Physicochemical and rheological properties of cross-linked inulin with different degree of polymerization

Rheological properties, microstructure, and encapsulation efficiency of inulin-type dietary fiber-based gelled emulsions at different concentrations

Gelled emulsion systems offer promising matrices for encapsulating bioactive compounds, enhancing stability, bioavailability, and controlled release. Incorporating inulin-type dietary fibers into emulsion-filled gels can innovate food products. This study explored the impact of inulin concentration (0-15 % w/w) on visual aspect, microstructure, particle size distribution, creaming stability, rheological behavior, and encapsulation efficiency of emulsions and gelled emulsions with clove bud oil rich in eugenol. Regardless of inulin concentration, systems exhibited evenly distributed small oil droplets, ensuring good creaming stability. Emulsions with 10-15 % inulin formed gels upon natural cooling to approximately 30 °C. Viscoelastic properties varied with inulin concentration, attributed to increased polymer chain approximation and mobility. Higher inulin content decreased the transition temperature (66 °C, 56 °C, and 54 °C for 10 %, 12.5 %, and 15 % inulin, respectively). While inulin did not enhance creaming stability, it acted as a physical barrier, improving encapsulation efficiency of eugenol to nearly 100 %. Inulin-based emulsion-filled gels offer potential for functional food development, enriching nutritional value and health benefits.

Construction and digestive characterization of emulsions stabilized with octenyl succinic anhydride-modified curdlan

To expand the scope of application of the insoluble polysaccharide curdlan (CUR), this study modified CUR with octenyl succinic anhydride (OSA) and evaluated the performance of the emulsion formed from the modified CUR derivative. Fourier transform infrared spectroscopy, differential scanning calorimetry, and X-ray diffraction analysis showed that properties such as the molecular structure, crystallinity, and hydrophobicity of the OSA-modified CUR (COSA) changed significantly compared with those of the original CUR, indicating that the hydroxyl group of CUR was successfully replaced by OSA. Subsequently, a stable oil-in-water emulsion system of COSA loaded with curcumin was established. The stability of the emulsions was evaluated by analyzing their microstructure, rheological properties, and curcumin retention. The digestion characteristics of the emulsions were evaluated by in vitro simulated digestion experiments, and the COSA emulsion had higher stability and was better able to improve the chemical stability of curcumin compared to CUR. The OSA grafting resulted in emulsions with higher curcumin release rates and antioxidant capacities. These results indicate that COSA has the potential to be used as an encapsulating material for lipophilic nutrient emulsions and provides theoretical support for expanding the applications of chemically modified CUR derivatives.

Comparative study on composition and functional properties of brewer's spent grain proteins precipitated by citric acid and hydrochloric acid

Brewer's spent grain (BSG) is an abundant agro-industrial residue and a sustainable low-cost source for extracting proteins. The composition and functionality of BSG protein concentrates are affected by extraction conditions. This study examined the use of citric acid (CA) and HCl to precipitate BSG proteins. The resultant protein concentrates were compared in terms of their composition and functional properties. The BSG protein concentrate precipitated by CA had 10% lower protein content, 5.8% higher carbohydrate, and 5.4% higher lipid content than the sample precipitated by HCl. Hydrophilic/hydrophobic protein and saturated/unsaturated fatty acid ratios increased by 16.9% and 26.5% respectively, in the sample precipitated by CA. The formation of CA-cross-linkages was verified using shotgun proteomics and Fourier transform infrared spectroscopy. Precipitation by CA adversely affected protein solubility and emulsifying properties, while improving foaming properties. This study provides insights into the role of precipitants in modulating the properties of protein concentrates.

Study of the structural characterization, physicochemical properties and antioxidant activities of phosphorylated long-chain inulin with different degrees of substitution

In this study, phosphorylated derivatives of long-chain inulin with different substitution degrees were prepared. The synthesized samples were named PFXL-1, PFXL-2, PFXL-3, and PFXL-4 according to their degree of substitution (from low to high). The structures of FXL and PFXL were characterized by infrared spectroscopy and nuclear magnetic resonance spectroscopy, and the results indicated the successful introduction of phosphate groups. FXL and PFXL were composed of two types of sugar, fructose and glucose, with a molar ratio of 0.977:0.023. The SEM results showed that phosphorylation changed the morphology of FXL from an irregular mass to small spherical aggregates. The XRD pattern showed that the crystallinity was reduced by the introduction of phosphate groups. The Mw of FXL was 2649 g/mol, and the Mw of PFXL-4 increased the most (2965 g/mol). Additionally, PFXL was more stable and uniform, and the absolute value of the PFXL potential reached 7.83 mV. Phosphorylation decreased the weight loss rate of FXL and improved the viscoelastic properties and antioxidant activity of FXL. This study presents a method for the modification of FXL, demonstrating that phosphorylation can enhance its physicochemical properties and physiological activity and suggesting its potential as a functional food and quality modifier.

Production, effects, and applications of fructans with various molecular weights

Fructan, a widespread functional polysaccharide, has been used in the food, pharmaceutical, cosmetic, and material production fields because of its versatile physicochemical properties and biological activities. Inulin from plants and levan from microorganisms are two of the most extensively studied fructans. Fructans from different plants or microorganisms have inconsistent molecular weights, and the molecular weight of fructan affects its properties, functions, and applications. Recently, increasing attention has been paid to the production and application of fructans having various molecular weights, and biotechnological processes have been explored to produce tailor-made fructans from sucrose. This review encompasses the introduction of extraction, enzymatic transformation, and fermentation production processes for fructans with diverse molecular weights. Notably, it highlights the enzymes involved in fructan biosynthesis and underscores their physiological effects, with a special emphasis on their prebiotic properties. Moreover, the applications of fructans with varying molecular weights are also emphasized.

Differences in physicochemical, rheological, and prebiotic properties of inulin isolated from five botanical sources and their potential applications

This study compares the physicochemical and prebiotic properties of inulin isolated from five botanical sources. The average degree of polymerization (DP) for inulin ranged from 5.00 to 13.33. Notably, inulin from Dahlia tubers (DP = 13) and Platycodonis Radix (DP = 8) demonstrated granular, clustered morphology under SEM, semi-crystalline structures via X-ray diffraction, and exhibited shear-thinning behaviors from shear rate 1 s-1 to 500 s-1. In contrast, inulin from Jerusalem artichoke (DP = 5), chicory root (DP = 7), and Asparagi Radix (DP = 5) showcased rough flake morphologies under SEM, amorphous structures in X-ray patterns, and similar shear-thinning behaviors. All inulin types showed acid stability at pH levels below 2.0, with a reducing sugar conversion ratio (RRS) under 1 %. Furthermore, the isolated inulin from the different sources presented prebiotic capacity when added as a sole carbon source in the culture media of the probiotics Lactobacillus paracasei and Bifidobacterium longum. This study provides the properties of inulin from various sources, thereby offering a reference for the selection of appropriate inulin in industrial applications based on the desired characteristics of the final product.

Effect of extraction methods on the chemical, structural, and rheological attributes of fructan derived from Arctium lappa L. roots

The focus of this study was the evaluation of how extraction techniques impact the chemical, structural, and rheological attributes of fructans extracted from Arctium lappa L. roots. Three distinct extraction procedures were used, utilizing water as solvent, infusion extraction conducted at ambient temperature (25 °C for 5 min), thermal extraction employing reflux (100 °C for 2 h), and ultrasound-assisted extraction (50 °C for 1.38 h with a 158 W output). Chemical characterization by Nuclear Magnetic Resonance (NMR) and colorimetric analyses revealed the obtaining of inulin-type fructans (yield 83 %). The degree of polymerization (DP) was found to be the lowest for ultrasound-assisted extraction (14.38), followed by the room-temperature (20.41) and thermal (21.14) extraction techniques. None of the extraction techniques appeared to modify the molecular structure of the isolated compounds. In X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analyses, distinct crystallization patterns were observed for the room-temperature and thermal extraction techniques, though all fractions consistently exhibited characteristic bands of inulin-type fructan. Rheological assessments indicated a viscoelastic nature of the fractions, with those extracted thermally demonstrating a greater viscosity. This study shows that the choice of extraction method can influence the structural characteristics of inulin-type fructans derived from the burdock root.

Extraction-depended and thermally-modulated physical and chemical properties of powders produced from cranberry pomace extracts

Recovering bioactives from botanical by-products in the form of powders has been attempted through a number of multidirectional approaches. Yet understanding the processing of such plant formulations requires dedicated research owing to the manifold factors shaping the quality of powders. Therefore, the study aimed at production of cranberry powders from pomace extracts and to evaluate how different solvent type, carriers and drying techniques modulate their physico-chemical properties. Freeze- and vacuum drying significantly differentiated samples in terms of physical properties, while the extraction solvent and carrier type had substantial impact on chemical ones. For carrier-added products pomace extraction with acidified 50% ethanol resulted in the highest content of identified phenolics in powders (up to 5.87 g · 100 g-1 dry matter), while 30% acetone in the lowest (on average, 3.94 g · 100 g-1 dry matter). Acetone extraction strengthened the formation of hydroxymethyl-L-furfural that was higher when compared to acidified 50% ethanol, while trace amounts were reported for non-acidified counterpart. Similar observation was made in the case of flavan-3-ols. Addition of carriers during powders production led to the lower hydroxymethyl-L-furfural formation even down to 74% with regard to carrier-free samples. The study confirmed feasibility of managing cranberry pomace into high-value powders in extraction-depended and thermally-modulated quality matter.

Inulin Functionalized "Giuncata" Cheese as a Source of Prebiotic Fibers

The development of functional foods in the dairy sector represents a flourishing field of technological research. In this study, an Italian fresh cheese as "giuncata" was enriched with inulin, a dietary fiber, with the aim of developing a product with improved nutritional properties in terms of prebiotic action on intestinal microbiota. An inulin concentration of ~4% w/w was determined in the fresh cheese after the fortification process, enabling the claim of being a "source of dietary fiber" (inulin > 3 g/100 g) according to the European regulation. The addition of inulin has no effect on the pH of cheese and does not relevantly influence its color as well as the total fat content (fat reduction ~0.61%) in comparison to the control. Mechanical properties of the cheese were also not markedly affected as evidenced from rheological and tensile testing analyses. Indeed, the incorporation of inulin in "giuncata" only exerts a slight "softening effect" resulting in a slightly lower consistency and mechanical resistance in comparison to the control. Overall, this study demonstrates the feasibility of producing a fiber-enriched dairy functional food from a large consumed fresh and soft cheese as "giuncata".

Inulin for surimi gel fortification: Performance and molecular weight-dependent effects

Inulin is a prebiotic carbohydrate widely used in food industry due to its health benefits and unique rheological properties. For the first time, this study explores the potential of natural inulin as a sustainable food additive to enhance surimi gel characteristics, specifically focusing on understanding its molecular weight effects. The good solubility of inulin facilitates the conversion of α-helix to other secondary conformations which are favorable for protein denaturation and aggregation during gelation. Moreover, the abundant -OH groups at the surface of inulin can boost the chemical forces within surimi proteins to reinforce the gel network. Compared to short-chain inulin, long-chain inulin can alleviate proteolysis, enhance hydrophobic interactions and intertwine with myosin molecules, thereby reinforcing the gel network. A more viscous long-chain inulin solution formed within surimi gels fills the space between aggregated proteins and facilitates the lock of water molecules, improving the water-holding capacity (WHC). Thus, an addition of 12 % long-chain inulin leads to an enhanced hardness of surimi gel from 943 to 1593 and improved WHC from 72 % to 85 %. A new inulin-myosin interaction mechanism model is also proposed to provide useful guidelines for surimi processing and expanding the application of inulin within the food industries.

Preparation, structural characterization and prebiotic potential of mulberry leaf oligosaccharides

The present study shows the purification of a main oligosaccharide fraction (MLO 1-2) from the enzymatic hydrolysate of mulberry leaf polysaccharides by DEAE-52 cellulose and gel column chromatography. The physicochemical properties of MLO 1-2 were characterized. The structure of MLO 1-2 was obtained as follows: α-(2-OAc)-Manp-1 → 2-β-Glcp-1 → 4-β-Glcp-1 → 4-α-Glcp-1 → 2-α-Glcp-1 → 2-α-Galp-1 → 2-β-Galp-1 → 2-β-Galp-1, which was elucidated by methylation and NMR analysis. The molecular weight of MLO 1-2 showed no significant change after simulated saliva, gastric and intestinal digestion. This indicated that MLO 1-2 could pass through the digestive system without being degraded to safely reach the colon to regulate the gut microbiota. Additionally, MLO 1-2, more than glucose or galactooligosaccharides, promoted the proliferation of Bifidobacterium bifidum, B. adolescentis, Lacticaseibacillus rhamnosus and Lactobacillus acidophilus. Furthermore, the acetic and lactic acid concentrations of bacterial cultures inoculated with MLO 1-2 were higher than those inoculated with glucose and galactooligosaccharide (GOS). These results suggest that MLO 1-2 could be an excellent prebiotic for intestinal flora regulation and the promotion of gut health.

Jerusalem artichoke inulin supplementation ameliorates hepatic lipid metabolism in type 2 diabetes mellitus mice by modulating the gut microbiota and fecal metabolome

The main focus of this study was on the protection mechanism of Jerusalem artichoke inulin (DI) against type 2 diabetes mellitus (T2DM) associated with abnormal hepatic lipid metabolism and gut microbiota dysfunction in T2DM mice.

Modification of carboxymethyl inulin with heterocyclic compounds: Synthesis, characterization, antioxidant and antifungal activities

A series of novel inulin derivatives were designed and synthesized by the introduction of amino heterocyclic moieties onto carboxymethyl inulin with the aid of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinimide. The target products were prepared via three - step chemical synthesis, and structures were identified by FTIR and ¹H NMR spectroscopy. Antioxidant activities of inulin derivatives including DPPH - radical scavenging assay, superoxide - radical scavenging assay, hydroxyl - radical scavenging assay, and reducing power were estimated. Meanwhile, their antifungal activities, including Colletotrichum lagenarium and Botrytis cinerea, were also explored by hyphal measurement. In particular, inulin derivatives bearing heterocyclic moieties exhibited a remarkable improvement over inulin on antioxidant and antifungal activities, and their bioactivities decreased roughly in the order of 2ATCMI > 4APCMI > 3APCMI > 2APCMI > 3ATCMI > CMI > inulin. Furthermore, the cytotoxicities of inulin derivatives against L929 cells were evaluated by CCK-8 in vitro, and all samples showed weak cytotoxicities. In a nutshell, the paper provides a practical approach to synthesize novel inulin derivatives with dramatically enhanced bioactivity and good biocompatibility. The product described in paper might serve as a new leading structure for further design of antioxidants or antifungal agents in biomedicine, cosmetics, and other fields.

Production and Physicochemical Properties of Food-Grade High-Molecular-Weight Lactobacillus Inulin

Inulin has been widely applied in food, pharmaceuticals, and many other fields because of its versatile physicochemical properties and physiological functions. Previous research showed that inulosucrase from microorganisms could produce higher-molecular-weight inulin than vegetal inulin. Herein, a food-grade recombinant Bacillus subtilis expression system was constructed to produce inulosucrase from Lactobacillus gasseri DSM 20604 without antibiotic resistance genes. The produced inulosucrase was used to biosynthesize inulin with an average molecular weight of 5.8 × 10⁶ Da. The physicochemical properties of the produced Lactobacillus inulin were evaluated including microstructure, thermal characteristics, crystallinity, rheological behaviors, and storage stability. By comparing with vegetal inulin and other polymers, the biosynthesized microbial inulin showed some superior properties, such as better gel-forming capability and storage stability in aqueous solution than vegetal inulin. These results opened up possibilities for further investigations aimed at developing microbial inulin in the food industry.

Study on quality characteristics of cassava flour and cassava flour short biscuits

In this paper, the basic components, nutrient composition, and processing characteristics of cassava flour were determined. In addition, the effects of xanthan gum and inulin on the pasting properties, microstructure, and thermal properties of cassava flour were studied. Biscuits were prepared using cassava flour as the main raw material and the optimal technology and formula for the biscuits were determined by single-factor and orthogonal tests. The effects of xanthan gum and inulin on the quality of cassava flour short biscuits were also investigated, and volatile components in the biscuits were determined using electronic nose technique. The addition of xanthan gum improved the pasting properties and microstructure of cassava flour, and improved the taste and increased hardness and brittleness of the biscuits, making their quality similar to that of commercially available short biscuits. The addition of inulin inhibited the setback of starch and improved starch gelatinization. However, inulin was not suitable for processing of cassava flour biscuits as it decreased their hardness, brittleness, and taste. The optimal formula and baking conditions of cassava flour short biscuits were as follows: cassava flour 100 g, water 24 g, shortening 25 g, sugar 30 g, baking powder 0.6 g, salt 1 g, and egg 25 g; the surface fire and primer fire temperatures were 180°C, and the baking time was 9 min. In addition, although the main aroma volatile components present in cassava flour and low gluten wheat flour short biscuits were similar, the proportions of each component were different.