Influence of anionic, neutral, and cationic polysaccharides on the in vitro digestibility of raw and gelatinized potato starch

Natural but threatening? (II) A systematic terrestrial ecotoxicity evaluation of biopolymers and modified natural polymers

Polymers can be found in various agrotechnical products. While synthetic polymers and modified natural polymers are subject to EC 2023/2055 regulation, biopolymers can be regarded as unregulated substituents. However, there is no comprehensive data-based evidence which proves environmental harmlessness of (modified) natural polymer exposure to the terrestrial ecosystem. In order to assess the ecotoxicity potential, we conducted a systematic study with the six economically relevant bio- and modified natural polymers alginate, chitosan, the cellulose fibres Jelucel® HM 200, xanthan, CMC and the modified starch Emwaxy® Jel 100. We hypothesised, that the selected polymers are not ecotoxic within the test concentration range of 10 to 1000 mg/kg. As an evaluation strategy for the ecotoxicity of polymers is missing in the European regulation, we considered different terrestrial faunistic levels within the agricultural landscape for testing. We investigated the ecotoxicity impact on soil micro-, meso- and macrofauna with the OECD TG 216, ISO 15685, ISO 20130, OECD TG 232, ISO 17512-1 and OECD TG 222. Bacterial and archaeal amoA gene abundance was additionally analysed to link functional to structural diversity. Adverse effects were predominantly found for microbial soil functions related to potential nitrification. Collembola and earthworm reproduction, as well as earthworm movement behaviour, were mostly not impaired. Overall, the results indicate that biopolymers and modified natural polymers do have concentration-dependent effects on soil-living organisms and ecotoxicity tests with focus on the terrestrial compartment should be considered in an exposure-related hazard assessment framework.

Impact of pectin or xanthan addition to mashed potatoes gelled with κ-carrageenan on texture and rheology, oral processing behavior, bolus properties and in mouth starch digestibility

Oral processing behavior affects starch bioavailability, but the impact of the oral phase on starch digestibility in potato dishes enriched with polysaccharides has not been clearly established. Therefore, pectin (1 %) or xanthan (1 %) were added to mushed potatoes (MP), which was gelled with κ-carrageenan (0.6 %), to produce the samples named MP-CarP MP-CarX, and MP-Car, respectively. Rheological, textural, sensory and electromyographic tests were conducted on the samples, along with bolus analysis. Both pectin and xanthan softened MP by 23 and 30 %, respectively, and reduced gel strength. The MP-CarP and MP-CarX were orally processed for shorter chewing times; however, their boluses exhibited a 20 % increase in cohesiveness. Chewing the MP-CarP highly enhanced salivation, resulting in a 45 % increase in bolus fragmentation, while the MP-CarX had the highest cohesiveness and lowest fragmentation. The variations in oral processing of MP with pectin or xanthan resulted in differing levels of starch hydrolysis and glucose release in the mouth. Chewing the MP-CarX resulted in lower levels of these processes, highlighting the importance of considering the oral phase of digestion when studying the hypoglycemic effects of polysaccharides. This is essential for developing new and effective approaches to improving glycemic control by incorporating fibers into commonly consumed starchy foods.

Natural but threatening? (I) A systematic aquatic ecotoxicity evaluation of biopolymers and modified natural polymers

Synthetic polymers and modified natural polymers are subject to EC 2023/2055, whereas biopolymers can be considered as important unregulated substituents. However, as regulatory requirements for biopolymers and a regulatory accepted hazard evaluation concept for polymers in general is missing, potential ecotoxicological effects are unknown. Biopolymers are often categorized as environmentally uncritical due to their origin, even though supporting data are missing. To assess potential environmental effects, we considered six biopolymers and modified natural polymers in a systematic ecotoxicity screening with aquatic organisms, hypothesising that the selected polymers are not ecotoxic. We tested alginate, chitosan, cellulose fibres Jelucel® HM 200, xanthan, carboxymethyl cellulose and modified starch Emwaxy® Jel 100 in OECD TG 201 (standard), 202 (miniaturised) and 236 (adapted to include OMICs) with algae, daphnids and zebrafish embryos, respectively. A screening of transcriptomic changes in zebrafish embryos was used to identify potential toxic modes-of-action of the polymers in fish. The polymers were applied in a concentration range of 1-100 mg/L as filtrates to consider potential intrinsic effects. Additionally, the impact of particulate polymers was evaluated by exposing algae and daphnids to polymer suspensions. Physical interactions were determined in algae growth studies leading to reduction of cell growth (lowest LOEC 10 mg/L). Daphnid immobility was observed with exposure to particulate chitosan (LOEC 100 mg/L). In zebrafish embryos, predominantly Emwaxy® Jel 100 affected the expression of genes involved in metabolic and catabolic processes (607 up- and 1002 down-regulated genes). Overall, polymer filtrates usually had no significant impact within the concentration range.

Understanding the role of Radix Paeoniae Alba polysaccharide for corn starch gel amelioration: Physicochemical, structural, and digestive properties

To ameliorate the limitations of corn starch (CS) processing, Radix Paeoniae Alba polysaccharide (RPAP) was used to modulate the physicochemical and digestive properties of CS. The main purpose of this paper is to investigate the effects of RPAP on the pasting, rheological, thermal, structural, and digestive properties of CS. The results show that the addition of RPAP could increase the peak viscosity and final viscosity of CS gel, and RPAP could increase the apparent viscosity, storage modulus, loss modulus, hardness, and strength of CS gel, implying that RPAP can effectively improve the pasting and viscoelasticity properties of CS. Moreover, RPAP could be bound to CS through non-covalent interaction, and RPAP could improve the relative crystallinity and thermal stability, whereas decreased the spin relaxation time (T2) of CS from 312.16 to 203.25 ms. The microstructure of CS-RPAP gels showed a honeycomb-like porous structure, and RPAP could increase the pore size and thickness of CS-RPAP gels. Furthermore, RPAP could inhibit the digestibility of CS, while increased the resistant starch (RS) content. The findings can provide important references for expanding the application of starch-based products in various fields including food industry, pharmaceuticals, textiles, papermaking, and biodegradable materials.

Effects of yeast β-glucan on gelatinization, structure and digestibility of potato starch

BACKGROUND

Potato starch (PS) is widely used in food, but its application is limited because of its poor heat resistance and easy aging. Therefore, it is necessary to adopt some modification methods to improve its performance and expand its application range.

RESULTS

To improve these shortcomings of PS, the effect of yeast β-glucan (YG) at different concentrations (0%, 1%, 2% and 3%, w/v) on the gelatinization, structure and in vitro digestive properties of PS were investigated. The interaction of YG with PS was different because of different molecular weights. The addition of YG reduced the peak viscosity and increased the final viscosity of PS. YG made the texture of PS gel softer, and the effect of low molecular weight YG was more obvious. YG enhanced the thermal stability of PS. Fourier transform infrared spectroscopy showed that YG and PS interacted through hydrogen bonds. In addition, YG reduced the digestibility of PS in vitro.

CONCLUSION

Collectively, the addition of β-glucan to PS can serve as a new approach to enhance the technological properties of PS in food applications. These results will provide theoretical basis for PS to develop into functional food. © 2024 Society of Chemical Industry.

Effect of cationized guar gum on stability and bioaccessibility of curcumin-loaded Pickering emulsion stabilized by starch nanoparticles

To enhance stability and bioaccessibility of curcumin in Pickering emulsions stabilized by starch nanoparticles (SNP), cationized guar gum (CGG) was incorporated into the emulsion. Zeta potential results revealed that SNP and CGG formed electrostatic interactions, resulting in stable interfacial layer with higher hydrophobicity. Adding 0.4 % CGG maintained a homogeneous phase without significant droplet size change for up to one month. The emulsion with 0.4 % CGG demonstrated stable storage under varying pH (4-10), ionic strength (0-10 mM NaCl), and freeze-thaw cycles (up to 3). When optimized Pickering emulsion system was applied to curcumin encapsulation, curcumin-loaded emulsions were stably maintained for up to one month. The curcumin retained approximately 100 % stability under thermal (90 °C) and UV (12h) treatments. In the optimized emulsion, starch components resisted digestion in oral and gastroenteric phases but were primarily digested in small intestine, resulting in an increasing bioaccessibility from 88.23 to 96.92 %.

Design, characterization and digestibility of β-carotene-loaded emulsion system stabilized by whey protein with chitosan and potato starch addition

The physicochemical properties and gastrointestinal fate of β-carotene-loaded emulsions and emulsion gels were examined. The emulsion was emulsified by whey protein isolate and incorporated with chitosan, then the emulsion gels were produced by gelatinizing potato starch in the aqueous phase. The rheology properties, water distribution, and microstructure of emulsions and emulsion gels were modulated by chitosan combination. A standardized INFOGEST method was employed to track the gastrointestinal fate of emulsion systems. Significant changes in droplet size, zeta-potential, and aggregation state were detected during in vitro digestion, including simulated oral, stomach, and small intestine phases. The presence of chitosan led to a significantly reduced free fatty acids release in emulsion, whereas a slightly increasing released amount in the emulsion gel. β-carotene bioaccessibility was significantly improved by hydrogel formation and chitosan addition. These results could be used to formulate advanced emulsion systems to improve the gastrointestinal fate of hydrophobic nutraceuticals.

Comprehensive Assessment of Polysaccharides Extracted from Squash by Subcritical Water under Different Conditions

The effects of subcritical water microenvironment on the physiochemical properties, antioxidant activity and in vitro digestion of polysaccharides (SWESPs) from squash were investigated. After single-factor experiments, twenty samples were successfully prepared at different extraction temperatures (110, 130, 150, 170 and 190 °C) and extraction times (4, 8, 12 and 16 min). Under a low temperature environment, the whole process was mainly based on the extraction of SWESP. At this time, the color of SWESP was white or light gray and the molecular mass was high. When the temperature was 150 °C, since the extraction and degradation of SWESP reached equilibrium, the maximum extraction rate (18.67%) was reached at 150 °C (12 min). Compared with traditional methods, the yield of squash SWESP extracted by subcritical water was 3-4 times higher and less time consuming. Under high temperature conditions, SWESPs were degraded and their antioxidant capacity and viscosity were reduced. Meanwhile, Maillard and caramelization reactions turned the SWESPs yellow-brown and produced harmful substances. In addition, different SWESPs had different effects on in vitro digestion. In brief, SWESPs prepared under different conditions have different structures and physicochemical properties, allowing the obtainment of the required polysaccharide. Our results show that squash polysaccharides prepared in different subcritical water states had good development potential and application in the food industry.

Guar gum series affect nanostructured lipid carriers via electrostatic assembly or steric hindrance: Improving their oral delivery for phytosterols

Surface modification of nanostructured lipid carriers (NLCs) can be an effective way to improve their oral delivery for active ingredients. In this study, four type of guar gum series modified NLCs for the delivery of phytosterols (PS) were constructed and the effects of the polysaccharides on their structure and physicochemical properties were studied. DLS and AFM results revealed that positively charged polysaccharides could bind to PS-NLCs through electrostatic attraction and made the complexes finally take positive charges, while negatively charged polysaccharides were more likely to fill in the gaps of NLC systems to achieve a balance between electrostatic repulsion and intermolecular forces. Although all four polysaccharides exhibited good storage stability and controlled release of PS in simulated intestinal digestion, PS-NLCs modified with partially hydrolyzed cationic guar gum (PHCG) at medium or high concentrations exhibited better gastric stability, mucoadhesion, and cellular uptake, which had considerable significance for improving the oral bioavailability of PS. This might be related to the coating structure of PHCG-PS-NLCs confirmed by AFM, FTIR, and Raman characterization. This study provide a reference value for designing suitable PS-NLC complexes without synthetic surfactants.

Polysaccharide‑platinum complexes for cancer theranostics

Platinum anticancer drugs have been explored and developed in recent years to reduce systematic toxicities and resist drug resistance. Polysaccharides derived from nature have abundant structures as well as pharmacological activities. The review provides insights on the design, synthesis, characterization and associating therapeutic application of platinum complexes with polysaccharides that are classified by electronic charge. The complexes give birth to multifunctional properties with enhanced drug accumulation, improved tumor selectivity and achieved synergistic antitumor effect in cancer therapy. Several techniques developing polysaccharides-based carriers newly are also discussed. Moreover, the lasted immunoregulatory activities of innate immune reactions triggered by polysaccharides are summarized. Finally, we discuss the current shortcomings and outline potential strategies for improving platinum-based personalized cancer treatment. Using platinum-polysaccharides complexes for improving the immunotherapy efficiency represents a promising framework in future.

Progress and prospects of polysaccharide-based nanocarriers for oral delivery of proteins/peptides

The oral route has long been recognized as the most preferred route for drug delivery as it offers high patient compliance and requires minimal expertise. Unlike small molecule drugs, the harsh environment of the gastrointestinal tract and low permeability across the intestinal epithelium make oral delivery extremely ineffective for macromolecules. Accordingly, delivery systems that are rationally constructed with suitable materials to overcome barriers to oral delivery are exceptionally promising. Among the most ideal materials are polysaccharides. Depending on the interaction between polysaccharides and proteins, the thermodynamic loading and release of proteins in the aqueous phase can be realized. Specific polysaccharides (dextran, chitosan, alginate, cellulose, etc.) endow systems with functional properties, including muco-adhesiveness, pH-responsiveness, and prevention of enzymatic degradation. Furthermore, multiple groups in polysaccharides can be modified, which gives them a variety of properties and enables them to suit specific needs. This review provides an overview of different types of polysaccharide-based nanocarriers based on different kinds of interaction forces and the influencing factors in the construction of polysaccharide-based nanocarriers. Strategies of polysaccharide-based nanocarriers to improve the bioavailability of orally administered proteins/peptides were described. Additionally, current restrictions and future trends of polysaccharide-based nanocarriers for oral delivery of proteins/peptides were also covered.

Targeted delivery of food functional ingredients in precise nutrition: design strategy and application of nutritional intervention

With the high incidence of chronic diseases, precise nutrition is a safe and efficient nutritional intervention method to improve human health. Food functional ingredients are an important material base for precision nutrition, which have been researched for their application in preventing diseases and improving health. However, their poor solubility, stability, and bad absorption largely limit their effect on nutritional intervention. The establishment of a stable targeted delivery system is helpful to enhance their bioavailability, realize the controlled release of functional ingredients at the targeted action sites in vivo, and provide nutritional intervention approaches and methods for precise nutrition. In this review, we summarized recent studies about the types of targeted delivery systems for the delivery of functional ingredients and their digestion fate in the gastrointestinal tract, including emulsion-based delivery systems and polymer-based delivery systems. The building materials, structure, size and charge of the particles in these delivery systems were manipulated to fabricate targeted carriers. Finally, the targeted delivery systems for food functional ingredients have gained some achievements in nutritional intervention for inflammatory bowel disease (IBD), liver disease, obesity, and cancer. These findings will help in designing fine targeted delivery systems, and achieving precise nutritional intervention for food functional ingredients on human health.

Dietary compounds slow starch enzymatic digestion: A review

Dietary compounds significantly affected starch enzymatic digestion. However, effects of dietary compounds on starch digestion and their underlying mechanisms have been not systematically discussed yet. This review summarized the effects of dietary compounds including cell walls, proteins, lipids, non-starchy polysaccharides, and polyphenols on starch enzymatic digestion. Cell walls, proteins, and non-starchy polysaccharides restricted starch disruption during hydrothermal treatment and the retained ordered structures limited enzymatic binding. Moreover, they encapsulated starch granules and formed physical barriers for enzyme accessibility. Proteins, non-starchy polysaccharides along with lipids and polyphenols interacted with starch and formed ordered assemblies. Furthermore, non-starchy polysaccharides and polyphenols showed robust abilities to reduce activities of α-amylase and α-glucosidase. Accordingly, it can be concluded that dietary compounds lowered starch digestion mainly by three modes: (i) prevented ordered structures from disruption and formed ordered assemblies chaperoned with these dietary compounds; (ii) formed physical barriers and prevented enzymes from accessing/binding to starch; (iii) reduced enzymes activities. Dietary compounds showed great potentials in lowering starch enzymatic digestion, thereby modulating postprandial glucose response to food and preventing or treating type II diabetes disease.

Unraveling the impact of viscosity and starch type on the in vitro starch digestibility of different gels

Starch is one of the most important carbohydrates that is present in many foods. Gelatinization is an important property of starch, associated with physical changes that promote an increase in viscosity. The objective of this research was to understand how the viscosity of starch gels affects their hydrolysis and whether that effect was dependent on the type of starch. Different gels (corn, wheat, and rice) with variable or constant viscosity were analyzed using diverse methodologies to determine the changes in the pasting behavior. A rapid force analyzer, a vibration viscometer and a rheometer were used to differentiate the gels based on the starch source and concentration. At a fixed starch concentration, corn gel displayed the highest viscosity, slowing the enzymatic starch hydrolysis. The higher viscosity of those gels prepared with a fixed starch concentration significantly enhanced the slowly digestible starch (SDS) and reduced the kinetic constant (k). Nevertheless, gels with constant viscosity (550 mPa s) showed comparable hydrolysis kinetics, obtaining similar SDS, total hydrolyzed starch and k. The correlation matrix confirmed the relationship between k and gel viscosity (r = -0.82), gelatinization rate (α-slope) (r = -0.87), breakdown (r = -0.84) and elastic modulus (G' 37 °C) (r = -0.73). Therefore, these parameters could be used as predictors of the hydrolysis performance of starch gels as well as in reverse engineering for the design of healthy foods.

Effect of four viscous soluble dietary fibers on the physicochemical, structural properties, and in vitro digestibility of rice starch: A comparison study

The effect of carboxymethyl cellulose (CMC), high-methoxyl pectin (HMP), konjac glucomannan (KGM), and xanthan gum (XG) on the physicochemical, structural properties, and digestibility of rice starch were investigated and compared. The four viscous soluble dietary fibers (VSDFs) increased the viscosity, storage modulus and loss modulus while decreased the pasting temperature and gelatinization enthalpy. Moreover, XG produced the lowest peak viscosity and dynamic modulus compared with the other VSDFs. Furthermore, the degree of short-range ordered structure of starch with KGM increased from 0.8448 to 0.8716; and the relative crystallinity of starch with XG increased by 12%. An ordered and reunited network structure was observed in SEM. In addition, VSDF inhibited the digestibility of rice starch and significantly increased the resistant starch content. This study compared the effect of four VSDFs on the physicochemical, structural and digestion properties of rice starch to fully understand and develop their application to starchy foods.