RESUMO
In many insects the surface of the eye is nanostructured by arrays of protuberances termed ommatidial gratings which provide the cuticle with anti-reflective, anti-wetting and self-cleaning properties. The hypothesised anti-contamination role of the gratings against dust and pollen results from theoretical predictions on grating geometry and experiments on synthetic replicas of ommatidia surfaces but has not yet been proven in an animal. Whiteflies are biological test beds for anti-contamination surfaces because they deliberately distribute wax particles extruded from abdominal plates over their entire bodies. The numerous particles protect the animal against water evaporation and radiation, but may severely impair vision. Using scanning electron microscopy (SEM) and CryoSEM, we here show that the cornea of whiteflies exhibits ~ 220 nm wide mesh-like structures forming hexagonal gratings with thin ~ 40 nm connecting walls. Quantitative measurements of wax particles on the eye show that the nanostructures reduce particle contamination by more than ~ 96% compared to other areas of the cuticle. Altogether, our study is the first description of a predicted optimized grating geometry for anti-contamination in an arthropod. The findings serve as evidence of the high effectiveness of nanostructured surfaces for reducing contact area and thus adhesion forces between biological surfaces and contaminating particles.
Assuntos
Hemípteros , Nanoestruturas , Animais , Nanoestruturas/química , Hemípteros/fisiologia , Olho , Microscopia Eletrônica de Varredura , Propriedades de Superfície , Ceras/químicaRESUMO
These days, a growing consumer demand and scientific interest can be observed for nutraceuticals of natural origin, including apiculture products. Due to the growing emphasis on environmental protection, extensive research has been conducted on the pesticide and heavy metal contamination of bee products; however, less attention is devoted on other food safety aspects. In our review, scientific information on the less-researched food safety hazards of honey, bee bread, royal jelly, propolis, and beeswax are summarized. Bee products originating from certain plants may inherently contain phytotoxins, like pyrrolizidine alkaloids, tropane alkaloids, matrine alkaloids, grayanotoxins, gelsemium alkaloids, or tutin. Several case studies evidence that bee products can induce allergic responses to sensitive individuals, varying from mild to severe symptoms, including the potentially lethal anaphylaxis. Exposure to high temperature or long storage may lead to the formation of the potentially toxic 5-hydroxymethylfurfural. Persistent organic pollutants, radionuclides, and microplastics can potentially be transferred to bee products from contaminated environmental sources. And lastly, inappropriate beekeeping practices can lead to the contamination of beekeeping products with harmful microorganisms and mycotoxins. Our review demonstrates the necessity of applying good beekeeping practices in order to protect honeybees and consumers of their products. An important aim of our work is to identify key knowledge gaps regarding the food safety of apiculture products.
Assuntos
Criação de Abelhas , Inocuidade dos Alimentos , Mel , Abelhas/efeitos dos fármacos , Mel/análise , Animais , Contaminação de Alimentos/análise , Própole/efeitos adversos , Própole/química , Ceras/efeitos adversos , Ceras/química , Ácidos GraxosRESUMO
Plants have, throughout evolution, developed a hydrophobic cuticle to protect them from various stresses in the terrestrial environment. The cuticle layer is mainly composed of cutin and cuticular wax, a mixture of very-long-chain fatty acids and their derivatives. With the progress of transcriptome sequencing and other research methods, the key enzymes, transporters and regulatory factors in wax synthesis and metabolism have been gradually identified, especially the study on the regulation of wax metabolism by transcription factors and others in response to plant stress has become a hot topic. Drought is a major abiotic stress that limits plant growth and crop productivity. Plant epidermal wax prevents non-stomatal water loss and improves water use efficiency to adapt to arid environments. In this study, the ways of wax synthesis, transport, metabolism and regulation at different levels are reviewed. At the same time, the regulation of wax by different transcription factors and plant hormones in response to drought is elaborated, and key research questions and important directions for future solutions are proposed to enhance the potential application of epidermal wax in agriculture and the environment.
Assuntos
Secas , Regulação da Expressão Gênica de Plantas , Reguladores de Crescimento de Plantas , Estresse Fisiológico , Fatores de Transcrição , Ceras , Ceras/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Epiderme Vegetal/metabolismo , Epiderme Vegetal/fisiologia , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genéticaRESUMO
Making ingestible devices edible facilitates diagnosis and therapy inside the body without the risk of retention; however, food materials are generally soft, absorb water molecules, and are not suitable for electronic devices. Here, we fabricated an edible water diffusion barrier film made by gelatin-beeswax composites for the encapsulation of transient electronics. Hydrophobic beeswax and hydrophilic gelatin are inherently difficult to mix; therefore, we created an emulsion simply by raising the temperature high enough to melt the materials and vigorous stirring them. As they cool, the beeswax with a relatively high solidification temperature aggregates and forms microspheres, which increases the gelatin gel's viscoelasticity and immobilizes the emulsion structure in the film. The thermoresponsive gelatin imparts degradability to the barrier and its stickiness also enables transfer of metal patterned electronics. Furthermore, we designed an edible resonator on the film and demonstrated its operation in an abdominal phantom environment; the resonator was made to be degradable in a warm aqueous solution by optimizing the composition ratio of the gelatin and beeswax. Our findings provide insight into criteria for making transient electronics on hydrophilic substrates with hydrophobic water diffusion barriers. This proof-of-concept study expands the potential of operating edible electronics in aqueous environments in harmony with the human body and nature.
Assuntos
Gelatina , Água , Ceras , Gelatina/química , Ceras/química , Água/química , Difusão , Temperatura , Interações Hidrofóbicas e Hidrofílicas , Eletrônica , HumanosRESUMO
Beeswaxes are used as a coating agent or as a wrapping material for food products making them potentially ingested by consumers. There is no regulation yet in Europe giving maximum levels of contaminants in this type of product. Nevertheless, being a natural product, they are exposed to environmental pollution, thus it appears necessary to establish their contamination rate in order to evaluate potential human exposure. In this study, a method of extraction of different environmental contaminants including pesticides, phthalates, PAHs and phenols was developed. Based on a hot Soxhlet extraction, followed by cleaning steps, the method was validated for the quantitation of the cited contaminants by LC-MS/MS and GC-(MS)/MS. Three different types of waxes were analyzed including typical white waxes (Cera Alba) and yellow waxes (Cera Flava). It was shown that all waxes had the presence of at least one contaminant and that phthalates, in particular DEHP, was present in all beeswax samples. Insecticides were found in majority among all the classes of pesticides screened. The yellow waxes were found to be contaminated with the highest rates of PAHs (60%), pesticides (75%) and phenols (40%). The detection frequency of PAHs, in contrast to phthalates, was the lowest for all the types of waxes combined.
Assuntos
Cromatografia Gasosa-Espectrometria de Massas , Espectrometria de Massas em Tandem , Ceras , Ceras/análise , Ceras/química , Espectrometria de Massas em Tandem/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Reprodutibilidade dos Testes , Poluentes Ambientais/análise , Cromatografia Líquida/métodos , Hidrocarbonetos Policíclicos Aromáticos/análise , Limite de Detecção , Fenóis/análise , Praguicidas/análise , Ácidos Ftálicos/análise , Modelos LinearesRESUMO
MAIN CONCLUSION: We identified tomato leaf cuticle and root suberin monomers that play a role in the response to nitrogen deficiency and salinity stress and discuss their potential agronomic value for breeding. The plant cuticle plays a key role in plant-water relations, and cuticle's agronomic value in plant breeding programs is currently under investigation. In this study, the tomato cutin mutant cd1, with altered fruit cuticle, was physiologically characterized under two nitrogen treatments and three salinity levels. We evaluated leaf wax and cutin load and composition, root suberin, stomatal conductance, photosynthetic rate, partial factor productivity from applied N, flower and fruit number, fruit size and cuticular transpiration, and shoot and root biomass. Both nitrogen and salinity treatments altered leaf cuticle and root suberin composition, regardless of genotype (cd1 or M82). Compared with M82, the cd1 mutant showed lower shoot biomass and reduced partial factor productivity from applied N under all treatments. Under N depletion, cd1 showed altered leaf wax composition, but was comparable to the WT under sufficient N. Under salt treatment, cd1 showed an increase in leaf wax and cutin monomers. Root suberin content of cd1 was lower than M82 under control conditions but comparable under higher salinity levels. The tomato mutant cd1 had a higher fruit cuticular transpiration rate, and lower fruit surface area compared to M82. These results show that the cd1 mutation has complex effects on plant physiology, and growth and development beyond cutin deficiency, and offer new insights on the potential agronomic value of leaf cuticle and root suberin for tomato breeding.
Assuntos
Lipídeos de Membrana , Mutação , Nitrogênio , Folhas de Planta , Raízes de Plantas , Salinidade , Solanum lycopersicum , Solanum lycopersicum/genética , Solanum lycopersicum/fisiologia , Solanum lycopersicum/metabolismo , Nitrogênio/metabolismo , Lipídeos de Membrana/metabolismo , Folhas de Planta/genética , Folhas de Planta/fisiologia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/fisiologia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Lipídeos , Frutas/genética , Frutas/crescimento & desenvolvimento , Frutas/efeitos dos fármacos , Frutas/fisiologia , Fotossíntese , Transpiração Vegetal , Estresse Salino/genética , Ceras/metabolismo , Biomassa , Flores/genética , Flores/fisiologia , Flores/crescimento & desenvolvimento , Flores/efeitos dos fármacosRESUMO
Inspired by the citrus oil gland and cuticular wax, a multifunctional material that stably and continuously released the carvacrol and provided physical defenses was developed to address issues of fresh-cut fruits to microbial infestation and moisture loss. The results confirmed that low molecular weight and loose structure of starch nanoparticles prepared by the ultrasound-assisted Fenton system were preferable for octenyl succinic anhydride modification compared to native starch, achieving a higher degree of substitution (increased by 18.59 %), utilizing in preparing nanoemulsions (NEs) for encapsulating carvacrol (at 5 % level: 81.58 %). Furthermore, the NEs-based gelatin (G) film improved with surface hydrophobic modification by myristic acid (MA) successfully replicated the citrus oil gland and cuticular wax, providing superior antioxidant (enhanced by 3-4 times) and antimicrobial properties (95.99 % and 84.97 % against Staphylococcus aureus and Escherichia coli respectively), as well as the exceptional UV shielding (nearly 0 transmittance in the UV region), mechanical (72 % increase in tensile strength), and hydrophobic (WCA 133.63°). Moreover, the 5%NE-G@MA film inhibited foodborne microbial growth (reduced by 50 %) and water loss (controlled below 15 %), extending the shelf life of fresh-cut navel orange and kiwi. Thus, the multifunctional film was a potential shield for preserving perishable fresh-cut products.
Assuntos
Citrus , Emulsões , Escherichia coli , Frutas , Gelatina , Nanopartículas , Staphylococcus aureus , Amido , Ceras , Gelatina/química , Nanopartículas/química , Citrus/química , Emulsões/química , Amido/química , Amido/análogos & derivados , Staphylococcus aureus/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Frutas/química , Ceras/química , Antioxidantes/química , Antioxidantes/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Interações Hidrofóbicas e Hidrofílicas , Cimenos/química , Cimenos/farmacologia , Óleos de Plantas/química , Óleos de Plantas/farmacologia , Ácido Mirístico/química , Ácido Mirístico/farmacologia , Conservação de Alimentos/métodosRESUMO
Bone wax is an important hemostatic agent used in neurosurgical practice from more than a century. It acts by mechanical tamponade effect to stop the oozing from cancellous bone. Bone wax application over the skull surface over the vertex is easy and can be applied with fingers. In deeper areas, one uses dissector to apply the bone wax; however, it becomes difficult at times to apply in transnasal surgery using the same dissectors. Author designed a cost-effective 20-cm-long different angled bone wax applicator for skull base transnasal surgery. This applicator is cost-effective and not described previously in English literature.
Assuntos
Palmitatos , Base do Crânio , Ceras , Humanos , Base do Crânio/cirurgia , Palmitatos/economia , Análise Custo-Benefício , Procedimentos Neurocirúrgicos/métodos , Procedimentos Neurocirúrgicos/instrumentação , Procedimentos Neurocirúrgicos/economiaRESUMO
This study assessed the nutritional profile of camellia oil through its fatty acid composition, highlighting its high oleic acid content (81.4%), followed by linoleic (7.99%) and palmitic acids (7.74%), demonstrating its excellence as an edible oil source. The impact of beeswax (BW) and glycerol monolaurate (GML) on camellia oil oleogels was investigated, revealing that increasing BW or GML concentrations enhanced hardness and springiness, with 10% BW oleogel exhibiting the highest hardness and springiness. FTIR results suggested that the structure of the oleogels was formed by interactions between molecules without altering the chemical composition. In biscuits, 10% BW oleogel provided superior crispness, expansion ratio, texture, and taste, whereas GML imparted a distinct odor. In sausages, no significant differences were observed in color, water retention, and pH between the control and replacement groups; however, the BW group scored higher than the GML group in the sensory evaluation. The findings suggest that the BW oleogel is an effective fat substitute in biscuits and sausages, promoting the application of camellia oil in food products.
Assuntos
Camellia , Lauratos , Monoglicerídeos , Compostos Orgânicos , Óleos de Plantas , Ceras , Camellia/química , Ceras/química , Óleos de Plantas/química , Lauratos/química , Compostos Orgânicos/química , Compostos Orgânicos/análise , Monoglicerídeos/química , Produtos da Carne/análise , Paladar , Ácidos Graxos/química , Ácidos Graxos/análiseRESUMO
The main aim of this study is to experimentally investigate the yield of extraction and the presence of wax in the extracted yield from Musaacuminata (banana) biomass based on various functional groups that are present in natural wax. Extraction of natural wax from Musaacuminata (banana) biomass has been done by using the Soxhlet apparatus method in the presence of both polar (ethyl acetate and ethanol) and non-polar (toluene and hexane) solvents. The extracted yield has been found as 3.58% from hexane, 5.16% from toluene, 7.03% from ethyl acetate, and 10.26% from ethanol. The wax was also found in the extracted yield only in the case of nonpolar solvents (toluene and hexane). The novelty of this work is that Musaacuminata (banana) waste biomass has been utilized to recover the natural wax using nonpolar solvents and also compared with that of polar solvents to check the scope of wax extraction using polar solvents. Also, statistical analysis has been performed of the extracted yield using both solvents. Thin Layer Chromatography (TLC) and Fourier Transform Infrared Spectroscopy (FTIR) methods have been used to determine the various hydrocarbon chains present in the extracted yield which is similar to that of natural wax.
Assuntos
Biomassa , Musa , Solventes , Ceras , Ceras/química , Solventes/química , Musa/química , Espectroscopia de Infravermelho com Transformada de Fourier , Cromatografia em Camada Fina , Hexanos/química , Etanol/química , Tolueno/química , Tolueno/análise , Acetatos/químicaRESUMO
BACKGROUND: Ideally, the barrier properties of a fruit's cuticle persist throughout its development. This presents a challenge for strawberry fruit, with their rapid development and thin cuticles. The objective was to establish the developmental time course of cuticle deposition in strawberry fruit. RESULTS: Fruit mass and surface area increase rapidly, with peak growth rate coinciding with the onset of ripening. On a whole-fruit basis, the masses of cutin and wax increase but on a unit surface-area basis, they decrease. The decrease is associated with marked increases in elastic strain. The expressions of cuticle-associated genes involved in transcriptional regulation (FaSHN1, FaSHN2, FaSHN3), synthesis of cutin (FaLACS2, FaGPAT3) and wax (FaCER1, FaKCS10, FaKCR1), and those involved in transport of cutin monomers and wax constituents (FaABCG11, FaABCG32) decreased until maturity. The only exceptions were FaLACS6 and FaGPAT6 that are presumably involved in cutin synthesis, and FaCER1 involved in wax synthesis. This result was consistent across five strawberry cultivars. Strawberry cutin consists mainly of C16 and C18 monomers, plus minor amounts of C19, C20, C22 and C24 monomers, ω-hydroxy acids, dihydroxy acids, epoxy acids, primary alcohols, carboxylic acids and dicarboxylic acids. The most abundant monomer is 10,16-dihydroxyhexadecanoic acid. Waxes comprise mainly long-chain fatty acids C29 to C46, with smaller amounts of C16 to C28. Wax constituents are carboxylic acids, primary alcohols, alkanes, aldehydes, sterols and esters. CONCLUSION: The downregulation of cuticle deposition during development accounts for the marked cuticular strain, for the associated microcracking, and for their high susceptibility to the disorders of water soaking and cracking.
Assuntos
Fragaria , Frutas , Lipídeos de Membrana , Ceras , Fragaria/crescimento & desenvolvimento , Fragaria/genética , Fragaria/metabolismo , Fragaria/enzimologia , Frutas/crescimento & desenvolvimento , Frutas/genética , Frutas/metabolismo , Ceras/metabolismo , Lipídeos de Membrana/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genéticaRESUMO
This study aimed to develop an eco-friendly active biogenic nanocomposite film through the complexation of silver nanoparticles (AgNPs), berry wax (BYW), and chitosan (CT) for maintiaing rabbit functional meat freshness. AgNPs were synthesized using Chinese medicinal paeoniaceae petal extract, and they were loaded at various concentrations (0.5 %, 0.75 %, 1.0 %, 1.25 %, and 1.5 % based on CT w/w) into the CT/BYW complex. The AgNPs exhibited an average size of 55 nm and a zeta potential of -26.3 mV with a spherical shape. The particle size and zeta potential of the film dispersions were 370.5-529.5 nm and 40.17-49.345 mV, respectively. FTIR, SEM, and XRD results showed compatibility among AgNPs and CT/BYW structure. The film water vapor permeability and light transparency decreased from 6.5 to 3.5 and 10 to 0.78 %, respectively, while opacity increased from 1.76 to 9.96 % with increasing concentrations of AgNPs. Among them, the film composite CT/BYW/AgNPs1.5% had better antioxidant and antibacterial properties, which was then applied for rabbit meat preservation at 4 °C for 16 days of storage. CT/BYW/AgNPs1.25%-packed sample had lower values of TVB-N, TBARS, TVC, and pH with greater retention of color properties compared to the control sample, which describes its ability to maintain meat freshness.
Assuntos
Quitosana , Conservação de Alimentos , Nanopartículas Metálicas , Prata , Ceras , Animais , Coelhos , Quitosana/química , Prata/química , Nanopartículas Metálicas/química , Ceras/química , Conservação de Alimentos/métodos , Antibacterianos/farmacologia , Antibacterianos/química , Carne/análise , Antioxidantes/química , Antioxidantes/farmacologia , Nanocompostos/química , Embalagem de Alimentos/métodos , Frutas/química , Permeabilidade , Tamanho da PartículaRESUMO
MIXTA-like transcription factors AtMYB16 and AtMYB106 play important roles in the regulation of cuticular wax accumulation in dicot model plant Arabidopsis thaliana, but there are very few studies on the MIXTA-like transcription factors in monocot plants. Herein, wheat MIXTA-like transcription factors TaMIXTA1 and TaMIXTA2 were characterized as positive regulators of cuticular wax accumulation. The virus-induced gene silencing experiments showed that knock-down of wheat TaMIXTA1 and TaMIXTA2 expressions resulted in the decreased accumulation of leaf cuticular wax, increased leaf water loss rate, and potentiated chlorophyll leaching. Furthermore, three wheat orthologous genes of ECERIFERUM 5 (TaCER5-1A, 1B, and 1D) and their function in cuticular wax deposition were reported. The silencing of TaCER5 by BSMV-VIGS led to reduced loads of leaf cuticular wax and enhanced rates of leaf water loss and chlorophyll leaching, indicating the essential role of the TaCER5 gene in the deposition of wheat cuticular wax. In addition, we demonstrated that TaMIXTA1 and TaMIXTA2 function as transcriptional activators and could directly stimulate the transcription of wax biosynthesis gene TaKCS1 and wax deposition gene TaCER5. The above results strongly support that wheat MIXTA-Like transcriptional activators TaMIXTA1 and TaMIXTA2 positively regulate cuticular wax accumulation via activating TaKCS1 and TaCER5 gene transcription.
Assuntos
Regulação da Expressão Gênica de Plantas , Proteínas de Plantas , Fatores de Transcrição , Triticum , Ceras , Ceras/metabolismo , Triticum/metabolismo , Triticum/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Folhas de Planta/metabolismo , Folhas de Planta/genética , Clorofila/metabolismo , Transativadores/metabolismo , Transativadores/genética , Epiderme Vegetal/metabolismoRESUMO
Copper (Cu) is a necessary mineral nutrient for plant growth and development and is involved in several morphological, physiological, and biochemical processes; however, high concentrations of Cu can negatively impact these processes. The role of stomata in responding to various biotic and abiotic stimuli has not been studied in Bruguiera gymnorhiza, particularly in terms of their coordinated interactions at the molecular, physiological, and biochemical levels. Moreover, numerous plants employ strategies such as the presence of thick waxy cuticles on their leaf epidermis and the closing of stomata to reduce water loss. Thus, this study investigates the accumulation of Cu in B. gymnorhiza and its effect on leaf morphology and the molecular response under different Cu treatments (0, 200, and 400â¯mgâ¯L⻹, Cu0, Cu200, and Cu400, respectively) during a two years stress period. The results show that Cu stress affected accumulation and transport, increased the activities of peroxidase and ascorbate peroxidase, concentrations of soluble sugar, proline, and H2O2, and decreased the activity of catalase and content of malondialdehyde. Also, Cu-induced stress decreased the uptake of phosphorus and nitrogen and inhibited plant photosynthesis, which consequently led to reduced plant growth. Scanning electron microscopy combined with gas chromatography-mass spectrometry showed that B. gymnorhiza leaves had higher wax crystals and compositions under increased Cu stress, which forced the leaf's stomata to be closed. Also, the contents of alkanes, alcohols, primary alcohol levels (C26:0, C28:0, C30:0, and C32:0), n-Alkanes (C29 and C30), and other wax loads were significantly higher, while fatty acid (C12, C16, and C18) was lower in Cu200 and Cu400 compared to Cu0. Furthermore, the transcriptomic analyses revealed 1240 (771 up- and 469 downregulated), 1000 (723 up- and 277 down-regulated), and 1476 (808 up- and 668 downregulated) differentially expressed genes in Cu0 vs Cu200, Cu0 vs Cu400, and Cu200 vs Cu400, respectively. RNA-seq analyses showed that Cu mainly affected eight pathways, including photosynthesis, cutin, suberin, and wax biosynthesis. This study provides a reference for understanding mangrove response to heavy metal stress and developing novel management practices.
Assuntos
Cobre , Folhas de Planta , Estômatos de Plantas , Ceras , Cobre/toxicidade , Folhas de Planta/efeitos dos fármacos , Estômatos de Plantas/efeitos dos fármacos , Estômatos de Plantas/fisiologia , Estresse Fisiológico/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Onagraceae/efeitos dos fármacos , Onagraceae/fisiologia , Transcriptoma/efeitos dos fármacos , Poluentes do Solo/toxicidade , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/efeitos dos fármacosRESUMO
Cucumber (Cucumis sativus L.) is an important horticultural crop in China. Consumer requirements for aesthetically pleasing appearances of horticultural crops are gradually increasing, and cucumbers having a good visual appearance, as well as flavor, are important for breeding and industry development. The gloss of cucumber fruit epidermis is an important component of its appeal, and the wax layer on the fruit surface plays important roles in plant growth and forms a powerful barrier against external biotic and abiotic stresses. The wax of the cucumber epidermis is mainly composed of alkanes, and the luster of cucumber fruit is mainly determined by the alkane and silicon contents of the epidermis. Several genes, transcription factors, and transporters affect the synthesis of ultra-long-chain fatty acids and change the silicon content, further altering the gloss of the epidermis. However, the specific regulatory mechanisms are not clear. Here, progress in research on the luster of cucumber fruit epidermis from physiological, biochemical, and molecular regulatory perspectives are reviewed. Additionally, future research avenues in the field are discussed.
Assuntos
Cucumis sativus , Frutas , Regulação da Expressão Gênica de Plantas , Cucumis sativus/genética , Cucumis sativus/metabolismo , Cucumis sativus/crescimento & desenvolvimento , Frutas/genética , Frutas/metabolismo , Epiderme Vegetal/metabolismo , Epiderme Vegetal/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Ceras/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
Multilayer film packaging (MLP) waste was decomposed completely at 500 °C. Catalysts were employed to convert residue polymer to waxes via pyrolysis at 500 °C. The activities achieved from using mordenite (Si/Al = 10), H-ZSM-5 (Si/Al = 25), MCM-41, and Al-MCM-41 (Si/Al ratio of 25, 50, and 75) catalysts were studied. The yield and property of the wax were improved with the use of the catalysis with various acidity and porous structure. The low yield of the waxes, when using mordenite and H-ZSM-5 catalysts, was caused by the microporous structure and strong acidic properties of the catalysts resulting in larger amount of gas production. The MCM-41 catalyst modified with various aluminum content raised the wax yield to 60 %. Al-MCM-41(50) produced the largest amount of wax when compared to Al-MCM-41(25), Al-MCM-41(75), and MCM-41. The mild acidity and mesoporous structure of Al-MCM-41(50) significantly enhanced the paraffins structure of the obtained waxes over other structures, while lower Si/Al ratios favored the conversion of paraffins toward olefin structure. The pyrolysis of MLP with Al-MCM-41(50) produced paraffins and olefins with the middle carbon ranging (C11-20) which were similar quality to pharmaceutical grade of petroleum wax. The spent catalysts of Al-MCM-41 series gradually decreased in wax yield and paraffins composition during the sequential MLP pyrolysis; however, the activity of catalysts was recovered after calcination of the spent catalysts. Furthermore, the viscosity of waxes obtained from Al-MCM-41(50) was 2384 Pa.s at 25 °C similar to the viscosity from commercial petroleum jelly base of 2333 Pa.s.
Assuntos
Pirólise , Ceras , Ceras/química , Catálise , Embalagem de Produtos , Eliminação de Resíduos/métodosRESUMO
The unique properties of per- and polyfluoroalkyl substances (PFAS) have led to their extensive use in consumer products, including ski wax. Based on the risks associated with PFAS, and to align with PFAS regulations, the international ski federation (FIS) implemented a ban on products containing "C8 fluorocarbons/perfluorooctanoate (PFOA)" at all FIS events from the 2021/2022 season, leading manufactures to shift their formulations towards short-chain PFAS chemistries. To date, most studies characterising PFAS in ski waxes have measured a suite of individual substances using targeted analytical approaches. However, the fraction of total fluorine (TF) in the wax accounted for by these substances remains unclear. In this study, we sought to address this question by applying a multi-platform, fluorine mass balance approach to a total of 10 commercially available ski wax products. Analysis of TF by combustion ion chromatography (CIC) revealed concentrations of 1040-51700 µg F g-1 for the different fluorinated waxes. In comparison, extractable organic fluorine (EOF) determined in methanol extracts by CIC (and later confirmed by inductively-coupled plasma-mass spectrometry and 19F- nuclear magnetic resonance spectroscopy) ranged from 92 to 3160 µg g-1, accounting for only 3-8.8 % of total fluorine (TF). Further characterisation of extracts by cyclic ion mobility-mass spectrometry (IMS) revealed 15 individual PFAS with perfluoroalkyl carboxylic acid concentrations up to 33 µg F g-1, and 3 products exceeding the regulatory limit for PFOA (0.025 µg g-1) by a factor of up to 100. The sum of all PFAS accounted for only 0.01-1.0 % of EOF, implying a high percentage of unidentified PFAS, thus, pyrolysis gas chromatography-mass spectrometry was used to provide evidence of the nature of the non-extractable fluorine present in the ski wax products.
Assuntos
Flúor , Fluorocarbonos , Ceras , Fluorocarbonos/análise , Fluorocarbonos/química , Flúor/análise , Flúor/química , Ceras/química , Ceras/análise , Caprilatos/análise , Caprilatos/químicaRESUMO
Utilizing waxes to gel oils presents a viable approach for diminishing trans and saturated fat levels in commercial fats such as margarines. This technique ensures that oleogels mimic traditional fats in terms of rheological properties, oil-binding capacity, and overall structure. Our study employed cooling-shear rates to finely adjust physical characteristics, evaluating rheology via SAOS-LAOS, oil retention, and crystal structure of wax oleogels, compared against commercial margarines as benchmarks. Findings indicate that wax oleogels, under specific cooling/shear conditions, exhibit softer yet more ductile-like behavior, akin to margarine, while retaining oil effectively. This similarity is evidenced through Lissajous curves and plastic dissipation ratio during yielding, reflecting a ductile yielding response characterized by square-like Lissajous curves and a plastic dissipation ratio index approximating one. Although these crystallization conditions influence the mechanical properties of wax oleogels, they do not alter oil losses or wax characteristics.
Assuntos
Margarina , Compostos Orgânicos , Reologia , Ceras , Ceras/química , Compostos Orgânicos/química , Margarina/análise , CristalizaçãoRESUMO
High concentrations of carnauba waxes (CRWs) that can compromise organoleptic properties are required to create self-sustained and functional oleogels. The weak physical properties and stability of 4% w/w CRW-rice bran oil (RBO) oleogel were addressed by substituting CRW with beeswax (BW) in different weight ratios. The texture profile analyzer revealed that substituting only 10% (weight ratio) of CRW with BW improved the hardness compared to the mono-CRW oleogel. The hardness of binary oleogels increased gradually as the proportion of BW increased. At a BW ratio of 70% or more, the hardness was three times higher than that of mono-BW oleogel. Rheology analysis showed the same trend as the large deformation test; however, the hardest binary oleogels had lower critical strain and yield point compared to the mono-wax oleogels, implying that they are more prone to lose their structure upon applied stress. Nevertheless, nearly all binary mixtures (except for 10%BW90%CRW) showed oil-binding capacities above 99%, suggesting improved nucleation and crystallization process. Polarized light microscopy showed the coexistence of BW and CRW crystals and changes in the size and arrangement of wax crystals upon proportional changes of the two waxes. X-ray diffraction confirmed no differences in the peaks' location, and all oleogels had ß' polymorphism. Differential scanning calorimetry showed eutectic melting behavior in some binary blends. Oxidation stability in the binary wax oleogels improved as compared to the mono-wax oleogel and bulk RBO. BW and CRW mixtures have promising oil-structuring abilities and have various properties at different ratios that have the potential to be used as solid fat substitutes. PRACTICAL APPLICATION: As a trending green oil-structuring technology, oleogelation has shown great potential to reduce saturated fats in food systems. The current research provides valuable fundamental information on the strong synergistic interactions between beeswax and carnauba wax that have the potential to be used as solid fat substitutes created with a much lower total concentration of the required wax. This will help create wax oleogels with better organoleptic properties and less negative waxy mouthfeel. Such knowledge could prove beneficial for the development of healthy products that have potential applications in meat, bakery, dairy, pharmaceutical, as well as cosmetic industries.
Assuntos
Compostos Orgânicos , Oxirredução , Reologia , Ceras , Ceras/química , Compostos Orgânicos/química , Difração de Raios XRESUMO
While studies on the sublethal effects of chemical residues in beeswax on adult honey bees are increasing, the study protocols assessing the impacts on honey bee brood in realistic conditions still need to be investigated. Moreover, little is known about the residue's effect on gene expression in honey bee brood. This study reports the effects of chlorpyriphos-ethyl, acrinathrin and stearin worker pupae exposure through contaminated or adulterated beeswax on the gene expression of some key health indicators, using a novel in vivo realistic model. Larvae were reared in acrinathrin (12.5, 25, 10 and 100 ppb) and chlorpyriphos-ethyl (5, 10, 500 and 5000 ppb) contaminated or stearin adulterated beeswax (3, 4, 5, 6 and 9%) in newly formed colonies to reduce the influence of external factors. On day 11, mortality rates were assessed. Honey bee pupae were extracted from the comb after 19 days of rearing and were analysed for the gene expression profile of four genes involved in the immune response to pathogens and environmental stress factors (Imd, dorsal, domeless and defensin), and two genes involved in detoxifications mechanisms (CYP6AS14 and CYP9Q3). We found no linear relation between the increase in the pesticide concentrations and the brood mortality rates, unlike stearin where an increase in stearin percentage led to an exponential increase in brood mortality. The immune system of pupae raised in acrinathrin contaminated wax was triggered and the expression of CYP6AS14 was significantly upregulated (exposure to 12.5 and 25 ppb). Almost all expression levels of the tested immune and detoxification genes were down-regulated when pupae were exposed to chlorpyrifos-contaminated wax. The exposure to stearin triggered the immune system and detoxification system of the pupae. The identification of substance-specific response factors might ultimately serve to identify molecules that are safer for bees and the ecosystem's health.