Everyone who enters a marathon has their own way of doing things.This applies to the training done in preparation for the big day,but it also applies to the actual marathon itself.Clothing is a big consideration for t...Everyone who enters a marathon has their own way of doing things.This applies to the training done in preparation for the big day,but it also applies to the actual marathon itself.Clothing is a big consideration for these daring runners-you should make sure youll be comfy and not get too warm!But few people have an accessory quite like Moshe Lederfien.Every time you spot him in a marathon,without fail,he will have a pineapple on his head.The 70⁃year⁃old Israeli marathoner who has become famous for balancing a pineapple on his head during marathons,has received scrutiny(详细审查)from Spanish citizens.展开更多
[Objective] The aim was to compare effects of nitrogen and potassium fertigation on yield and quality of pineapple during the late growing period. [Method] Urea, potassium sulfate, and potassium chloride were taken as...[Objective] The aim was to compare effects of nitrogen and potassium fertigation on yield and quality of pineapple during the late growing period. [Method] Urea, potassium sulfate, and potassium chloride were taken as three fertilizers which were set at three levels, respectively, and the group without additional fertilizers was taken as control group. [Result] Compared with control group, weight of individual pineapple was significantly increased by fertigation of urea at 7.5 kg or potassium sulfate at 18 kg per 667 m 2 and the increase yields were 22.5% and 28.9%, respectively. Effects of nitrogen and potassium fertigation on yield and quality of pineapple were compared. [Conclusion] Potassium sulfate fertigation would promote sugar accumulation and improve quality of fruits. Furthermore, chlorophyll content can be enhanced and photosynthetic capacity can be reinforced.展开更多
[Objective]The pathogen of pineapple anthracnose were isolated and identified,and the biological characteristics of the pathogen were studied.[Method]Pathogen was isolated and purified from the leaves collected from d...[Objective]The pathogen of pineapple anthracnose were isolated and identified,and the biological characteristics of the pathogen were studied.[Method]Pathogen was isolated and purified from the leaves collected from different areas in Hainan province which had been infected by pineapple anthracnose,and the biological characteristics were studied as well as morphological identification of the pathogen.[Results] The pathogen of pineapple anthracnose was identified as Colletorichum gloeosprioides Penz.through morphological characteristics.The results of biological characteristic test showed that the optimum temperature for mycelium growth and spore germination were 25-30 and 28-30 ℃,respectively;and the optimum pH value was 6.0-8.0;complete darkness was the best condition for growth of mycelium,while alternative light and darkness was most beneficial for spore germination;the best carbon sources for mycelium growth were glucose,D-fructose and maltose;except for L-arabinose and D-galactose,the other carbon sources all had promotion effect on spore germination;yeast extract,peptone and beef extract were proved to be beneficial for mycelium growth and spore germination.Aspartic acid was only beneficial for spore germination;spores were just able to germinate when the relative humidity（RH）was greater than 90%,spore germination was the highest under water drops condition.[Conclusion]The results laid preliminary basis for the control of pineapple anthracnose.展开更多
Objective:To investigate the ability of the methanolic extract of pineapple peel to modulate alcohol-induced lipid peroxidation,changes in catalase activities and hepatic biochemical marker levels in blood plasma.Meth...Objective:To investigate the ability of the methanolic extract of pineapple peel to modulate alcohol-induced lipid peroxidation,changes in catalase activities and hepatic biochemical marker levels in blood plasma.Methods:Oxidative stress was induced by oral administration of ethanol(20%w/v) at a dosage of 5 niL/kg bw in rats.After 28 days of treatment,the rats were fasted overnight and sacrificed by cervical dislocation.Blood was collected with a 2 mL syringe by cardiac puncture and was centrifuged at 3000 rpm for 10 min.The plasma was analyzed to evaluate malondialdehyde(MDA),catalase activity,aspartate aminotransferase(AST),alkaline phosphatase(ALP) and alanine aminotransferase(ALT) concentrations.Results:Administration of alcohol caused a drastic increase(87.74%) in MDA level compared with the control.Pineapple peel extract significantly reduced the MDA level by 60.16%at 2.S mL/kg bw.Rats fed alcohol only had the highest catalase activity,treatment with pineapple peel extract at 2.5 mL/kg bw however, reduced the activity.Increased AST,ALP and ALT activities were observed in rats fed alcohol only respectively,treatment with pineapple peel extract drastically reduced their activities. Conclusions:The positive modulation of lipid peroxidation,catalase activities as well as hepatic biomarker levels of blood plasma by the methanolic extract of pineapple peels under alcoholinduced oxidative stress is an indication of its protective ability in the management of alcoholinduced toxicity.展开更多
This study deals with the analysis of dynamic mechanical,thermal and flammability properties of treated and untreated pineapple leaf fiber(PALF)and kenaf fiber(KF)phenolic composites.Results indicated that storage mod...This study deals with the analysis of dynamic mechanical,thermal and flammability properties of treated and untreated pineapple leaf fiber(PALF)and kenaf fiber(KF)phenolic composites.Results indicated that storage modulus was decreased for all composites with increases in temperature and pattern of slopes for all composites,having almost the same values of E′at glass transition temperature(Tg).The peak of the loss modulus of pure phenolic composites was shown to be much less.After the addition of kenaf/PALF,peaks were higher and shifted towards a high temperature.The Tan delta peak height was low for pure phenolic composites and maximum for 60%PALF phenolic composites.Cole-Cole analysis was carried out to understand the phase behavior of the composite samples.Thermogravimetric analysis(TGA)results indicated that pure phenolic composites have better thermal stability than PALF and kenaf phenolic composites.Vertical and horizontal UL-94 tests were conducted and showed pure phenolic resin is highly fire resistant.The overall results showed that treated KF composites enhanced the dynamic mechanical and thermal properties among all PALF/KF composites.展开更多
In this paper, the biomass productivity and nutrient cycling in an agroforestry system of coconut (Cocus nucifera) interplanted with pineapple (Ananas comosus) had been studied. The result showed that the biomass prod...In this paper, the biomass productivity and nutrient cycling in an agroforestry system of coconut (Cocus nucifera) interplanted with pineapple (Ananas comosus) had been studied. The result showed that the biomass productivity of this ecosystem was 47 460 kg...hm2...a?1, which was 4.3 times as much as that of pure coconut plantation. In the biological cycling of N, P. K elements, the total annual retention was 559.470 kg...hm?2, the annual return was 410.745 kg...hm?2, the annual uptake was 970.475 kg...hm?2, respectively. The average circulation rate in three nutrient elements (N, P, K) was 42.32%, which was 27.53% more than that in pure coconut stands. Coconut interplanted with pineapple was proved to be one of optimum cultural patterns, which had the higher biomass productivity, and better usage efficiency of environment resources in tropical areas.展开更多
In this study,pineapple leaf fiber(PALF),kenaf fiber(KF)and PALF/KF/phenolic(PF)composites were fabricated and their mechanical properties were investigated.The mechanical properties(tensile,flexural and impact)of the...In this study,pineapple leaf fiber(PALF),kenaf fiber(KF)and PALF/KF/phenolic(PF)composites were fabricated and their mechanical properties were investigated.The mechanical properties(tensile,flexural and impact)of the PALF/KF/PF hybrid composites were investigated and compared with PALF/KF composites.The 3P7K exhibited enhanced tensile strength(46.96 MPa)and modulus(6.84 GPa),flexural strength(84.21 MPa)and modulus(5.81 GPa),and impact strength(5.39 kJ/m2)when compared with the PALF/PF and KF/PF composites.Scanning electron microscopy(SEM)was used to observe the fracture surfaces of the tensile testing samples.The microstructure of the 7P3K hybrid composite showed good interfacial bonding and the addition of KF improved the interfacial strength.It has been concluded that the 3P7K ratio allowed obtaining materials with better mechanical properties(tensile,flexural and impact strengths)than PALF/PF and KF/PF composites.The results obtained in this study will be used for further comparative study of untreated hybrid composites with treated hybrid composites.展开更多
Polylactic acid(PLA)possesses good mechanical and biodegradability properties which make it a suitable material for polymer composites whereas brittleness and high costs limit its utilization in various applications.T...Polylactic acid(PLA)possesses good mechanical and biodegradability properties which make it a suitable material for polymer composites whereas brittleness and high costs limit its utilization in various applications.The reinforcement of natural fibres with biopolymers has been formed to be an efficient technique to develop composites having the ability to be fully biodegradable.This study concerns with the incorporation of various percentages of untreated and alkali-treated Coir Fibres(CF)and pineapple leaf fibres(PALF)in PLA biocomposites and characterizations of flexural,morphological and dynamic mechanical properties.Flexural properties showed that the treated C1P1 hybrid composites(C1P1A)displayed highest flexural strength(35.81 MPa)and modulus(5.28 GPa)among all hybrid biocomposites.Scanning Electron Microscopy(SEM)revealed a behaviour of fibre-matrix adhesion in untreated treated biocomposites.SEM observation revealed good dispersion of the fillers in PLA.Dynamic mechanical analysis revealed that C1P1A showed highest glass transition temperature(Tg)and storage modulus(E')while untreated C3P7 displayed the least Tg and E'.Overall findings showed that alkali-treated hybrid biocomposites(CF/PALF/PLA)especially C1P1A have improved flexural properties,dynamic and morphological properties over untreated biocomposites.Success of these findings will provide attracting consideration of these hybrid biocomposites for various lightweight uses in a broad selection of industrial applications such as biomedical sectors,automobile,construction,electronics equipment,and hardware tools.展开更多
Somaclonal variation in tissue culture is a common phenomenon induced by various external or internal environmental conditions,resulting in heritable or non-heritable alterations in gene expression. One crucial mechan...Somaclonal variation in tissue culture is a common phenomenon induced by various external or internal environmental conditions,resulting in heritable or non-heritable alterations in gene expression. One crucial mechanism involved in plant growth and development is epigenetic regulation. A highly dynamic epigenome can respond to environmental changes by regulating gene expression. DNA methylation is one of these epigenetic modifications that can alter gene expression in tissue-cultured pineapple plants. The underlying mechanism of such somaclonal variations in pineapple and the epigenetic regulation involvement in somaclonal variations has not been studied. This study performed DNA methylome and transcriptome sequencing of wild-type(WT) and mutant pineapple plants(WS, HW, and TW). We observed altered DNA methylation patterns in chlorophyll development in the mutants. Specifically, we noticed that the methylation levels in the CHG and CHH contexts were lower in the gene body regions compared to the upstream and downstream regions. We identified several thousand differentially methylated regions(DMRs) located at the gene body regions, some of which overlapped with the differentially expressed genes(DEGs). Functional enrichment analyses suggested that these genes were involved in chlorophyll metabolism. Thus, our results revealed that the transcriptional regulation of many chlorophyll metabolic essential genes could be regulated by DNA methylation caused by somaclonal variations and provided insights into epigenetic mechanisms underlying the regulation of chlorosis in pineapple plants.展开更多
Pineapple industry has played important roles in China’s economics in tropical- and subtropical-areas. Pineapple industry in China has been damaged by water-heart fruit. The objective of this research is to clarify t...Pineapple industry has played important roles in China’s economics in tropical- and subtropical-areas. Pineapple industry in China has been damaged by water-heart fruit. The objective of this research is to clarify the mechanism underlying water-heart fruit of pineapple and find ways for preventing water-heart fruit. We found that water logging can cause water-heart pineapple. The longer the pineapple plants were water logged, the more fruits were found water heart. With the development of fruits, the fruits’ sensitivity to water logging increased. Spraying potassium sulfate onto the fruits after the plants are water logged can decrease the rate of pineapple water-heart. But this effect became less with the fruit development. When sucrose and its precursors in intracellular space were transferred into sink cells, hydrogen ions were required. Because of lacking hydrogen ions, sucrose and its precursors were stopped in intracellular space and seized water from cells. Water-heart fruit formed. If potassium can be gotten in intracellular space, the roles of hydrogen ions might be replaced with potassium ions. With the help of potassium ions, sucrose and its precursors were transported into sink cells and the water-heart symptoms alleviated.展开更多
Pineapple is the third largest tropical fruit in China. Pineapple industry played important roles in developing economies in tropical- and subtropical-areas in China. However, the structure of varieties is simple. The...Pineapple is the third largest tropical fruit in China. Pineapple industry played important roles in developing economies in tropical- and subtropical-areas in China. However, the structure of varieties is simple. The harvesting period is centralized. The price of pineapple fruits is often low. These challenges hindered the further development of pineapple industry. The people engaged in pineapple industry should select and cultivate new varieties with higher qualities and that can be harvested in a longer period. More work should be done in the technology on inducing inflorescence of new varieties. Precision fertilization for new varieties should be researched and developed. The technology for cultivating tissue-culture seedlings fast and at low cost should also be studied. The diseases in fruits should be prevented and controlled before harvesting.展开更多
An experiment was carried out at Mkuranga Research Station of National Coconut Development Programme （NCDP） to study the effect of light regimes on three different crops which are sweet potato, cowpea and pineapple ...An experiment was carried out at Mkuranga Research Station of National Coconut Development Programme （NCDP） to study the effect of light regimes on three different crops which are sweet potato, cowpea and pineapple between 1995 and 1996. Four light intensities with nominal values of light transmission namely L0 = 100%, L 1 = 75%, L2 = 50%, L3 = 25% were provided by nylon netting materials which filtered sunlight to varying light percentages. The experiment was a split-plot on randomized complete block design, replicated four times. Growth measurements and yield were recorded at a regular interval in all crops. Leaf morphological characteristics were carried out only on sweet potato. Result on the leaf morphological characteristics showed light intensity strongly influenced growth and development of sweet potato. Specific leaf area values in full light were smaller than those in under heavy shade. The light intensity increased the cowpea seed yield significantly （P 〈 0.01） and the interaction between seasons （year） x light regimes was significant （P 〈 0.01）. In low intensity, pineapple flowered earlier and yielded more than in high intensity. These results have provided useful information in planning intercropping models in coconut based-farming systems in Tanzania.展开更多
It has become necessary to assess how food processing methods affect qualitative qualities due to the increased consumer awareness of the health benefits of various nutrients in food. In the current study, the effects...It has become necessary to assess how food processing methods affect qualitative qualities due to the increased consumer awareness of the health benefits of various nutrients in food. In the current study, the effects of ultrasound treatment (37°C, 5 min), pasteurization (90°C, 5 min), and their combination on quality parameters, including pH, total soluble solids (TSSs), titratable acidity (TA), color values (L*, a*, b*), ascorbic acid (AA), total phenolic content (TPC), and antioxidant activity (DPPH), of pineapple juice from ripe and overripe pineapples were assessed. Color values (L*), ascorbic acid (AA), total phenolic content (TPC), and DPPH radical scavenging activity in all juice samples that were sonicated alone and in combination with pasteurization improved significantly (p and color value (a* and b*) decreased in comparison to the control. Whereas pH and acidity did not change significantly (p < 0.05). Pasteurization significantly (p , but sonicated samples significantly (p quality parameters and antioxidant activity, notably in ripe juice. Overall, pasteurization degraded these liquids but sonication, either alone or in combination with it, was advantageous for preserving their quality by retaining nutrients.展开更多
Unfavorable environmental cues severely affect crop productivity resulting in significant economic losses to farmers. In plants, multiple regulatory genes, such as the WRKY transcription factor (TF) family, modulate t...Unfavorable environmental cues severely affect crop productivity resulting in significant economic losses to farmers. In plants, multiple regulatory genes, such as the WRKY transcription factor (TF) family, modulate the expression of defense genes. However, the role of the pineapple WRKY genes is poorly understood. Here, we studied the pineapple WRKY gene, AcWRKY28, by generating AcWRKY28 over-expressing transgenic pineapple plants. Overexpression of AcWRKY28 enhanced the salt stress resistance in transgenic pineapple lines. Comparative transcriptome analysis of transgenic and wild-type pineapple plants showed that “plant-pathogen interaction” pathway genes, including 9calcium-dependent protein kinases (CPKs), were up-regulated in AcWRKY28 over-expressing plants. Furthermore, chromatin immunoprecipitation and yeast one-hybrid assays revealed AcCPK12, AcCPK3, AcCPK8, AcCPK1, and AcCPK15 as direct targets of AcWRKY28. Consistently, the study of AcCPK12 over-expressing Arabidopsis lines showed that AcCPK12 enhances salt, drought, and disease resistance. This study shows that AcWRKY28 plays a crucial role in promoting salt stress resistance by activating the expression of AcCPK genes.展开更多
Poly(lactic acid)(PLA)composite films reinforced with microcrystalline cellulose(MCC)extracted from pineapple leaf fibers(PALF)were prepared by a solution casting procedure.In an attempt to improve the interaction bet...Poly(lactic acid)(PLA)composite films reinforced with microcrystalline cellulose(MCC)extracted from pineapple leaf fibers(PALF)were prepared by a solution casting procedure.In an attempt to improve the interaction between PLA and cellulose,two approaches were adopted;first,poly(ethylene glycol)(PEG)was used as a surfactant,and second,the cellulosic fibers were pre-treated using tert-butanol(TBA).Lignocellulosic and cellulosic substrates were characterized using Fourier transform infrared(FTIR),wide-angle X-ray scattering(WAXS),and thermogravimetrical analysis(TGA).MCC from PALF showed good thermal stability,left few residues after decomposing,and exhibited high crystallinity index.Mechanical,thermal and thermomechanical properties of the PLA composites were also evaluated.Multiple PLA endotherms were observed in composites with TBA-treated MCC due to crystal nucleation effects.The ultimate tensile strain values for all composites were lower than that of the pristine PLA.However,4 wt.%MCC content provided balanced engineering properties in terms of static and dynamic tensile properties.展开更多
Nowadays,the production of consumer goods is based on the use of non-renewable raw materials,which in recent years has been performing as a problem for the environment.Considering the large number of available biofibe...Nowadays,the production of consumer goods is based on the use of non-renewable raw materials,which in recent years has been performing as a problem for the environment.Considering the large number of available biofibers in nature,their use in the development of polymeric composites has inevitably emerged,it is also necessary to take into account the countless discarded plastics that still have the potential to be reused.In this work,fibers were extracted from pineapple crown residues and utilized to compose sustainable composites using recycled polypropylene from cups discarded in the trash as a matrix.However,it is known that for good performance,it is necessary to achieve a good chemical interaction between the fiber and the matrix.In order to improve this interaction,alkaline mercerization treatment was carried out on the surface of the fibers removing some components incompatible with the polymer.In this work,the effect of the mercerization treatment on the properties of the fibers was studied,as well as their interaction with the matrix.The effect of fiber concentration on the mechanical and thermal properties of composites was also evaluated.Levels of 5 and 7 wt%were used for both natural and mercerized fibers.A decrease in the number of degradation stages was observed through thermogravimetry analyses(from four in natural fiber to two in mercerized fibers),showing that the mercerization performed on the fibers was effective.An increase in the degree of crystallinity of mercerized fibers was also observed through the results of X-ray diffraction.Both techniques indicate that amorphous compounds,such as hemicellulose and lignin,were partially removed.Through the tensile test,it could be noted that all composites presented higher values of de elastic modulus than recycled polypropylene without added load;however,there were no differences in the elastic modulus between the different types of fibers and load levels.Therefore,it is interesting to use fibers as reinforcing agents in polymers;however,the treatment did not increase the mechanical properties of the composites.In parallel,other factors,such as the dispersion of the components,must be taken into account to justify this result.展开更多
Waste is the main problem for the environment.Handling waste for various useful applications has a benefit for the future.This work has been studied for handling pineapple peel waste to make composite film bacterial c...Waste is the main problem for the environment.Handling waste for various useful applications has a benefit for the future.This work has been studied for handling pineapple peel waste to make composite film bacterial cellulose nanocomposite membrane(BCNM)with addition graphite nanoplatelet(GNP).The concentration of GNP in the membrane influence the membrane properties.The bacterial cellulose(BC)pellicle was synthesized by using media from pineapple peel waste extract.BC pellicle is cleaned with water and NaOH solution to be free from impactors.BCNM is synthesized through the mechanical disintegration stage.The results of disintegration using high pressure homogenizer at 150 bar and five cycles.BCNM/GNP is synthesized with varying addition of GNP of 2.5,5.0,10 and 100 wt%of dry bacterial nanocellulose(BNC).The BC and GNP solution were dried in an oven for 14 h at 80℃.BCNM morphology was observed using SEM.GNP is dispersed and distributed in the BC matrix as reinforcement.FTIR analysis shows many peaks of BNC less pronounced with increasing of GNP.The higher concentration of GNP,the rougher of BCNM.The optimum tensile strength of BCNM was achieved after addition GNP of 2.5 wt%.展开更多
Pineapple leaf nanofibers(PLNFs)extracted from pineapple leaf fiber were used for reinforcing biobased polyurethane foam(BPU).The dispersion performance of PLNF in the foaming mixture system,nanocomposite foaming beha...Pineapple leaf nanofibers(PLNFs)extracted from pineapple leaf fiber were used for reinforcing biobased polyurethane foam(BPU).The dispersion performance of PLNF in the foaming mixture system,nanocomposite foaming behavior,cell morphology,cell size,density,compressive strength and dimensional stability were investigated.The viscosity of the mixtures increased with increasing the PLNF content.The addition of a tiny amount of PLNF did not influence the exothermic temperature of the foam system,but reduced the expansion and gel time of the nanocomposite foams.This reduced time was found to increase the production efficiency.Scanning electron microscopy(SEM)images showed that the PLNF neither affected the cell shape nor size.While the density of the foam was not obviously altered with the addition of a small amount of PLNF,the compressive strength and dimensional stability were significantly improved.展开更多
文摘Everyone who enters a marathon has their own way of doing things.This applies to the training done in preparation for the big day,but it also applies to the actual marathon itself.Clothing is a big consideration for these daring runners-you should make sure youll be comfy and not get too warm!But few people have an accessory quite like Moshe Lederfien.Every time you spot him in a marathon,without fail,he will have a pineapple on his head.The 70⁃year⁃old Israeli marathoner who has become famous for balancing a pineapple on his head during marathons,has received scrutiny(详细审查)from Spanish citizens.
基金Supported by Fund on Basic Scientific Research Project of Nonprofit Central Research Institutions (sscri200718)948 Project of Ministry of Agriculture [2006-G34(A)]the R&D Special Fund for Public Welfare Industry (3-41)~~
文摘[Objective] The aim was to compare effects of nitrogen and potassium fertigation on yield and quality of pineapple during the late growing period. [Method] Urea, potassium sulfate, and potassium chloride were taken as three fertilizers which were set at three levels, respectively, and the group without additional fertilizers was taken as control group. [Result] Compared with control group, weight of individual pineapple was significantly increased by fertigation of urea at 7.5 kg or potassium sulfate at 18 kg per 667 m 2 and the increase yields were 22.5% and 28.9%, respectively. Effects of nitrogen and potassium fertigation on yield and quality of pineapple were compared. [Conclusion] Potassium sulfate fertigation would promote sugar accumulation and improve quality of fruits. Furthermore, chlorophyll content can be enhanced and photosynthetic capacity can be reinforced.
基金Supported by Basic Research Operational Funds in Central Nonprofit Research Institutes"Research on Control Technology of the Major Pests and Diseases in Pineapple"(NO.2009hzs1J027)Scientific Operating Expenses in Hainan Province"Research on Demonstration of Quality Variety Introduction and Rapid Propagation Technology of Pineapple"(Qiong Financial Budget[2007]NO.134)Scientific Operating Expenses in Hainan Province"Research on Safety Regulation during TN 16 Pineapple Production Stage and Enhancement of Fruit Quality Technology"(Qiong Financial Budget[2010]NO.139)~~
文摘[Objective]The pathogen of pineapple anthracnose were isolated and identified,and the biological characteristics of the pathogen were studied.[Method]Pathogen was isolated and purified from the leaves collected from different areas in Hainan province which had been infected by pineapple anthracnose,and the biological characteristics were studied as well as morphological identification of the pathogen.[Results] The pathogen of pineapple anthracnose was identified as Colletorichum gloeosprioides Penz.through morphological characteristics.The results of biological characteristic test showed that the optimum temperature for mycelium growth and spore germination were 25-30 and 28-30 ℃,respectively;and the optimum pH value was 6.0-8.0;complete darkness was the best condition for growth of mycelium,while alternative light and darkness was most beneficial for spore germination;the best carbon sources for mycelium growth were glucose,D-fructose and maltose;except for L-arabinose and D-galactose,the other carbon sources all had promotion effect on spore germination;yeast extract,peptone and beef extract were proved to be beneficial for mycelium growth and spore germination.Aspartic acid was only beneficial for spore germination;spores were just able to germinate when the relative humidity（RH）was greater than 90%,spore germination was the highest under water drops condition.[Conclusion]The results laid preliminary basis for the control of pineapple anthracnose.
文摘Objective:To investigate the ability of the methanolic extract of pineapple peel to modulate alcohol-induced lipid peroxidation,changes in catalase activities and hepatic biochemical marker levels in blood plasma.Methods:Oxidative stress was induced by oral administration of ethanol(20%w/v) at a dosage of 5 niL/kg bw in rats.After 28 days of treatment,the rats were fasted overnight and sacrificed by cervical dislocation.Blood was collected with a 2 mL syringe by cardiac puncture and was centrifuged at 3000 rpm for 10 min.The plasma was analyzed to evaluate malondialdehyde(MDA),catalase activity,aspartate aminotransferase(AST),alkaline phosphatase(ALP) and alanine aminotransferase(ALT) concentrations.Results:Administration of alcohol caused a drastic increase(87.74%) in MDA level compared with the control.Pineapple peel extract significantly reduced the MDA level by 60.16%at 2.S mL/kg bw.Rats fed alcohol only had the highest catalase activity,treatment with pineapple peel extract at 2.5 mL/kg bw however, reduced the activity.Increased AST,ALP and ALT activities were observed in rats fed alcohol only respectively,treatment with pineapple peel extract drastically reduced their activities. Conclusions:The positive modulation of lipid peroxidation,catalase activities as well as hepatic biomarker levels of blood plasma by the methanolic extract of pineapple peels under alcoholinduced oxidative stress is an indication of its protective ability in the management of alcoholinduced toxicity.
文摘This study deals with the analysis of dynamic mechanical,thermal and flammability properties of treated and untreated pineapple leaf fiber(PALF)and kenaf fiber(KF)phenolic composites.Results indicated that storage modulus was decreased for all composites with increases in temperature and pattern of slopes for all composites,having almost the same values of E′at glass transition temperature(Tg).The peak of the loss modulus of pure phenolic composites was shown to be much less.After the addition of kenaf/PALF,peaks were higher and shifted towards a high temperature.The Tan delta peak height was low for pure phenolic composites and maximum for 60%PALF phenolic composites.Cole-Cole analysis was carried out to understand the phase behavior of the composite samples.Thermogravimetric analysis(TGA)results indicated that pure phenolic composites have better thermal stability than PALF and kenaf phenolic composites.Vertical and horizontal UL-94 tests were conducted and showed pure phenolic resin is highly fire resistant.The overall results showed that treated KF composites enhanced the dynamic mechanical and thermal properties among all PALF/KF composites.
文摘In this paper, the biomass productivity and nutrient cycling in an agroforestry system of coconut (Cocus nucifera) interplanted with pineapple (Ananas comosus) had been studied. The result showed that the biomass productivity of this ecosystem was 47 460 kg...hm2...a?1, which was 4.3 times as much as that of pure coconut plantation. In the biological cycling of N, P. K elements, the total annual retention was 559.470 kg...hm?2, the annual return was 410.745 kg...hm?2, the annual uptake was 970.475 kg...hm?2, respectively. The average circulation rate in three nutrient elements (N, P, K) was 42.32%, which was 27.53% more than that in pure coconut stands. Coconut interplanted with pineapple was proved to be one of optimum cultural patterns, which had the higher biomass productivity, and better usage efficiency of environment resources in tropical areas.
文摘In this study,pineapple leaf fiber(PALF),kenaf fiber(KF)and PALF/KF/phenolic(PF)composites were fabricated and their mechanical properties were investigated.The mechanical properties(tensile,flexural and impact)of the PALF/KF/PF hybrid composites were investigated and compared with PALF/KF composites.The 3P7K exhibited enhanced tensile strength(46.96 MPa)and modulus(6.84 GPa),flexural strength(84.21 MPa)and modulus(5.81 GPa),and impact strength(5.39 kJ/m2)when compared with the PALF/PF and KF/PF composites.Scanning electron microscopy(SEM)was used to observe the fracture surfaces of the tensile testing samples.The microstructure of the 7P3K hybrid composite showed good interfacial bonding and the addition of KF improved the interfacial strength.It has been concluded that the 3P7K ratio allowed obtaining materials with better mechanical properties(tensile,flexural and impact strengths)than PALF/PF and KF/PF composites.The results obtained in this study will be used for further comparative study of untreated hybrid composites with treated hybrid composites.
基金gratitude to Institute of Tropical Forestry and Forest Products(INTROP),Universiti Putra Malaysia for supporting the funding of research through Grant No:6369108funded by Researchers Supporting Project number(RSP-2021/117),King Saud University,Riyadh,Saudi Arabia.
文摘Polylactic acid(PLA)possesses good mechanical and biodegradability properties which make it a suitable material for polymer composites whereas brittleness and high costs limit its utilization in various applications.The reinforcement of natural fibres with biopolymers has been formed to be an efficient technique to develop composites having the ability to be fully biodegradable.This study concerns with the incorporation of various percentages of untreated and alkali-treated Coir Fibres(CF)and pineapple leaf fibres(PALF)in PLA biocomposites and characterizations of flexural,morphological and dynamic mechanical properties.Flexural properties showed that the treated C1P1 hybrid composites(C1P1A)displayed highest flexural strength(35.81 MPa)and modulus(5.28 GPa)among all hybrid biocomposites.Scanning Electron Microscopy(SEM)revealed a behaviour of fibre-matrix adhesion in untreated treated biocomposites.SEM observation revealed good dispersion of the fillers in PLA.Dynamic mechanical analysis revealed that C1P1A showed highest glass transition temperature(Tg)and storage modulus(E')while untreated C3P7 displayed the least Tg and E'.Overall findings showed that alkali-treated hybrid biocomposites(CF/PALF/PLA)especially C1P1A have improved flexural properties,dynamic and morphological properties over untreated biocomposites.Success of these findings will provide attracting consideration of these hybrid biocomposites for various lightweight uses in a broad selection of industrial applications such as biomedical sectors,automobile,construction,electronics equipment,and hardware tools.
基金supported by the Science and Technology Major Project of Guangxi (Grant No. Guike AA22068096)Guangxi Distinguished Experts Fellowship to YQ, Science and Technology Major Project of Guangxi (Grant No. Guike 2018-266-Z01)+4 种基金Project of Guangxi featured fruit innovation team on pineapple breeding and cultivation post under national modern agricultural industry technology system (Grant No. nycytxgxcxtd-17-05)Science and Technology Program of Fujian Province (Grant No. 2019N5008)Science and technology innovation project of Pingtan Science and Technology Research Institute (Grant Nos. PT2021007, PT2021003)China Postdoctoral Science Foundation (Grant No. 2018M632564)the National Natural Science Foundation of China (31970333, U1605212)。
文摘Somaclonal variation in tissue culture is a common phenomenon induced by various external or internal environmental conditions,resulting in heritable or non-heritable alterations in gene expression. One crucial mechanism involved in plant growth and development is epigenetic regulation. A highly dynamic epigenome can respond to environmental changes by regulating gene expression. DNA methylation is one of these epigenetic modifications that can alter gene expression in tissue-cultured pineapple plants. The underlying mechanism of such somaclonal variations in pineapple and the epigenetic regulation involvement in somaclonal variations has not been studied. This study performed DNA methylome and transcriptome sequencing of wild-type(WT) and mutant pineapple plants(WS, HW, and TW). We observed altered DNA methylation patterns in chlorophyll development in the mutants. Specifically, we noticed that the methylation levels in the CHG and CHH contexts were lower in the gene body regions compared to the upstream and downstream regions. We identified several thousand differentially methylated regions(DMRs) located at the gene body regions, some of which overlapped with the differentially expressed genes(DEGs). Functional enrichment analyses suggested that these genes were involved in chlorophyll metabolism. Thus, our results revealed that the transcriptional regulation of many chlorophyll metabolic essential genes could be regulated by DNA methylation caused by somaclonal variations and provided insights into epigenetic mechanisms underlying the regulation of chlorosis in pineapple plants.
文摘Pineapple industry has played important roles in China’s economics in tropical- and subtropical-areas. Pineapple industry in China has been damaged by water-heart fruit. The objective of this research is to clarify the mechanism underlying water-heart fruit of pineapple and find ways for preventing water-heart fruit. We found that water logging can cause water-heart pineapple. The longer the pineapple plants were water logged, the more fruits were found water heart. With the development of fruits, the fruits’ sensitivity to water logging increased. Spraying potassium sulfate onto the fruits after the plants are water logged can decrease the rate of pineapple water-heart. But this effect became less with the fruit development. When sucrose and its precursors in intracellular space were transferred into sink cells, hydrogen ions were required. Because of lacking hydrogen ions, sucrose and its precursors were stopped in intracellular space and seized water from cells. Water-heart fruit formed. If potassium can be gotten in intracellular space, the roles of hydrogen ions might be replaced with potassium ions. With the help of potassium ions, sucrose and its precursors were transported into sink cells and the water-heart symptoms alleviated.
文摘Pineapple is the third largest tropical fruit in China. Pineapple industry played important roles in developing economies in tropical- and subtropical-areas in China. However, the structure of varieties is simple. The harvesting period is centralized. The price of pineapple fruits is often low. These challenges hindered the further development of pineapple industry. The people engaged in pineapple industry should select and cultivate new varieties with higher qualities and that can be harvested in a longer period. More work should be done in the technology on inducing inflorescence of new varieties. Precision fertilization for new varieties should be researched and developed. The technology for cultivating tissue-culture seedlings fast and at low cost should also be studied. The diseases in fruits should be prevented and controlled before harvesting.
文摘An experiment was carried out at Mkuranga Research Station of National Coconut Development Programme （NCDP） to study the effect of light regimes on three different crops which are sweet potato, cowpea and pineapple between 1995 and 1996. Four light intensities with nominal values of light transmission namely L0 = 100%, L 1 = 75%, L2 = 50%, L3 = 25% were provided by nylon netting materials which filtered sunlight to varying light percentages. The experiment was a split-plot on randomized complete block design, replicated four times. Growth measurements and yield were recorded at a regular interval in all crops. Leaf morphological characteristics were carried out only on sweet potato. Result on the leaf morphological characteristics showed light intensity strongly influenced growth and development of sweet potato. Specific leaf area values in full light were smaller than those in under heavy shade. The light intensity increased the cowpea seed yield significantly （P 〈 0.01） and the interaction between seasons （year） x light regimes was significant （P 〈 0.01）. In low intensity, pineapple flowered earlier and yielded more than in high intensity. These results have provided useful information in planning intercropping models in coconut based-farming systems in Tanzania.
文摘It has become necessary to assess how food processing methods affect qualitative qualities due to the increased consumer awareness of the health benefits of various nutrients in food. In the current study, the effects of ultrasound treatment (37°C, 5 min), pasteurization (90°C, 5 min), and their combination on quality parameters, including pH, total soluble solids (TSSs), titratable acidity (TA), color values (L*, a*, b*), ascorbic acid (AA), total phenolic content (TPC), and antioxidant activity (DPPH), of pineapple juice from ripe and overripe pineapples were assessed. Color values (L*), ascorbic acid (AA), total phenolic content (TPC), and DPPH radical scavenging activity in all juice samples that were sonicated alone and in combination with pasteurization improved significantly (p and color value (a* and b*) decreased in comparison to the control. Whereas pH and acidity did not change significantly (p < 0.05). Pasteurization significantly (p , but sonicated samples significantly (p quality parameters and antioxidant activity, notably in ripe juice. Overall, pasteurization degraded these liquids but sonication, either alone or in combination with it, was advantageous for preserving their quality by retaining nutrients.
基金supported by the Natural Science Foundation of Guangxi (Grant No.2022GXNSFBA035523)the China Postdoctoral Science Foundation (Grant No.2022MD713731)+1 种基金the Science and Technology Major Project of Guangxi Gui Ke (Grant No.AA22067096)the project of Guangxi featured fruit innovation team on pineapple breeding and cultivation post under national modern agricultural industry technology system (Grant No.nycytxgxcxtd-17-05)。
文摘Unfavorable environmental cues severely affect crop productivity resulting in significant economic losses to farmers. In plants, multiple regulatory genes, such as the WRKY transcription factor (TF) family, modulate the expression of defense genes. However, the role of the pineapple WRKY genes is poorly understood. Here, we studied the pineapple WRKY gene, AcWRKY28, by generating AcWRKY28 over-expressing transgenic pineapple plants. Overexpression of AcWRKY28 enhanced the salt stress resistance in transgenic pineapple lines. Comparative transcriptome analysis of transgenic and wild-type pineapple plants showed that “plant-pathogen interaction” pathway genes, including 9calcium-dependent protein kinases (CPKs), were up-regulated in AcWRKY28 over-expressing plants. Furthermore, chromatin immunoprecipitation and yeast one-hybrid assays revealed AcCPK12, AcCPK3, AcCPK8, AcCPK1, and AcCPK15 as direct targets of AcWRKY28. Consistently, the study of AcCPK12 over-expressing Arabidopsis lines showed that AcCPK12 enhances salt, drought, and disease resistance. This study shows that AcWRKY28 plays a crucial role in promoting salt stress resistance by activating the expression of AcCPK genes.
文摘Poly(lactic acid)(PLA)composite films reinforced with microcrystalline cellulose(MCC)extracted from pineapple leaf fibers(PALF)were prepared by a solution casting procedure.In an attempt to improve the interaction between PLA and cellulose,two approaches were adopted;first,poly(ethylene glycol)(PEG)was used as a surfactant,and second,the cellulosic fibers were pre-treated using tert-butanol(TBA).Lignocellulosic and cellulosic substrates were characterized using Fourier transform infrared(FTIR),wide-angle X-ray scattering(WAXS),and thermogravimetrical analysis(TGA).MCC from PALF showed good thermal stability,left few residues after decomposing,and exhibited high crystallinity index.Mechanical,thermal and thermomechanical properties of the PLA composites were also evaluated.Multiple PLA endotherms were observed in composites with TBA-treated MCC due to crystal nucleation effects.The ultimate tensile strain values for all composites were lower than that of the pristine PLA.However,4 wt.%MCC content provided balanced engineering properties in terms of static and dynamic tensile properties.
基金The authors would like to thank CAPES(Finance Code 001 and Process PNPD20131474-33001014004P9)and CNPq for financial support.
文摘Nowadays,the production of consumer goods is based on the use of non-renewable raw materials,which in recent years has been performing as a problem for the environment.Considering the large number of available biofibers in nature,their use in the development of polymeric composites has inevitably emerged,it is also necessary to take into account the countless discarded plastics that still have the potential to be reused.In this work,fibers were extracted from pineapple crown residues and utilized to compose sustainable composites using recycled polypropylene from cups discarded in the trash as a matrix.However,it is known that for good performance,it is necessary to achieve a good chemical interaction between the fiber and the matrix.In order to improve this interaction,alkaline mercerization treatment was carried out on the surface of the fibers removing some components incompatible with the polymer.In this work,the effect of the mercerization treatment on the properties of the fibers was studied,as well as their interaction with the matrix.The effect of fiber concentration on the mechanical and thermal properties of composites was also evaluated.Levels of 5 and 7 wt%were used for both natural and mercerized fibers.A decrease in the number of degradation stages was observed through thermogravimetry analyses(from four in natural fiber to two in mercerized fibers),showing that the mercerization performed on the fibers was effective.An increase in the degree of crystallinity of mercerized fibers was also observed through the results of X-ray diffraction.Both techniques indicate that amorphous compounds,such as hemicellulose and lignin,were partially removed.Through the tensile test,it could be noted that all composites presented higher values of de elastic modulus than recycled polypropylene without added load;however,there were no differences in the elastic modulus between the different types of fibers and load levels.Therefore,it is interesting to use fibers as reinforcing agents in polymers;however,the treatment did not increase the mechanical properties of the composites.In parallel,other factors,such as the dispersion of the components,must be taken into account to justify this result.
基金the Universitas Negeri Malang through the PNBP Research Grant 2021 with PUI/CAMRY scheme by Contract No.5.3.837/UN32.14.1/LT2021.
文摘Waste is the main problem for the environment.Handling waste for various useful applications has a benefit for the future.This work has been studied for handling pineapple peel waste to make composite film bacterial cellulose nanocomposite membrane(BCNM)with addition graphite nanoplatelet(GNP).The concentration of GNP in the membrane influence the membrane properties.The bacterial cellulose(BC)pellicle was synthesized by using media from pineapple peel waste extract.BC pellicle is cleaned with water and NaOH solution to be free from impactors.BCNM is synthesized through the mechanical disintegration stage.The results of disintegration using high pressure homogenizer at 150 bar and five cycles.BCNM/GNP is synthesized with varying addition of GNP of 2.5,5.0,10 and 100 wt%of dry bacterial nanocellulose(BNC).The BC and GNP solution were dried in an oven for 14 h at 80℃.BCNM morphology was observed using SEM.GNP is dispersed and distributed in the BC matrix as reinforcement.FTIR analysis shows many peaks of BNC less pronounced with increasing of GNP.The higher concentration of GNP,the rougher of BCNM.The optimum tensile strength of BCNM was achieved after addition GNP of 2.5 wt%.
文摘Pineapple leaf nanofibers(PLNFs)extracted from pineapple leaf fiber were used for reinforcing biobased polyurethane foam(BPU).The dispersion performance of PLNF in the foaming mixture system,nanocomposite foaming behavior,cell morphology,cell size,density,compressive strength and dimensional stability were investigated.The viscosity of the mixtures increased with increasing the PLNF content.The addition of a tiny amount of PLNF did not influence the exothermic temperature of the foam system,but reduced the expansion and gel time of the nanocomposite foams.This reduced time was found to increase the production efficiency.Scanning electron microscopy(SEM)images showed that the PLNF neither affected the cell shape nor size.While the density of the foam was not obviously altered with the addition of a small amount of PLNF,the compressive strength and dimensional stability were significantly improved.
