Prediction of Pectin Yield and Quality by FTIR and Carbohydrate Microarray Analysis

Extraction of cellulose from halophytic plants for the synthesis of a novel biocomposite

Cellulose nanofibers, a sustainable and promising material with widespread applications, exhibit appreciable strength and excellent mechanical and physicochemical properties. The preparation of cellulosic nanofibers from food or agricultural residue is not sustainable. Therefore, this study was designed to use three halophytic plants (Cressa cretica, Phragmites karka, and Suaeda fruticosa) to extract cellulose for the subsequent conversion to cellulosic nanofibers composites. The other extracted biomass components including lignin, hemicellulose, and pectin were also utilized to obtain industrially valuable enzymes. The maximum pectinase (31.56 IU mL-1), xylanase (35.21 IU mL-1), and laccase (15.89 IU mL-1) were produced after the fermentation of extracted pectin, hemicellulose, and lignin from S. fruticosa, P. karka, and C. cretica, respectively. Cellulose was methylated (with a degree of substitution of 2.4) and subsequently converted into a composite using polyvinyl alcohol. Scanning electron microscopy and Fourier-transform infrared spectroscopy confirmed the successful synthesis of the composites. The composites made up of cellulose from C. cretica and S. fruticosa had a high tensile strength (21.5 and 15.2 MPa) and low biodegradability (47.58% and 44.56%, respectively) after dumping for 3 months in soil, as compared with the composite from P. karka (98.79% biodegradability and 4.9 MPa tensile strength). Moreover, all the composites exhibited antibacterial activity against gram-negative bacteria (Escherichia coli and Klebsiella pneumoniae) and gram-positive bacteria (Staphylococcus aureus). Hence, this study emphasizes the possibility for various industrial applications of biomass from halophytic plants.

Hawthorn Fruit (Crataegus spp.) Polysaccharides Exhibit Immunomodulatory Activity on Macrophages via TLR4/NF-κB Signaling Activation

The immunostimulatory effects and the involved molecular mechanisms of polysaccharides from hawthorn fruit (Crataegus spp.) have not been well understood. In this study, the chemical composition, monosaccharide composition, uronic acid content, and structural features of hawthorn fruit polysaccharides (HFP) and the two collected fractions were analyzed. Both AF1-2 and AF2 have pectic-like structural features rich in galacturonic acid. AF2 showed superior proinflammatory effects on macrophages which significantly increased the secretion of pro-inflammatory cytokines interleukin-1β, interleukin-6, and tumor necrosis factor-α, but not AF1-2. AF2 was found to activate the nuclear factor-κB signaling pathway with suppressed expression of IκBα but up-regulated expression of p-IκBα and nuclear factor-κB P65. The surface binding site of AF2 on macrophage cells was characterized and toll like receptor-4 was responsible for AF2 induced activation of down-stream nuclear factor-κB signaling pathways. AF2 from hawthorn fruit could be potentially used as a natural source of immunomodulator in functional foods.

Effectiveness of a natural coagulant based on common mallow (Malva sylvestris) in urban wastewater treatment

This study evaluated the effectiveness of a natural coagulant based on common mallow (Malva sylvestris) to remove turbidity in urban wastewater. A 22 factorial design was selected to determine the optimal dose and the working pH of the natural coagulant. Its potential was studied in 50.0-450 mg/L and 4.00-10.0 ranges of doses and pH, respectively. A simplex lattice mixture evaluated its effectiveness as a coagulant aid combined with aluminum sulfate (conventional coagulant). Mixture proportions 0.000-1.00 were studied for each component, finding the proportion more effective. Results showed that the coagulation treatment could be feasible since a turbidity removal efficiency of 73.7% can be achieved under optimal conditions (50.0 mg/L and pH of 10.0). Likewise, a turbidity removal of 58.9% is obtained using 250 mg/L and maintaining wastewater pH (7.45). This efficiency can be increased using 31.0% natural coagulant mixed with 69.0% aluminum sulfate at 250 mg/L without modifying the wastewater pH. This improvement was associated with the natural coagulant's high molecular weight and long-chained structure since these properties enhance settling time, floc size and strength, and low sludge production. These results support using common mallow as a natural coagulant, making its use more feasible in alkaline water pH or as a coagulant aid combined with aluminum sulfate for urban wastewater treatment. A cost of USD 370/Kg of natural coagulant was estimated, which is higher than conventional coagulants. However, a cost-effectiveness analysis of its implementation should be performed since process scaling costs could significantly reduce its price.

Properties of lime peel pectin as mainly influenced by ethanol and protein-based purification methods

BACKGROUND

Lime peel, obtained from juice factory waste, is considered as a source of pectin. Lime peel pectin samples, extracted by three extraction procedures of 90 °C heating for 120 min, 90 °C heating for 90 min and then 32 min of ultrasound, and 80 °C heating for 60 min and then 22 min of ultrasound, and purified by two methods using ethanol and sodium caseinate (SC), were prepared and characterized.

RESULTS

The results showed that the purification method significantly affected the lime pectin samples properties. Pectin samples purified with SC had a transparent and film-like appearance, whereas the ethanol-purified pectin samples showed an amorphous and opaque appearance. Pectin samples purified with ethanol showed higher extraction recovery (approximately 20%), whereas the lowest pectin yield was observed for the purification with SC (approximately 10%). Although SC purification did not enhance the pectin yield, it diminished the level of 'non-pectin' components and resulted in purer pectin. The bands at 1045-1076 cm-1 , relating to neutral sugars, had higher intensities in ethanol-purified pectin samples, indicating their higher sugar contents. Also the samples purified with SC exhibited more thermal stability, probably as a result of the presence of protein in their structure.

CONCLUSION

In the present study, under the same or varying extraction conditions, the most important element distinguishing pectins in terms of appearance, physicochemical, thermal and Fourier transform infrared characteristics was the type of purification method. Purification with SC may result in pectins with more non-esterified galacturonic acids from the homogalacturonan fraction. © 2023 Society of Chemical Industry.

Potential role of cell wall pectin polysaccharides, water state, and cellular structure on twice "increase-decrease" texture changes during kohlrabi pickling process

Pickled kohlrabi is a traditional and favored vegetable product in China. During pickling, the hardness, springiness, and chewiness of kohlrabi all experienced a typical change with twice "increase-decrease" trend. However, little is known about its mechanism. In this study, in situ analysis including immunofluorescence, low field nuclear magnetic, and transmission electron microscopy were used to explore the effects of cell wall pectin, water state, and cellular structure on kohlrabi texture changes during pickling. Results revealed that at the early stage, due to the rapid loss of water after three times salting, the cells shrank and the interstitial space reduced, resulting in the first increase on kohlrabi texture. Subsequently, the dehydration-rehydration caused by the first brine processing resulted in the first decrease on kohlrabi texture. Then under the action of PME enzyme, more low-esterified pectin was produced, and chelate-soluble pectin with more branched structure was further formed, leading to another elevation of the sample texture. As the pickling continued, under the combined action of PG and PME, the molecular weight of pectin was decreased and the rigidity of the cell tissue was destroyed, caused kohlrabi texture continued to decline. These researches could provide important information and guidance for better maintaining the texture of pickled vegetables during processing.

Valorization of coffee bean processing waste for the sustainable extraction of biologically active pectin

The dry method of coffee processing generates a significant amount of coffee husk, an agricultural waste for which currently there is a lack of profitable use, and their disposal constitutes a major environmental problem. Pectin was extracted from coffee husk using citric acid solution (pH 1.5) by microwave-assisted extraction method, followed by using ice-cold ethanol. The coffee husk pectin (CHP) with a yield of 40.2% was characterized using SEM, FT-IR, and XRD techniques. The CHP exhibited significant in-vitro antioxidant activity as measured by using 2,2-diphenyl-1-picrylhydrazyl; (IC50 value of 395.1 ± 0.42 μg/mL), ferrous reducing antioxidant capacity (A700 nm = 0.55 ± 0.08), 2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging (42.02 ± 0.38%) and ascorbic acid auto-oxidation inhibition (92.01 ± 0.28%) assays. CHP demonstrated antibacterial activity against Escherichia coli and Bacillus cereus with an inhibition diameter of 20 ± 1.01 mm and 18 ± 0.84 mm, respectively. Interestingly, CHP showed a significant anti-inflammatory effect by negatively modulating the expressions of TNF-α and TGF- β in LPS-stimulated macrophage cell lines. Collectively, our findings suggest that the coffee husk is a potential source of commercial pectin, microwave-assisted extraction has a great potency on the commercial pectin extraction from the coffee husk and CHP demonstrates significant biological activity.

Spectroscopic Analyses Highlight Plant Biostimulant Effects of Baker's Yeast Vinasse and Selenium on Cabbage through Foliar Fertilization

The main aim of this study is to find relevant analytic fingerprints for plants' structural characterization using spectroscopic techniques and thermogravimetric analyses (TGAs) as alternative methods, particularized on cabbage treated with selenium-baker's yeast vinasse formulation (Se-VF) included in a foliar fertilizer formula. The hypothesis investigated is that Se-VF will induce significant structural changes compared with the control, analytically confirming the biofortification of selenium-enriched cabbage as a nutritive vegetable, and particularly the plant biostimulant effects of the applied Se-VF formulation on cabbage grown in the field. The TGA evidenced a structural transformation of the molecular building blocks in the treated cabbage leaves. The ash residues increased after treatment, suggesting increased mineral accumulation in leaves. X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) evidenced a pectin-Iα-cellulose structure of cabbage that correlated with each other in terms of leaf crystallinity. FTIR analysis suggested the accumulation of unesterified pectin and possibly (seleno) glucosinolates and an increased network of hydrogen bonds. The treatment with Se-VF formulation induced a significant increase in the soluble fibers of the inner leaves, accompanied by a decrease in the insoluble fibers. The ratio of soluble/insoluble fibers correlated with the crystallinity determined by XRD and with the FTIR data. The employed analytic techniques can find practical applications as fast methods in studies of the effects of new agrotechnical practices, while in our particular case study, they revealed effects specific to plant biostimulants of the Se-VF formulation treatment: enhanced mineral utilization and improved quality traits.

Effects of Surface Morphology and Type of Cross-Linking of Chitosan-Pectin Microspheres on Their Degree of Swelling and Favipiravir Release Behavior

The cross-linked microspheres were prepared and loaded with Favipiravir SARS-CoV-2 antiviral drug, by copolymerization of chitosan (CS) with a polysaccharide extracted from fresh pomegranate peels. Moreover, glutaraldehyde (Glu) has been used as a chemical cross-linker and sodium hexametaphosphate (SHMP) as a physical cross-linker. The extracted polysaccharide was analyzed, and different techniques have been used. The analyses lead to the conclusion that it is pectin. The surface morphology of the prepared microspheres was studied using a scanning electron microscope, where the size and shape factor (S) of the Glu microspheres showed high values (74.27 μm) and (0.852), respectively, meaning their surfaces tend to be rough, whereas the SHMP microspheres showed a smaller size particle (20.47 μm) and a smaller shape factor (0.748), which gives an indication that the SHMP microspheres have smooth surfaces. The swelling studies have shown that Glu microspheres have a higher degree of swelling, which means SHMP microspheres are more compact. The prepared microspheres have shown a higher loading percentage of Favipiravir antiviral drug in SHMP microspheres (37% w/w) in comparison with Glu microspheres (35% w/w), where the electrostatic interaction between the Favipiravir ions and SHMP anions helps for more loading. The microspheres prepared under different types of cross-linking have shown initial burst release of Favipiravir, followed by a step of controlled release for a certain period of time, whose period depends on the pH of the release medium. Both Glu and SHMP cross-linked microspheres have shown high controlled release times in buffered release solutions at pH = 7.4 and for shorter periods at pH = 1.3 and pH = 9.4, which may be related to the type of electrostatic interactions between drug and polymer systems and their reactions with release solution ions.

Formulation and Characterization of Emulgel-Based Jelly Candy: A Preliminary Study on Nutraceutical Delivery

The development of consumer-friendly nutraceutical dosage forms is highly important for greater acceptance. In this work, such dosage forms were prepared based on structured emulsions (emulgels), where the olive oil phase was filled within the pectin-based jelly candy. The emulgel-based candies were designed as bi-modal carriers, where oil-soluble curcumin and water-soluble riboflavin were incorporated as the model nutraceuticals. Initially, emulsions were prepared by homogenizing varied concentrations (10% to 30% (w/w)) of olive oil in a 5% (w/w) pectin solution that contained sucrose and citric acid. Herein, pectin acted as a structuring agent-cum-stabilizer. Physico-chemical properties of the developed formulations were thoroughly analyzed. These studies revealed that olive oil interferes with the formation of polymer networks of pectin and the crystallization properties of sugar in candies. This was confirmed by performing FTIR spectroscopy and DSC studies. In vitro disintegration studies showed an insignificant difference in the disintegration behavior of candies, although olive oil concentration was varied. Riboflavin and curcumin were then incorporated into the jelly candy formulations to analyze whether the developed formulations could deliver both hydrophilic and hydrophobic nutraceutical agents. We found that the developed jelly candy formulations were capable of delivering both types of nutraceutical agents. The outcome of the present study may open new directions for designing and developing oral nutraceutical dosage forms.

Structural and Thermal Characteristics of Buriti Tree Gum (Mauritia flexuosa)

A polysaccharide was isolated from the exudate of a buriti tree trunk (Mauritia flexuosa). The molecular structure, thermal stability, morphology, crystallinity, and elemental composition of the product were investigated through spectroscopic techniques, such as Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR 1H and 13C), and energy-dispersive X-ray spectroscopy (EDS); thermogravimetric analysis (TG), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and X-ray diffraction (XRD). In addition to NMR molecular modeling studies, were performed to confirm the 1H and 13C chemical shifts to Gal and Xyl conformers. Buriti tree gum (BG) is an arabinogalactan, containing Rha, Ara, Xyl, and Gal, and degrades almost completely (98.5%) at 550 °C and has a maximum degradation peak at 291.97 °C, with a mass loss of 56.33%. In the temperature range of 255–290 °C, the energy involved in the BG degradation process was approximately 17 J/g. DSC indicated a glass transition temperature of 27.2 °C for BG, which had an irregular and heterogeneous morphology, with smooth or crumbling scaly regions, demonstrating the amorphous nature of BG that was confirmed by the XRD standard. EDS revealed the presence of carbon and oxygen, as well as calcium, magnesium, aluminum, silicon, chlorine, and potassium, in the BG composition.

Microwave-assisted extraction of pectin from jackfruit rags: Optimization, physicochemical properties and antibacterial activities

While fruit biowastes pose an environmental hazard, they can be utilized as a source of beneficial biopolymers such as pectin. However, conventional extraction techniques require long processing time with low, impure yields, and microwave assisted extraction (MAE) can suffer from these drawbacks. Here, MAE was applied to extract pectin from jackfruit rags and compared with conventional heating reflux extraction (HRE). Response surface methodology was adopted to optimize pectin yield, based on pH (1.0-2.0), solid-liquid ratio (1:20-1:30), time (5-90 min), and temperature (60-95 °C). Pectin extraction by MAE required lower temperatures (65.99 °C) and shorter reaction times (10.56 min). Pectin HRE resulted in a product with amorphous structures and rough surfaces, while pectin-MAE was high crystalline with smooth surfaces. Although both pectin samples showed shear-thinning behavior, pectin-MAE exhibited higher antioxidant and antibacterial activities. Therefore, microwave assisted extraction was an efficient method to extract pectin from jackfruit rags.

Fabrication of phenylalanine amidated pectin using ultra-low temperature enzymatic method and its hydrogel properties in drug sustained release application

In this study, pectin was modified with phenylalanine by ultra-low temperature enzymatic method to improve its gel properties. The grafting ratio of phenylalanine amidated pectin was studied under different reaction conditions. The highest value (29.21 %) was reached a reaction temperature of -5 °C and time of 12 h. Further analysis indicated that phenylalanine and high methoxyl pectin combined at the solid-liquid two phase interface under the catalysis of papain to form phenylalanine amidated pectin. Moreover, the physicochemical properties of pectin hydrogel and its feasibility as a sustained-release drug carrier were discussed. The results showed that phenylalanine amidated pectin can form hydrogel with a certain strength under acidic conditions, and there is no need to add a lot of soluble solids and divalent cations. Besides, the phenylalanine amidated pectin hydrogel as a sustained release carrier of drugs showed more sustained and complete drug release.

New valorization approach of Algerian dates (Phoenix dactylifera L.) by ultrasound pectin extraction: Physicochemical, techno-functional, antioxidant and antidiabetic properties

To exploit the great fortune of date fruits, the current study aimed to valorize an Algerian common variety by extracting pectins. Response surface methodology (RSM) was applied as process optimization tool to achieve the highest yield using ultrasound-assisted extraction (UAE) as compared to conventional acid extraction (CAE). The experimental yield value (6.7%) was well matched with the predicted one (6.6%) at the optimum conditions (60 °C, 90 min, pH 1.5), confirming the validity of the model. The evaluation of the monomeric composition showed higher content of galacturonic acid and lower of neutral sugars in UAE pectin, as compared to CAE pectin. Conventional treatments decreased the molecular weight (Mw) of the extracted pectins (539 kDa) in a higher extent than ultrasound treatment (800 kDa). Fourier-Transform Infrared Spectroscopy (FT-IR) spectral analysis showed that both samples were low-methoxyl pectins. CAE gave rise to pectins with slightly upper technological samples in terms of water and oil holding capacity (5.2 and 3.8 g/g, respectively), and emulsifying activity (38.5 m²/g). Moreover, date pectins obtained by UAE presented enhanced antioxidant activity (24.3 and 61.0 mg/g DW for DPPH and FRAP assays, respectively), and in vitro antidiabetic properties, showing higher glucose adsorption capacity (4 mmol g^-1 at 200 min), as well as α-amylase inhibition (73.7%) and potential capacity to decrease glucose diffusion (1.4 mmol mM g^-1 at 150 min), which could improve the ability to retard starch digestion (0.1 mmol mM g-1 at 150 min), providing potential health-promoting properties.

The Influence of Extraction Conditions on the Yield and Physico-Chemical Parameters of Pectin from Grape Pomace

Grape pomace is one of the most abundant by-products generated from the wine industry. This by-product is a complex substrate consisted of polysaccharides, proanthocyanidins, acid pectic substances, structural proteins, lignin, and polyphenols. In an effort to valorize this material, the present study focused on the influence of extraction conditions on the yield and physico-chemical parameters of pectin. The following conditions, such as grape pomace variety (Fetească Neagră and Rară Neagră), acid type (citric, sulfuric, and nitric), particle size intervals (<125 µm, ≥125−<200 µm and ≥200−<300 µm), temperature (70, 80 and 90 °C), pH (1, 2 and 3), and extraction time (1, 2, and 3 h) were established in order to optimize the extraction of pectin. The results showed that acid type, particle size intervals, temperature, time, and pH had a significant influence on the yield and physico-chemical parameters of pectin extracted from grape pomace. According to the obtained results, the highest yield, galacturonic acid content, degree of esterification, methoxyl content, molecular, and equivalent weight of pectin were acquired for the extraction with citric acid at pH 2, particle size interval of ≥125−<200 µm, and temperature of 90 °C for 3 h. FT-IR analysis confirmed the presence of functional groups in the fingerprint region of identification for polysaccharide in the extracted pectin.

Effect of chitosan coatings on the evolution of sodium carbonate-soluble pectin during sweet cherry softening under non-isothermal conditions

The inhibiting effect of chitosan coating (2%) on the softening and sodium carbonate-soluble pectin (SSP) evolution of sweet cherries during non-isothermal storage was investigated. Chitosan coating significantly extend the softening (6.4% greater than the control group), maintained the SSP content (6.6% greater than the control group), and reduced the degradation of SSP by inhibiting the expression of the paPME1-5 genes, which regulating pectin methylesterase activity of sweet cherries under temperature variation. In addition, the results of methylation and monosaccharide composition indicated that the chitosan coating reduced demethylation of SSP and the loss of RG-I main and side chain neutral sugars. Atomic force microscopy images revealed that the coated sweet cherries contained more linked, branched, and long SSP chains and maintained the width of the pectin backbone (>140 nm). These results indicated that a chitosan coating is feasible to preserve postharvest fruit under non-isothermal conditions.

Evaluation of Kluyveromyces marxianus endo-polygalacturonase activity through ATR-FTIR

The endo-polygalacturonase enzyme (endoPG: EC 3.2.1.15) plays an important role in the fruit juice and wine industries, so the development of new tools for the quantitative and qualitative analysis of its enzymatic action is necessary. In this work, we report the development of a simple, fast and practical method that did not use any chemical reagent to identify and evaluate the action of the endoPG enzyme, produced by the yeast Kluyveromyces marxianus CCT3172, using attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy combined with principal component analysis-linear discriminant analysis (PCA-LDA). This method evaluated the action of the endoPG enzyme on the polygalacturonic acid (PGA) substrate at 5 different times (0, 10, 15, 20 and 30 minutes), and at each time interval the samples were analyzed by ATR-FTIR. It was demonstrated that there was clear segregation between the samples that were and that were not subjected to the action of the endoPG enzyme, and it was also possible to distinguish the samples that were subjected to different incubation times with the enzyme. Through PCA-LDA it was possible to obtain wavelengths that are biomarkers for this enzymatic reaction and the observed changes as a function of hydrolysis duration were found to be in agreement with the breakdown of the glycosidic chain (1011 cm^-1-CH-O- CH stretching) of PGA and release of oligosaccharides (1078 cm^-1 C-OH elongation). The activity of the endoPG enzyme and the release of galacturonic acid were verified by the dinitrosalicylic acid (DNS) method in all samples. The efficacy of an automatic classifier using a principal component analysis-linear discriminant classifier (PCA-LDC) was evaluated to diagnose the action of the endoPG enzyme. The results showed an accuracy of 100% for the identification of the endoPG enzyme action and from 91.67% to 100% for classification according to the hydrolysis duration in which PGA was exposed to endoPG. The present study indicates that this methodology may be a new approach for the qualitative evaluation of the endoPG enzyme with the potential to be used in laboratories and industries.

Raw material quality assessment approaches comparison in pectin production

Different opportunities are explored to evaluate quality variation in raw materials from biological origin. Assessment of raw materials attributes is an important step in a bio-based production as fluctuations in quality are a major source of process disturbance. This can be due to a variety of biological, seasonal, and supply scarcity reasons. The final properties of a product are invariably linked with the initial properties of the raw material. Thus, the operational conditions of a process can be tuned to drive the product to the required specification based on the quality assessment of the raw material being processed. Process analytical technology tools which enable this assessment in a far more informative and rapid manner than current industrial practices that rely on rule-of-thumb decisions are assessed. An example with citrus peels is used to demonstrate the conceptual and performance differences of distinct quality assessment approaches. The analysis demonstrates the advantage of characterization through multivariate data analysis coupled with a complementary spectroscopic technique, near-infrared spectroscopy. The quantitative comparative analysis of three different approaches, discriminant classification based on expert-knowledge, unsupervised classification, and spectroscopic correlation with reference physicochemical variables, is performed in the same dataset context. © 2018 Her Majesty the Queen in Right of Canada © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 35: e2762, 2019.

Comparison of Pectin Layers for Nicotine Transdermal Patch Preparation

Purpose: The objective of the present investigation was to prepare and evaluate transdermal patches for nicotine.

Methods: Pectin isolated from the hulls of Monthong durian or leaves of Krueo Ma Noy was used as a matrix membrane for the controlled release of nicotine and compared with commercial pectin. The mechanical properties, moisture uptake, and Fourier transform infrared spectra were characterized. The in vitro stability of these patches was evaluated and compared to commercial nicotine patches.

Results: The mechanical properties of the patches made from isolated pectin were greater than those prepared from commercial pectin; brittle commercial patches were obtained after nicotine loading. The moisture uptake of the patches made with isolated pectin was in the range of 30.20-44.29%. There was no incompatibility between the ingredients of the nicotine transdermal patches or any degradation of the drug. The matrix layer made from isolated pectin controlled the nicotine release more effectively than did commercial nicotine patches. In addition, these patches were stable at in a refrigerator (approximately 4±2 °C) and at ambient temperature (approximately 30±2 °C) for 3 months, retaining 90% of the loaded nicotine.

Conclusion: Our study suggests that using isolated pectin as the matrix layer should control the release of nicotine from transdermal patches.

Autotemplate Microcapsules of CaCO3/Pectin and Nonstoichiometric Complexes as Sustained Tetracycline Hydrochloride Delivery Carriers

New types of composites were obtained by an autotemplate method for assembling hollow CaCO₃ capsules by using pH-sensitive polymers. Five pectin samples, which differ in the methylation degree and/or amide content, and some nonstoichiometric polyelectrolyte complex dispersions, prepared with the pectin samples and poly(allylamine hydrochloride), were used to control the crystal growth. The morphology of the composites was investigated by scanning electron microscopy, and the polymorphs characteristics were investigated by FTIR spectroscopy. The presence of the polymer in the composite particles was evidenced by X-ray photoelectron spectroscopy, particle charge density, and zeta-potential. The new CaCO₃/pectin hollow capsules were tested as a possible matrix for a tetracycline hydrochloride carrier. The kinetics of the drug release mechanism was followed using Higuchi and Korsmeyer-Peppas mathematical models.

Innovative "Green" and Novel Strategies for the Extraction of Bioactive Added Value Compounds from Citrus Wastes-A Review

Citrus is a major processed crop that results in large quantities of wastes and by-products rich in various bioactive compounds such as pectins, water soluble and insoluble antioxidants and essential oils. While some of those wastes are currently valorised by various technologies (yet most are discarded or used for feed), effective, non-toxic and profitable extraction strategies could further significantly promote the valorisation and provide both increased profits and high quality bioactives. The present review will describe and summarize the latest works concerning novel and greener methods for valorisation of citrus by-products. The outcomes and effectiveness of those technologies such as microwaves, ultrasound, pulsed electric fields and high pressure is compared both to conventional valorisation technologies and between the novel technologies themselves in order to highlight the advantages and potential scalability of these so-called "enabling technologies". In many cases the reported novel technologies can enable a valorisation extraction process that is "greener" compared to the conventional technique due to a lower energy consumption and reduced utilization of toxic solvents.

Systematic synthesis of pectin-g-(sodium acrylate-co-N-isopropylacrylamide) interpenetrating polymer network for superadsorption of dyes/M(ii): determination of physicochemical changes in loaded hydrogels

Superadsorbent hydrogel with excellent physicochemical properties is used for mere/synergic chemisorption of dyes and M(ii).