Encapsulation of tangeretin into debranched-starch inclusion complexes: Structure, properties and stability

Encapsulation of chrysin and rutin using self-assembled nanoparticles of debranched quinoa, maize, and waxy maize starches

Chrysin and rutin are natural polyphenols with multifaceted biological activities but their applications face challenges in bioavailability. Encapsulation using starch nanoparticles (SNPs) presents a promising approach to overcome the limitations. In this study, chrysin and rutin were encapsulated into self-assembled SNPs derived from quinoa (Q), maize (M), and waxy maize (WM) starches using enzyme-hydrolysis. Encapsulation efficiencies ranged from 74.3 % to 79.1 %, with QSNPs showing superior performance. Simulated in vitro digestion revealed sustained release and higher antioxidant activity in QSNPs compared to MSNPs and WMSNPs. Variations in encapsulation properties among SNPs from different sources were attributed to the differences in the structural properties of the starches. The encapsulated SNPs exhibited excellent stability, retaining over 90 % of chrysin and 85 % of rutin after 15 days of storage. These findings underscore the potential of SNP encapsulation to enhance the functionalities of chrysin and rutin, facilitating the development of fortified functional foods with enhanced bioavailability and health benefits.

Interaction of high amylose corn starch with polyphenols: Modulating the stability of polyphenols with different structure against thermal processing

Polyphenols are known to undergo thermal degradation and their bioactivity is reduced. In this study, the thermal degradation of polyphenols was modulated by the complexation between polyphenols and high amylose corn starch (HACS). The inclusion complex between ferulic acid with hydrophobic group methoxy and HACS had the highest encapsulation efficiency (EE = 26.15 %), loading efficiency (LE = 2.38 %) and thermal stability (DPPH radical scavenging activity was reduced by only 5.99 % after baking). After complexing with HACS, protocatechuic acid with ortho-position hydroxyl group had a higher encapsulation rate and thermal stability than 3, 5-dihydroxybenzoic acid with meta-position hydroxyl. In addition, soy isoflavone with the higher logarithmic value of octanol-water partition coefficient (Log P = 3.66) resulted in higher encapsulation rate and thermal stability than naringenin (Log P = 2.11). The results suggest that the complexation between polyphenols and starch protects the bioactivity of polyphenols and improves the processing suitability of polyphenols.

The interaction and physicochemical properties of the starch-polyphenol complex: Polymeric proanthocyanidins and maize starch with different amylose/amylopectin ratios

This study investigated the impact of polymeric proanthocyanidins (PPC) on the physicochemical characteristics of maize starch with varying amylose content, and their potential interaction mechanism. PPC with a lower content (1 %) reduced the viscoelasticity of the high amylose maize starch (HAM) system, inhibited amylose rearrangement, and enhanced its fluidity. However, excessive PPC restrained the interaction between PPC and amylose. In contrast to HAM, PPC improved the gelation ability of waxy maize starch (WAM) as PPC concentration was raised. PPC suppressed the recrystallization of starch during storage, and PPC had a superior inhibition influence on the retrogradation of WAM in comparison to HAM. This indicated that amylopectin was more likely to interact with PPC than amylose. Hydrogen bonds were the main driving force between PPC and starch chains, which was clarified by Fourier transform-infrared, nuclear magnetic resonance, X-ray diffraction, iodine bonding reaction, and dynamic light scattering data. Additionally, the mechanism of interaction between PPC and the two starch components may be similar, and variance in physicochemical attributes can be primarily credited to the percentage of amylose to amylopectin in starch.

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.

Review of phytochemical and nutritional characteristics and food applications of Citrus L. fruits

Since the dietary regimen rich in fruits is being widely recognized and encouraged, Citrus L. fruits have been growing in popularity worldwide due to their high amounts of health-promoting phytonutrients and bioactive compounds, such as flavonoids, phenolic acids, vitamins, carotenoids, pectins, and fatty acids. The diverse physicochemical properties and multiple utilization of citrus fruits in food industry are associated with their unique chemical compositions. Throughout the world, citrus has been used for producing various value-added and nutritionally enhanced products, including juices, wines, jams, canned citrus, and dried citrus. However, the current studies regarding the phytochemical and nutritional characteristics and food applications of citrus are scattered. This review systematically summarizes the existing bibliography on the chemical characteristics, functional and nutraceutical benefits, processing, and potential applications of citrus. A thorough understanding of this information may provide scientific guidance for better utilizing citrus as a functional fruit and benefit the extension of citrus value chain.

New Techniques in Structural Tailoring of Starch Functionality

Inherent characteristics of native starches such as water insolubility, retrogradation and syneresis, and instability in harsh processing conditions (e.g., high temperature and shearing, low pH) limit their industrial applications. As starch properties mainly depend on starch composition and structure, structural tailoring of starch has been important for overcoming functional limitations and expanding starch applications in different fields. In this review, we first introduce the basics of starch structure, properties, and functionalities and then describe the interactions of starch with lipids, polysaccharides, and phenolics. After reviewing genetic, chemical, and enzymatic modifications of starch, we describe current progress in the areas of porous starch and starch-based nanoparticles. New techniques, such as using the CRISPR-Cas9 technique to tailor starch structures and using an emulsion-assisted approach in forming functional starch nanoparticles, are only feasible when they are established based on fundamental knowledge of starch. Expected final online publication date for the Annual Review of Food Science and Technology, Volume 13 is March 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Characterization of Cationic Modified Short Linear Glucan and Fabrication of Complex Nanoparticles with Low and High Methoxy Pectin

In this study, we chemically modified the short linear glucan (SLG) using the 3-chloro-2-hydroxypropyl trimethylammonium chloride to introduce a positive surface charge via cationization (CSLG). We then prepared CSLG-based binary nanocomplex particles through electrostatic interactions with low and high methoxyl pectin. The two new types of binary nanocomplex were comprehensively characterized. It was found that the nanocomplex particles showed a spherical shape with the particle size of <700 nm, smooth surface, homogeneous distribution, and negative surface charge. Fourier transform infrared spectroscopy (FTIR) revealed that the driving forces to form nanocomplex were primarily electrostatic interactions and hydrogen bonding. In addition, increasing the CSLG concentration in the nanocomplex significantly enhanced both thermal stability and digestive stability. By comparing the two complex nanoparticles, the HMP-CSLG has a larger particle size and better stability under the GI condition due to the high content of the methoxy group. Additionally, the HMP-CSLG nanoparticle has a higher encapsulation efficiency and slower release rate under simulated gastrointestinal fluid for tangeretin compared with the LMP-CSLG. These results provide new insights into designing the CSLG-based nanocomplex as a potential oral delivery system for nutraceuticals or active ingredients.

Effect of chain length on the structure and physicochemical properties of active compound/linear dextrin composites

Three linear dextrins (LDs) with different chain length were obtained through fractionating short-chain LD by gradient precipitation with 65%, 70% and 75% alcohol, signed as 65LD, 70LD, and 75LD, respectively. The LDs were employed to encapsulate arachidonic acid (ARA) and geranic acid (GA). Fourier infrared spectrometry, differential scanning calorimetry and thermogravimetric analysis confirmed the formation of ARA/LD and GA/LD composites. The ARA/65LD and GA/75LD composites showed higher crystallinity, indicating the formation of more ordered and compact structures in ARA/65LD and GA/75LD composites. The micromorphology of ARA/65LD composite was a clear ellipsoidal like structure, whereas GA/75LD composite presented a spherical shape. The release behavior, thermal, photochemical and antioxidant abilities of ARA and GA were improved after forming composites. Overall, the longer chain LD displayed better encapsulation efficiency with the longer chain ARA, while the shorter chain LD had higher encapsulation capability with GA.

Starch-based materials encapsulating food ingredients: Recent advances in fabrication methods and applications

Encapsulation systems have gained significant interest in designing innovative foods, as they allow for the protection and delivery of food ingredients that have health benefits but are unstable during processing, storage and in the upper gastrointestinal tract. Starch is widely available, cheap, biodegradable, edible, and easy to be modified, thus highly suitable for the development of encapsulants. Much efforts have been made to fabricate various types of porous starch and starch particles using different techniques (e.g. enzymatic hydrolysis, aggregation, emulsification, electrohydrodynamic process, supercritical fluid process, and post-processing drying). Such starch-based systems can load, protect, and deliver various food ingredients (e.g. fatty acids, phenolic compounds, carotenoids, flavors, essential oils, irons, vitamins, probiotics, bacteriocins, co-enzymes, and caffeine), exhibiting great potentials in developing foods with tailored flavor, nutrition, sensory properties, and shelf-life. This review surveys recent advances in different aspects of starch-based encapsulation systems including their forms, manufacturing techniques, and applications in foods.

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

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.

Encapsulation and delivery of bioactive citrus pomace polyphenols: a review

Citrus pomace consists of the peel, pulp, and membrane tissues remaining after juice expression. Globally, around one million tons of citrus pomace are generated annually, which contains a variety of bioactive constituents that could be used as value-added functional ingredients in foods. However, the polyphenols in citrus pomace are not currently being utilized to their full potential, even though they can be used as nutraceuticals in functional foods and beverages. Citrus phenolics face significant roadblocks to their successful incorporation into these products. In particular, they have poor water solubility, chemical stability, and bioavailability. This review describes the diverse range of colloidal systems that have been developed to encapsulate and deliver citrus phenolics. Examples of the application of these systems for the encapsulation, protection, and delivery of polyphenols from citrus pomace are given. The use of colloidal delivery systems has been shown to improve the stability, dispersibility, and bioaccessibility of encapsulated polyphenols from citrus pomace. The selection of an appropriate delivery system determines the handling, storage, shelf life, encapsulation efficiency, dispersibility, and gastrointestinal fate of the citrus polyphenols. Furthermore, the purity, solubility, and chemical structure of the polyphenols are key factors in delivery system selection.

Preparation of amylose-poly(methyl methacrylate) inclusion complex as a smart nanocarrier with switchable surface hydrophilicity

Amylose, as a linear biopolymer, tends to form helical inclusion complexes with suitable guest species. This is of great importance for a variety of applications, especially in the pharmaceutical and food industry. In this study, we propose an approach for the preparation of a novel inclusion complex with switchable surface hydrophilicity. For this purpose, amylose was first conjugated to ethylene diamine hydrophilic residues. Then, the short chains of the hydrophobic poly(methyl methacrylate, PMMA) were grafted onto the cavity of amylose through atom transfer radical polymerization (ATRP). According to CD spectroscopy results, the amylose-PMMA inclusion complexes displayed solvent-directed helical chirality inversion using either DMSO or water as a solvent. Fluorescence imaging, AFM and DLS techniques revealed the solvent-dependent surface hydrophilicity of the amylose-PMMA inclusion complex. Interestingly, its morphological studies displayed a central cavity, which makes it suitable for carrying cargoes in drug delivery applications. Obtaining the amylose-polymer inclusion complexes with tailorable hydrophilicity of both the exterior surface and the interior cavity can be of paramount importance for a wide variety of bio-applications.

Encapsulation of tangeretin in PVA/PAA crosslinking electrospun fibers by emulsion-electrospinning: Morphology characterization, slow-release, and antioxidant activity assessment

In this work, water-resistant poly (vinyl alcohol) (PVA)/poly (acrylic acid) (PAA) electrospun fibers encapsulating tangeretin (Tan) were fabricated by emulsion-electrospinning. To optimize the electrospinning condition, the size and morphology of electrospun fibers were characterized by dynamic light scattering (DLS), optical light microscope, fluorescence microscopy, and scanning electron microscopy (SEM), respectively. The optimized initial concentration of PVA/PAA was 10% (w/w) with a mass ratio of 3:7. The time and temperature of optimized thermal crosslinking treatment were 2 h and 145 °C, respectively. The results of XRD and SEM showed that the Tan was successfully incorporated into smooth PVA/PAA electrospun fibers and those fibers possessed nano-diameter size and high porosity. The encapsulation of Tan had no significant impact on the antioxidant activity of PVA/PAA/Tan crosslinking electrospun fibers. The in vitro release test showed the PVA/PAA/Tan crosslinking electrospun fibers achieved durable release profiles and lower burst release rates than that from the pure Tan emulsion. Based on these results, it is concluded that PVA/PAA/Tan crosslinking electrospun fibers prepared by emulsion-electrospinning serve as a promising technique in the fields of water-insoluble drug delivery and slow-release.