Bleaching Treatment Research Articles

Microcellulose From Pineapple Leaf Fiber as a PotentialSustainable Material: Extraction And Characterization

Pineapple leaf fiber is consideredan agricultural waste during the harvesting process. Pineapple leaves are rich in cellulose, which made it applicable in many industrial applications. This study aims to extract and characterize microcellulose from pineapple leaf waste in Kampar district, Riau. Pineapple fibers were isolated by alkalization (5 % NaOH) at 70 ºC for 150 minutes, followed by bleaching treatment(3% H2O2) at 60°C for 60minutes. Microcellulosewascharacterized through various techniques, namely chemical composition analysis, Fourier transform analysis (FTIR), X-ray diffraction (XRD), and thermogravimetric analysis (DT/TGA). The results reveal that the extractedmicrocellulose has significantcellulose content (72.45%) with a crystallinity index of 73.48%. The FTIR spectra of microcellulose indicatethat alkalization and bleaching treatments removed lignin and hemicellulose in varying degrees. Moreover, the extracted microcelluloseshows high thermal stability, the maximum decompositionoccurredat 347 ºC (weight residue 16.37%).Pineappleleaf fiber in Kampar district, Riau, can be a source of microcellulose as a renewable, eco-friendly, and sustainable material for future industrial applications.

Association between dental appearance satisfaction and sociodemographic characteristics in Samarinda city, Indonesia

Background: Confidence in the appearance of teeth affects a person's physical and psychological health. The appearance of teeth is influenced by factors such as age, gender, educational level and economic status. The aim of this study was to find out the relationship between dental satisfaction and sociodemographic characteristics. Methods: A cross-sectional study has been conducted on 384 people aged 17 to 45 years in Samarinda City, Indonesia. The research instrument is a questionnaire on age, gender, educational level, family income, and six satisfaction questions about tooth appearance. Data analyzed descriptively and tested chi-square. Results: A total of 222 respondents (57.8%) felt dissatisfied with the appearance of their teeth. Respondents with a younger age tend to be 1.262 times more dissatisfied compared to older ones. There was a significant relationship between age and satisfaction with the appearance of the teeth (p=0.017). No significant relationship was found between teeth appearance satisfaction with gender, educational level and economic status. Respondents who did not want to do orthodontic care tended to be 1.920 times more satisfied than those who wanted to do ortodontic treatment. The most desirable treatments respondents wanted to improve dental aesthetics were bleaching (57.6%) and orthodontist treatment (43.2%). Conclusions: There is a significant correlation between teeth appearance satisfaction and age factor in the Samarinda Indonesian population who are 17 to 45 years old; there is a meaningful relationship between desire for orthodontic care and teeth satisfaction.

Reasonable multi-functionality of cotton fabric with superior flame retardancy and antibacterial ability using ammonium diphosphate as cross-linker

Ammonium phosphates have been proven to be efficient and durable flame retardants for cellulose fabric. However, a facile process for their multifunctional flame-retardant modification has not yet been reported. In order to achieve this goal, we synthesized an ammonium diphosphate of ethylene glycol (AP) and used it as a crosslinker to fabricate flame-retardant and antibacterial cellulose fabric with a dihydroxyl N-halamine precursor (BD) via a one-pot process. The AP/BD modified fabric exhibited superior flame retardancy, with a LOI value of 32.9% and self-extinguishing behavior at only 11.0% weight gain. The heat release was significantly inhibited, with an 81% reduction in peak heat release rate (PHRR) and a 60% reduction in total heat release (THR). Furthermore, the modified fabric maintained its self-extinguishing properties even after undergoing 50 washing cycles, demonstrating excellent washing durability with a LOI value of 30.5%. In addition to its outstanding flame retardancy, the AP/BD modified fabric also displayed excellent biocidal efficacy due to the formation of N-Cl bonds through simple bleaching treatment. All inoculated bacteria were killed within just 5 min of contact without any noticeable dissolution occurring. Moreover, the oxidative chlorine that acted as an antibacterial factor could be recharged after long periods of storage and washing. Importantly, no significant changes in whiteness, air permeability or hand feeling were observed after the AP/BD modification process. Therefore, this work presents a common and facile approach for preparing highly-efficient flame-retardant cellulose fabrics with multifunctionality.

The extraction process of nanocellulose from organic waste and incorporating it into biopolymers for mechanical property enhancement

Nanocellulose possesses excellent properties such as an elastic modulus of 220 GPa, Young’s modulus of 10- 150 GPa, low density of around 1.6 g/cm3, and high thermal stability. To enhance mechanical flexibility, nanocellulose can strengthen the bio-polymers. This research project aims to review the extraction methods and the characterization of the nanocellulose extracted from organic waste materials such as banana peel, pineapple leaf fiber, crown, corncob, palm oil, etc., focusing on the possibility of adding the nanocellulose to enhance the properties such as tensile strength, young’s modulus, water vapor permeability of the biopolymers. Chemical extraction methods like alkaline treatment, bleaching treatment, sulfuric and formic acid hydrolysis, TEMPO-mediated oxidation, and mechanical extraction methods such as ball milling, ultrasonication, high-pressure homogenization, and grinding have been studied. The results obtained from all the characterization techniques have been tabulated. From the results tabulation, the length of cellulose nanocrystal and cellulose nanofiber is 100-350 nm and 350 nm and above, respectively. The hydrolysis time and the types of acid used will affect the yield and aspect ratio; the acid concentration will also affect the degradation temperature. Mechanical treatment results in a higher yield of the nanocellulose, but mechanical treatment is not economically solvent due to the heavy use of power. Considering that nanocellulose extracted via chemo-mechanical treatment has outstanding characteristics that can potentially improve the mechanical properties when incorporated into the biopolymers.

Synthesis and characterization of cellulose nanocrystal derived from paper as nanofiller for polymer insulation materials

The synthesis and characterization of cellulose nanocrystal by utilizing filter paper as the source of material deserves to be an advanced approach. Nanocellulose has received enormous attention due to its unique properties. Being the most abundant organic polymer on earth, nanocellulose is the most suitable candidate for alternative replacement of petroleum-based products. The cellulose was extracted from filter paper by chemical processes involved alkali treatment, bleaching treatment, and acid hydrolysis. Cellulose nanocrystal has been characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and Electrical Impedance Spectroscopy (EIS). The dielectric permittivity of the prepared CNC have been investigated in the different temperatures. The nanofiller CNC exhibits a higher real permittivity value at elevated temperatures (60 °C) in the low-frequency region. At high-frequency region, the real permittivity is independent on temperature. In brief, the studies point to the application potential of CNC for future insulation materials.

Effect of the β-tricalcium phosphate particle on dental enamel associated with 10% carbamide peroxide bleaching.

Since bleaching gels can cause adverse effects on tooth enamel, it is important to evaluate new remineralizing agents on the market and their effects. Seventy-five bovine enamel/dentin blocks (4x4x3mm) were randomly divided into six groups (n=10): Negative Control (NC) with no bleaching treatment or brushing; 10 CP (Carbamide Peroxide) (no brushing - Whiteness Perfect FGM); CT12 + 10 CP (Colgate Total® 12); ES + 10 CP (Elmex® Sensitive); BPC + 10 CP (Bianco® ProClinical); CMP + 10 CP (Colgate® Máxima Proteção Anticáries). The color was evaluated by reflectance spectrophotometry (∆E*ab, ∆E00, and ∆WID) at times T1 (baseline), T2 (24 hours after brushing), and T3 (24 hours after bleaching). Knoop microhardness (KHN) analysis were performed at T3. The enamel surface was qualitatively analyzed by Scanning Electron Microscopy (SEM). The data were analyzed using generalized linear models through descriptive and exploratory analyses, and a significance level of 5% was considered. Significant differences were observed when the bleached groups were compared to the NC group for ∆E*ab, ∆E00, and ∆WID at time T3 (p= <0.0001). However, the bleached groups presented no significant differences regarding studied times (p> 0.05). KHN did not differ significantly among the six groups (p=0.7585). Toothpastes with tricalcium phosphate (β-TCP) do not intervene with the efficacy of bleaching treatment with 10% carbamide peroxide. Although a slight mineral deposition on enamel surface can be observed on SEM images, KHN was not significantly altered, and the polishing of the samples were maintained. Key words:Dental Bleaching, Carbamide Peroxide, Hydrogen Peroxide, Dental Enamel, Tricalcium Phosphate.

Does the whitening dentifrice containing activated charcoal interfere with the properties of dental enamel? Microhardness, surface roughness and colorimetry analyzes.

The study evaluated the influence of whitening dentifrice containing activated charcoal on microhardness (MH), surface roughness (Ra) and colorimetry of tooth enamel. A total of 60 healthy bovine incisor teeth were used and divided into: G1 (regular non-whitening toothpaste), G2 (conventional whitening toothpaste), G3 (activated charcoal based whitening toothpaste) and G4 (10% carbamide peroxide gel - PC10). Groups G1, G2 and G3 underwent simulated toothbrushing for 14 days, while G4 received bleaching treatment for the same time. The readings of MH, Ra and colorimetry were performed before any intervention (T0 - baseline) and at the end of 14 days of the proposed treatments (T1). After confirming the normality of the data, the results of MH, Ra and colorimetry were subjected to 2-factor ANOVA for repeated measures (α = 5%). For MH, there were no statistical differences in G1, G2 and G3, only in G4. Considering Ra, a significant increase was observed in G2 and G3, with no statistical differences found in the other groups. Regarding colorimetry, the average color difference (ΔE) was greater in the G4 group (11.30 ± 4.31), even compared to the groups submitted to the whitening dentifrices: G2 (5.13 ± 2.75) and G3 (5.86 ± 3.66). It was concluded that the use of a whitening toothpaste containing activated charcoal caused deleterious effects on the enamel Ra, but did not affect the microhardness of the substrate, besides promoting a color change inferior to the regular non-bleaching toothpaste or PC10 gel. Key words:Whitening dentifrice, charcoal, roughness, microhardness.

PREPARAÇÃO DE BIOCOMPÓSITO À BASE DE AMIDO TERMOPLÁSTICO REFORÇADO COM FIBRAS DE EUCALIPTO: AVALIAÇÃO DO EFEITO DO TAMANHO DAS FIBRAS NAS PROPRIEDADES MECÂNICAS E DE SORÇÃO

PREPARATION OF BIOCOMPOSITE BASED ON THERMOPLASTIC STARCH REINFORCED WITH EUCALYPTUS FIBERS: EVALUATION OF FIBERS SIZE EFFECT ON MECHANICAL AND SORPTION PROPERTIES. This study investigated the preparation of a thermoplastic starch-based (ATP) biocomposite reinforced with eucalyptus fibers (FE), focusing on how fiber size affects the properties. The natural fibers were chemically processed using alkaline and bleaching treatments of eucalyptus bark. Subsequently, they were characterized by infrared spectroscopy (FTIR) and X-ray diffraction (XRD) to evaluate alterations in fiber composition and crystalline structure. Samples of biocomposites were prepared with a fixed fiber content (20 wt.%) and variations in particle size (dp): ATP/FE600 (600 μm ≤ dp &lt; 1180 μm), ATP/FE250 (250 μm ≤ dp &lt; 600 μm), and ATP/FE75 (75 μm ≤ dp &lt; 250 μm). The samples were characterized by optical and scanning electron microscopy, mechanical tests, moisture absorption, and swelling analysis. Results indicated significant effects of fiber size on the biocomposite properties. Notably, the larger fibers present in ATP/FE600 exhibited superior tensile strength and elastic modulus, while this sample demonstrated reduced moisture absorption and swelling tendencies. Microscopic images revealed enhanced matrix-fiber adhesion in ATP/FE600, highlighting the importance of proper fiber size. The optimization of fiber size emerges as a relevant strategy for improving the mechanical attributes and mitigating moisture/water absorption tendencies in starch-based thermoplastic biocomposites, contributing to sustainable and high-performance materials.

Surface disinfection of wheat kernels using gas phase hydroxyl-radical processes: Effect on germination characteristics, microbial load, and functional properties.

Wheat kernels harbor a diverse microflora that can negatively affect the suitability of the grains for further processing. To reduce surface microflora, a kernel disinfection method is required that does not affect grain functionality. Three different versions of gas phase hydroxyl-radical processes were compared with the common method for grain disinfection, that is, a bleach treatment. The gas phase hydroxyl-radicals are generated by the UV-C mediated degradation of hydrogen peroxide and/or ozone in a near water-free process. It was found that treating kernels with a bleach solution could reduce total aerobic count (TAC) and fungal count to below the level of enumeration. In comparison, the gas phase hydroxyl-radical treatment, that is, H2 O2 -UV-ozone treatment, could support a 1.3 log count reduction (LCR) in TAC and a 1.1 LCR in fungal count. The microbial load reduction for the wholemeal samples was less pronounced as endophytic microorganisms were less affected by all treatments, hinting at a limited penetration depth of the treatments. Despite reducing the microbial load on the kernel surface through the bleach and H2 O2 -UV-ozone treatments, none of these treatments resulted in a reduced microbial count on grains that underwent sprouting after the treatments. No negative effect on germination power or development of the seedling was observed for any of the treatments. The gluten aggregation behavior and xylanase activity of the wholemeal also remained unchanged after the gas phase hydroxyl-radical treatments. Our findings suggest that UV-H2 O2 -ozone treatment shows promise for dry-kernel disinfection, but further optimization of the processing parameters is required.

Pickering emulsions stabilized by cellulose nanocrystals extracted from hazelnut shells: Production and stability under different harsh conditions

Cellulose nanocrystals (CNCs) are biodegradable particles that have emerged as promising stabilizers for Pickering emulsions. This study investigated the effectiveness of CNCs in forming the Pickering emulsion from hazelnut shells (HS), an agricultural waste. Following the alkaline and bleaching treatments applied to HS, CNCs were obtained from treated hazelnut shell with acid hydrolysis. The physicochemical characteristics of CNCs were investigated using dynamic light scattering, XRD, FTIR, SEM, and TEM. A high crystalline (69.6 %) CNCs with a spherical shape were obtained. Contact angle and interfacial tension tests were conducted and showed that CNCs had amphiphilic nature. Pickering emulsions were investigated for their size, zeta potential, and stability under varying CNC concentrations. The results showed that when CNCs concentration increased from 0.5 to 2.0 wt%, droplet diameter decreased approximately 1.8 times and zeta potential increased. Creaming was not observed during 28 days of storage in a concentration of 2.0 wt% CNCs. The CNC stabilized emulsions exhibited high stability within a range of pH, temperatures, and salt concentrations. This study demonstrated that CNCs extracted from HS as environmentally friendly and cost-effective materials, could serve as a new stabilizer for Pickering emulsions especially for high temperature and low pH sensitive products such as mayonnaise.

Application of an edible coating developed with Andean potato starch and carboxymethyl-cellulose for lipid reduction during frying

This work aimed to search for alternative uses for different varieties of Andean potatoes (Solanum tuberosum ssp andigenum) which have been reintroduced in north-western Argentina. Specifically, the development of simple and compound films made with hydrocolloids such as carboxymethyl-cellulose (CMC) and starch (S) extracted from Andean potatoes var. Runa, and its application as a cover in the deep frying of Andean potato chips var. Waycha was studied to minimize oil absorption. The effect of prior bleaching of the chips with different media was also evaluated: water, calcium chloride solution, and ascorbic acid. The coatings were applied to potatoes chips before being fried. The results showed that the type of oil used did not affect absorption by the chips. The bleaching treatments with calcium chloride and coating with S/CMC, showed a significant reduction in oil absorption (39.5 % ± 0.7), delayed its oxidation, and decreased the loss of tocopherols during the frying process. It also contributed to the physical and sensory characteristics of the final product, which presented high acceptability by consumers.

Cellulose fibers and ellagitannin-rich extractives from rambutan (Nephelium Lappaceum L.) peel by an eco-friendly approach

This study assesses the viability of an accelerated solvent extraction technique employing environmentally friendly solvents to extract ellagitannins while producing cellulose-rich fibers from rambutan peel. Two sequential extraction protocols were investigated: 1) water followed by acetone/water (4:1, v:v), and 2) acetone followed by acetone/water (4:1, v:v), both performed at 50 °C. The first protocol had a higher extraction yield of 51 %, and the obtained extractives featured a higher total phenolic (531.4 ± 22.0 mg-GAE/g) and flavonoid (487.3 ± 16.9 mg-QE/g) than the second protocol (495.4 ± 32.8 mg-GAE/g and 310.6 ± 31.4 mg-QE/g, respectively). The remaining extractive-free fibers were processed by bleaching using either 2 wt% sodium hydroxide with 3 wt% hydrogen peroxide or 4–5 wt% peracetic acid. Considering bleaching efficiency, yield, and process sustainability, the single bleaching treatment with 5 wt% of peracetic acid was selected as the most promising approach to yield cellulose-rich fibers. The samples were analyzed by methanolysis to determine the amount and type of poly- and oligosaccharides and studied by 13C solid-state nuclear magnetic resonance spectroscopy and thermal gravimetric analysis. The products obtained from the peels demonstrate significant potential for use in various sectors, including food, nutraceuticals, cosmetics, and paper production.

Recycled UHT Milk Carton Cellulose Substrate for Colorimetric and Electrochemical Sensor of Lactate

Recycled cellulose prepared from UHT milk carton waste was employed as a novel substrate for colorimetric and electrochemical lactate sensors to evaluate the milk quality. The cellulose is initially extracted by chemical method (alkali and bleach treatment) to prepare the dual-sensing substrate. For colorimetric sensor, an enzyme immobilization was performed on the recycled cellulose substrate prior to enhancing specificity for lactate detection. Subsequently, the recycled cellulose substrate was dipped in an aluminum solution extracted from aluminum foil from the packaging to create a conductive working electrode with improved surface roughness compared with recycled cellulose substrate, confirmed by atomic force microscopy. For the physical and chemical characterization, scanning electron micrograph demonstrated 3D fibrous network with the porous in between, and X-ray photoelectron spectroscopy presented the binding energy with the Al-O peak at 73.256 eV, verifying the existence of aluminum on the recycled cellulose substrate after surface modification. For the sensing performance, the colorimetric sensor provides the increasing purpleness intensity with the increment of lactate concentration, while the aluminum-modified recycled cellulose substrate exhibited the increased current response upon the increased lactate concentration. Furthermore, this dual-lactate sensor can offer a linearity of 0.125-2 M, covering a cut-off lactate level (1.0 M) for milk spoilage. Ultimately, this sensor is successfully utilized for lactate determination in real milk samples, showing its high efficiency as an alternative platform for milk quality evaluation.

Biodegradable packaging films from banana peel fiber

Plastics are the most popular choice for packaging materials due to their strength, flexibility, and affordability. Their non-biodegradability, however, is an environmental concern and a serious human health issue that necessitates the development of sustainable and biodegradable alternatives. Towards this end, lignocellulosic residue from biowaste stands out as a viable option due to its robust structure, biocompatibility, biodegradability, low density, and non-toxicity. Herein, the lignocellulosic fiber from banana peel was extracted by alkali and bleaching treatment, solubilized in 68% ZnCl2 solution, and crosslinked through a series of Ca2+ ion concentrations, and films prepared. Results suggest that increasing Ca2+ ions concentration significantly increases the film's tensile strength but decreases moisture content, transparency, moisture absorption, water solubility, water vapor permeability, and percentage elongation. Films have a half-life of 15.26–20.72 days and biodegrade more than 50% of their weight within 3 weeks at a soil moisture of 21%. Overall, banana peel fiber could aid in designing and developing biodegradable films and offer a sustainable solution to limit the detrimental effects of plastics.

Bleach Cleaning of Commercially Available Gold Nanopillar Arrays for Surface-Enhanced Raman Spectroscopy (SERS).

Surface-enhanced Raman spectroscopy (SERS) is a highly sensitive technique that can assist in trace analysis for biomedical, diagnostic, and environmental applications. However, a major limitation of SERS is surface contamination of the substrates used, which can complicate the spectral reproducibility, limits of detection, and detection of unknown analytes. This is especially prevalent with commercially available substrates as shipping under a controlled and clean environment is difficult. Here we report a method using dilute bleach solutions to remove surface contamination from commercially available substrates consisting of gold-coated nanopillar arrays that maintains functionality. The results show that this method can be used to remove background signals associated with typical surface contamination in commercially available substrates as well as remove thiolated self-assembled monolayers (SAMs). Results indicate the bleach oxidizes the surface contaminants, which can then be easily washed away. Although the metallic surface also becomes oxidized in this process, the surface can be reduced without loss of SERS activity. The SERS intensity of SAMs improved following bleach treatment across all concentrations studied.

The potential of DBD plasma pretreatment for the isolation of micro- and nano-cellulose fibers from the walnut shells

This study investigated the use of dielectric barrier discharge (DBD) plasma as a pretreatment to extract micro and nano-cellulose fibers from walnut shells (WS). The powdered WS was subjected to plasma at 18 and 20 kV before undergoing sodium hydroxide alkaline, sodium chlorite bleaching, or both alkaline and bleaching treatments. A control sample was also prepared without plasma treatment. The extracted cellulose was then analyzed for extraction efficiency, chemical composition, color, crystallinity index, FTIR, thermal properties, microstructure, and surface composition. The results showed that the plasma pretreatment reduced the cellulose extraction efficiency from ∼26 % to ∼22 % which was accompanied by a decrease in the C-C/C-H and C-OH/C-O-C bonds. The 20 kV plasma pretreatment prior to both alkaline and bleaching treatments resulted in the conversion of microfibrils into nanofibrils, with an average diameter of 80 ± 10 nm. These changes in the fiber structure were likely caused by the disruption of hydrogen-bonding interactions in the plasma-treated samples, leading also to a reduction in crystallinity index. The plasma-treated sample exhibited a different weight loss pattern below 100 °C compared with the control, originating from changes in water absorption. Overall, the study demonstrated that plasma pretreatment can successfully produce micro and nano-cellulose fibers from WS.

Synergistic Stabilization of Nanoemulsion Using Nonionic Surfactants and Salt-Sensitive Cellulose Nanocrystals.

Soybean stover is a lignocellulose biomass that is rich in cellulose. In the present study, soybean cellulose nanocrystals (CNCs) were prepared from soybean stover by alkaline treatment, bleaching treatment, acid hydrolysis, dialysis and ultrasonication. The as-prepared soybean CNC was characterized by transmission electron microscopy (TEM), zetasizer and rheometer. The effects of NaCl on the particle size, zeta potential, and viscosity of soybean CNC was studied. Soybean CNC was explored as an emulsion stabilizer for lemongrass-essential-oil-loaded emulsions. Soybean CNCs could stabilize the oil-in-water emulsion against coalescence but not flocculation. The addition of NaCl reduced the creaming index and enhanced the encapsulation efficiency and freeze-thaw stability of the CNC-stabilized emulsion. Salted CNC (i.e., CNC in the presence of NaCl) enhanced the thermodynamic stability (i.e., heating-cooling and freeze-thaw stability) of Tween 80 stabilized emulsion, while unsalted CNC did not. Synergistic effects existed between Tween 80 and salted CNC in stabilizing oil-in-water emulsions. The nanoemulsion stabilized with Tween 80 and salted CNC had a mean particle size of ~70 nm, and it was stable against all thermodynamic stability tests. This is the first study to report the synergistic interaction between salted CNC and small molecular weight surfactants (e.g., Tween 80) to improve the thermodynamic stability of nanoemulsion.

Effect of Three Chemical Agents on Stain Removal from Dentin Caries Lesions Treated with Silver Diamine Fluoride

Introduction: This in vitro study aimed to evaluate the effect of three different chemical agents on stain removal and mineral uptake of artificial dentin caries (ADC) lesions treated with silver diamine fluoride (SDF). Methods: Baseline L*a*b* values were determined in polished human permanent dentin blocks, and ADC lesions were induced with an acid gel for 1 week. Samples were assigned to four groups; in three groups, half of each sample received SDF (30% SDF for 3 min), while the other half received SDF followed by a bleaching treatment protocol (garlic extract, bentonite, or 35% hydrogen peroxide). The fourth group had one SDF-treated half and one half without SDF. Color changes (ΔE) were measured by spectrometry, and transversal microradiography was used to quantify integrated mineral loss (ΔZ) 24 h after treatment (SDF or SDF + bleaching). A two-way mixed ANOVA was applied to thirty percent. Results: SDF application increased mineral uptake by ADC (p = 0.001). The type of chemical agent evaluated (p < 0.0001), time (p = 0.01), and their interaction (p < 0.0001) bleached the ADC treated with SDF. However, 35% hydrogen peroxide was the only compound with a bleaching effect (p < 0.001), without returning to baseline color. None of the compounds altered the mineral uptake effect of SDF (p = 0.30). Conclusion: This in vitro study showed mineral uptake effect in ACD within 24 h after SDF application and the ability of hydrogen peroxide to partially remove (reduction of 24%) the staining caused by SDF without affecting its mineral uptake effect.

The promising stability of carboxylpyranocyanidin-3-O-glucoside during food processing and simulated digestion and its bioavailability research.

Pyranoanthocyanins are stable anthocyanin derivatives. Carboxylpyranoanthocyanin is one of the simplest pyranoanthocyanin, among which the production of carboxylpyranocyanidin-3-O-glucoside (crboxyl-pycy-3-gluc) is most feasible as a result of the abundance of its reactant, cyanidin-3-O-glucoside (Cy-3-gluc). In the present study, carboxyl-pycy-3-gluc was synthesized and its stability during processing and after ingestion as well as its bioavailability in vivo were comprehensively evaluated. Our results indicated that the color of carboxyl-pycy-3-gluc remained more stable compared to Cy-3-gluc when facing the large-span pH variation. The high retention of anthocyanin symbolized the superb stability under thermal processing, sulfur dioxide bleaching and ultrasonic treatment of carboxyl-pycy-3-gluc. Because of the stability under the alkaline condition, carboxyl-pycy-3-gluc is more stable after oral-gastrointestinal digestion. After in vitro gut microbiota fermentation, the retention of carboxyl-pycy-3-gluc was significantly higher than that of Cy-3-gluc. The larger molecular size made absorption of carboxyl-pycy-3-gluc into blood more difficult than its precursor. The present study demonstrated the promising stability of carboxyl-pycy-3-gluc during food processing and after digestion, confirming the potential of carboxyl-pycy-3-gluc as a colorant. © 2023 Society of Chemical Industry.

Biodegradable films from the lignocellulosic residue of switchgrass

Plastics thrown out as trash are an everlasting threat to our biosphere and ecosystem. A sustainable remedy within our reach is the use of agricultural biomass. Herein, the lignocellulosic residue of switchgrass biomass, extracted using alkaline and bleaching treatments and solubilized in ZnCl2 solution followed by crosslinking with calcium ions, is used to develop biodegradable films. The films have been characterized for color, transparency, thickness, moisture, water solubility, water absorption, water vapor permeability, tensile strength, elongation, and soil biodegradation. Mathematical modeling of the water absorption and biodegradation behavior have also been studied. The films are transparent, possess high tensile strength and low water vapor permeability, and biodegrade completely within 40 days at 30% soil moisture. The tensile strength and whiteness of films increase with CaCl2 concentration, but elongation, water absorption, water solubility, water vapor permeability, and biodegradation decrease. Overall, the strong and biodegradable switchgrass residue-based films open up a new window of opportunities to design and develop reusable, recyclable, and compostable films from underutilized, inexpensive, and abundant agricultural biomass contributing to the circular bioeconomy in a friendly and sustainable manner.