Ultrasound (US) triggered alterations in the viscoelastic behavior of the procaine-loaded ionically gelatinized pectin hydrogel matrix, and drug release was observed using a sono-device rheometer. ...The gel softened immediately upon activation of the ultrasound operated at 43 kHz and remained in a softened state throughout the irradiation. Upon cessation of ultrasound, the gel promptly reverted to its original hardness. This cycle of softening was consistently observed in ionically crosslinked pectin hydrogels, resulting in the promotion of procaine release, particularly with higher US power and lower calcium concentration. As the amount of loaded procaine increased, the gel weakened due to ion exchange with the calcium crosslinker and procaine. The most substantial release efficiency, reaching 82 % with a concentration of 32 μg/ml, was achieved when the hydrogels contained 0.03 % procaine within the gelatinized hydrogel medicine at a calcium concentration of 0.9 M, representing a six-fold increase compared to that without US. Notably, US exposure affected the 3D porous structure and degradation rate, leading to hydrogel collapse and facilitating medicine release. Additionally, the procaine-loaded pectin hydrogels with 0.9 M calcium exhibited improved fibroblast cell viability, indicating non-toxicity compared to those hydrogels prepared at a higher Ca2+ concentration of 2.4 M.
The study aims to develop gel beads with improved functional properties and biocompatibility from hogweed (HS) pectin. HS4 and AP4 gel beads were prepared from the HS pectin and apple pectin (AP) ...using gelling with calcium ions. HS4 and AP4 gel beads swelled in PBS in dependence on pH. The swelling degree of HS4 and AP4 gel beads was 191 and 136%, respectively, in PBS at pH 7.4. The hardness of HS4 and AP4 gel beads reduced 8.2 and 60 times, respectively, compared with the initial value after 24 h incubation. Both pectin gel beads swelled less in Hanks' solution than in PBS and swelled less in Hanks' solution containing peritoneal macrophages than in cell-free Hanks' solution. Serum protein adsorption by HS4 and AP4 gel beads was 118 ± 44 and 196 ± 68 μg/cm
after 24 h of incubation. Both pectin gel beads demonstrated low rates of hemolysis and complement activation. However, HS4 gel beads inhibited the LPS-stimulated secretion of TNF-α and the expression of TLR4 and NF-κB by macrophages, whereas AP4 gel beads stimulated the inflammatory response of macrophages. HS4 gel beads adsorbed 1.3 times more LPS and adhered to 1.6 times more macrophages than AP4 gel beads. Thus, HS pectin gel has advantages over AP gel concerning swelling behavior, protein adsorption, and biocompatibility.
The acid-induced gelation of pectin in potato cell walls has been gradually recognized to be related to the improvement in the cell wall integrity after heat processing. The aim of this study was to ...characterize the acid-induced gelation of original pectin from a potato cell wall (OPP). Rheological analyses showed a typical solution–sol–gel transition process of OPP with different additions of gluconic acid-δ-lactone (GDL). The gelation time (Gsub.t) of OPP was significantly shortened from 7424 s to 2286 s. The complex viscosity (η*) of OPP gradually increased after 4000 s when the pH was lower than 3.13 and increased from 0.15 to a range of 0.20~6.3 Pa·s at 9000 s. The increase in shear rate caused a decrease in η, indicating that OPP belongs to a typical non-Newtonian fluid. Furthermore, a decrease in ζ-potential (from −21.5 mV to −11.3 mV) and an increase in particle size distribution (from a nano to micro scale) was observed in OPP after gelation, as well as a more complex (fractal dimension increased from 1.78 to 1.86) and compact (cores observed by cryo-SEM became smaller and denser) structure. The crystallinity of OPP also increased from 8.61% to 26.44%~38.11% with the addition of GDL. The above results call for an investigation of the role of acid-induced OPP gelation on potato cell walls after heat processing.
A gelling strategy for HP was proposed in this study, ammonium sulfate (AS) as a co-solute could induce the gelling of HP in acidic environment. The solubility and Zeta potential of HP dramatically ...decreased in AS solution, which indicated AS could promote the aggregation of HP. The rheological results confirmed the gelling of HP (G′ > G″) with AS: 25–30 wt% and pH ≤ 3.0, and the gel strength is mainly depended on HP rather than AS concentration. Smaller AS crystals (SEM) and reduced T2 values (LF-NMR) were observed in HP gels, suggested the gel network of HP could limit the migration of AS and water. Finally, it was found that the release process of NH4+ in HP + AS gel was lagged behind that of pure AS, which verified the potential of HP + AS gel in the field of sustained-release fertilizers.
The Acid/AS induced gelling of high esterified pectin, and sustained release of NH4+ in HP + AS gels. Display omitted
When boron (B) deficiency and aluminum (Al) toxicity co-exist in acidic soils, crop productivity is limited. In the current study, we found that 3 μM of B pretreatment significantly enhances rice ...root elongation under Al toxicity conditions. Pretreatment with B significantly decreases the deposition of Al in rice apoplasts, suppresses the synthesis of cell wall pectin, inhibits cell wall pectin methylesterase (PME) activity and its gene expression, and increases the expression of OsSTAR1 and OsSTAR2, which are responsible for reducing the Al content in the cell walls. In addition, B pretreatment significantly increases OsALS1 expression, thereby facilitating the transfer of Al from the cytoplasm to the vacuoles. However, B pretreatment had no effect on Al uptake and citric acid secretion. Pretreatment with B significantly increases the activity of ascorbate peroxidase (APX), peroxidase (POD), and catalase (CAT), thus increasing the elimination rate of H
O
in rice roots. Co-treatment using B and H
O
does not increase root growth under Al toxicity conditions; it also improves pectin synthesis, enhances PME activity, and increases Al deposition in root cell walls. However, the co-treatment of B and H
O
scavenger 4-hydroxy-TEMPO has an opposite effect. The above results indicate that applying B fertilizers in acidic soil can help decrease the side effects of Al toxicity on rice growth.
Pectin is an integral component of non-graminaceous plant cell walls. It is believed to form an interconnected network structure independent of the cellulose-xyloglucan network structure. Pectin gels ...are often used as a model for the pectin network structure within the plant cell wall. Atomic force microscopy studies of calcium-induced gel precursors, and fragments released from gels, suggest that association leads to a branched fibrous structure within the gels. Enzymatic de-esterification of high-methoxyl pectin in the presence of calcium ions can induce gelation of the pectin. Thus pectin gel networks may provide a model for a self-assembled network structure within the middle lamella region of the plant cell wall. The pectin network in plant cell walls is a source of soluble and insoluble fibre. In addition to the health benefits associated with the dietary fibre aspects of pectin new health claims are emerging. Recently published
in vitro and
in vivo animal studies, and human studies, suggest that oral consumption of a modified form of pectin may have anti-cancer properties. These studies suggest that the modified pectin may act on a range of cancers at several stages of progression of the cancer. It has been hypothesised that this generic action is due to the modification allowing release of bioactive fragment(s) which are claimed to bind specifically to and inhibit the action of the mammalian lectin galectin 3 (Gal3). Gal3 is a key regulator of cellular homeostasis and plays important roles in several stages of cancer metastasis. Studies using force spectroscopy, flow cytometry and fluorescence microscopy suggest that the bioactive fragments of pectin may be pectin-derived galactans.
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Passion fruit (
Passiflora edulis f. flavicarpa L.) yellow variety is composed of 50–55
g peel per 100
g of fresh fruit which is discarded as waste during processing. Utilization of passion fruit ...peel for pectin extraction was studied. Passion fruit peel obtained after juice extraction was blanched in boiling water for 5
min, dehydrated in a cross flow hot air drier at 60
±
1
°C to a moisture content of 4
g/100
g of dried peel. The dehydrated passion fruit peel was used for extraction experiments of pectin. The effect of pH, peel to extractant ratio, and number of extractions, extraction time and temperature on the yield and quality characteristics of pectin were investigated. The optimized conditions for extraction of pectin from passion fruit peel yielded 14.8
g/100
g of dried peel. Pectin extracted from the dried peels had a methoxyl content of 9.6
g/100
g, galacturonic acid content of 88.2
g/100
g and jelly grade of 200. Extraction of pectin from dried peels of passion fruit may be considered for effective utilization of passion fruit processing waste.
•Extraction of pectin from melon (Cucumis melo L.) peel was optimized.•Central composite design was used to model the yield and DE.•Citric acid was identified as the most effective acid for pectin ...extraction.•Optimum condition for pectin extraction at pH=1 was 95°C for 200min with SSR 10.•Melon peel pectin is classified as low methoxyl pectin.
In this study, acidic extraction (citric acid) was used for the extraction of pectin from melon peel. A central composite design (CCD) was applied to study the effect of temperature (35–95°C), time (40–200min), pH (1–3) and solvent to sample ratio (10–50v/w) on the yield and degree of esterification (DE). The results showed that the yield and DE ranged from 2.87 to 28.98% and 1.33–29.33%, respectively. Also, the highest extraction yield (29.48±1.7%) was obtained under optimal conditions (pH of 1, temperature of 95°C and ratio of 10v/w after 200min). The protein, ash, carbohydrate and galacturonic acid content of pectin obtained under optimal conditions were about 1.5, 3.5, 10 and 48%, respectively. Rheological experiments determined that melon peel pectin dispersions behaved as a weak gel at concentrations of 1%w/v. The emulsifying activity was 35% and also, the emulsion stability was higher at 4°C than at 23°C.
•CUR-PPI-HMP complex was successfully fabricated by a self-assembly approach.•Highest CUR LA (33.19 μg/mg) was obtained in CUR-PPI-HMP ternary complex.•BC emulsion with CUR-PPI-HMP ternary complex ...showed highest physical stability.•BC retention with CUR-PPI-HMP was highest (76.15%) after 8 h UV light exposure.•CUR-PPI-HMP showed highest protection of BC against heat-induced degradation.
There is an ever-increasing need to protect health-beneficial β-carotene (BC) from degradation with novel ingredients. Natural antioxidant-loaded protein-polysaccharide ternary complex has great potential for BC emulsions stabilization. In this study, curcumin (CUR)-loaded pea protein isolate (PPI), and high methoxyl pectin (HMP) ternary complex (804.0 nm) was fabricated by a self-assembly approach for BC emulsions stabilization. Highest CUR loading amount (LA, 33.19 μg/mg) was obtained in CUR-PPI-HMP complex. Hydrophobic interaction and hydrogen bonding were the prime driving forces for ternary complex formation. XRD results showed that CUR was amorphous. BC emulsion with PPI-HMP and CUR-PPI-HMP possessed higher droplet sizes (357.8 and 360.2 nm) than that with PPI and CUR-PPI (325.6, and 313.5 nm). Excellent physical stability with PPI-HMP and CUR-PPI-HMP was observed. BC retention with CUR-PPI-HMP was highest exposure to UV light (76.15%, 8 h), or heat treatment at 25 (91.50%) and 50 °C (74.35%) for 30 days.
•Sugar beet pectin only weakly affected the viability of colon cancer cells.•Alkali treatment increased the effect of sugar beet pectin by inducing apoptosis.•Alkali treatment increased the ratio of ...rhamnogalacturonan I to homogalacturonan.•Removal of the neutral sugar side-chains decreased the effect on cancer cells.
Pectins extracted from a variety of sources and modified with heat and/or pH have previously been shown to exhibit activity towards several cancer cell lines. However, the structural basis for the anti-cancer activity of modified pectin requires clarification. Sugar beet and citrus pectin extracts have been compared. Pectin extracted from sugar beet pulp only weakly affected the viability of colon cancer cells. Alkali treatment increased the anti-cancer effect of sugar beet pectin via an induction of apoptosis. Alkali treatment decreased the degree of esterification (DE) and increased the ratio of rhamnogalacturonan I (RGI) to homogalacturonan. Low DE per se did not play a significant role in the anti-cancer activity. However, the enzymatic removal of galactose and, to a lesser extent, arabinose from the pectin decreased the effect on cancer cells indicating that the neutral sugar-containing RGI regions are important for pectin bioactivity.
