Starch is a versatile and a widely used ingredient, with applications in many industries including adhesive and binding, paper making, corrugating, construction, paints and coatings, chemical, ...pharmaceutical, textiles, oilfield, food and feed. However, native starches present limited applications, which impairs their industrial use. Consequently, starch is commonly modified to achieve desired properties. Chemical treatments are the most exploited to bring new functionalities to starch. However, those treatments can be harmful to the environment and can also bring risks to the human health, limiting their applications. In this scenario, there is a search for techniques that are both environmentally friendly and efficient, bringing new desired functionalities to starches. Therefore, this review presents an up-to-date overview of the available literature data regarding the use of environmentally friendly treatments for starch modification. Among them, we highlighted an innovative chemical treatment (ozone) and different physical treatments, as the modern pulsed electric field (PEF), the emerging ultrasound (US) technology, and two other treatments based on heating (dry heating treatment - DHT, and heat moisture treatment - HMT). It was observed that these environmentally friendly technologies have potential to be used for starch modification, since they create materials with desirable functionalities with the advantage of being categorized as clean label ingredients.
Poly(ethylene 2,5‐furandicarboxylate) (PEF) is an emergent biobased polyester whose chemical structure is analogous to poly(ethylene terephthalate). Pilot‐scale PEF is synthesized through the direct ...esterification process from 2,5‐furandicarboxylic acid and bio‐ethylene glycol. Wide‐angle X‐ray diffraction (WAXD) measurements reveal similar crystallinities and unit cell structures for melt‐crystallized and glass‐crystallized samples. The non‐isothermal crystallization of PEF sample is investigated by means of DSC experiments both from the glass and the melt. The temperature dependence of the effective activation energy of the growth rate is obtained from these data, and the results show that the glass and early stage of the melt crystallization share common dynamics. Hoffman–Lauritzen parameters and the temperature at maximum crystallization rate are evaluated. It is found that the melt‐crystallization kinetics undergo a transition from regime I to II; however, the crystal growth rate from the melt shows an atypical depression at T < 171 °C compared with the predicted Hoffman–Lauritzen theory.
Non‐isothermal crystallization kinetics of a new prospective biobased polymer, poly(ethylene 2,5‐furandicarboxylate) (PEF), whose chemical structure is analogous to poly(ethylene terephthalate) (PET), is undertaken for both melt and glass crystallization by combining isoconversional analysis, the Hoffman–Lauritzen theory, and the Ozawa analysis. Change in the crystallization regimes is highlighted. The temperature at maximum crystallization rate is estimated using measurements and simulations.
The segmental and local dynamics of the bio‐based polyester poly(ethylene‐2,5‐furanoate) (PEF) are investigated by dielectric spectroscopy (DS) at atmospheric pressure as a function of temperature ...and frequency for samples prepared with different degrees of crystallinity. Crystallization significantly alters the segmental process as this is manifested in the dielectric strength and the distribution of relaxation times. Enhanced crystallinity by the different annealing protocols increases the glass temperature of the mobile amorphous fraction. A two‐phase model is adequate in describing the dynamics associated with the β‐process within the glassy state. However, the same model fails in describing the segmental dynamics at and above the glass temperature. The combined differential scanning calorimetry and DS results provide evidence that for samples with a degree of crystallinity of ≈40%, approximately a third of segments are located within the restricted amorphous fraction.
Poly(ethylene furanoate) (PEF) is a fully bio‐based polyester and an alternative to poly(ethylene terephthlate) (PET) with improved barrier properties. The dynamics of PEF pertinent to penetrant diffusion are investigated as a function of the degree of crystallinity by combining differential scanning calorimetry with dielectric spectroscopy. They provide clear evidence that a third of segments are located within the restricted amorphous fraction.
In this work, a TiO2-decorated electrode was fabricated by dip coating activated carbon fibers (ACF) with TiO2, which were then used as a cathode for the photoelectro-Fenton (PEF) treatment of the ...pharmaceutical enalapril, an angiotensin-converting enzyme inhibitor that has been detected in several waterways. The TiO2 coating was found to principally improve the electrocatalytic properties of ACF for H2O2 production via the 2-e- O2 reduction, in turn increasing enalapril degradation by PEF. The effect of the current density on the mineralization of enalapril was evaluated and the highest TOC removal yield (80.5% in 3 h) was obtained at 8.33 mA cm−2, in the presence of 0.5 mmol L−1 of Fe2+ catalyst. Under those conditions, enalapril was totally removed within the first 10 min of treatment with a rate constant k = 0.472 min−1. In contrast, uncoated ACF only achieved 60% of TOC removal in 3 h at 8.33 mA cm−2. A degradation pathway for enalapril mineralization is proposed, based on the degradation by-products identified during treatment. Overall, the results demonstrate the promises of TiO2 cathodes for PEF, a strategy that has often been overlooked in favor of photoelectrocatalysis (PEC) based on TiO2-modified photoanodes.
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•TiO2 coating improved H2O2 cathodic generation on activated carbon fibers (ACF).•TOC removal reached 80.5% after 3 h of photoelectro-Fenton treatment.•Enalapril was totally removed within 10 min with a rate constant k = 0.472 min−1.•Electrocatalysis was the dominant mechanism, followed by photolysis.•First report of enalapril treatment and of its electrochemical degradation pathway.
Calcium is an element that performs many important functions in the human body. A study was conducted on the use of a pulsed electric field (PEF) to enrich cells of Lactobacillus rhamnosus B 442 in ...calcium ions. The highest concentration of calcium ions in bacterial cells (7.30 mg/g d.m.) was obtained at ion concentration of 200 μg/ml of medium and with the use of the following PEF parameters: field strength 3.0 kV/cm, exposure time 10 min, pulse width 75 ms and 20 h of culturing after which bacteria were treated with the field. Cell biomass varied in the range from 0.09 g/g d.m. to 0.252 g/g d.m., and the total number of bacteria ranged from 10 10 CFU/ml to 10 12 CFU/ml. Microscope photographs prove that calcium ions were situated within the cells of the bacteria, and electroporation contributed to an increase in the effectiveness of the ion bioaccumulation process. Samples containing calcium and subjected to electroporation displayed intensive fluorescence. The significance of this research was the possibility of using probiotic bacteria enriched with calcium ions for the production of functional food in subsequent studies.
•The PEF/TiO2 NWs composites were successfully prepared via in-situ polymerization.•The introduction of TiO2 nanowires improved the impact strength of PEF obviously.•The UV and blue light shielding ...of PEF increase with the addition of TiO2 nanowires.•The nanocomposite could kill 98 % of E.coli mostly by exposing to UV light for 30 min.•Furthermore, the elongation at break of nanocomposite reaches 47.69 % at PSR of 2.
As a candidate of fossil-based poly(ethylene terephthalate) (PET), bio-based poly(ethylene 2,5-furandicarboxylate) (PEF) that could be converted from renewable resources has attracted attention from academia and industry. Here, we prepare a series of new type of PEF/TiO2 NWs composites from 2,5-furandicarboxylic acid (FDCA), ethylene glycol (EG), titanium dioxide nanowire (TiO2 NWs, diameter∼100 nm, length∼20 µm) and dipentaerythritol (Di-PE) via in-situ polymerization. The TiO2 nanowires (0.5∼10 wt‰ based on PEF) and Di-PE (3 mol‰ based on FDCA) were added as fillers and extenders. TiO2 nanowires were distributed in the PEF uniformly, shown by SEM. Compared with pure PEF, the Tg and thermal stability of all nanocomposites got improved. And the impact strength of nanocomposites could reach 60 kJ/m2 in contrast to brittle pure PEF. The UV-A and blue-light shielding of nanocomposites increased from 53 % to 98 % and 28 % to 86 %, respectively, and the nanocomposites still maintained good gas barrier properties. Moreover, the antibacterial activity of nanocomposites against E. coli had increased to 98 %, better than that of the PEF/Ag NWs composites. By uniaxial pre-stretching, the tensile modulus and the elongation at break were improved obviously, from 1840 MPa to 5466 MPa and 4 % to 54 % respectively with pre-stretching ratio increasing. Compared to the PET/TiO2 NWs composites, the PEF/TiO2 NWs composites shows batter thermal property and mechanical property. The PEF/TiO2 NWs composites exhibit potential foreground in the packaging application.
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Poly (ethylene 2,5-furandicarboxylate) (PEF) has attracted more attention due to its excellent properties and great potential to be the substitute of the petroleum-based polyethylene ...terephthalate (PET). However, the improvement of toughness and functionality from nano materials were limited. Here, we prepared novel PEF/TiO2 nanocomposites from dimethyl 2,5-furandicarboxylate (DMFD), ethylene glycol (EG), pyromellitic dianhydride (PMDA) and TiO2 nanoparticles via one-pot polycondensation. The optimized PMDA (5‰ mol/mol of DMFD), TiO2 (60 nm, 0.5-10‰ wt./wt. of PEF) or TiO2 (30 nm or 100 nm, 3‰) served as extender, fillers, and comparison, respectively. The Tgs (∼88 °C) and the thermal stability of all nanocomposites were higher than pure PEF. The crystallization rate of the nanocomposites (60 nm-TiO2, 3‰) was improved mostly, and its half-crystallization time (t1/2) decreased to 6.16 min at 160 °C. The impact strength of nanocomposites (60 nm-TiO2, 10‰) could reach to 52.2 × 103 J/m2. Interestingly, the ultraviolet and blue-light shielding of PEF/TiO2 nanocomposites increased from 45.4% to 93.5% and 21.5% to 74.3%, respectively. The antibacterial activity of nanocomposites against E. coli also increased to 83%. The maximum migration of Ti during 35 d was 1.82 µg/g (FDA and EU guidance level are 10 µg/g). PEF/TiO2 nanocomposites shown great potential in industrial production and application.
Piper retrofractum Vahl. have the potential to be developed into standardized medicinal ingredients. However, the extraction process of the active compounds in Piper retrofractum Vahl. needs further ...exploration to get the right method. This is necessary because previous studies state that conventional extraction requires a long time, while modern extraction technology has the disadvantage of being difficult to apply in society. Therefore the aim of this study was to obtain the PEF pre-treatment conditions in the extraction process which affected the quality of the Piper retrofractum Vahl. extract obtained. The stages in this study included the pre-treatment of Piper retrofractum Vahl. with PEF at a voltage (T1 = 5000, T2 = 5000, and T3=6000 volt) and an exposure time (W1=240 and W2=480 seconds), and was macerated using 96% ethanol solvent. The results of Piper retrofractum Vahl. extract with PEF pre-treatment produced a thick extract, dark brown color, characteristic odor, and spicy taste with a yield of 10.64±1.67%, water content 6.30±0.18%, total ash content 0.14±0.03%, acid insoluble ash content 0.25±0.01%, essential oil content 3.00±0.00% and piperine content of 40.38±2.44%.
Effects of pulsed electric fields (PEF: 1–2 kV/cm, 20 μs) used alone and combined with carbon dioxide (CO2: 70%) and high hydrostatic pressure (HP: 150 MPa, 5 min) on the physicochemical properties ...and microbiological shelf life of coho salmon under pre- and post-rigor conditions were studied during refrigerated storage (25 days). The PEF + CO2 + HP treatments reduced color changes in pre-rigor more than in post-rigor salmon. Texture changes of pre- and post-rigor salmon differed between untreated and treated salmon. Combined treatments also effectively reduced the protease and lipase activity of pre-rigor salmon. Collagenase activity of post-rigor salmon remained low in all treatments. Principal component analysis showed a clear difference between pre- and post-rigor states in the evaluated parameters; however, microbiological shelf life increased with PEF + CO2 regardless of the rigor condition. In conclusion, combined PEF, CO2, and HP treatments can improve salmon quality during refrigerated storage and thus extend its microbial shelf life.
The current demand for processed seafood that is similar to fresh products has created a new area of development in non-thermal processing technologies. Refrigeration and freezing have been applied for many years to extend the shelf life of seafood products, but there is deterioration regardless of the preservation method. Therefore, the combination of non-thermal processing technologies (PEF + CO2 + HP) could be applied to a large variety of seafood industries. Seafood products could be treated by PEF combined with CO2 and HP to further evaluate quality attributes under different rigor conditions during chilled storage and estimate the shelf life of the processed product.
•PEF + CO2 + HP changed pre/post-rigor color and texture during refrigerated storage.•PEF + CO2 + HP treatments reduced pre/post-rigor pH and enzyme activity in storage.•PCA showed an influence of the rigor condition on salmon parameter changes.•Sample microbiological shelf life improved when applying PEF + CO2 and not HP.
Emerging extraction techniques, including pulsed electric field (PEF) and ultrasound (US), are attracting considerable interest in the recovery of bioactives. Though, limited work has focused on PEF ...application as pre-treatment for US assisted extraction to enhance the release of phenolics from herbs. Hence, the present study investigated the use of an optimized PEF pre-treatment to enhance the recovery of phenolics from fresh rosemary and thyme by-products in a subsequent US assisted extraction step. Total phenolic content (TPC), 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and ferric reducing antioxidant power (FRAP) were assessed as an index of extraction efficacy. Qualitative and quantitative analyses were performed through liquid chromatography-mass spectrometry analyses to evaluate the influence of the methods on individual phenolic compounds and the formation of potential derivatives. The results indicated that in a number of cases PEF pre-treatment enhanced (p < 0.05) the recovery of phenolic compounds and antioxidant capacity compared to US individually.
•Pulsed electric field pre-treatment enhanced phenolic and antioxidant recovery in rosemary and thyme by-products compared to ultrasound.•Fresh inhomogeneous plant material that mimics non-idealistic laboratory conditions were utilized.•A higher recovery of phenolic compounds was indicated even with the use of low energy inputs.
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