Impact of Oil Addition on Physicochemical Properties and In Vitro Digestibility of Extruded Pineapple Stem Starch.

The effects of palm oil (PO) and coconut oil (CO) additions on the physicochemical properties and in vitro starch digestibility of extruded pineapple stem starch (PSS) were studied. The native PSS was adjusted to 15% moisture and blended with PO or CO in amounts of 5 and 10% (w/w of starch), while the control sample without added oil was adjusted to 25% moisture before being extruded with a twin-screw extruder at a maximum barrel temperature of 140 °C. Due to the lubricating effect, the added oils reduced the expansion ratio of the extrudates, which led to an increase in cell wall thickness, bulk density, hardness, and water adsorption index, but to a reduction in the water solubility index, especially with 10% oils. PO had a greater impact on the physicochemical changes in the extrudates than CO. Surprisingly, no amylose-lipid complex was observed in the extrudates with added oil, as shown by XRD, DSC, and FTIR results. The phenolic compounds contained in PSS remained in all extrudates, which could affect the formation of the amylose-lipid complex during extrusion. The addition of 5% oil had no effect on the digestibility of the starch compared to the control extrudates, while the 10% oils, both PO and CO, reduced the rapidly digestible starch content but significantly increased the resistant starch content of the extruded PSS.

Eggshell-Derived Copper Calcium Hydroxy Double Salts and Their Activity for Treatment of Highly Polluted Wastewater.

By using methyl orange (MO) removal as a model reaction, the best temperatures for processing eggshells are 750 °C and above to obtain biobased CaO materials, a raw material for producing CuCa hydroxy double salt (HDS) materials with high efficiency in treatments of highly polluted wastewater (the initial concentration of MO is 500 ppm). Characterization techniques employed in this study include power X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, nitrogen adsorption-desorption analysis, and the colorimetric method, as well as energy-dispersive X-ray, infrared-, and electron spin resonance spectroscopies. Complete MO removal and high chemical oxygen demand (COD) efficiencies (>90%) can be achieved after 3 min treatments of the aqueous MO with the calcined eggshell-derived CuCa HDS materials. The spent, deactivated HDS materials can be regenerated by an acid wash method. The activity of CuCa HDS materials in MO removal is unaffected by eggshell sources, implying that sorting steps may be unnecessary when eggshell food waste (duck, quail, and hen eggshells) is collected to produce biobased CaO. The findings of this study demonstrated that eggshells can be used in place of limestone and could be a more sustainable, renewable, and cost-effective source for material development and other applications.

Alternating current properties of bulk- and nanosheet-graphitic carbon nitride compacts at elevated temperatures.

The investigations of temperature-dependent electrical properties in graphitic carbon nitride (g-C3N4) have been largely performed at/below room temperature on devices commonly fabricated by vacuum techniques, leaving the gap to further explore its behaviors at high-temperature. We reported herein the temperature dependence (400 → 35 °C) of alternating current (AC) electrical properties in bulk- and nanosheet-g-C3N4 compacts simply prepared by pelletizing the powder. The bulk sample was synthesized via the direct heating of urea, and the subsequent HNO3-assisted thermal exfoliation yielded the nanosheet counterpart. Their thermal stability was confirmed by variable-temperature X-ray diffraction, demonstrating reversible interlayer expansion/contraction upon heating/cooling with the thermal expansion coefficient of 2.2 × 10-5-3.1 × 10-5 K-1. It is found that bulk- and nanosheet-g-C3N4 were highly insulating (resistivity ρ ∼ 108 Ω cm unchanged with temperature), resembling layered van der Waals materials such as graphite fluoride but unlike electronically insulating oxides. Likewise, the dielectric permittivity ε', loss tangent tan δ, refractive index n, dielectric heating coefficient J, and attenuation coefficient α, were weakly temperature- and frequency-dependent (103-105 Hz). The experimentally determined ε' of bulk-g-C3N4 was reasonably close to the in-plane static dielectric permittivity (8 vs. 5.1) deduced from first-principles calculation, consistent with the anisotropic structure. The nanosheet-g-C3N4 exhibited a higher ε' ∼ 15 while keeping similar tan δ (∼0.09) compared to the bulk counterpart, demonstrating its potential as a highly insulating, stable dielectrics at elevated temperatures.

Development of Biodegradable Rigid Foams from Pineapple Field Waste.

Pineapple materials sourced from agricultural waste have been employed to process novel bio-degradable rigid composite foams. The matrix for the foam consisted of starch extracted from pineapple stem, known for its high amylose content, while the filler comprised non-fibrous cellulosic materials sourced from pineapple leaf. In contrast to traditional methods that involve preparing a batter, this study adopted a unique approach where the starch gel containing glycerol were first formed using a household microwave oven, followed by blending the filler into the gel using a two-roll mill. The resulting mixture was then foamed at 160 °C using a compression molding machine. The foams displayed densities ranging from 0.43-0.51 g/cm3 and exhibited a highly amorphous structure. Notably, the foams demonstrated an equilibrium moisture content of approximately 8-10% and the ability to absorb 150-200% of their own weight without disintegration. Flexural strengths ranged from 1.5-4.5 MPa, varying with the filler and glycerol contents. Biodegradability tests using a soil burial method revealed complete disintegration of the foam into particles measuring 1 mm or smaller within 15 days. Moreover, to showcase practical applications, an environmentally friendly single-use foam tray was fabricated. This novel method, involving gel formation followed by filler blending, sets it apart from previous works. The findings highlight the potential of pineapple waste materials for producing sustainable bio-degradable foams with desirable properties and contribute to the field of sustainable materials.

Photocatalytic removal of 2-chlorophenol from water by using waste eggshell-derived calcium ferrite.

A new approach to recycling low-value eggshell food waste was to produce a CaFe2O4 semiconductor with a narrow band gap (Eg = 2.81 eV) via hydrothermal treatments of powdered eggshell suspended in aqueous ferric salt (Fe3+) solutions at varying Fe loadings. It was possible to obtain a single phase of CaFe2O4 without any Ca(OH)2 and CaO impurities using an optimal Fe loading (30 wt% of Fe3+ by eggshell weight). The CaFe2O4 material was used as a photocatalyst for the breakdown of 2-chlorophenol (2-CP, a herbicide model chemical) as a pollutant in water. The CaFe2O4 with a Fe loading of 7.1 wt% exhibited a high 2-CP removal efficiency of 86.1% after 180 min of UV-visible light irradiation. Additionally, the eggshell-derived CaFe2O4 photocatalyst can be effectively reused, giving a high removal efficiency of 70.5% after the third cycle, without the requirement of regeneration processes (washing or re-calcination). Although radical trapping experiments confirmed that hydroxyl radicals were generated in the photocatalytic reactions, photogenerated holes play a significant role in the high 2-CP degradation efficiencies. The performance of the bioderived CaFe2O4 photocatalysts in the removal of pesticides from water demonstrated the benefits of resource recycling in the area of materials science and in environmental remediation and protection.

Toward a Circular Bioeconomy: Exploring Pineapple Stem Starch Film as Protective Coating for Fruits and Vegetables.

In order to reduce our dependence on nonrenewable plastics and solve the problem of non-biodegradable plastic waste, there has been much attention paid to the development of biodegradable plastics from natural resources. Starch-based materials have been widely studied and developed for commercial production, primarily from corn and tapioca. However, the use of these starches could generate food security problems. Therefore, the use of alternative starch sources, such as agricultural waste, would be of great interest. In this work, we investigated the properties of films prepared from pineapple stem starch, which has a high amylose content. Pineapple stem starch (PSS) films and glycerol-plasticized PSS films were prepared and characterized using X-ray diffraction and water contact angle measurements. All films exhibited some degree of crystallinity, making them water-resistant. The effect of glycerol content on mechanical properties and gas (oxygen, carbon dioxide and water vapor) transmission rates was also studied. The tensile modulus and tensile strength of the films decreased with increasing glycerol content, while gas transmission rates increased. Preliminary studies showed that coatings made from PSS films could slow down the ripening process of bananas and extend their shelf life.

Synergistic effects between acidity and the crystalline phases of thermally activated layered Zn hydroxide nitrate on the methanolysis of acidic soybean oils.

Layered hydroxyl salts (LHS) is a promising catalyst in the field of methanolysis (transesterification and esterification reactions) of oil feedstocks. The catalytic activity of the catalyst can be enhanced with heat treatment. The present study investigated the relationship between thermal stability of the layered Zn hydroxide nitrate (ZHN), their acid-base properties, and the catalytic conversion of oil feedstocks to methyl ester. The solid, predominantly acidic catalyst was prepared at various temperatures (70-170 °C) and tested for the acidic/basic properties using the Hammett indicators and titration method followed by functional group analysis using FTIR, crystallization using X-ray diffraction, and surface morphology using SEM. The combination of various characterization techniques gave an insight into the changes in the phases of the layered Zn hydroxide nitrate catalysts upon thermal treatment. Major phase changes occurred at temperatures somewhat above 80, and 140 °C. The catalysts were extensively studied to understand the underlying effects on the FAME yields obtained from catalytic conversion of oleic acid spiked soy bean oil (a model of an acidic oil feedstock) into methyl esters. The results of the optimization reactions reaffirmed the effect of the phase changes when the highest FAME yield was observed from two activated samples namely, Zn5_80 and Zn5_140. The optimized reactions condition of catalytic conversion of SO containing 10% OA at 5 °C/min heating rate, 3 wt % catalyst concentration, 30:1 methanol to oil molar ratio, reaction time of 100 °C for 2 h gave 92% FAME yield when Zn5_140 was used as the catalyst. The detected of the single phase of Zn5(OH)8(NO3)2 in Zn5_80, Zn5(OH)8(NO3)2 and ZnO in Zn5_140 (2-phase system), including Zn5(OH)8(NO3)2, Zn3(OH)4(NO3)2, and ZnO in Zn5_170 (3-phase system), suggested all three phases contributes to the high catalytic activity in methanolysis of the acidic oils. Both Zn5_140 and Zn5_170 gave a comparably high FAME yields based on statistical analyses. This study ascertained the synergistic effects of the high acidity (>0.4 mmol/g) and the dominant active phases of the thermally treated layered Zn hydroxide nitrate on the high catalytic activity that favours esterification of acidic oil feedstocks.

Toward a Circular Bioeconomy: Exploring Pineapple Stem Starch Film as a Plastic Substitute in Single Use Applications.

In this study, biodegradable starch film was developed from pineapple stem waste as a substitute for non-biodegradable petroleum-based films for single-use applications where strength is not too demanding. High amylose starch from a pineapple stem was used as the matrix. Glycerol and citric acid were used as additives to adjust the ductility of the material. Glycerol content was fixed at 25% while that of citric acid varied from 0 to 15% by weight of starch. Films with a wide range of mechanical properties can be prepared. As more citric acid is added, the film becomes softer and weaker, and has greater elongation at the break. Properties range from a strength of about 21.5 MPa and 2.9% elongation to a strength of about 6.8 MPa and 35.7% elongation. An X-ray diffraction study showed that the films were semi-crystalline. The films were also found to be water-resistant and can be heat-sealed. An example of a single-use package was demonstrated. A soil burial test confirmed that the material was biodegradable and completely disintegrated into sizes smaller than 1 mm within one month.

Physicochemical, Rheological, In-Vitro Digestibility, and Emulsifying Properties of Starch Extracted from Pineapple Stem Agricultural Waste.

In this study, the physicochemical, rheological, in vitro starch digestibility, and emulsifying properties of starch extracted from pineapple stem agricultural waste were investigated in comparison with commercial cassava, corn, and rice starches. Pineapple stem starch had the highest amylose content (30.82%), which contributed to the highest pasting temperature (90.22 °C) and the lowest paste viscosity. It had the highest gelatinization temperatures, gelatinization enthalpy, and retrogradation. Pineapple stem starch gel had the lowest freeze-thaw stability, as evidenced by the highest syneresis value of 53.39% after five freeze-thaw cycles. Steady flow tests showed that pineapple stem starch gel (6%, w/w) exhibited the lowest consistency coefficient (K) and the highest flow behavior index (n), while dynamic viscoelastic measurements gave the gel strength in the following order: rice > corn > pineapple stem > cassava starch gel. Interestingly, pineapple stem starch provided the highest slowly digestible starch (SDS) (48.84%) and resistant starch (RS) (15.77%) contents compared to other starches. The oil-in-water (O/W) emulsion stabilized with gelatinized pineapple stem starch exhibited higher emulsion stability than that stabilized with gelatinized cassava starch. Pineapple stem starch could therefore be used as a promising source of nutritional SDS and RS, and as an emulsion stabilizer for food applications.

Toward a Circular Bioeconomy: Development of Pineapple Stem Starch Composite as a Plastic-Sheet Substitute for Single-Use Applications.

Plastic waste poses a significant challenge for the environment, particularly smaller plastic products that are often difficult to recycle or collect. In this study, we developed a fully biodegradable composite material from pineapple field waste that is suitable for small-sized plastic products that are difficult to recycle, such as bread clips. We utilized starch from waste pineapple stems, which is high in amylose content, as the matrix, and added glycerol and calcium carbonate as the plasticizer and filler, respectively, to improve the material's moldability and hardness. We varied the amounts of glycerol (20-50% by weight) and calcium carbonate (0-30 wt.%) to produce composite samples with a wide range of mechanical properties. The tensile moduli were in the range of 45-1100 MPa, with tensile strengths of 2-17 MPa and an elongation at break of 10-50%. The resulting materials exhibited good water resistance and had lower water absorption (~30-60%) than other types of starch-based materials. Soil burial tests showed that the material completely disintegrated into particles smaller than 1 mm within 14 days. We also created a bread clip prototype to test the material's ability to hold a filled bag tightly. The obtained results demonstrate the potential of using pineapple stem starch as a sustainable alternative to petroleum-based and biobased synthetic materials in small-sized plastic products while promoting a circular bioeconomy.

Antifungal Activity of Water-Based Adhesives Derived from Pineapple Stem Flour with Apple Cider Vinegar as an Additive.

As a byproduct of bromelain extraction procedures, pineapple stem flour is underutilized. Since water glues derived from gelatinization typically have poor mold resistance, this study aims to produce flour-based value-added products, such as mold-resistant water-based adhesives. To address this issue, this study explored the use of apple cider vinegar (ACV) as a low-cost, non-toxic, commercially available antifungal agent to improve the mold resistance of adhesives. Furthermore, laurate flour was produced via a transesterification of the flour and methyl laurate using a K2CO3 catalyst. Both the unmodified flour and the functionalized flour were employed to prepare water-based adhesives. For both flour systems, adding ACV at concentrations of at least 2.0% v/v enhanced the mold resistance of the adhesives and completely inhibited the development of A. niger mycelia for up to 90 days of storage. The adhesives made from the transesterified flour exhibited a higher shear strength for the paper bonding (ca. 8%) than the unmodified ones. Additionally, the ACV additive had no negative effects on the shear strengths of the water-based adhesives. All of the flour-based adhesives developed in this study had a higher shear strength for paper substrates than two locally available commercial water glues.

Insight into the Molecular Weight of Hydrophobic Starch Laurate-Based Adhesives for Paper.

Instead of using finite petroleum-based resources and harmful additives, starch can be used as a biodegradable, low-cost, and non-toxic ingredient for green adhesives. This work employs K3PO4 catalyzed transesterifications of cassava starch and methyl laurate at varying reaction times (1-10 h), resulting in the enhanced hydrophobicity of starch laurates. At longer reaction times, starch laurates having higher degrees of substitution (DS) were obtained. While starch laurates are the major products of transesterification, relatively low-molecular-weight byproducts (1%) were detected and could be hydrolyzed starches based on gel permeation chromatography results. Contact angle measurements confirmed the relatively high hydrophobicity of the modified starches compared with that of native starch. The modified starches were then employed to prepare water-based adhesives on paper (without any additional additives). Notably, the shear strength of the esterified starch adhesives appears to be independent of the DS of esterified samples, hence the transesterification reaction times. Additionally, the shear strength of water-based adhesives (0.67-0.73 MPa) for bonding to paper substrates is superior to that of two other commercially available glues by a factor of 10 to 80 percent.

TiO2/graphitic carbon nitride nanosheet composite with enhanced sensitivity to atmospheric water.

Understanding the fundamentals of transport properties in two-dimensional (2D) materials is essential for their applications in devices, sensors, and so on. Herein, we report the impedance spectroscopic study of carbon nitride nanosheets (CNNS) and the composite with anatase (TiO2/CNNS, 20 atom% Ti), including their interaction with atmospheric water. The samples were characterized by X-ray diffraction, N2 adsorption/desorption, solid state 1H nuclear magnetic resonance spectroscopy, thermogravimetric analysis, and transmission electron microscopy. It is found that CNNS is highly insulating (resistivity ρ ∼ 1010 Ω cm) and its impedance barely changes during a 20 min-measurement at room temperature and 70% relative humidity. Meanwhile, incorporating the semiconducting TiO2 nanoparticles (∼10 nm) reduces ρ by one order of magnitude, and the decreased ρ is proportional to the exposure time to atmospheric water. Sorbed water shows up at low frequency (<102 Hz) with relaxation time in milliseconds, but the response intrinsic to CNNS and TiO2/CNNS is evident at higher frequency (>104 Hz) with relaxation time in microseconds. These two signals apparently correlate to the endothermic peak at ≤110 °C and >250 °C, respectively, in differential scanning calorimetry experiments. Universal power law analysis suggests charge hopping across the 3D conduction pathways, consistent with the capacitance in picofarad typical of grain response. Our work demonstrates that the use of various formalisms (i.e., impedance, permittivity, conductivity, and modulus) combined with a simple universal power law analysis provides insights into water-induced transport of the TiO2/CNNS composite without complicated curve fitting procedure or dedicated humidity control.

In-situ development of boron doped g-C3N4 supported SBA-15 nanocomposites for photocatalytic degradation of tetracycline.

In this study, versatile boron-doped graphitic carbon nitride (gCN) incorporated mesoporous SBA-15 (BGS) composite materials were prepared by thermal polycondensation method using boric acid & melamine as a B-gCN source material and SBA-15 as mesoporous support. The prepared BGS composites are utilized sustainably using solar light as the energy source for the continuous flow of photodegradation of tetracycline (TC) antibiotics. This work highlights that the photocatalysts preparation was carried out with an eco-friendly strategy, solvent-free and without additional reagents. To alter the amount of boron quantity (0.124 g, 0.248 g, and 0.49 g) have to prepare three different composites using a similar procedure, the obtained composites viz., BGS-1, BGS-2 and BGS-3, respectively. The physicochemical property of the prepared composites was investigated by X-ray diffractometry, Fourier-transform infrared spectroscopy, Raman, Diffraction reflectance spectra, Photoluminescence, Brunauer-Emmett-Teller and transmission electron microscopy (TEM). The results shows that 0.24 g boron- loaded BGS composites degrade TC up to 93.74%, which is much higher than the rest of the catalyst. The addition of mesoporous SBA-15 incresed the specific surface area of the g-CN, and heteroatom of boron increased the interplanar stracking distance of g-CN, enlarged the optical absorption range, reducing the energy bandgap and enhanced the photocatalytic activity of TC. Additionally, the stability and recycling efficiency of the representative photocatalysts viz., BGS-2 was observed to be good even at the fifth cycle. The photocatalytic process using the BGS composites demonstrated to be capable candidate for the removal of tetracycline biowaste from aquesous media.

Photocatalytic Activity of TiO2/g-C3N4 Nanocomposites for Removal of Monochlorophenols from Water.

This research employed g-C3N4 nanosheets in the hydrothermal synthesis of TiO2/g-C3N4 hybrid photocatalysts. The TiO2/g-C3N4 heterojunctions, well-dispersed TiO2 nanoparticles on the g-C3N4 nanosheets, are effective photocatalysts for the degradation of monochlorophenols (MCPs: 2-CP, 3-CP, and 4-CP) which are prominent water contaminants. The removal efficiency of 2-CP and 4-CP reached 87% and 64%, respectively, after treatment of 25 ppm CP solutions with the photocatalyst (40TiO2/g-C3N4, 1 g/L) and irradiation with UV-Vis light. Treatment of CP solutions with g-C3N4 nanosheets or TiO2 alone in conjunction with irradiation gave removal efficiencies lower than 50%, which suggests the two act synergically to enhance the photocatalytic activity of the 40TiO2/g-C3N4 nanocomposite. Superoxide and hydroxyl radicals are key active species produced during CP photodegradation. In addition, the observed nitrogen and Ti3+ defects and oxygen vacancies in the TiO2/g-C3N4 nanocomposites may improve the light-harvesting ability of the composite and assist preventing rapid electron-hole recombination on the surface, enhancing the photocatalytic performance. In addition, interfacial interactions between the MCPs (low polarity) and thermally exfoliated carbon nitride in the TiO2/g-C3N4 nanocomposites may also enhance MCP degradation.

Modified Starch-Based Adhesives: A Review.

Consumer trends towards environmentally friendly products are driving plastics industries to investigate more benign alternatives to petroleum-based polymers. In the case of adhesives, one possibility to achieve sustainable production is to use non-toxic, low-cost starches as biodegradable raw materials for adhesive production. While native starch contains only hydroxyl groups and has limited scope, chemically modified starch shows superior water resistance properties for adhesive applications. Esterified starches, starches with ester substituents, can be feasibly produced and utilized to prepare bio-based adhesives with improved water resistance. Syntheses of esterified starch materials can involve esterification, transesterification, alkylation, acetylation, succinylation, or enzymatic reactions. The main focus of this review is on the production of esterified starches and their utilization in adhesive applications (for paper, plywood, wood composites, fiberboard, and particleboard). The latter part of this review discusses other processes (etherification, crosslinking, grafting, oxidation, or utilizing biobased coupling agents) to prepare modified starches that can be further applied in adhesive production. Further discussion on the characteristics of modified starch materials and required processing methods for adhesive production is also included.

The Influence of Metal-Doped Graphitic Carbon Nitride on Photocatalytic Conversion of Acetic Acid to Carbon Dioxide.

Metal-doped graphitic carbon nitride (MCN) materials have shown great promise as effective photocatalysts for the conversion of acetic acid to carbon dioxide under UV-visible irradiation and are superior to pristine carbon nitride (g-C3N4 , CN). In this study, the effects of metal dopants on the physicochemical properties of metal-doped CN samples (Fe-, Cu-, Zn-, FeCu-, FeZn-, and CuZn-doped CN) and their catalytic activity in the photooxidation of acetic acid were investigated and discussed for their correlation, especially on their surface and bulk structures. The materials in the order of highest to lowest photocatalytic activity are FeZn_CN, FeCu_CN, Fe_CN, and Cu_CN (rates of CO2 evolution higher than for CN), followed by Zn_CN, CuZn_CN, and CN (rates of CO2 evolution lower than CN). Although Fe doping resulted in the extension of the light absorption range, incorporation of metals did not significantly alter the crystalline phase, morphology, and specific surface area of the CN materials. However, the extension of light absorption into the visible region on Fe doping did not provide a suitable explanation for the increase in photocatalytic efficiency. To further understand this issue, the materials were analyzed using two complementary techniques, reversed double-beam photoacoustic spectroscopy (RDB-PAS) and electron spin resonance spectroscopy (ESR). The FeZn_CN, with the highest electron trap density between 2.95 and 3.00 eV, afforded the highest rate of CO2 evolution from acetic acid photodecomposition. All Fe-incorporated CN materials and Cu-CN reported herein can be categorized as high activity catalysts according to the rates of CO2 evolution obtained, higher than 0.15 µmol/min-1, or >1.5 times higher than that of pristine CN. Results from this research are suggestive of a correlation between the rate of CO2 evolution via photocatalytic oxidation of acetic acid with the threshold number of free unpaired electrons in CN-based materials and high electron trap density (between 2.95 and 3.00 eV).

One-step Preparation of Carbon-based Solid Acid Catalyst from Water Hyacinth Leaves for Esterification of Oleic Acid and Dehydration of Xylose.

Carbon-based solid acid catalysts were successfully obtained via one-step hydrothermal carbonization (HTC) of water hyacinth (WH) in the presence of p-toluenesulfonic acid (PTSA). Increasing the HTC temperature from 180 to 240 °C resulted in carbonaceous materials with increased sulfur content and less adsorbed water. The material obtained at 220 °C (WH-PTSA-220) contains the highest amount of acid sites and promotes the highest initial rate of two transformations, that is, methanolysis of oleic acid and dehydration of xylose to furfural. While all PSTA-treated WH catalysts gave comparable fatty acid conversions (≈97 %) and furfural yields (≈60 %) after prolonged reaction times, the WH-PTSA-240 system bearing a relatively low acid density maintains the most favorable reusability profile. Higher HTC temperatures (220-240 °C) improved the catalyst reusability profiles due to graphitization and hydrophobicity of the carbon surface. The catalyst systems derived herein from biomass may have potential applications in biorefining platforms, utilizing the conversion of waste biomass to chemicals.

Rapid screening for anthocyanins in cane sugars using ESR spectroscopy.

Anthocyanin, which is soluble in water and released into sugar steam during extraction, was investigated in this study. The anthocyanin content in refined sugar, plantation white sugar, soft brown sugar and raw sugar was determined using electron spin resonance (ESR) spectroscopy, which was operated at room temperature, and compared with spectra from standard anthocyanin. The ESR spectra of red and violet anthocyanins was predominantly g ≈ 2.0055, which corresponded to an unpaired electron located in the pyrylium ring. Signals for Fe(III) and Mn(II), which naturally occur in plants, were found in raw sugar, soft brown sugar and standard anthocyanin but were absent from refined sugar and plantation white sugar due to the refining process. In addition, the ESR results were correlated with the apparent colour of the sugar, which was determined using the method of the International Commission for Uniform Methods of Sugar Analysis and inductively coupled plasma optical emission spectroscopy.

The effect of surfactant composition on the chemical and structural properties of nanostructured lipid carriers.

Fine-tuning the nanoscale structure and morphology of nanostructured lipid carriers (NLCs) is central to improving drug loading and stability of the particles. The role of surfactant charge on controlling the structure, the physicochemical properties and the stability of NLCs has been investigated using three surfactant types (cationic, anionic, non-ionic), and mixed surfactants. Either one, a mixture of two, or a mixture of three surfactants were used to coat the NLCs, with these classified as one, two and three surfactant systems, respectively. The mixed (two and three) surfactant systems produced smaller NLC particles and yielded NLCs with lower crystallinity than the one surfactant system. The combined effects of the ionic and the non-ionic surfactants may play a key role in assisting the lipid-oil mixing, as well as maintaining colloidal repulsion between NLC particles. In contrast, for the three surfactant system, the lipid-oil mixture in the NLCs appeared less homogenous. This was also reflected in the results of the stability study, which indicated that NLC particle sizes in two surfactant systems appeared to be retained over longer periods than for other surfactant systems.