Fruit Wax Research Articles

The restructuring of grape berry waxes by calcium changes the surface microbiota

The observation that exogenous Ca shifted the polyphenolic profile of grape berries and conferred a glossy appearance to mature fruits led us to hypothesize that the composition of grape berry waxes and thus surface microbiota are modified. In two cultivars sharing the same microclimate, the triterpenoid and steroid profile of berry cuticle was characterized by a targeted metabolomic approach, and surface microbial communities were surveyed by ITS and 16S metabarcoding. Results showed that Ca strongly decreased the levels of oleanolic acid, while steroids and neutral triterpenoids were affected in a cultivar-dependent manner. A total of 174 fungi and 192 bacteria OTUs were identified, with Dothideomycetes, Leotiomycetes, Alphaproteobacteria and Gammaproteobacteria comprising the most abundant classes. Ca decreased fungi biodiversity, favoring the growth of Basidiomycetes, and shifting fungi-bacteria relationships. Metabolite-microbiota networks revealed a tight relationship between microbial communities and triterpenoid components of fruit waxes, mainly stigmasterol, tremulone and oleanolic acid.

Soluble cuticular wax composition and antimicrobial activity of the fruits of Chaenomeles species and an interspecific hybrid

Plants of the genus Chaenomeles Lindl. (Rosaceae) naturally grow in Southeast Asia and represent the richest resource of biologically active compounds with beneficial properties for humans. Plants of C. japonica (Thunb.) Lindl. and C. speciosa (Sweet) Nakai species, and interspecific hybrid C. × superba (Frahm) Rehder (C. japonica × C. speciosa, Superba group) have been successfully introduced in the steppe zone of Ukraine and bear fruits. In this study, we evaluated chemical composition of fruit cuticular waxes and antimicrobial activity of fruit extracts. The soluble waxes were characterized using gas chromatography-mass spectrometry (GC-MS), and 26–36 compounds, representing 91.7–96.6% of the total soluble cuticular waxes, were identified. Waxes of Chaenomeles fruits belonged to six classes, namely fatty acids, alcohols, aldehydes, esters, ethers and alkanes. Aldehydes 7-hexadecenal and heptacosanal, and alkanes hexatriacontane and tetrapentacontane were the main constituents in the soluble cuticular waxes of C. speciosa and C. × superba fruits, accounting for more than half of the total contents. However, alkane tetrapentacontane, alcohol 8,10-hexadecadien-1-ol and heptacosanal prevailed in C. japonica fruit waxes. Isopropanolic fruit extracts exhibited dose-dependent antimicrobial activity against four Gram-negative bacteria, five Gram-positive bacteria and one fungal strain in the disc diffusion assay. In general, extracts from the Chaenomeles fruits demonstrated higher activity against Gram+ bacteria than Gram- strains. The strongest inhibiting activity was shown against Staphylococcus epidermidis (by the fruit extracts of C. × superba and C. speciosa), Micrococcus lysodeikticus and Candida albicans (both by C. × superba fruit extract). Results of the study confirmed accumulation of the bioactive compounds in the fruit waxes of different Chaenomeles species and antimicrobial ability of Chaenomeles fruits as well. These findings revealed the bioactive compounds in fruit cuticular waxes and suggested health-promoting properties of introduced Chaenomeles species.

Soluble cuticular wax composition and antimicrobial activity of the fruits of Chaenomeles species and an interspecific hybrid

Plants of the genus Chaenomeles Lindl. (Rosaceae) naturally grow in Southeast Asia and represent the richest resource of biologically active compounds with beneficial properties for humans. Plants of C. japonica (Thunb.) Lindl. and C. speciosa (Sweet) Nakai species, and interspecific hybrid C. × superba (Frahm) Rehder (C. japonica × C. speciosa, Superba group) have been successfully introduced in the steppe zone of Ukraine and bear fruits. In this study, we evaluated chemical composition of fruit cuticular waxes and antimicrobial activity of fruit extracts. The soluble waxes were characterized using gas chromatography-mass spectrometry (GC-MS), and 26–36 compounds, representing 91.7–96.6% of the total soluble cuticular waxes, were identified. Waxes of Chaenomeles fruits belonged to six classes, namely fatty acids, alcohols, aldehydes, esters, ethers and alkanes. Aldehydes 7-hexadecenal and heptacosanal, and alkanes hexatriacontane and tetrapentacontane were the main constituents in the soluble cuticular waxes of C. speciosa and C. × superba fruits, accounting for more than half of the total contents. However, alkane tetrapentacontane, alcohol 8,10-hexadecadien-1-ol and heptacosanal prevailed in C. japonica fruit waxes. Isopropanolic fruit extracts exhibited dose-dependent antimicrobial activity against four Gram-negative bacteria, five Gram-positive bacteria and one fungal strain in the disc diffusion assay. In general, extracts from the Chaenomeles fruits demonstrated higher activity against Gram+ bacteria than Gram- strains. The strongest inhibiting activity was shown against Staphylococcus epidermidis (by the fruit extracts of C. × superba and C. speciosa), Micrococcus lysodeikticus and Candida albicans (both by C. × superba fruit extract). Results of the study confirmed accumulation of the bioactive compounds in the fruit waxes of different Chaenomeles species and antimicrobial ability of Chaenomeles fruits as well. These findings revealed the bioactive compounds in fruit cuticular waxes and suggested health-promoting properties of introduced Chaenomeles species.

Chemical Composition, Crystal Morphology, and Key Gene Expression of the Cuticular Waxes of Goji (Lycium barbarum L.) Berries.

The cuticular wax of fruit is closely related to quality, storability, and pathogen susceptibility after harvest. However, little is known about the cuticular wax of goji berry (Lycium barbarum L.) cultivars. In the present study, the chemical composition, crystal structures, and expression levels of associated genes of the cuticular wax of six goji cultivars were investigated. We detected 70 epicuticular wax compounds in six goji cultivars. Among them, fatty acids, alkanes, and primary alcohols were the major components of the cuticular wax of goji berries, which were related to the formation of irregular lamellar crystal structures. The terpenoid compounds in the cuticular wax of goji berries were highly resistant to Alternaria rot. Moreover, the CER1, CER6, LACS1, MAH1, LTP4, ABC11, MYB96, and WIN1 genes in goji berries might be closely related to wax synthesis. These results provide valuable information for breeding and screening goji cultivars suitable for postharvest storage.

AaPKAc Regulates Differentiation of Infection Structures Induced by Physicochemical Signals From Pear Fruit Cuticular Wax, Secondary Metabolism, and Pathogenicity of Alternaria alternata.

Alternaria alternata, the casual agent of black rot of pear fruit, can sense and respond to the physicochemical cues from the host surface and form infection structures during infection. To evaluate the role of cyclic AMP-dependent protein kinase (cAMP-PKA) signaling in surface sensing of A. alternata, we isolated and functionally characterized the cyclic adenosine monophosphate-dependent protein kinase A catalytic subunit gene (AaPKAc). Gene expression results showed that AaPKAc was strongly expressed during the early stages of appressorium formation on hydrophobic surfaces. Knockout mutants ΔAaPKAc were generated by replacing the target genes via homologous recombination events. We found that intracellular cAMP content increased but PKA content decreased in ΔAaPKAc mutant strain. Appressorium formation and infection hyphae were reduced in the ΔAaPKAc mutant strain, and the ability of the ΔAaPKAc mutant strain to recognize and respond to high hydrophobicity surfaces and different surface waxes was lower than in the wild type (WT) strain. In comparison with the WT strain, the appressorium formation rate of the ΔAaPKAc mutant strain on high hydrophobicity and fruit wax extract surface was reduced by 31.6 and 49.3% 4 h after incubation, respectively. In addition, AaPKAc is required for the hypha growth, biomass, pathogenicity, and toxin production of A. alternata. However, AaPKAc negatively regulated conidia formation, melanin production, and osmotic stress resistance. Collectively, AaPKAc is required for pre-penetration, developmental, physiological, and pathological processes in A. alternata.

Fertile Intersectional F1 Hybrids of 4x Vaccinium meridionale (Section Pyxothamnus) and Highbush Blueberry, V. corymbosum (Section Cyanococcus)

Vaccinium meridionale (section Pyxothamnus), a tetraploid species native to higher altitude locations in Jamaica, Colombia, and Venezuela, is of considerable interest to blueberry breeders for its profuse, concentrated flowering and monopodial plant structure, both of which may be useful in breeding for mechanical harvest. In this study, tetraploid V. meridionale was successfully hybridized as a male with 4x V. corymbosum (section Cyanococcus, highbush blueberry). The first-generation hybrids with highbush blueberry selections were intermediate in morphology and notably vigorous. The 4x F1 hybrids displayed variable branching structure, dormancy, prolificacy, fruit wax, etc.; however, most appear to be deciduous to semi-evergreen, with small, dark-colored fruit. The F1 hybrids displayed good fertility as females in backcrosses to 4x highbush and these crosses have produced numerous offspring morphologically indistinguishable from 4x highbush at the seedling stage. Evaluations of male fertility found variation for pollen production and quality but, significantly, found some clones with very good shed, high stainability, and almost complete tetrad production. The fertility suggests that these hybrids, despite being derived from intersectional crosses, might be conventionally used without significant difficulty. These hybrids also have potential value for the nascent V. meridionale breeding efforts occurring in Colombia, South America.

The chemical composition and potential role of epicuticular and intracuticular wax in four cultivars of table grapes

Abstract Plant cuticular wax is the first barrier to resist biotic and abiotic stress. However, little is known about the compositional differences between the epicuticular and intracuticular wax in grape berry. The compositional, morphological and functional features of cuticular wax in grape berries of Vitis vinifera cv. ‘Kyoho’, ‘Muscat Hamburg’, ‘Redglobe’, and ‘Zuijinxiang’ were investigated. The total and epicuticular wax of four berries were mainly composed of terpenoids, hydrocarbons, alcohols, fatty acids and esters. Oleanolic acid was the most abundant terpenoid among the four cultivars. Scanning electron microscopy revealed the crystalline flakes structure of the cuticular wax. Additionally, the removal of epicuticular wax accelerated the weight loss, browning, and softening of grape berries, indicating the plastic-wrap-like effect of the cuticular wax on postharvest quality. This study provided the theoretical basis for further application of the fruit wax or waxy analogue.

Hybrid oil-in-water emulsions applying wax(lecithin)-based structured oils: Tailoring interface properties

This study addressed the impact of fruit wax(lecithin)-based oleogels as dispersed phase in formation and stability of oil-in-water emulsions. These hybrid emulsions were prepared above the melting point of the oleogels, using Tween 80 (T80) or whey protein isolate (WPI) as emulsifiers. Both mono- and mixed-component oleogels comprised of fruit wax (FW) or FW + lecithin (FWLEC), respectively, were studied as lipid phases. After hot-homogenization, emulsions were submitted to quiescent cooling and stored over 14 days at 5 or 25 °C, in such temperatures supposed to assist or hinder oleogelation, respectively. Time course promoted a slight decrease in zeta potential only for WPI-stabilized emulsions and particle size distribution was shifted to larger size values, but showing a lesser extent to those stored at 5 °C. The presence of oleogels improved kinetic stability of emulsions compared to liquid oil at both temperatures, disclosing the role of the combined effects of the type of emulsifier and oleogelator(s)-emulsifier interactions. These outcomes are associated with the interfacial activity played by both oleogelators, but mainly lecithin that led to lower values of interfacial tension. In addition FWLEC combined with WPI showed the lowest complex modulus from dilational rheology, which can be related with WPI-LEC complex formation. Overall, results suggest that oleogelators migrated to the O/W interface of dispersed droplets, no longer reflecting oleogel bulk properties and showing a more complex behavior. However, the formation of more complex structures at the interface favored greater stability of the emulsions. Thus, the new perspective of oleogel-inspired fat droplets in hybrid systems can expand the conventional approach of oil structuring to create mixed interfaces tailoring oil-in-water emulsions properties.

Wax composition and concentration in jujube (Ziziphus jujuba Mill.) cultivars with differential resistance to fruit cracking

Fruit cracking is a key problem restricting the development of the jujube (Ziziphus jujuba) industry, and is closely related to the distribution of the wax layer on the surface of the fruit. Three jujube cultivars with different levels of cracking resistance, namely ‘Popozao’, ‘Banzao’, and ‘Hupingzao’, were selected for comparison. Cracks on the cuticular membrane (CM) of ‘Hupingzao’ widened and deepened during the coloring period. The wax level of highly cracking-resistant ‘Popozao’ was significantly higher than that of ‘Hupingzao’ during the fruit coloring period. The fruit wax composition of the three jujube cultivars were quite similar, consisting mainly of alkanes, triterpenoids, aldehydes, amines, phenols, esters, ketones, fatty acids, primary alcohols, and other, unclassified compounds. Fatty acids, primary alcohols, and alkanes were the predominant fruit wax compounds of the three cultivars. We further analyzed the carbon chain length of aliphatic compounds and found that the concentration of fatty acids in ‘Popozao’ was significantly lower than that in ‘Banzao’ and ‘Hupingzao’ during the coloring period. Moreover, C28–30 were the most abundant primary alcohols during fruit development.Highly cracking-resistant cultivar ‘Popozao’ contains more very-long-chain alkanes and aldehydes (carbon atom >20) than ‘Banzao’ and ‘Hupingzao’ during the coloring period. In addition, we assessed the expression levels of 11 genes involved in fatty acid biosynthesis, elongation, and degradation, and in wax biosynthesis. Gene expression analysis indicated that KCS1, CER1, CYP86B1, and CYP86A play crucial roles in wax formation on jujube fruit. In conclusion, fruit cracking was correlated with whether wax synthesis is coordinated with fruit enlargement and‘Popozao’ has a stronger ability to synthesize very-long-chain alkanes and aldehydes. Understanding the diff ;erences in the cuticular wax and the activities of the corresponding genes in jujube cultivars with different sensitivities to cracking will provide a specific way to prevent fruit cracking.

Morphological Variation of Castor Bean (Ricinus communis L.) on Peatland Area in Kepulauan Meranti Riau Indonesia

Castor (Ricinus communis L.) has been reported as source of raw material for various products, including biofuel, cosmetic and pharmaceutical industries. This plant is known as an adaptive plant which perform well-growth and development in unfertile soil. We observed that castor plants grow and develop in Kepulauan Meranti, Riau Province, Indonesia where peatland mostly dominates. Objective of the study was to evaluate genetic diversity of castor bean germplasm in Kepulauan Meranti grown in fired-peatland area based on morphological characters. Sampled plants were tagged and parts of plant were photographed and characterized. Some plant organs such as leaves and fruits were taken for more identification. We observed 12 castor accessions showing distinctive phenotypes. Morphological characters that varied among genotypes were plant architecture; stem anthocyanin; stem wax; stem color; adaxial leaf surface; fruit wax; form of racemic; main seed coloration; secondary coloration of seed; and type of secondary coloration of seed. All genotypes showed prickle existence on fruit surface. The result indicates that castor germplasm in Kepulauan Meranti serve diverse genetic variability. Further studies including assessment based on agronomic, biochemical and molecular approaches are still required for supporting castor breeding program to develop new cultivars particularly that adaptive to peat soil area.

Cuticular wax of mandarin fruit promotes conidial germination and germ tube elongation, and impairs colony expansion of the green mold pathogen, Penicillium digitatum

Abstract The cuticle of citrus is known to modulate fruit postharvest quality and is hypothesized to be involved in resistance against the fungal pathogen, Penicillium digitatum. However, only scarce information is available on the effect of cuticular wax on the conidial germination, germ tube elongation, and colony development of P. digitatum. Utilizing a versatile Formvar®-based in vitro system, we were able to assess the development of P. digitatum in the absence of secondary effects of its host. In vivo and in vitro, we found that the cuticular wax of mandarin (Citrus reticulata) fruit impaired P. digitatum colony expansion. Compared with the colony size of P. digitatum on intact fruit, the area of colonies on fruit supplemented with mandarin cuticular wax decreased significantly by 1.7 times, whereas it increased 1.6 times on dewaxed fruit 72 h post inoculation. Similar results were observed at 96 h post inoculation. Thus, the cuticular wax of mandarin fruit, acting as a physical barrier, impairs the colony expansion of P. digitatum, making it a viable alternative for citrus fruit coating that effectively controls green mold colony formation during postharvest storage. Interestingly, in vitro cuticular wax of mandarin fruit dramatically stimulated conidial germination and germ tube elongation of this pathogen. These results suggest that the cuticular wax might be the chemical cue for P. digitatum during host-recognition processes. Overall, our results suggest that the cuticular wax of mandarin fruit plays meaningful roles in the interaction between the citrus fruit and P. digitatum, and hence, can be considered for postharvest disease management.

Phospholipase C From Alternaria alternata Is Induced by Physiochemical Cues on the Pear Fruit Surface That Dictate Infection Structure Differentiation and Pathogenicity.

To investigate the mechanisms of phospholipase C (PLC)-mediated calcium (Ca2+) signaling in Alternaria alternata, the regulatory roles of PLC were elucidated using neomycin, a specific inhibitor of PLC activity. Three isotypes of PLC designated AaPLC1, AaPLC2, and AaPLC3 were identified in A. alternata through genome sequencing. qRT-PCR analysis showed that fruit wax extracts significantly upregulated the expression of all three PLC genes in vitro. Pharmacological experiments showed that neomycin treatment led to a dose-dependent reduction in spore germination and appressorium formation in A. alternata. Appressorium formation was stimulated on hydrophobic and pear wax-coated surfaces but was significantly inhibited by neomycin treatment. The appressorium formation rates of neomycin treated A. alternata on hydrophobic and wax-coated surfaces decreased by 86.6 and 47.4%, respectively. After 4 h of treatment, exogenous CaCl2 could partially reverse the effects of neomycin treatment. Neomycin also affected mycotoxin production in alternariol (AOH), alternariol monomethyl ether (AME), altenuene (ALT), and tentoxin (TEN), with exogenous Ca2+ partially reversing these effects. These results suggest that PLC is required for the growth, infection structure differentiation, and secondary metabolism of A. alternata in response to physiochemical signals on the pear fruit surface.

Effects of palmitic acid (16:0), hexacosanoic acid (26:0), ethephon and methyl jasmonate on the cuticular wax composition, structure and expression of key gene in the fruits of three pear cultivars.

The chemical composition, crystal morphology and expression levels of associated genes involved in the cuticular wax of three pear cultivars 'Housui', 'Cuiguan' and 'Yuluxiang' after treatment with palmitic acid (PA), hexacosanoic acid (HA), ethephon and methyl jasmonate (Meja) were determined. A total of 59 cuticular wax compounds were detected across all samples. The wax coverage of 'Housui' fruits increased by 71.74, 93.48 and 89.13% after treatment with PA, ethephon and Meja, respectively, and treatment with PA, HA and Meja also increased the wax coverage in 'Cuiguan' (65.33, 20.00 and 21.33% respectively) and in 'Yuluxiang' (38.60, 63.16 and 42.11% respectively) fruits. Heatmap clustering analysis and partial least-squares-discriminate analysis (PLS-DA) also revealed that the different treatments exerted various influences on cuticular wax among the different cultivars. In addition, the wax component coverage and wax crystal structures showed variations among the different cultivars as well as different treatments. Gene expression analysis revealed 11 genes likely to be involved in pear fruit wax synthesis, transport and regulation. Taken together, the results of this study demonstrate that the differences in the cuticular waxes of the fruits of different cultivars after treatment with PA, HA, ethephon or Meja might lead to a better understanding of the regulatory effect of a substrate or elicitor on the composition and deposition of cuticular waxes.

Waxing and cultivar affect Salmonella enterica persistence on cucumber (Cucumis sativus L.) fruit

A dearth of knowledge exists on the pathogen-commodity association of Salmonella enterica on cucumber, despite cucumbers being implicated in multiple salmonellosis outbreaks in recent years in the U.S. Data are lacking on cultivar susceptibility to Salmonella colonization in relation to heterogeneity in fruit surface morphology. Further, fruit waxing is a common practice in wholesale cucumber to preserve the water content of fruit and prolong shelf-life, but its impact on epiphytic microbiota is not well studied. This study investigated the survival of Salmonella Newport and S. Javiana on the surface of six cucumber cultivars of varying surface morphology and the effect of fruit waxing on the persistence of S. Newport. S. Newport and S. Javiana were spot inoculated onto fruit of cultivars ‘Marketmore 97’, ‘Patio Snacker’ and ‘Corinto’ (varieties with trichomes or spines), and ‘Bella’, ‘Pepinex’ and ‘Summer Dance’ (glabrous or smooth varieties). Cucumbers were held at room temperature for 24 h before inoculated sections of exocarp were excised for enteropathogen enumeration. S. Javiana persisted at higher populations than S. Newport (1.0 and 1.5 log CFU g−1 exocarp decline, respectively) after 24 h (P < 0.05). Fruit waxing lessened S. Newport population decline after 24 h on all cultivars tested (P < 0.01). While there was a ~2 log CFU g−1 exocarp decline in populations on unwaxed cucumbers, the reduction on waxed cucumbers was ~1 log CFU g−1 exocarp. A cultivar effect was also observed; ‘Summer Dance’ supported consistently higher and ‘Corinto’ and ‘Marketmore 97’ (though for S. Javiana only) consistently lower Salmonella levels. Cultivars with trichomes were associated with lower populations than glabrous cultivars (P < 0.05). Our data showed that Salmonella persistence on fruit differed for the two serotypes tested and that cultivar differences play a role in determining cucumber surface favourability for pathogen colonization. Additionally, fruit waxing may elevate the risk of Salmonella persistence on cucumber.

β-Amyrin Ameliorates Alzheimer's Disease-Like Aberrant Synaptic Plasticity in the Mouse Hippocampus.

Alzheimer’s disease (AD) is a progressive and most frequently diagnosed neurodegenerative disorder. However, there is still no drug preventing the progress of this disorder. β-Amyrin, an ingredient of the surface wax of tomato fruit and dandelion coffee, is previously reported to ameliorate memory impairment induced by cholinergic dysfunction. Therefore, we tested whether β-amyrin can prevent AD-like pathology. β-Amyrin blocked amyloid β (Aβ)-induced long-term potentiation (LTP) impairment in the hippocampal slices. Moreover, β-amyrin improved Aβ-induced suppression of phosphatidylinositol-3-kinase (PI3K)/Akt signaling. LY294002, a PI3K inhibitor, blocked the effect of β-amyrin on Aβ-induced LTP impairment. In in vivo experiments, we observed that β-amyrin ameliorated object recognition memory deficit in Aβ-injected AD mice model. Moreover, neurogenesis impairments induced by Aβ was improved by β-amyrin treatment. Taken together, β-amyrin might be a good candidate of treatment or supplement for AD patients.

Ameliorative effect of ursolic acid on ochratoxin A-induced renal cytotoxicity mediated by Lonp1/Aco2/Hsp75

Ochratoxin A (OTA) is a mycotoxin ubiquitous in feeds and foodstuffs. The water-insoluble pentacyclic triterpene bioactive compound, ursolic acid (UA), is widespread in various cuticular waxes of edible fruits, food materials, and medicinal plants. Although studies have reported that oxidative stress was involved in both the nephrotoxicity of OTA and the renoprotective function of UA, the role of stress-responsive Lon protease 1 (Lonp1) in the renoprotection of UA against OTA is still unknown. In this study, cell viability, reactive oxygen species (ROS) production, and several proteins’ expressions of human embryonic kidney 293T (HEK293T) cells in response to UA, OTA, and/or Lonp1 inhibitor CDDO-me treatment were detected to reveal the protective mechanism of UA against OTA-induced renal cytotoxicity. Results indicated that a 2 h-treatment of 1 μM UA could significantly alleviate the ROS production and cell death induced by a 24 h-treatment of 8 μM OTA in HEK293T cells (P < 0.05). Compared with the control, the protein expressions of Lonp1, Aco2 and Hsp75 were significantly inhibited after 8 μM OTA treating for 24 h (P < 0.05), which could be notably reversed by the pre-treatment and post-treatment of 1 μM UA (P < 0.05). The protein expressions of Lonp1, Aco2 and Hsp75 were inhibited by the addition of CDDO-me. The three protein expression trends were similar before and after the addition of CDDO-me. In conclusion, OTA could inhibit the expression of Lonp1, suppressing Aco2 and Hsp75 as a result, thereby activating ROS and inducing cell death in HEK293T cells, which could be alleviated by UA pre-treatment.

Transcriptomic and Gas Chromatography-Mass Spectrometry Metabolomic Profiling Analysis of the Epidermis Provides Insights into Cuticular Wax Regulation in Developing 'Yuluxiang' Pear Fruit.

The layer of cuticular wax covering fruits plays important roles in protecting against disease, preventing non-stomatal water loss, and extending shelf life. However, the molecular basis of cuticular wax biosynthesis in pear (Pyrus) fruits remains elusive. Our study thoroughly investigates cuticular wax biosynthesis during pear fruit development from morphologic, transcriptomic, and gas chromatography-mass spectrometry metabolomic perspectives. Our results showed that cuticular wax concentrations increased during the early stage [20-80 days after full bloom (DAFB)] from 0.64 mg/cm2 (50 DAFB) to 1.75 mg/cm2 (80 DAFB) and then slightly decreased to 1.22 mg/cm2 during the fruit ripening period (80-140 DAFB). Scanning electron microscopy imaging indicated that wax plate crystals increased and wax structures varied during the pear fruit development. The combined transcriptomic and metabolomic profiling analysis revealed 27 genes, including 12 genes encoding transcription factors and a new structural gene (Pbr028523) encoding β-amyrin synthase, participating in the biosynthesis, transport, and regulation of cuticular wax according to their expression patterns in pear fruit. The quantitative real-time polymerase chain reaction experiments of 18 differentially expressed genes were performed and confirmed the accuracy of the RNA-Seq-derived transcript expression. A model of VLCFAs and cuticular wax synthesis and transport in pear fruit is proposed, providing a mechanistic framework for understanding cuticular wax biosynthesis in pear fruit. These results and data sets provide a foundation for the molecular events related to cuticular wax in 'Yuluxiang' pear fruit and may also help guide the functional analyses of candidate genes important for improving the cuticular wax of pear fruit in the future.

Deposition of plant lipids after single application of a lip care product determined by confocal raman spectroscopy, corneometry and transepidermal water-loss.

ObjectiveLip treatment products often incorporate oils and waxes in their formulations, and a desired outcome of their use is to prevent lip dryness and roughness as well as help to repair this condition. The objective of this study was to combine confocal Raman spectroscopy with skin capacitance (corneometry) and transepidermal water loss (closed chamber Aquaflux system) measurements, in the evaluation of the degree of moisturization and lip skin penetration of a fruit wax (Rhus vernicula peel cera) and natural oil‐based (Cocos nucifera fruit oil and Olea europea oil) lip care product, following a single application.MethodsThe study was conducted on a total of 15 healthy female volunteers. Instrumental measurements were performed before and 30 min, 2 h and 6 h after a single application of the product.ResultsLip skin barrier function as well as lip hydration were significantly improved and penetration of olive oil was maintained for at least 6 h post product application. The deposition of the three component lipids (berry fruit wax, coconut oil and olive oil) into the stratum corneum after a single application of the lip care product was maintained and data significant for 2–6 h post product application. Lipid deposition was regarded as a positive long‐lasting skin care (depot‐) effect combined with a profound hydrating effect for about 6 h.ConclusionThe tri‐method approach taken in this study is deemed relevant and valid for measuring lip hydration offering a complimentary assessment of the barrier function of lip skin and interactive effects of cosmetic ingredients.

Colour and quality maintenance of cured 'Magallanes' pummelo fruit coated with chitosan

This study evaluated the efficacy of chitosan at various concentrations (0%, 0.5%, 1.0%, and 1.5%) and a commercial fruit wax in maintaining the quality of cured 'Magallanes' pummelo fruit stored in ambient room conditions for 12 weeks. Chitosan at 1.5% reduced weight loss of pummelo up to nine weeks after treatment (WAT). Compared to the control, fruit treated with fruit wax and chitosan, regardless of the concentration, had better visual quality. Chitosan slowed down the peel colour change as indicated by lower a*. Fruit treated with 1.5% chitosan exhibited lower granulation percentage than all other treatments. Electrolyte leakage varied only at 12 WAT. Chitosan did not affect shrivelling, decay, L*, b*, hue, chroma, total soluble solids, and juice content of pummelo. Chitosan at 1.5% has a potential in maintaining better quality of cured 'Magallanes' pummelo fruit with lower weight loss and electrolyte leakage, lesser granulation, and slower degreening.

Colour and quality maintenance of cured 'Magallanes' pummelo fruit coated with chitosan

This study evaluated the efficacy of chitosan at various concentrations (0%, 0.5%, 1.0%, and 1.5%) and a commercial fruit wax in maintaining the quality of cured 'Magallanes' pummelo fruit stored in ambient room conditions for 12 weeks. Chitosan at 1.5% reduced weight loss of pummelo up to nine weeks after treatment (WAT). Compared to the control, fruit treated with fruit wax and chitosan, regardless of the concentration, had better visual quality. Chitosan slowed down the peel colour change as indicated by lower a*. Fruit treated with 1.5% chitosan exhibited lower granulation percentage than all other treatments. Electrolyte leakage varied only at 12 WAT. Chitosan did not affect shrivelling, decay, L*, b*, hue, chroma, total soluble solids, and juice content of pummelo. Chitosan at 1.5% has a potential in maintaining better quality of cured 'Magallanes' pummelo fruit with lower weight loss and electrolyte leakage, lesser granulation, and slower degreening.