This study investigates the properties of high-purity starches extracted from Polygonum multiflorum(PMS)and Smilax glabra(SGS).The starches were characterized by scanning electron microscopy,Fouriertransform infrared ...This study investigates the properties of high-purity starches extracted from Polygonum multiflorum(PMS)and Smilax glabra(SGS).The starches were characterized by scanning electron microscopy,Fouriertransform infrared spectroscopy,X-ray diffraction,high-performance anion-exchange chromatography,and differential scanning calorimetry.Significant differences were observed in their morphological,physicochemical,and functional properties.PMS had a smaller particle size(13.68 μm),irregular polygonal shape,A-type,lower water absorption(62.67 %),and higher oil absorption(51.17 %).In contrast,SGS exhibited larger particles(31.75 μm),a nearly spherical shape,B-type,higher crystallinity(50.66 %),and greater amylose content(21.54 %),with superior thermal stability,shear resistance,and gelatinization enthalpy.SGS also contained higher resistant starch(83.28 %) and longer average chain length(20.58 %),but showed lower solubility,swelling power,light transmittance,and freeze-thaw stability.The physicochemical properties differences in crystal pattern and particle morphology between PMS and SGS lead to distinct behaviors during in vitro digestion and fermentation.These findings highlight the potential of medicinal plant starches in functional ingredients and industrial processes.展开更多
In this work,we proposed a strategy for the hydrolysis of native corn starch after the treatment of corn starch in an ionic liquid aqueous solution,and it is an awfully“green”and simple means to obtain starch with l...In this work,we proposed a strategy for the hydrolysis of native corn starch after the treatment of corn starch in an ionic liquid aqueous solution,and it is an awfully“green”and simple means to obtain starch with low molecular weight and amorphous state.X-ray diffraction results revealed that the natural starch crystalline region was largely disrupted by ionic liquid owing to the broken intermolecular and intramolecular hydrogen bonds.After hydrolysis,the morphology of starch changed from particles of native corn starch into little pieces,and their molecular weight could be effectively regulated during the hydrolysis process,and also the hydrolyzed starch samples exhibited decreased thermal stability with the extension of hydrolysis time.This work would counsel as a powerful tool for the development of native starch in realistic applications.展开更多
Acetogenins are lipidic polyketides with antioxidant,antimicrobial,cytotoxic,and antitumor properties,mainly found in the roots,stems,bark,leaves,and fruits(particularly the seeds)of Annonaceae species.Previous studie...Acetogenins are lipidic polyketides with antioxidant,antimicrobial,cytotoxic,and antitumor properties,mainly found in the roots,stems,bark,leaves,and fruits(particularly the seeds)of Annonaceae species.Previous studies have identified acetogenins in the peel and pulp of soursop(Annona muricata L.)fruits.In this research,acetogenins present in starch and pectin extracted from these fruits were analyzed and identified,given their potential importance in the pharmaceutical and possibly in the food industries.The objective was to identify and quantify acetogenins in starch and pectin of soursop fruits.Extraction of both polysaccharides was performed using conventional and ultrasound-assisted methods,obtaining two types of pastes(white and brown).These were characterized by Fourier Transform Infrared Spectroscopy(FTIR).Methanolic extracts from the pastes were analyzed by thin-layer chromatography and open-column fractionation.Acetogenins were identified and quantified by high-performance liquid chromatography(HPLC).The compounds identified were pseudoannonacin and anonacin.In pectin,the concentration(μg g^(−1)of dry basis P/A)of pseudoannonacin was 340.06(conventional)and 452.80(ultrasound-assisted),while for anonacin it was 302.29(conventional)and 397.23(ultrasound-assisted).In starch,the concentration(μg g^(−1)of dry basis P/A)of pseudoannonacin was 20.72(conventional)and 21.60(ultrasound-assisted),whereas anonacin showed concentrations of 1.63(conventional)and 3.12(ultrasound-assisted).These results confirm the presence of anonacin and pseudoannonacin in both starch and pectin of soursop fruits,with pseudoannonacin being the most abundant acetogenin detected.展开更多
Melt blending of biodegradable polyesters such as poly(lactic acid)(PLA)and poly(butylene adipate co-terephthalate)(PBAT)with a compatibilizer and natural filler offers a chance to develop biodegradable biocomposites ...Melt blending of biodegradable polyesters such as poly(lactic acid)(PLA)and poly(butylene adipate co-terephthalate)(PBAT)with a compatibilizer and natural filler offers a chance to develop biodegradable biocomposites with improved performance.In this study,we examined how PLA/PBAT blends behave during ultimate biodegradation(mineralization),both with and without compatibilizer and algae as a reinforcement,under controlled composting conditions using carbon dioxide(CO_(2))respirometry techniques.Throughout the biodegradation process,the disintegration behaviour,thermal,chemical,and morphological properties of test samples before and after biodegradation were analyzed using FTIR,TGA,DSC,and SEM techniques.The results from CO_(2)biodegradation showed that PLA/PBAT blend exhibits a higher rate of biodegradation compared to neat PLA and PBAT.The addition of algae to a compatibilized PLA/PBAT blend showed an enhanced biodegradation rate due to hydrolytic cleavage and microbial assimilation.This was further supported by the disintegration test,where algae-reinforced composites showed fragmentation within 30 days.FTIR,TGA and SEM analysis revealed the structural changes that occurred during biodegradation,highlighting the role of algae in affecting the thermal stability and surface morphology.After the compost biodegradation step,eco-toxicity seed germination was conducted on the test samples.Plant seed germination test results confirmed that all test samples achieved maximumgermination.This indicates there were no toxic residues,suggesting that the degraded materials are environmentally safe.Overall,this study contributes to the understanding of biodegradation mechanisms and the ecological impact of bio-based polymer composites as eco-friendly materials and products.展开更多
High temperature stress (HT) significantly reduces maize yield by impairing starch accumulation in kernels.However,the mechanism by which HT affects starch synthesis remains controversial-whether through reduced assim...High temperature stress (HT) significantly reduces maize yield by impairing starch accumulation in kernels.However,the mechanism by which HT affects starch synthesis remains controversial-whether through reduced assimilate supply or direct inhibition on kernel metabolism.To clarify these mechanisms,a heat-sensitive maize hybrid,Xianyu 335 (XY),was exposed to 30℃/20℃ (maximum/minimum temperature,control) and 40℃/30℃ for seven consecutive days during the seed setting stage.Synchronous pollination (SP),apical pollination (AP),and shading treatments were applied to manipulate the inherent source–sink ratio in maize plants.Results showed that apical kernel weight decreased by 11.9%under 40℃ in the SP treatment.The ^(13)C content,starch accumulation,and cell-wall invertase (CWIN) activity also declined by 15.9,36.7,and 16.4%,respectively,under HT.In the shading treatment,40℃/30℃ caused even greater reductions in^(13)C content,starch accumulation,and CWIN activity due to diminished assimilate supply.Conversely,in the AP treatment,starch content and CWIN activity increased by 22.0 and 18.5%,respectively,under 40℃/30℃,resulting in kernel weight and ^(13)C content similar to those in SP and shading treatments regardless of temperature.Consistent with apical kernels under AP,HT did not negatively affect middle kernels in either SP or shading treatments,as kernel weight and starch content remained unchanged under HT.Although all kernels were exposed to the same HT or control environment,their responses varied a lot.The impaired starch synthesis in apical kernels under HT was rescued by increasing carbon supply via AP treatment.The contrasting performance among middle kernels,apical kernels under AP,and apical kernels under SP or shading indicates that reduced carbon supply is a critical factor underlying inhibited starch accumulation.Our findings provide a theoretical basis for further understanding kernel abortion under HT.展开更多
This study investigates the potential of starch extracted from underutilized agro-industrial resources as non-food-competing raw materials for the development of flexible bioplastics for food packaging applications.St...This study investigates the potential of starch extracted from underutilized agro-industrial resources as non-food-competing raw materials for the development of flexible bioplastics for food packaging applications.Starch was extracted from three biomass sources:rubber cassava(Manihot glaziovii),banana stem,and banana peel from Ambonese banana(Musa acuminata L.).Rubber cassava starch(SRC)exhibited the highest starch yield(50.68±0.28%),significantly surpassing banana stem(SBS,14.20±0.25%)and banana peel(SBP,3.07±0.15%).The amylose contents of SRC,SBS,and SBP were 28.18%,52.80%,and 56.57%,respectively,while their amylopectin contents were 71.83%,47.20%,and 43.43%.FTIR spectra confirmed the absence of cyanogenic groups in SRC,indicating its safety for packaging applications.XRD analysis revealed that PSRC films were predominantly amorphous,while PSBS and PSBP showed higher crystallinity.The enhancement of mechanical properties,specifically PSBS,showed the highest tensile strength at 16.04±0.56 MPa,whereas PSRC demonstrated the highest elongation at break at 23.57±0.40%,which could be attributed to the inherent characteristics of the starch sources.Additionally,PSRC film exhibited the highest transparency at 60.2%,the greatest water solubility at 34.92%,and the lowest water contact angle at 41.58○,confirming its more hydrophilic nature compared to other films.This work highlights the potential of low-cost,sustainable,and non-food agro-industrial starch sources as promising candidates for the development of flexible,eco-friendly bioplastics.展开更多
Thermoplastic starch is a kind of modified starch produced by mixing starch with additives and processing the mixture in an extruder. The mechanical properties, including tensile strength and elongation at break, biod...Thermoplastic starch is a kind of modified starch produced by mixing starch with additives and processing the mixture in an extruder. The mechanical properties, including tensile strength and elongation at break, biodegradability and rheological properties were studied. Glycerol and urea, to some extent, can both decrease the tensile strength and increase percentage elongation at break, because the former acts as a plasticizer and the latter can break down interactions among starch macromolecules. Thermoplastic starch shows thermoplasticity and its melt behaves as a pseudoplastic liquid at a low shear rate. Its biodegrading extent is slightly higher than that of native starch. The molecular weight of starch displays a decreasing tendency after thermoplastic modification.展开更多
[Objective] The aim was to investigate the effects of plant growth regulators on contents of reducing sugar and starch in potato（Solanum tuberosum L.）.[Method]A potato cultivar named ＇Holand-212＇ with three treatm...[Objective] The aim was to investigate the effects of plant growth regulators on contents of reducing sugar and starch in potato（Solanum tuberosum L.）.[Method]A potato cultivar named ＇Holand-212＇ with three treatments by spraying Diethyl aminoethyl hexanoate（DTA-6）,Uniconazole（S3307）and SOD mimics（SODM）were employed to compare differences of the contents of reducing sugar and starch in potato leaves,stolons and tubers in a field experiment.[Result]DTA-6 treatment could significantly reduce the contents of starch and reducing sugar in potato stolons in the period of 100-110 d after seeding,and it could also reduce the content of reducing sugar in tubers,but there is an opposite result in leaves in the same period,significantly.S3307 could extremely significantly increase the content of starch,and can promote the transfer of starch in stolons,in addition,it also could reduce the content of reducing sugar in tubers,and extremely significantly increase the content of starch in leaves at the 110 d after sowing.Moreover,there is a similar effect between SODM and S3307.[Conclusion]The research results are significant for understanding mechanisms of plant growth regulators and promoting application of plant growth regulator in potato.展开更多
The granular structure, crystal structure and gelatinization temp. of thermoplastic starch were studied with a polarized light microscope and a scanning electron microscope, and the crystallinity and crystalline patte...The granular structure, crystal structure and gelatinization temp. of thermoplastic starch were studied with a polarized light microscope and a scanning electron microscope, and the crystallinity and crystalline patterns were determined through X ray diffraction. The results indicate that the original granular structure and spherical crystalline structure of starch were disrupted by the action of pressure, heat and shear force with the help of additives. The starch can be melted during extrusion, and part of the spheric crystal was destroyed and changed into a continual amorphous with a few crystalline fractions dispersed in it. The configuration of starch molecules changed from double helices to single helix, which indicated the formation of the complex.展开更多
Based on known cDNAs of rice starch synthase isoforms,we constructed dsRNA interference vectors for starch synthase I(SSI)to produce transgenic plants containing starch with a moderately high amylose content.We invest...Based on known cDNAs of rice starch synthase isoforms,we constructed dsRNA interference vectors for starch synthase I(SSI)to produce transgenic plants containing starch with a moderately high amylose content.We investigated the effect of SSI suppression on grain quality traits,starch biosynthesis,and amylopectin chain distribution in rice plants exposed to two different temperature regimes.The activities and transcripts of BEs,DBEs,and other SS isoforms were further investigated to clarify the effect of SSI suppression on these key enzymes and their specific isoforms under different temperature treatments.Suppression of SSI by RNAi altered grain starch component and amylopectin chain distribution,but it exerted only a slight effect on total starch content(%)and accumulation amount(mg kernel?1)and on starch granule morphology and particle size distribution.Under normal temperature(NT),insignificant differences in kernel weight,chalky kernel proportion,chalky degree,and starch granule morphology between SSI-RNAi line and its wild type(WT)were observed.However,amylose content(AC)level and granule-bound starch synthase(GBSS)activity in rice endosperms were markedly increased by SSI-RNAi suppression.The chalky kernel proportion and chalky degree of SSIRNAi lines were significantly higher than those of WT under high temperature(HT)exposure at filling stage.Inhibition of SSI by RNAi affected amylopectin chain distribution and raised starch gelatinization temperature(GT)in two ways:directly from the SSI deficiency itself and indirectly by reducing BEIIb amounts in an SSI-deficient background.The deficiency of SSI expression led to an alteration in the susceptibility of grain chalkiness occurrence and starch gelatinization temperature to HT exposure,owing to a pleiotropic effect of SSI deficiency on the expression of other genes associated with starch biosynthesis.展开更多
The effects of adding poly （ethylene glycol） （PEG） into polylactic acid/thermoplastic starch blends （PLA/TPS） on the properties were investigated by DSC, SEM and mechanical property-testing. The blends of PLA/TP...The effects of adding poly （ethylene glycol） （PEG） into polylactic acid/thermoplastic starch blends （PLA/TPS） on the properties were investigated by DSC, SEM and mechanical property-testing. The blends of PLA/TPS blended with increasing content PEG exhibited lower temperature of glass transition （T） and lower temperature of melting （T） as well as higher melt flow index （MFI）, which indicates the plasticization and proeessability of the composites were dramatically improved. The tensile strength, flexural strength and izod impact strength of PLA/TPS （80/20） increased at first and then decreased with increasing content of PEG due to stronger interfacial adhesion. The optimized mechanical property can be obtained for the blend with 3 wt % PEG. The samples containing PEG after soil burial for 5 months showed quicker degradation being accompanied with large weight loss and mechanical properties loss.展开更多
Tuber starch content and plant maturity are two important agronomic traits of potato. To investigate the complex genetic basis of these traits in the cultivated potato, as well as the relationship between them, we dev...Tuber starch content and plant maturity are two important agronomic traits of potato. To investigate the complex genetic basis of these traits in the cultivated potato, as well as the relationship between them, we developed a linkage map in a tetraploid population of 192 clones derived from the cross Longshu 8 × Zaodabai and mapped quantitative trait loci(QTL) for tuber starch content and plant maturity using data collected in three diverse environments over two years. We detected eleven QTL for tuber starch content distributed on seven chromosomes, of which four, on chromosomes I, II, and VIII, were expressed in at least three environments. For plant maturity, we identified six QTL on chromosomes II, IV,V, VII, and XI, one of which, on chromosome V, showed LOD peaks ranging from 45.2 to 62.5 cM and explained 21.6%–26.6% of phenotypic variation was expressed in five of the six environments. Because the reproducible QTL for plant maturity and tuber starch content mapped to different chromosomes and neither overlapping QTL, nor any genetic interaction between QTL were detected, we infer that tuber starch content and plant maturity are controlled by independent genetic loci. This inference supports the prospect of breeding potato for both early maturity and high starch content.展开更多
基金supported by the National Natural Science Foundation of China (No.82174074)。
文摘This study investigates the properties of high-purity starches extracted from Polygonum multiflorum(PMS)and Smilax glabra(SGS).The starches were characterized by scanning electron microscopy,Fouriertransform infrared spectroscopy,X-ray diffraction,high-performance anion-exchange chromatography,and differential scanning calorimetry.Significant differences were observed in their morphological,physicochemical,and functional properties.PMS had a smaller particle size(13.68 μm),irregular polygonal shape,A-type,lower water absorption(62.67 %),and higher oil absorption(51.17 %).In contrast,SGS exhibited larger particles(31.75 μm),a nearly spherical shape,B-type,higher crystallinity(50.66 %),and greater amylose content(21.54 %),with superior thermal stability,shear resistance,and gelatinization enthalpy.SGS also contained higher resistant starch(83.28 %) and longer average chain length(20.58 %),but showed lower solubility,swelling power,light transmittance,and freeze-thaw stability.The physicochemical properties differences in crystal pattern and particle morphology between PMS and SGS lead to distinct behaviors during in vitro digestion and fermentation.These findings highlight the potential of medicinal plant starches in functional ingredients and industrial processes.
文摘In this work,we proposed a strategy for the hydrolysis of native corn starch after the treatment of corn starch in an ionic liquid aqueous solution,and it is an awfully“green”and simple means to obtain starch with low molecular weight and amorphous state.X-ray diffraction results revealed that the natural starch crystalline region was largely disrupted by ionic liquid owing to the broken intermolecular and intramolecular hydrogen bonds.After hydrolysis,the morphology of starch changed from particles of native corn starch into little pieces,and their molecular weight could be effectively regulated during the hydrolysis process,and also the hydrolyzed starch samples exhibited decreased thermal stability with the extension of hydrolysis time.This work would counsel as a powerful tool for the development of native starch in realistic applications.
基金funded by the Sectoral Fund for Research in Agricultural,Livestock,Aquaculture,Agrobiotechnology,and Plant Genetic Resources(SADER-SECIHTI)Number 266891the Sectoral Fund for Research for Education(SEP-SECIHTI)Number 242718.
文摘Acetogenins are lipidic polyketides with antioxidant,antimicrobial,cytotoxic,and antitumor properties,mainly found in the roots,stems,bark,leaves,and fruits(particularly the seeds)of Annonaceae species.Previous studies have identified acetogenins in the peel and pulp of soursop(Annona muricata L.)fruits.In this research,acetogenins present in starch and pectin extracted from these fruits were analyzed and identified,given their potential importance in the pharmaceutical and possibly in the food industries.The objective was to identify and quantify acetogenins in starch and pectin of soursop fruits.Extraction of both polysaccharides was performed using conventional and ultrasound-assisted methods,obtaining two types of pastes(white and brown).These were characterized by Fourier Transform Infrared Spectroscopy(FTIR).Methanolic extracts from the pastes were analyzed by thin-layer chromatography and open-column fractionation.Acetogenins were identified and quantified by high-performance liquid chromatography(HPLC).The compounds identified were pseudoannonacin and anonacin.In pectin,the concentration(μg g^(−1)of dry basis P/A)of pseudoannonacin was 340.06(conventional)and 452.80(ultrasound-assisted),while for anonacin it was 302.29(conventional)and 397.23(ultrasound-assisted).In starch,the concentration(μg g^(−1)of dry basis P/A)of pseudoannonacin was 20.72(conventional)and 21.60(ultrasound-assisted),whereas anonacin showed concentrations of 1.63(conventional)and 3.12(ultrasound-assisted).These results confirm the presence of anonacin and pseudoannonacin in both starch and pectin of soursop fruits,with pseudoannonacin being the most abundant acetogenin detected.
文摘Melt blending of biodegradable polyesters such as poly(lactic acid)(PLA)and poly(butylene adipate co-terephthalate)(PBAT)with a compatibilizer and natural filler offers a chance to develop biodegradable biocomposites with improved performance.In this study,we examined how PLA/PBAT blends behave during ultimate biodegradation(mineralization),both with and without compatibilizer and algae as a reinforcement,under controlled composting conditions using carbon dioxide(CO_(2))respirometry techniques.Throughout the biodegradation process,the disintegration behaviour,thermal,chemical,and morphological properties of test samples before and after biodegradation were analyzed using FTIR,TGA,DSC,and SEM techniques.The results from CO_(2)biodegradation showed that PLA/PBAT blend exhibits a higher rate of biodegradation compared to neat PLA and PBAT.The addition of algae to a compatibilized PLA/PBAT blend showed an enhanced biodegradation rate due to hydrolytic cleavage and microbial assimilation.This was further supported by the disintegration test,where algae-reinforced composites showed fragmentation within 30 days.FTIR,TGA and SEM analysis revealed the structural changes that occurred during biodegradation,highlighting the role of algae in affecting the thermal stability and surface morphology.After the compost biodegradation step,eco-toxicity seed germination was conducted on the test samples.Plant seed germination test results confirmed that all test samples achieved maximumgermination.This indicates there were no toxic residues,suggesting that the degraded materials are environmentally safe.Overall,this study contributes to the understanding of biodegradation mechanisms and the ecological impact of bio-based polymer composites as eco-friendly materials and products.
基金financially supported by the National Natural Science Foundation of China (32071978)the National Key Research and Development Program of China (2022YFD2300901 and 2022YFD2300905)。
文摘High temperature stress (HT) significantly reduces maize yield by impairing starch accumulation in kernels.However,the mechanism by which HT affects starch synthesis remains controversial-whether through reduced assimilate supply or direct inhibition on kernel metabolism.To clarify these mechanisms,a heat-sensitive maize hybrid,Xianyu 335 (XY),was exposed to 30℃/20℃ (maximum/minimum temperature,control) and 40℃/30℃ for seven consecutive days during the seed setting stage.Synchronous pollination (SP),apical pollination (AP),and shading treatments were applied to manipulate the inherent source–sink ratio in maize plants.Results showed that apical kernel weight decreased by 11.9%under 40℃ in the SP treatment.The ^(13)C content,starch accumulation,and cell-wall invertase (CWIN) activity also declined by 15.9,36.7,and 16.4%,respectively,under HT.In the shading treatment,40℃/30℃ caused even greater reductions in^(13)C content,starch accumulation,and CWIN activity due to diminished assimilate supply.Conversely,in the AP treatment,starch content and CWIN activity increased by 22.0 and 18.5%,respectively,under 40℃/30℃,resulting in kernel weight and ^(13)C content similar to those in SP and shading treatments regardless of temperature.Consistent with apical kernels under AP,HT did not negatively affect middle kernels in either SP or shading treatments,as kernel weight and starch content remained unchanged under HT.Although all kernels were exposed to the same HT or control environment,their responses varied a lot.The impaired starch synthesis in apical kernels under HT was rescued by increasing carbon supply via AP treatment.The contrasting performance among middle kernels,apical kernels under AP,and apical kernels under SP or shading indicates that reduced carbon supply is a critical factor underlying inhibited starch accumulation.Our findings provide a theoretical basis for further understanding kernel abortion under HT.
基金supported by the RIIM BRIN and LPDP Grants,grant number B-2880/II.7.5/KS.00/4/2025 dan B-7930/III.6/TK.01.03/4/2025 under the scheme BRIN-KONEKSI Joint Call for Proposalsthe theme“Indonesia's Bioeconomy:Maximising Sustainable Marine Biodiversity Utilisation 2024”No 6/II.7/HK/2025.
文摘This study investigates the potential of starch extracted from underutilized agro-industrial resources as non-food-competing raw materials for the development of flexible bioplastics for food packaging applications.Starch was extracted from three biomass sources:rubber cassava(Manihot glaziovii),banana stem,and banana peel from Ambonese banana(Musa acuminata L.).Rubber cassava starch(SRC)exhibited the highest starch yield(50.68±0.28%),significantly surpassing banana stem(SBS,14.20±0.25%)and banana peel(SBP,3.07±0.15%).The amylose contents of SRC,SBS,and SBP were 28.18%,52.80%,and 56.57%,respectively,while their amylopectin contents were 71.83%,47.20%,and 43.43%.FTIR spectra confirmed the absence of cyanogenic groups in SRC,indicating its safety for packaging applications.XRD analysis revealed that PSRC films were predominantly amorphous,while PSBS and PSBP showed higher crystallinity.The enhancement of mechanical properties,specifically PSBS,showed the highest tensile strength at 16.04±0.56 MPa,whereas PSRC demonstrated the highest elongation at break at 23.57±0.40%,which could be attributed to the inherent characteristics of the starch sources.Additionally,PSRC film exhibited the highest transparency at 60.2%,the greatest water solubility at 34.92%,and the lowest water contact angle at 41.58○,confirming its more hydrophilic nature compared to other films.This work highlights the potential of low-cost,sustainable,and non-food agro-industrial starch sources as promising candidates for the development of flexible,eco-friendly bioplastics.
文摘Thermoplastic starch is a kind of modified starch produced by mixing starch with additives and processing the mixture in an extruder. The mechanical properties, including tensile strength and elongation at break, biodegradability and rheological properties were studied. Glycerol and urea, to some extent, can both decrease the tensile strength and increase percentage elongation at break, because the former acts as a plasticizer and the latter can break down interactions among starch macromolecules. Thermoplastic starch shows thermoplasticity and its melt behaves as a pseudoplastic liquid at a low shear rate. Its biodegrading extent is slightly higher than that of native starch. The molecular weight of starch displays a decreasing tendency after thermoplastic modification.
基金Supported by Daqing Scientific and Technological Project in Heilongjiang Province(SGG2007-054)Demonstration and Promotion Projects of Potato Comprehensive High Yield Cultivation Technologyin Western Regions of Heilongjiang Province(PC07B09)~~
文摘[Objective] The aim was to investigate the effects of plant growth regulators on contents of reducing sugar and starch in potato（Solanum tuberosum L.）.[Method]A potato cultivar named ＇Holand-212＇ with three treatments by spraying Diethyl aminoethyl hexanoate（DTA-6）,Uniconazole（S3307）and SOD mimics（SODM）were employed to compare differences of the contents of reducing sugar and starch in potato leaves,stolons and tubers in a field experiment.[Result]DTA-6 treatment could significantly reduce the contents of starch and reducing sugar in potato stolons in the period of 100-110 d after seeding,and it could also reduce the content of reducing sugar in tubers,but there is an opposite result in leaves in the same period,significantly.S3307 could extremely significantly increase the content of starch,and can promote the transfer of starch in stolons,in addition,it also could reduce the content of reducing sugar in tubers,and extremely significantly increase the content of starch in leaves at the 110 d after sowing.Moreover,there is a similar effect between SODM and S3307.[Conclusion]The research results are significant for understanding mechanisms of plant growth regulators and promoting application of plant growth regulator in potato.
文摘The granular structure, crystal structure and gelatinization temp. of thermoplastic starch were studied with a polarized light microscope and a scanning electron microscope, and the crystallinity and crystalline patterns were determined through X ray diffraction. The results indicate that the original granular structure and spherical crystalline structure of starch were disrupted by the action of pressure, heat and shear force with the help of additives. The starch can be melted during extrusion, and part of the spheric crystal was destroyed and changed into a continual amorphous with a few crystalline fractions dispersed in it. The configuration of starch molecules changed from double helices to single helix, which indicated the formation of the complex.
基金the National Key Research and Development Program of China (2017YFD0300103)the National Natural Science Foundation of China (31571602, 31871566) for its financial support to this research project
文摘Based on known cDNAs of rice starch synthase isoforms,we constructed dsRNA interference vectors for starch synthase I(SSI)to produce transgenic plants containing starch with a moderately high amylose content.We investigated the effect of SSI suppression on grain quality traits,starch biosynthesis,and amylopectin chain distribution in rice plants exposed to two different temperature regimes.The activities and transcripts of BEs,DBEs,and other SS isoforms were further investigated to clarify the effect of SSI suppression on these key enzymes and their specific isoforms under different temperature treatments.Suppression of SSI by RNAi altered grain starch component and amylopectin chain distribution,but it exerted only a slight effect on total starch content(%)and accumulation amount(mg kernel?1)and on starch granule morphology and particle size distribution.Under normal temperature(NT),insignificant differences in kernel weight,chalky kernel proportion,chalky degree,and starch granule morphology between SSI-RNAi line and its wild type(WT)were observed.However,amylose content(AC)level and granule-bound starch synthase(GBSS)activity in rice endosperms were markedly increased by SSI-RNAi suppression.The chalky kernel proportion and chalky degree of SSIRNAi lines were significantly higher than those of WT under high temperature(HT)exposure at filling stage.Inhibition of SSI by RNAi affected amylopectin chain distribution and raised starch gelatinization temperature(GT)in two ways:directly from the SSI deficiency itself and indirectly by reducing BEIIb amounts in an SSI-deficient background.The deficiency of SSI expression led to an alteration in the susceptibility of grain chalkiness occurrence and starch gelatinization temperature to HT exposure,owing to a pleiotropic effect of SSI deficiency on the expression of other genes associated with starch biosynthesis.
文摘The effects of adding poly （ethylene glycol） （PEG） into polylactic acid/thermoplastic starch blends （PLA/TPS） on the properties were investigated by DSC, SEM and mechanical property-testing. The blends of PLA/TPS blended with increasing content PEG exhibited lower temperature of glass transition （T） and lower temperature of melting （T） as well as higher melt flow index （MFI）, which indicates the plasticization and proeessability of the composites were dramatically improved. The tensile strength, flexural strength and izod impact strength of PLA/TPS （80/20） increased at first and then decreased with increasing content of PEG due to stronger interfacial adhesion. The optimized mechanical property can be obtained for the blend with 3 wt % PEG. The samples containing PEG after soil burial for 5 months showed quicker degradation being accompanied with large weight loss and mechanical properties loss.
基金supported by Earmarked Fund for China Agriculture Research System(CARS-09-P07)the National Natural Science Foundation of China(31160299,31760410)
文摘Tuber starch content and plant maturity are two important agronomic traits of potato. To investigate the complex genetic basis of these traits in the cultivated potato, as well as the relationship between them, we developed a linkage map in a tetraploid population of 192 clones derived from the cross Longshu 8 × Zaodabai and mapped quantitative trait loci(QTL) for tuber starch content and plant maturity using data collected in three diverse environments over two years. We detected eleven QTL for tuber starch content distributed on seven chromosomes, of which four, on chromosomes I, II, and VIII, were expressed in at least three environments. For plant maturity, we identified six QTL on chromosomes II, IV,V, VII, and XI, one of which, on chromosome V, showed LOD peaks ranging from 45.2 to 62.5 cM and explained 21.6%–26.6% of phenotypic variation was expressed in five of the six environments. Because the reproducible QTL for plant maturity and tuber starch content mapped to different chromosomes and neither overlapping QTL, nor any genetic interaction between QTL were detected, we infer that tuber starch content and plant maturity are controlled by independent genetic loci. This inference supports the prospect of breeding potato for both early maturity and high starch content.
