-C3G increased from 433.57 ± 0.91 m2/kg to 440.93 ± 1.01 m2/kg. Surface fluorescence reduction was observed by confocal laser scanning microscopy, further X-ray diffraction patterns indicated the retention of partial spatial structure. Therefore, HPH opened the entry channels, increased contact area and preserved steric hindrance, which increased hydrogen bonding sites. At high temperatures and high pressures (> 40 °C, > 100 MPa), the increasing free starch chains provided new hydrogen bonding sites. Overall, HPH was an effective method to enhance the interaction by affecting starch structure.

Chitooligosaccharide-catechin conjugate loaded liposome using different stabilising agents: characteristics, stability, and bioactivities

AIM

To determine the optimum condition for preparing chitooligosaccharide-catechin conjugate (COS-CAT) liposomes using different stabilising agents.

METHODS

COS-CAT liposomes (0.1-1%, w/v) were prepared using soy phosphatidylcholine (SPC) (50-200 mM) and glycerol or cholesterol (25-100 mg). Encapsulation efficiency (EE), loading capacity (LC), physicochemical characteristics, FTIR spectra, thermal stability, and structure of COS-CAT liposomes were assessed.

RESULTS

COS-CAT loaded liposome stabilised by cholesterol (COS-CAT-CHO) showed higher stability as shown by the highest EE (76.81%) and LC (4.57%) and the lowest zeta potential (ZP) (-76.51 mV), polydispersity index (PDI) (0.2674) and releasing efficiency (RE) (53.54%) (p < 0.05). COS-CAT-CHO showed the highest retention and relative remaining bioactivities of COS-CAT under various conditions (p < 0.05). FTIR spectra revealed the interaction between the choline group of SPC and -OH groups of COS-CAT. Phase transition temperature of COS-CAT-CHO was shifted to 184 °C, which was higher than others (p < 0.05).

CONCLUSION

SPC and cholesterol-based liposome could be used as a promising vesicle for maintaining bioactivities of COS-CAT.

Complexation of starch and phenolic compounds during food processing and impacts on the release of phenolic compounds

Phenolic compounds can form complexes with starch during food processing, which can modulate the release of phenolic compounds in the gastrointestinal tract and regulate the bioaccessibility of phenolic compounds. The starch-phenolic complexation is determined by the structure of starch, phenolic compounds, and the food processing conditions. In this review, the complexation between starch and phenolic compounds during (hydro)thermal and nonthermal processing is reviewed. A hypothesis on the complexation kinetics is developed to elucidate the mechanism of complexation between starch and phenolic compounds considering the reaction time and the processing conditions. The subsequent effects of complexation on the physicochemical properties of starch, including gelatinization, retrogradation, and digestion, are critically articulated. Further, the release of phenolic substances and the bioaccessibility of different types of starch-phenolics complexes are discussed. The review emphasizes that the processing-induced structural changes of starch are the major determinant modulating the extent and manner of complexation with phenolic compounds. The controlled release of complexes formed between phenolic compounds and starch in the digestive tracts can modify the functionality of starch-based foods and, thus, can be used for both the modulation of glycemic response and the targeted delivery of phenolic compounds.

Development, application and future trends of starch-based delivery systems for nutraceuticals: A review

As a natural biopolymer, starch is ideally adapted as an encapsulant material for nutraceutical delivery systems due to its unique nature of extensive sources, versatility and high biocompatibility. This review offers an outline of recent advances in the development of starch-based delivery systems. The structure and functional properties of starch in encapsulating and delivering bioactive ingredients are first introduced. Structural modification of starch improves the functionalities and extends the applications of starch in novel delivery systems. Then, various nutraceutical delivery systems are systematically summarized, which include porous starch, starch particle, amylose inclusion complex, cyclodextrin, gel, edible film and emulsion. Next, the delivery process of nutraceuticals is discussed in two parts: digestion and release. Intestinal digestion plays an important role during the whole digestion process of starch-based delivery systems. Moreover, controlled release of bioactives can be achieved by porous starch, starch-bioactive complexation and core-shell structure. Finally, the challenges of the existing starch-based delivery systems are deliberated, and the directions for future research are pointed out. Composite delivery carriers, co-delivery, intelligent delivery, delivery in real food systems, and reuse of agricultural wastes may be the research trends for starch-based delivery systems in the future.

An investigation into structural properties and stability of debranched starch-lycopene inclusion complexes with different branching degrees

Debranched starch (DBS) has great probability as carrier for bioactive ingredients, but effects of branching degree (DB) on the complex formation of starch remain unclear. This study investigated the potential of DBS with different DB to load lycopene and characterized the structural properties of inclusion complexes. Glutinous rice starch was debranched to get DBS with different molecular weights, where DBS with a branching degree of 11.42 % had the greatest encapsulation efficiency (64.81 %). SEM, particle size, and zeta-potential results showed that the complexes form stable spherical crystals through electrostatic interactions. The structures of complexes were resolved by FTIR, XRD, TGA, and 13C CP/MAS NMR analytical techniques, indicating that lycopene can be loaded on DBS by the self-assembly through hydrophobic and hydrogen bonding interactions. Degradation experiments revealed that retention of complexes was significantly higher than the unencapsulated one. Our study reveals the structural features of the complex between DBS and lycopene, providing theoretical guidance for developing and producing novel nutraceuticals.

Encapsulation in Amylose Inclusion Complex Enhances the Stability and Release of Vitamin D

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.

Glutaraldehyde Crosslinked High Content of Amylose/Polyvinyl Alcohol Blend Films with Potent Tensile Strength and Young's Modulus

In recent years, with the development of green environmental protection, starch film has become of interest due to the wide availability of sources, low price, and biodegradability. Amylose/polyvinyl alcohol (PVA) blend films crosslinked with different amounts of glutaraldehyde (GLU) were prepared by a solution casting method. The cross-linking degree, water sorption, tensile property, crystallization and section morphology of the films were examined. With the increase in glutaraldehyde concentration, the cross-linking degree of the blend film was improved. The wide-angle X-ray scattering (WAXS) result indicated that cross-linking hindered the crystallization of film. The section morphology of films was examined by scanning electron microscope (SEM). The results showed that the cross-linking degree of amylose film improved while the crystallinity decreased with the increase in glutaraldehyde content. Cross-linking had no obvious effect on the water sorption property of the blend films. The cross-linking modification significantly enhanced the tensile strength and Young's modulus, while it reduced the elongation at break of the blend films. It was found that the film with 0.5 wt % glutaraldehyde possessed the best performance: the tensile strength increased by 115%, while the elongation at break decreased by 18% even at high relative humidity (RH) of 90% compared to non-crosslinked films. The developed amylose/PVA blend films have promising application prospects as agricultural mulch films and packaging materials.

Effects of apple polyphenols and hydroxypropyl-β-cyclodextrin inclusion complexes on the oxidation of myofibrillar proteins and microstructures in lamb during frozen storage

This study aimed to evaluate the effect of inclusion complexes (ICs) on the oxidative stability of myofibrillar proteins (MPs) and microstructures in lamb during frozen storage. The inclusion process between apple polyphenols (APs) and hydroxypropyl-β-cyclodextrin (HP-β-CD) was verified using Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and the antioxidant activity of APs. Results showed that the sensitivity of MPs to oxidation improved after 40 weeks. The ICs (0.2-1.6 mg/mL) significantly reduced the carbonyl content, particle size aggregation, protein degradation, fluorescence quenching effect, and decreased the α-helix contents loss of MPs. Additionally, the changes in protein oxidation showed a correlation with the microstructure of muscles, and the addition of 1.6 mg/mL IC remarkably improved the structure of muscle tissues while that of 3.2 mg/mL IC was detrimental to the structural properties. Overall, the exertion of antioxidant activity significantly influenced the cryoprotective effect of ICs on frozen lamb meat.

Starch inclusion complex for the encapsulation and controlled release of bioactive guest compounds

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.