Structural characterization and prebiotic activity of rhamnogalacturonan-I rich pumpkin pectic polysaccharide extracted by alkaline solution.

The present study aimed to investigate the structural and physicochemical characteristics of alkali-extracted pectic polysaccharide (AkPP) and to evaluate its prebiotic effects. AkPP was obtained from pumpkin pulp using an alkaline extraction method. AkPP, which had a molecular weight (Mw) of mainly 13.67 kDa and an esterification degree of 9.60%, was composed mainly of galacturonic acid (GalA), rhamnose (Rha), galactose, and arabinose. The ratio of the homogalacturonan (HG) region to the rhamnogalacturonan-I (RG-I) region in AkPP was 48.74:43.62. In the nuclear magnetic resonance spectrum, the signals indicating α-1,4-linked D-GalA, α-1,2-linked L-Rha, α-1,2,4-linked L-Rha residues were well resolved, demonstrating the presence of the HG and RG-I regions in its molecular structure. Collectively, AkPP was low methoxyl pectin rich in the RG-I region with short side chains and had a low Mw. Thermal analysis revealed that AkPP had good thermal stability. Compared to inulin, AkPP more effectively promoted the proliferation of Lactobacillus acidophilus, Lacticaseibacillus rhamnosus GG, Lacticaseibacillus casei, and Lacticaseibacillus paracasei and the production of lactic, acetic, and propionic acids. This study presents the unique structural features of AkPP and provides a scientific basis for further investigation of the potential of AkPP as a promising prebiotic.

Structural and flow rheological properties of pumpkin pectic polysaccharide extracted by citric acid.

The present study aimed to investigate the structural and physicochemical characteristics of acid-extracted pumpkin pectic polysaccharide (AcPP) and to evaluate their flow rheological properties. AcPP was extracted from pumpkin pulp using the citric acid extraction method. The physicochemical and structural properties were analyzed by chemical methods and instrumental analyses. The obtained results showed that AcPP consisted predominantly of GalA (85.99 %) and small amounts of Rha, Gal, and Ara, with the ratio of HG/RG-I being 81.39/16.75. In addition, AcPP had medium DE (45.34 %) and contained four macromolecular populations with different Mw of 106.03 (main), 10.15, 4.99, and 2.90 kDa. The NMR analysis further confirmed that AcPP contained a linear backbone consisting of α-1,4-linked GalA residues, some of which were partially methyl-esterified. Furthermore, AcPP was amorphous in nature and had favorable thermal stability. The effects of extrinsic factors on the flow rheological properties of AcPP were evaluated. In particular, the high concentrations of CaCl2 (8 mM) and MgCl2 (10 mM) were effective in enhancing the viscosity and non-Newtonian shear-thinning behavior of the AcPP solution. This study elucidates the unique molecular structure of AcPP and suggests the potential of AcPP as a rheology modifier in low-viscous and mineral-reinforced beverages.

Effects of NaCl on the Physical Properties of Cornstarch-Methyl Cellulose Blend and on Its Gel Prepared with Rice Flour in a Model System.

This study investigated the impact of NaCl on the physical properties of cornstarch-methyl cellulose (CS-MC) mixtures and their gels prepared with rice flour in a model system. Opposite trends were observed, showing that NaCl led to decreased viscosity of the CS-MC mixtures (liquid-based), whereas a more stable and robust structure was observed for the rice-flour-added gels (solid-based) with the addition of NaCl. The interference of NaCl with the CS-MS blend's ability to form a stable gel network resulted in a thinner consistency, as the molecules of the CS-MS blend may not bind together as effectively. On the contrary, NaCl showed the potential to enhance the protein network within CS-MC gels prepared with rice flour, thereby contributing to an augmentation in the stability or firmness of the cooked gels. Careful utilization of NaCl to optimize the physical properties of the CS-MC blends, as well as the gels based on rice flour, should be performed.

Development of soy protein isolate/sodium carboxymethyl cellulose synbiotic microgels by double crosslinking with transglutaminase and aluminum chloride for delivery system of Lactobacillus acidophilus.

This study was carried out to develop soy protein isolate (SPI)/sodium carboxymethyl cellulose (NaCMC) synbiotic microgels by applying a double-crosslinking technique using transglutaminase and different concentrations of AlCl3 (0 %, 6 %, 7 %, 8 %) and also by adding Lactobacillus acidophilus (L. acidophilus) and pectic oligosaccharide. Synbiotic microgels crosslinked using 8 % AlCl3 (SPI/NaCMC-Al3+8 microgels) showed the highest encapsulation efficiency (92 %). The double-crosslinked microgels exhibited a smooth surface as proved by SEM. FT-IR, XRD, and DSC analyses showed the possible interaction within matrices and demonstrated the higher thermal stability of synbiotic microgels prepared using a higher concentration of AlCl3. All in all, after exposure to simulated digestion fluid, heat treatment (72 °C, 15 s), and refrigerated storage, more cells in double-crosslinked microgels survived compared to single-crosslinked microgels. In particular, probiotic viability was highest in SPI/NaCMC-Al3+8 microgels. These results indicate that the SPI/NaCMC-Al3+8 microgels developed in this study can effectively protect L. acidophilus against the external environment.

Physicochemical, structural and in vitro gastrointestinal tract release properties of ι-carrageenan/sodium caseinate synbiotic microgels produced by double-crosslinking with calcium ions and transglutaminase.

The aim of this study was to develop ι-carrageenan (ιC)/sodium caseinate (NaCas) synbiotic microgels loading Lacticasebacillus paracasei produced by double-crosslinking with calcium ions and different concentrations (0, 5, 10, and 15 U/g protein) of transglutaminase (TGase). The synbiotic microgels were coated/filled with pectic oligosaccharide (POS). Field emission scanning electron microscope (FE-SEM) and X-ray diffraction (XRD) analyses indicated that L. paracasei was successfully microencapsulated in synbiotic microgels. In Fourier transform infrared (FT-IR) analysis, the new formation of covalent and ionic crosslinking was observed in double-crosslinked synbiotic microgels. The encapsulation efficiency of L. paracasei was significantly increased from 87.82 to 97.68 % by increasing the concentration of TGase from 0 to 15 U/g protein, respectively. After exposure to simulated gastric fluid for 2 h and simulated intestinal fluid for 4 h, the survival rate of L. paracasei was significantly increased as the concentration of TGase increased.

Rheological and Physicochemical Properties of Oleogel with Esterified Rice Flour and Its Suitability as a Fat Replacer.

The objectives of this study were to produce oleogel using esterified rice flour with citric acid (ERCA), to evaluate physicochemical and rheological properties of oleogels, and to investigate their suitability as a fat replacer. Rice flour was esterified with citric acid (30%, w/w) to produce ERCA. Emulsions and oleogels were prepared with different concentrations (0, 5, 10, and 15%, w/w) of ERCA. In the steady shear rheological analysis, it was found that the values of apparent viscosity (ηa, 100) and consistency index (K) of emulsions were significantly increased by increasing the concentrations of ERCA. Oleogels were prepared with different concentrations (0, 5, 10, and 15%, w/w) of ERCA. All oleogels showed a hydrophobic carbonyl bond in the Fourier transform infrared (FT-IR) spectra. The peaks on new hydrogen bonds and amorphous regions, which did not appear in oleogel prepared with 0% ERCA, were observed at 3300-3400 cm-1 and 1018 cm-1, respectively, in oleogels prepared with ERCA. With the increase in ERCA concentrations in oleogels, oil loss values were significantly decreased. In a time-dependent test, it was found that all oleogels exhibited thixotropic properties. The frequency sweep test revealed that storage modulus (G'), loss modulus (G″), and complex viscosity (η*) values of oleogels were elevated with an increase in the concentration of ERCA. Oleogels prepared with 15% ERCA exhibited the lowest peroxide, p-Anisidine, and Total Oxidation(TOTOX) values. The addition of oleogels to cookies did not considerably affect appearance. However, it increased the content of unsaturated fatty acid. These results indicate that oleogels prepared with ERCA can be used as a fat replacer in food industry.

Physicochemical, Structural, and In Vitro Gastrointestinal Tract Release Properties of Sodium Alginate-Based Cryogel Beads Filled with Hydroxypropyl Distarch Phosphate as a Curcumin Delivery System.

The objectives of this study were to produce sodium alginate (SA)-based cryogel beads filled with different concentrations (0, 0.4, 1.0, and 2.5%, w/w) of hydroxypropyl distarch phosphate (HDP) as a curcumin delivery system and to investigate the physicochemical, structural, and in vitro gastrointestinal tract release properties of the cryogel beads. According to FT-IR analysis, the formation of ionic crosslinking between SA and Ca2+ and the presence of HDP were found. XRD analysis demonstrated the successful encapsulation of curcumin in the beads by observing the disappearance of the characteristic peaks of curcumin. SEM analysis results revelated that SA-based cryogel beads exhibited a denser internal structure as the HDP concentration was increased. The encapsulation efficiency of curcumin in SA cryogel beads filled with HDP concentration from 0% to 2.5% was increased from 31.95% to 76.66%, respectively, indicating that HDP can be a suitable filler for the encapsulation of curcumin in the production of SA-based cryogel beads. After exposure to simulated gastric fluid (SGF) and simulated intestinal fluid (SIF), the release rate of curcumin was decreased as HDP concentration was increased. Accordingly, SA-based cryogel beads filled with HDP can be utilized for the delivery system of curcumin in the food industry.

Rheological properties of a neutral polysaccharide extracted from maca (Lepidium meyenii Walp.) roots with prebiotic and anti-inflammatory activities.

The rheological, prebiotic, and anti-inflammatory properties of neutral polysaccharide extracted from maca roots (MP) were investigated. MP was composed of arabinose, galactose, rhamnose, and glucose. In steady shear rheological properties, an increasing concentration of MP solution exhibited higher apparent viscosity (ηa,100) and consistency index (K) under acidic condition (pH 4). In dynamic rheological properties, the dynamic moduli (G' and G″) in the frequency sweep test from the MP solution were increased with increasing concentration and decreasing pH. The changes in dynamic moduli of the MP solution with various concentrations and pH values were stable during 1 h storage at 4 °C due to the enhancement of hydrogen bonding. According to the results of the temperature sweep test, an increasing concentration of MP solution increased dynamic moduli under acidic conditions. The prebiotic properties of MP induced a higher growth of Bifidobacterium longum ATCC15707 and Lactobacillus rhamnosus ATCC 7469 than inulin and increased acetic acid, propionic acid, and butyric acid more than inulin in vitro. Furthermore, MP inhibited lipopolysaccharide-induced NO production in RAW 264.7 cells, which indicated that an increasing concentration of MP enhanced anti-inflammatory activities. Therefore, MP is a potential functional material for the food and pharmaceutical industries.

Microencapsulation of a maca leaf polyphenol extract in mixture of maltodextrin and neutral polysaccharides extracted from maca roots.

The aim of the present study was to use microencapsulation technologies to create microcapsules containing polyphenol extracted from maca leaves, which were coated with maltodextrin (MD) and neutral polysaccharides extracted from maca roots (NPMR). NPMR was composed of arabinose, galactose, rhamnose, and glucose, with the main linkage types of →5)-α-L-Araf-(1→, →2,5)-α-L-Araf-(1→, α-L-Araf-(1→, →3)-ß-D-Galp-(1→, and ß-D-Rhap-(1→. The microencapsulation efficiency of the powdered microcapsules increased with an increasing MP concentration in the coating materials. SEM images showed that, according to the increase in the MP concentration, the powdered microcapsules were more spherical and smoother, with a smaller particle size. The polyphenols extracted from the maca leaves were successfully microencapsulated in an MD-NPMR coat, as confirmed by FT-IR spectra analysis. The storage stability was greater at several temperatures for the powdered microcapsules coated with MD-MP than for those of the microcapsules coated with only MD. In an in vitro study, the powdered microcapsules coated with MD-NPMR released a smaller amount of polyphenol than the microcapsules coated with only MD in simulated gastric and intestinal fluids. Furthermore, the powdered microcapsules coated with MD-NPMR produced greater Bifidobacterium longum probiotic growth than did the microcapsules coated only with MD.

Structural and in vitro digestibility properties of esterified maca starch with citric acid and its application as an oil-in-water (O/W) pickering emulsion stabilizer.

The objective of the present study was to determine structural and in-vitro digestibility properties of esterified maca starch with citric acid (EMSC) and explore its application in oil-in-water (O/W) pickering emulsion. EMSC was prepared by esterifying native maca starch (NMS) with different concentrations of citric acid (0, 10, 20, and 30%, w/w). The structural properties were characterized by SEM, FT-IR, XRD, and 13C and 1H NMR spectroscopy, which demonstrated that EMSC exhibited new ester linkages from citric acid in NMS. The in vitro digestibility results showed that EMSC had the significantly lower rapidly digestible starch contents and higher resistant starch contents compared to NMS. The properties of O/W pickering emulsion stabilized with NMS and EMSC were evaluated by microscopy, particle size, and zeta-potential. The results showed that the emulsion formed with EMSC had smaller particle size and improved stability than that formed with NMS. Therefore, EMSC could be used as source of the emulsifier or stabilizer in the food industry.

Characterization and storage stability of chlorophylls microencapsulated in different combination of gum Arabic and maltodextrin.

Detailed investigations on the physicochemical and structural characterization of chlorophyll loaded microcapsules and their storage stability have not previously been conducted. Therefore, our objective was to encapsulate unstable chlorophylls using different blends of gum Arabic (GA) and maltodextrin (MD) (GA-MD ratios of 5:5, 3:7, and 0:10) by spray-drying to improve storage stability of chlorophylls. An increase in concentration of MD in wall materials was associated with lower moisture content (0.56%), higher encapsulation efficiency (77.19%), chlorophyll content (46.78 µg/g dry powder), degree of crystallinity, and thermal stability of microcapsules. Furthermore, FTIR, XRD, and DSC analyses confirmed inclusion of chlorophylls within microcapsules. The entrapment of chlorophylls within microcapsules enhanced their storage stability at all temperatures (4, 20, and 40 °C) for ten days; notably, microcapsules coated with MD alone showed the highest storage stability (94.7-97.5%). In conclusion, microencapsulation of chlorophylls using MD alone was optimal for enhancing chlorophylls' storage stability.

Effect of Tara Gum Addition on Steady and Dynamic Shear Rheological Properties of Rice Starch Isolated from the Korean Rice Variety 'Boramchan'.

The present study was performed to investigate the influence of tara gum (TG) addition on the steady and dynamic shear rheological properties of rice starch (RS) isolated from the Korean rice variety 'Boramchan' flour. From X-ray diffraction and Fourier transform infrared spectra of RS, it was found that RS was purely isolated. All RS+TG pastes (4.7:0.3, 4.5:0.5, and 4.3:0.7, w/w) showed shear-thinning fluid characteristics. Adding TG significantly increased the values of apparent viscosity and consistency index of RS. In the dynamic shear rheological analysis, the dynamic moduli and complex viscosity of RS+TG pastes were significantly greater than those of the RS paste, indicating that RS+TG pastes had significantly higher viscoelastic properties than the RS paste. Light microscopy images of RS+TG pastes showed that the addition of TG can inhibit the RS granule from swelling.

Structural and rheological properties of pectic polysaccharide extracted from Ulmus davidiana esterified by succinic acid.

The present study was carried out to investigate the physicochemical and structural properties of pectic polysaccharide extracted from Ulmus davidiana (UDP) and to determine the physicochemical, structural, and rheological properties of esterified UDP with succinic acid (ES-UDP). The results indicated that UDP had high amounts of galacturonic acids and various neutral sugars, such as galactose, rhamnose, and glucose. UDP was identified as a low methoxyl pectin, consisting of 1,4-linked α-d-GalpA (the main backbone chain), supported by the results of Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction, and 1D Nuclear magnetic resonance (NMR) spectroscopy. In the FT-IR and XRD, no difference was detected between UPD and ES-UDPs. However, 1H and 13C NMR spectra revealed that the new ester bonds were formed between a hydroxyl group of UDP and a carboxyl group of succinic acid during esterification. In the steady shear rheological analysis, the consistency index (K) of ES-UDP was significantly higher than that of UDP and increased significantly with increasing concentration of succinic acid. In the dynamic rheological analysis, the tan δ values of all ES-UDP solutions were significantly lower than those of the UDP solution.

Structural Characterization of Cellulose Obtained from Extraction Wastes of Graviola (Annona muricata) Leaf.

Cellulose is one of the most common functional ingredients in food products and has been widely used as fat replacers and stabilizers. In the present study, the structural properties of cellulose obtained from extraction wastes of graviola (Annona muricata.) leaf (CWG) were characterized via scanning electron microscope (SEM), X-ray diffraction (XRD), fourier transform-infrared (FTIR), and 13C nuclear magnetic resonance (NMR) analyses. Extraction and purification of CWG were accomplished by alkali treatment and bleaching processes. An elongated, fibrous structure of CWG was observed in SEM analysis. The XRD, FTIR, and 13C NMR spectra of CWG were compared with microcrystalline cellulose (control cellulose) and it was found that CWG exhibited similar structural characteristics to the control. XRD diffractogram of CWG showed typical peaks (2θ=15° and 22.6°) of cellulose I. According to the specific peaks (898, 1,057, and 1,430 cm-1) and chemical shifts (104.5, 88.5, 72~75, and 64.6 ppm) obtained by FTIR and NMR analyses, respectively, it was cofirmed that cellulose was successfully extracted from CWG.

Physicochemical, molecular, emulsifying and rheological characterizations of sage (Salvia splendens) seed gum.

The objective was to investigate the physicochemical, molecular, rheological, and emulsifying properties of water soluble-sage seed gum (WSG). WSG mainly comprised galacturonic acid and xylose. FTIR and NMR analyses confirmed the presence of pectic polysaccharides in WSG. Additionally, the molecular weight of WSG was higher than that of pectin standard. Compared to pectin standard solutions, WSG solutions exhibited higher shear thinning behavior and higher values of apparent viscosity (ηa,100) and consistency index (K) in steady shear measurements. According to the results of frequency sweep test, the dynamic moduli (G' and G″) for WSG solutions were increased with increasing frequency and concentration. The changes in dynamic moduli of WSG solutions as a function of aging time at 4 °C indicated that WSG could form a more rigid network than pectin standard. According to the results of temperature sweep test, the dynamic moduli of WSG solutions were higher than those of pectin standard solutions. Emulsion capacity and stability analyses indicated that WSG (58 and 56%, respectively) had better emulsifying properties than pectin standard (46 and 37%). In conclusion, compared to pectin standard, superior rheological and emulsifying properties observed in WSG might be related to higher molecular weight and protein content, respectively.

The characterization, selenylation and anti-inflammatory activity of pectic polysaccharides extracted from Ulmus pumila L.

The specific objective of this study was to investigate characterization, selenylation, and anti-inflammatory activities of pectic polysaccharides extracted from Ulmus pumila L. (PPU). Four different monosaccharides were found in PPU, including galacturonic acid, galactose, rhamnose, and glucose. FT-IR spectra indicated that pectic polysaccharides were successfully extracted from Ulmus pumila L., and were probably low methoxyl pectin. GC-MS and NMR analysis of PPU suggested the major monosaccharide of PPU was α-1,4-linked galacturonic acid with α-1,2-linked rhamnose as the backbone and glucose or galactose residues as branches at C-3 and C-4 positions of rhamnose. Selenylation of PPU was synthesized by 0.2 and 0.4% of sodium selenites. Selenized-PPU (Se-PPU) inhibited LPS-induced nitric oxide production in RAW 264.7 cells, and increasing selenium content enhanced anti-inflammatory properties of PPU. Therefore, Se-PPU can be used as a potential source of bioactive compounds for nutraceuticals and pharmaceutical applications.

The preventive effects of nanopowdered red ginseng on collagen-induced arthritic mice.

This study was carried out to investigate the efficiency of red ginseng nanopowder in preventing collagen-induced arthritis (CIA) in mice. The mice were divided into five groups: normal group (no immunisation), control (CIA), powdered red ginseng (PRG), nanopowdered red ginseng (NRG) and methotrexate (MTX). Administering MTX, PRG and NRG to arthritic mice significantly decreased spleen indexes, clinical and histological scores compared to control group. Serum analysis of NRG and MTX groups showed a reduction in the cytokines such as the levels of tumour necrosis factor alpha (TNF-α), interleukin 6 (IL-6) and interleukin 1ß (IL-1ß) in comparison to PRG group. The levels of immunoglobulin M (IgM) and immunoglobulin G1 (IgG1) in the NRG group were significantly lower than those of the PRG group. In summary, the present study indicated that NRG can be effective in preventing type II collagen-induced rheumatoid arthritis in mice.

Synthesis, characterization, and functional properties of chlorophylls, pheophytins, and Zn-pheophytins.

The aims of this study were to synthesize chlorophyll derivatives, pheophytins and Zn-pheophytins, from chlorophylls extracted from spinach, characterize them, and evaluate their antioxidant and anti-inflammatory activities. The chlorophylls isolated from spinach were identified by means of FT-IR and NMR spectroscopies. The synthesis of pheophytins and Zn-pheophytins was confirmed by UV-Vis spectral analyses. The antioxidant activity of chlorophylls, pheophytins, and Zn-pheophytins was studied. The results revealed that the Zn-pheophytins showed the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and ß-carotene bleaching activities, followed by chlorophylls and pheophytins. Additionally, Zn-pheophytins showed substantial inhibitory activity against lipopolysaccharide (LPS)-induced NO production in RAW 264.7 cells. Furthermore, Zn-pheophytins remarkably suppressed LPS-induced expression of inducible nitric oxide synthase (iNOS) in RAW 264.7 cells and showed no cytotoxicity. Our findings indicated that Zn-pheophytins have strong antioxidant and anti-inflammatory properties and can therefore be a potential source of bioactive compounds for nutraceutical, cosmetic, and pharmaceutical applications.

Effects of Extraction Methods on In Vitro Biological Capacities and Rheological Properties of Polysaccharides from Red Pepper Stems.

The purposes of this study were to produce polysaccharides from red pepper stems using different extraction methods and evaluate their chemical composition, in vitro biological capacities, and rheological properties. Two polysaccharides were extracted from red pepper stems using an autoclave and alkali treatments, and the extracts were named PAU and PAL, respectively. The contents of total phenolics and flavonoids were significantly higher in PAU than those in PAL. PAU exhibited greater scavenging activities on 2,2-diphenyl-1-picrylhydrazyl radicals, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radicals, superoxide radicals, and nitrite compared to PAL, suggesting that PAU served as better antioxidants. Similarly, in vitro inhibitory abilities against carbohydrate hydrolyzing enzymes of PAU were higher than those of PAL. Steady shear rheological analysis demonstrated that PAU showed higher psuedoplastic shear-thinning behavior compared to PAL. Based on the results from dynamic shear rheological properties, it was found that both samples had predominantly viscous behavior rather than elastic behavior.

Physicochemical and Textural Properties of Noodles Prepared from Different Potato Varieties.

This study was performed to investigate the quality characteristics of noodles made from four different potato varieties: Atlantic, Go-un, Sae-bong, Jin-sun, and wheat flour. Quality characteristics of five noodles were analyzed by general components analysis, cooking quality (rate of water absorption, cooking loss, and volume increase), and mechanical textural properties. Some variations existed in wheat- or potato-based noodles for the general components analysis, but no clear trend was observed. Higher values in the rates of water absorption, cooking loss, and volume increase were observed for the wheat flour noodle, while some variations were observed for potato noodles depending on the variety. The wheat flour noodles exhibited higher values of textural characteristics obtained from the texture profile analysis, except for adhesiveness. Higher gluten contents as well as lower ash contents in the wheat flour noodles compared to the potato noodles are thought to be the two key factors contributing to this finding.