Valorization of pistachio industrial waste: Simultaneous recovery of pectin and phenolics, and their application in low-phenylalanine cookies for phenylketonuria.

This study introduces a sustainable approach to simultaneously produce pectin and phenolic compounds from pistachio industrial waste and applies them in the formulation of low-phenylalanine cookies. The co-optimization process was performed using the microwave-assisted technique and a Box-Behnken design, considering four variables and two responses: pectin yield and total phenolic content (TPC). The co-optimized condition (microwave power of 700 W, irradiation time of 210 s, pH level of 1.02, and LSR of 20 mL/g) resulted in a pectin yield of 15.85 % and a TPC of 10.12 %. The pectin obtained under co-optimized condition was evaluated for its physicochemical, structural, and thermal properties and the phenolic extract for its antiradical activity. Characterization of the pectin sample revealed a high degree of esterification (44.21 %) and a galacturonic acid-rich composition (69.55 %). The average molecular weight of the pectin was determined to be 640.236 kDa. FTIR and 1H NMR spectroscopies confirmed the structure of pectin, with an amorphous nature and high thermal stability observed through XRD and DSC analysis. Additionally, the extract exhibited significant antiradical activity comparable to butylated hydroxyanisole and ascorbic acid. The isolated ingredients were used to formulate low-protein, low-phenylalanine cookies for phenylketonuria patients. The addition of 0.5 % pectin and 1 mL/g extract led to increased moisture content (from 9.05 to 12.89 %) and specific volume (from 7.28 to 9.90 mL/g), decreased hardness (from 19.44 to 10.39 N × 102), and improved antioxidant properties (from 5.15 % to 44.60 % inhibition) of the cookies. Importantly, there was no significant increase observed in the phenylalanine content of the samples with pectin and extract addition. Furthermore, sensory evaluation scores demonstrated significantly higher scores for taste, odor, texture, and overall acceptability in cookies enriched with 0.5 % pectin and 1 mL/g extract, with scores of 4.53, 3.93, 4.40, and 4.60, respectively.

Membrane Life Cycle Management: An Exciting Opportunity for Advancing the Sustainability Features of Membrane Separations.

Membrane science and technology is growing rapidly worldwide and continues to play an increasingly important role in diverse fields by offering high separation efficiency with low energy consumption. Membranes have also shown great promise for "green" separation. A majority of the investigations in the field are devoted to the membrane fabrication and modification with the ultimate goals of enhancing the properties and separation performance of membranes. However, less attention has been paid to membrane life cycle management, particularly at the end of service. This is becoming very important, especially taking into account the trends toward sustainable development and carbon neutrality. On the contrary, this can be a great opportunity considering the large variety of membrane processes, especially in terms of the size and capacity of plants in operation. This work aims to highlight the prominent aspects that govern membrane life cycle management with special attention to life cycle assessment (LCA). While fabrication, application, and recycling are the three key aspects of LCA, we focus here on membrane (module) recycling at the end of life by elucidating the relevant aspects, potential criteria, and strategies that effectively contribute to the achievement of green development and sustainability goals.

Extraction optimization and characterization of pectin from sesame (Sesamum indicum L.) capsule as a new neglected by-product.

BACKGROUND: With production of over 6 million tonnes a year of sesame, its capsules are considered to be an unutilized waste. In this study, extraction of pectin from this novel source was optimized using a green method, and the functional and physiochemical characteristics of the resultant pectin were compared to commercial pectin. RESULTS: In this study, the sesame capsule pectin (SCP) extraction conditions were optimized to reach maximum yield, and the results showed that the maximum pectin extraction yield (138 g kg-1 ) was obtained under optimal conditions (microwave power 700 W, irradiation time 5 min, pH 1.5, and liquid-to-solid ratio 41.8 (mL g-1 ). The results showed that the pectin was low methoxyl type with a galacturonic acid content of 670 g kg-1 . The extracted pectin had a high molecular weight (341 kDa) and surface charge (34.09 ± 1.88 mV) and exhibited 66% DPPH radical scavenging. The obtained results from 1 H-nuclear magnetic resonance and Fourier transform infrared spectra validated the presence of pectin structure in the extracted sample. CONCLUSION: Sesame capsule pectin, when compared to commercial pectin, demonstrated better functional properties in terms of emulsifying properties, oil holding capacity, foaming capacity and antioxidant activity. SCP showed similar properties in comparison to its commercial counterpart, which suggests that it could well be considered as a new and suitable source for pectin extraction. © 2022 Society of Chemical Industry.

A review on I-III-VI ternary quantum dots for fluorescence detection of heavy metals ions in water: optical properties, synthesis and application.

Heavy metal contamination remains a major threat to the environment. Evaluating the concentrations of heavy metals in water environments is a crucial step towards a viable treatment strategy. Non-cadmium photo-luminescent I-III-VI ternary QDs have attracted increasing attention due to their low toxicity and extraordinary optical properties, which have made them popular in biological applications. Recently, ternary I-III-VI-QDs have gained growing interest as fluorescent detectors of heavy metal ions in water. Here, we review the research progress of ternary I-III-VI QDs for the fluorescence detection of heavy metal ions in water. First, we summarize the optical properties and synthesis methodologies of ternary I-III-VI QDs. Then, we present various detection mechanisms involved in the fluorescence detection of heavy metal ions, which are mostly attributed to direct interaction between these unique QDs and the metal ions, seen in the form of fluorescence quenching and fluorescence enhancement. We also display the potential applications in environmental remediation such as water treatment and associated challenges of I-III-VI QDs in the fluorescence detection of Cu2+ and other metal ions.

Almond hulls waste valorization towards sustainable agricultural development: Production of pectin, phenolics, pullulan, and single cell protein.

This research aimed to valorize almond hulls based on a zero-waste strategy towards sustainable agricultural developments for the recovery and production of valuable compounds. For this purpose, the potential to produce four products, including pectin (AHP), phenolic compounds (AHPC), pullulan (PUL), and single-cell protein (SCP), was examined. The acidic extraction factors were optimized using a Box-Behnken design for the simultaneous extraction of AHP and AHPC, and the obtained results showed that the maximum AHP (26.32% w/w) and AHPC (6.97% w/w) yields were achieved at 90 °C, pH of 1.4, 58.65 min, and liquid-solid ratio (LSR) of 20.13 v/w as the optimum point. In the next step, the solid residues that remained from the AHP and AHPC extraction process (PESR) were treated with cellulase enzyme and ultrasound and were used for simultaneous microbial production of PUL (34.29-24.56 g/L) and biomass containing SCP (19.31-13.44% w/w). Furthermore, the obtained results showed that AHP was low methylated (26.40%), rich in galacturonic acid (67.88%), and high in molecular weight (595.299 kDa). Also, the investigations of structural properties of AHP and PUL confirmed the presence of chemical structures of these polysaccharides in the formed supernatants. In addition, the AHPC showed considerable antioxidant activity compared with ascorbic acid (ASC) and BHA.

Effect of mung bean protein isolate/pullulan films containing marjoram (Origanum majorana L.) essential oil on chemical and microbial properties of minced beef meat.

In this study, the effect of marjoram essential oil (MEO) on the mechanical, barrier, antioxidant and antimicrobial properties of mung bean protein isolate (MPI)/pullulan (PU) composite films and its influence on the quality of minced beef meat during 14 days storage at 4 °C was studied. The Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM) results confirmed the compatibility between components. Also, depend on the different ratios of combination of MEO and MPI/PU, tensile strength (TS) and elongation at break (EAB) were varied. The results showed that an increase in the level of the MPI led to a significant increment in TS and water-proof properties of the composite films. Also, with addition of MEO, the EAB of the antimicrobial blend-films was decreased, while TS and water-proof properties were increased. In addition, enrichment of the films with MEO led to a considerable positive effect on DPPH radical scavenging and antibacterial activity against pathogenic bacteria (Staphylococcus aureus and Escherichia coli). Based on the bacterial and chemical analyses of the minced meat samples, MEO-incorporation in MPI/PU films enhanced oxidative stability of minced beef samples, and also showed effective antimicrobial activity against all of the tested bacteria.

Continuous Clarification of Barberry Juice with Pectinase Immobilised by Oxidized Polysaccharides.

RESEARCH BACKGROUND: Barberry juice is a rich source of bioactive compounds and shows different health properties such as antioxidant and anticancer activities. Clarification, as the removal process of suspended material, is an important step in the production of fruit juice due to its significant effect on the appearance, flavour and commercialisation of juice. Pectinase is the most important enzyme applied in juice clarification that breaks down the pectin polymer structure and reduces the undesirable turbidity. Pectinase immobilisation is a way to overcome free enzyme drawbacks such as instability, high cost, the difficulty of recovery and recyclability. Also, continuous clarification process which is highly preferred in fruit juice industry is not possible without enzyme immobilisation. EXPERIMENTAL APPROACH: Pectinase enzymes were immobilised on the functionalised glass beads (glass bead with (3-aminopropyl)triethoxysilane) by glutaraldehyde, polyaldehyde derivatives of pullulan and kefiran and the barberry juice was clarified in the batch and continuous processes in a packed bed reactor (PBR). Also, the effect of clarification on the physicochemical and antioxidant properties of the barberry juice samples was evaluated. RESULTS AND CONCLUSIONS: The optimum conditions for clarification in the PBR were: flow rate 0.5 mL/min, temperature 50 °C and treatment time 63 min. Clarification led to a decrease in turbidity, pH, total soluble solid content, viscosity, total phenolic content and antioxidant activity of the juice samples. Also, this process increased the clarity, acidity, reducing sugar concentration and the lightness parameter of the barberry juice. The greatest effect of clarification on the studied properties of barberry juice was related to the pectinase immobilised by the polyaldehyde of kefiran in the continuous process and both new cross-linkers (polyaldehyde derivatives of pullulan and kefiran) immobilised the enzyme better than the common cross-linker (glutaraldehyde). NOVELTY AND SCIENTIFIC CONTRIBUTION: For the first time, barberry juice was clarified with pectinase immobilised by polyaldehyde derivatives of pullulan and kefiran and the obtained results showed that the pectinase immobilisation by these new cross-linkers was much more efficient than by the glutaraldehyde as a common cross-linker. These findings can be of use for an industrialised production of fruit juices.

High-quality pectin from cantaloupe waste: eco-friendly extraction process, optimization, characterization and bioactivity measurements.

BACKGROUND: The rind from cantaloupe is an agricultural waste of cantaloupe industrial processing. The current study tried to (i) evaluate the potential use of cantaloupe rind as a pectin source, (ii) optimize the factors of microwave-assisted extraction process using Box-Behnken design, and (iii) characterize the isolated pectin using various physicochemical, structural, functional and bioactivity properties. RESULTS: Four variables of the extraction process were successfully optimized at a microwave power of 700 W, irradiation time of 112 s, pH value of 1.50 and liquid to solid (LS) value of 30 mL g-1 , with a yield of 181.4 g kg-1 . The analysis indicated a high-methylated galacturonic acid-rich (703.4 g kg-1 ) sample with an average molecular weight of 390.475 kDa. Also, the isolated pectin showed considerable functionality and antioxidant ability. The main functional groups, structural characteristics and crystallinity of samples were comparatively studied using Fourier transform infrared, nuclear magnetic resonance and X-ray diffraction spectroscopies. CONCLUSION: In comparison to commercial citrus pectin, isolated pectin showed a significantly higher value for most of the functional analysis such as oil holding capacity, emulsifying capacity, emulsion stability, DPPH• and ABTS•+ scavenging activity, and reducing power assay. In other analyses the isolated sample was close to the commercial one, indicating that cantaloupe rinds should be considered as a suitable additional resource for pectin production. © 2021 Society of Chemical Industry.

Combined effects of octenylsuccination and beeswax on pullulan films: Water-resistant and mechanical properties.

In this study, to improve the water resistance properties of pullulan (PU) edible-films, the combination of the modification with octenyl succinic anhydride (OSA) and beeswax (BW) incorporation was used. The FTIR spectra results confirmed the PU octenylsuccination and also the presence of the BW in the composite films. The scanning electron microscopy (SEM) micrographs showed that the PU modification with OSA powerfully retarded the coalescence of BW droplets in film casting process and led to their homogeneity in the dried films. Also, the findings indicated that the water-proof properties including water solubility, water vapor permeability and water contact angle in the PU films were improved by the PU modification and BW incorporation. In addition, the obtained data showed that the octenylsuccination of PU had a negative effect on the mechanical properties of the produced films, while BW incorporation into PU-OSA films led to resolve this drawback.

Octenyl succinylation of kefiran: Preparation, characterization and functional properties.

In this study, kefiran was esterified with octenyl succinic anhydride (OSA). The esterification reaction variables including pH (8.5), kefiran concentration (5% (w/w)), OSA concentration (12% (w/w)), temperature (~38 °C) and reaction time (~80 min) were found as optimum points to achieve the maximum degree of substitution (DS) (0.041 ± 0.002). Kefiran-OSA samples with DS of 0.021 (FDA suggested DS) and 0.041 (maximum DS) were prepared and compared with unmodified kefiran in all experiments. FTIR and 1H NMR spectroscopies proved the grafting of OSA on kefiran structure. XRD analysis revealed that with increase in DS, the physical state of kefiran to be more amorphous. In addition, the esterification modification led to a decrease in the degradation temperature and an increase in the apparent viscosity based on the obtained data from thermal analysis and viscosity measurement. The results of the foaming and emulsifying properties confirmed the improvement in surface properties of the modified kefiran. The frequency sweep test illustrated that with an increase in DS, the viscoelastic behavior of the kefiran cryogels to be more viscous. It can finally be stated that the modification with OSA was a high potential strategy to extend the industrial applications of the kefiran.

Chemical modification of pullulan exopolysaccharide by octenyl succinic anhydride: Optimization, physicochemical, structural and functional properties.

Pullulan (PU) is an exo-polysaccharide used in the food and pharmaceutical industries. However, the use of PU in different industries is limited due to its highly hydrophilic nature and consequently weakness in surface properties which can be remedied by its chemical modification with octenyl succinic anhydride (OSA). For this purpose, PU modification with OSA was optimized and the results showed that the maximum degree of substitution (0.061 ± 0.003) was obtained under pH of 9.0, pullulan concentration of 40% (w/w), temperature of ~40.90 °C, reaction time of ~101.21 min and OSA concentration of 14.96% (w/w). Also, the grafting of OSA on pullulan structure was confirmed by FTIR, 1H NMR and zeta-potential analyzes. Although this modification had no significant effect on the amorphousity of pullulan, it led to an increase in viscosity and a decrease in decomposition temperature and surface tension. Improvement of emulsifying properties of PU-OSA sample was proved by the evaluation of emulsifying capacity of un- and modified samples and also, zeta-potential, particle size and viscosity of the prepared emulsions. In line with surface characteristic results, an increase in foam capacity of modified samples was observed with decreasing the interfacial tension.

Optimization and characterization of pullulan produced by a newly identified strain of Aureobasidium pullulans.

In this study, a new strain suspected to be Aureobasidium pullulans was isolated from trees leaves. The molecular characterization and the resulting phylogenetic tree showed that the isolated strain was A. pullulans. Also, the results of methylation analysis, monosaccharide composition, FTIR, NMR and XRD confirmed that the obtained exo-polysaccharide from the mentioned strain was pullulan. The pullulan production optimization by central composite design (CCD) indicated that the maximum yield obtained under optimum conditions (pH of 6.5, sucrose concentration of 5.5% (w/v) and yeast extract concentration of 0.1% (w/v)) was 51.4 ± 0.50 g/L. The produced pullulan had an average molecular weight (Mw) of 2.07 × 105 g.mol-1 based on gel permeation chromatography results. The decomposition temperature (Td) of the produced pullulan was ~300 °C and also, the resulting pullulan had a Newtonian flow behavior in a wide range of concentrations.

High-methylated pectin from walnut processing wastes as a potential resource: Ultrasound assisted extraction and physicochemical, structural and functional analysis.

The ultrasound-assisted extraction of pectin from walnut processing waste was optimized by Box-Behnken design. The highest extraction yield (12.78 ± 0.83%) was obtained at ultrasound power of 200 W, sonication time of 10 min, pH of 1.5 and LS ratio of 15 v/w. The resulting pectin in these conditions was rich in galacturonic acid (69.44%) and was high in degree of esterification (59.21%) which was confirmed by NMR and FTIR spectra. In addition, the molecular weight distribution analysis showed that the obtained pectin had a heterogeneous natural with low molecular weight (6.30-158.48 kDa). The XRD spectrum of the walnut pectin showed an amorphous structure with few crystalline portions. Furthermore, walnut green husk pectin had good emulsifying properties, water and oil holding capacities, and radical-scavenging activity. Given that the obtained result, the extraction of pectin from this by-product in addition to being able to reduce environmental problems, it can also provide financial benefits for the walnut production sector.

Immobilization of pectinase on the glass bead using polyaldehyde kefiran as a new safe cross-linker and its effect on the activity and kinetic parameters.

For the first time, polyaldehyde kefiran was applied to immobilize the pectinase on the glass bead and the finding was compared with free enzyme. Polyaldehyde kefiran, produced by periodate oxidation of kefiran, showed an aldehyde content of 23.6 ±â€¯0.9% that was confirmed by FTIR. The results showed although the optimum temperature (50 °C) was not changed by immobilization, the optimum pH was shifted from 5.0 to 5.5. In optimal conditions, the specific activity of the free and immobilized pectinase was 2.93 ±â€¯0.13 and 1.87 ±â€¯0.24 unit/mg, respectively. Also, the immobilized pectinase had a higher thermal and pH stability than free enzyme. Km and Vmax of the immobilized pectinase were higher and lower than the free enzyme, respectively. In addition, SEM and AFM images illustrated a completely non-uniform surface after enzyme immobilization on the glass bead, which seemed to be related to the polyaldehyde kefiran strands.

An integrated valorization of industrial waste of eggplant: Simultaneous recovery of pectin, phenolics and sequential production of pullulan.

Based on a bio-refinery concept, the valorization of eggplant peel wastes (EPW) in the production of multiple value-added products was aimed. The acid-free extraction process was applied in the simultaneous recovery of pectin and phenolic compounds. The extraction variables were optimized by response surface methodology using a Box-Behnken design and the maximum yield of pectin (26.1%) and phenolic compounds (20.2%) was obtained in the extraction temperature of 90 °C, time of 90 min and liquid/solid ratio of 40 mL/g. After recovery of pectin and phenolic compounds from EPW, the solid leftovers were enzymatic hydrolyzed and the hydrolysates were used as a carbon source in the microbial production of pullulan by Aureobasidium pullulans. The produced pectin and pullulan were characterized through the chemical and structural features. The results of FT-IR and H-NMR analysis approved the predominant presence of these two polysaccharides in the isolated samples. On the other hand, the antioxidant activity of the recovered phenolic compounds extract was evaluated by DPPH and ABTS radical scavenging activity and reducing power assay.

Production optimization, characterization and gene expression of pullulan from a new strain of Aureobasidium pullulans.

In this study, a new yeast-like fungal was obtained from leaf surfaces collected from Kheyroodkenar forest, Mazandaran, Iran. The properties of this strain, such as morphology, DNA molecular, and product showed that it is related to Aureobasidium pullulans family and named A. pullulans MG271838. The pullulan production conditions by this strain were optimized using a Box-Behnken design. The results showed that the optimum production yield (37.55 ±â€¯0.45 g/l) was obtained in pH of 6.76, sucrose concentration of 6%w/v and yeast extract concentration of 0.2%w/v. The pullulan had a concentration-dependent flow behavior, amorphous structure based on XRD pattern and high thermal stability (decomposition temperature of 300 °C). Also, the chemical structure of pullulan was confirmed by FTIR spectroscopy. In addition, there was a direct relationship between pullulan yield and the gene expression of fks, pgm and ugp as the most important genes in pullulan production.

Utilization of food processing wastes of eggplant as a high potential pectin source and characterization of extracted pectin.

In the present study, the various properties of pectin extracted using microwave-assisted extraction (MAE) from eggplant peel and eggplant calyx (as food processing wastes of eggplant) were compared with each other. The eggplant peel pectin (EPP) exhibited higher extraction yield (29.17%) than eggplant calyx pectin (ECP; 18.36%). Both of EPP and ECP were high in methoxyl and rich in galacturonic acid. HPLC analysis showed that EPP was high in HG (homogalacturonan) (58.6%), while ECP was high in RG-I (rhamnogalacturonan-I) (44.9%). Also, higher phenolic contents were observed for EPP in comparing with ECP. Approximately in all of the functionalities (WHC (water holding capacity) and OHC (oil holding capacity), emulsifying and foaming properties, and antioxidant activity), EPP showed higher value rather than ECP. 1H NMR (hydrogen-1 nuclear magnetic resonance), FT-IR (Fourier transform-infrared) and XRD (x-ray diffraction) spectra confirmed the presence of high methylated crystalline pectin in both EPP and ECP.

Optimization and characterization of pectin extracted from sour orange peel by ultrasound assisted method.

In this work, a Box-Behnken design (BBD) with three variables (ultrasound power, irradiation time and pH) in three levels was applied for pectin extraction optimization. The optimization process showed that the maximum extraction yield was 28.07 ±â€¯0.67% in ultrasound power of 150 W, irradiation time of 10 min and pH of 1.5 (as optimum conditions). In these conditions, ash, moisture and protein contents of SOPP were 1.89 ±â€¯0.51, 8.81 ±â€¯0.68 and 1.45 ±â€¯0.23%, respectively. HPLC analysis indicated that 65.3% of the extracted pectin was galacturonic acid and approximately 72% of total neutral sugars was galactose. The optimized pectin had a total phenolic content of 39.95 ±â€¯3.13 mg gallic acid equivalents/g pectin, the surface tension of 46.56 ±â€¯0.23 and 42.14 ±â€¯0.61 mN/m in concentrations of 0.1 and 0.5%w/v, water holding capacity and oil holding capacity of 3.10 ±â€¯0.12 and 1.32 ±â€¯0.21 g water or oil/g pectin with a suitable emulsifying and antioxidant properties. In addition, SOPP with degree of esterification of 6.77 ±â€¯0.43% was classified as low methoxyl pectin, which confirmed by FTIR and 1H NMR analysis.

Pectin extraction from citron peel: optimization by Box-Behnken response surface design.

In this study, the effect of acidic extraction conditions (time of 30-90 min, temperature of 75-95 °C and pH of 1.5-3) on the yield and degree of esterification (DE) of citron peel pectin was investigated applying Box-Behnken design. The highest production yield of pectin (28.31 ± 0.11%) was achieved at extraction time of 90 min, temperature of 95 °C and pH of 1.5, as optimal extraction conditions, which was close to the predicted value (29.87%). Under optimum extraction conditions, the DE and the emulsifying activity were 51.33 and 46.2%, respectively. In addition, the emulsions were 93.9 and 93.5 stable at 4 °C, 93.7 and 93.1 at 23 °C after 1 and 30 days, respectively. The determination of flow behavior showed that the pectin solutions had a Newtonian behavior at low concentrations (< 1.0% w/v), while this behavior was changed to pseudoplastic with increasing concentration.

Significance, evolution and recent advances in adsorption technology, materials and processes for desalination, water softening and salt removal.

Desalination and softening of sea, brackish, and ground water are becoming increasingly important solutions to overcome water shortage challenges. Various technologies have been developed for salt removal from water resources including multi-stage flash, multi-effect distillation, ion exchange, reverse osmosis, nanofiltration, electrodialysis, as well as adsorption. Recently, removal of solutes by adsorption onto selective adsorbents has shown promising perspectives. Different types of adsorbents such as zeolites, carbon nanotubes (CNTs), activated carbons, graphenes, magnetic adsorbents, and low-cost adsorbents (natural materials, industrial by-products and wastes, bio-sorbents, and biopolymer) have been synthesized and examined for salt removal from aqueous solutions. It is obvious from literature that the existing adsorbents have good potentials for desalination and water softening. Besides, nano-adsorbents have desirable surface area and adsorption capacity, though are not found at economically viable prices and still have challenges in recovery and reuse. On the other hand, natural and modified adsorbents seem to be efficient alternatives for this application compared to other types of adsorbents due to their availability and low cost. Some novel adsorbents are also emerging. Generally, there are a few issues such as low selectivity and adsorption capacity, process efficiency, complexity in preparation or synthesis, and problems associated to recovery and reuse that require considerable improvements in research and process development. Moreover, large-scale applications of sorbents and their practical utility need to be evaluated for possible commercialization and scale up.