Amylose content has a profound impact on the contents of slowly digestible starch and resistant starch.Enzymatic debranching is a safe method to increase the amylose content,however,the lower substrate concentration a...Amylose content has a profound impact on the contents of slowly digestible starch and resistant starch.Enzymatic debranching is a safe method to increase the amylose content,however,the lower substrate concentration and high viscosity of fully gelatinized starch limit the efficiency and yield of this method.This paper aims to explore the effects of extrusion and enzymatic debranching on increasing the amylose content thereby increasing slowly digestible starch and resistant starch contents.Different starch concentrations (10%,15%,and 20%) of extruded corn starch (ECS) and extruded potato starch (EPS) were used to debranch.Both debranched ECS and debranched EPS showed high amylose content of approximately 90%,indicating that all samples with different starch concentrations achieved high-efficiency enzymatic debranching.The high-performance liquid chromatograph results indicated that the samples were mainly short amylose.The samples exhibit a typical B-type crystalline structure and the relative crystallinity of them exceeds 37%.The short amylose exhibited rapid rearrangement ability,with the gelatinization temperature range of rescanning determined as 80–125℃,this will facilitate the formation of slowly digestible starch and resistant starch.The slowly digestible starch and resistant starch contents of the samples (debranched ECS and debranched EPS) were between 23% and 30% and between 31% and 37%,respectively.These results indicate that the extrusion and enzymatic debranching of a high substrate concentration can efficiently increase the amylose content,thereby significantly reducing the digestibility of starch,and has broad prospects of the actual production of slowly digestible starch and resistant starch.展开更多
Dynamic changes of starch, amylose, sucrose contents and the activities of starch synthesis enzymes under shading treatments alter flowering were studied using two rice varieties IR72 （indica） and Nipponbare （japon...Dynamic changes of starch, amylose, sucrose contents and the activities of starch synthesis enzymes under shading treatments alter flowering were studied using two rice varieties IR72 （indica） and Nipponbare （japonica） as materials. Under shading treatments, the starch, amylose and sucrose contents decreased, while ADP-glucose pyrophosphorylase （ADPGPPase） activity only changed a little, soluble starch synthase activity and granule bound starch synthase activity decreased, soluble starch branching enzyme （SSBE, Q-enzyme） activity and granule bound starch branching enzyme （GBSBE, Q-enzyme） activity increased, and starch debranching enzyme （DBE, R-enzyme） activity varied with varieties. Correlation analyses showed that the changes of starch content were positively and significantly correlated with the changes of sucrose content in the weak light. Both ADPGPPase activity and SSBE activity were positively and significantly correlated with starch accumulation rate. It was implied that the decline of starch synthase activities was related to the decrease of starch content and the increase of the activity of starch branching enzyme played an important role in the decrease of the ratio of amylose to the total starch under the weak light.展开更多
The dynamic changes of the activities of enzymes involving in starch biosynthesis,including ADP-glucose pyrophosphorylase(AGPase),soluble starch synthases(SSS),starch branching enzyme(SBE)and starch debranching enzyme...The dynamic changes of the activities of enzymes involving in starch biosynthesis,including ADP-glucose pyrophosphorylase(AGPase),soluble starch synthases(SSS),starch branching enzyme(SBE)and starch debranching enzymes(DBE)were studied,and changes of fine structure of amy-lopectin were characterized by isoamylase treatment during rice grain development,using trans anti-waxy gene rice plants.The relationships between the activities of those key enzymes were also analyzed.The amylose synthesis was significantly inhibited in transgenic Wanjing 9522,but the total starch content and final grain weight were less affected as compared with those of non-transgenic Wanjing 9522 rice cultivar.Analyses on the changes of activities of enzymes involving in starch bio-synthesis showed that different enzyme activities were expressed differently during rice endosperm development.Soluble starch synthase is relatively highly expressed in earlier stage of endosperm de-velopment,whilst maximal expression of granule-bound starch synthase(GBSS)occurred in mid-stage of endosperm development.No obvious differences in changes of the activities of AGPase and SBE between two rice cultivars investigated,except the DBEs.Distribution patterns of branches of amy-lopectin changed continually during the development of rice grains and varied between two rice culti-vars.It was suggested that amylopectin synthesis be prior to the synthesis of amylose and different enzymes have different roles in controlling syntheses of branches of amylopectin.展开更多
Starch,a semi-crystalline energy storage form primarily found in plant plastids plays a crucial role in various food or no-food applications.Despite the starch biosynthetic pathway’s main enzymes have been characteri...Starch,a semi-crystalline energy storage form primarily found in plant plastids plays a crucial role in various food or no-food applications.Despite the starch biosynthetic pathway’s main enzymes have been characterized,their origin and evolution remained a subject of debate.In this study,we conducted the comprehensive phylogenetic and structural analysis of three types of starch biosynthetic enzymes:starch synthase(SS),starch branching enzyme(SBE)and isoamylase-type debranching enzyme(ISA)from 51,151 annotated genomes.Our findings provide valuable insights into the possible scenario for the origin and evolution of the starch biosynthetic pathway.Initially,the ancestor of SBE can be traced back to an unidentified bacterium that existed before the formation of the last eukaryotic common ancestor(LECA)via horizontal gene transfer(HGT).This transfer event likely provided the eukaryote ancestor with the ability to synthesize glycogen.Furthermore,during the emergence of Archaeplastida,one clade of SS was transferred from Deltaproteobacteria by HGT,while ISA and the other clade of SS originated from Chlamydiae through endosymbiosis gene transfer(EGT).Both these transfer events collectively contributed to the establishment of the original starch biosynthetic pathway.Subsequently,after the divergence of Viridiplantae from Rhodophyta,all three enzymes underwent multiple duplications and N-terminus extension domain modifications,resulting in the formation of functionally specialized isoforms and ultimately leading to the complete starch biosynthetic pathway.By shedding light on the evolutionary origins of key enzymes involved in the starch biosynthetic pathway,this study provides important insights into the evolutionary events of plants.展开更多
Starch nanoparticles(SNPs)are attracting attention due to their novel attributes beneficial to certain applications;their fabrication technique and physicochemical attributes have yet to be systematically investigated...Starch nanoparticles(SNPs)are attracting attention due to their novel attributes beneficial to certain applications;their fabrication technique and physicochemical attributes have yet to be systematically investigated.In this study,starch nanoparticles were fabricated from the debranched rice starches of three rice lines employing the mono-modification by annealing treatments for one and five days and the dual-modification by the combined annealing and heat-moisture treatments,and their physicochemical properties were characterized.The highest percent recovery of crystalline SNPs was obtained by the dual-modification treatments(32.6-45.6%),followed by the five-day annealing treatment(23.8-28.7%),and then the one-day annealing treatment(11.7-15.8%).The modified starches showed significant increases in oil absorption capacity,water holding capacity,and solubility and decreases in swelling power and volume fraction compared to their native counterparts.The crystal types were changed from A-type to B-type polymorphs by mono-modification treatment and to CA-type polymorphs by the dual-modification treatment with significant increases in relative crystallinity.The dual-modification treatment resulted in the highest increases in 1047/1022 cm^(-1),995/1022 cm^(-1),and 1047/1035 cm^(-1)band ratios and the highest melting temperatures and enthalpies.The resistant starch contents of the modified starches were markedly increased and strongly related to the percent recovery and the short-and long-range ordered structures.The results suggest that the dual-modified starches comprised the rigid and densely packing of nanoaggregates with superior oil/water absorption performance and water dispersibility,and high enzymatic resistance,which could be the contributing factors for their utilizations as novel ingredients in food-related applications.展开更多
Excessive fat intake can have adverse health effects.Thus,consumers often look for alternative,low-fat ice cream options,but decreased fat content in ice cream can affect the taste and quality.Therefore,this study inv...Excessive fat intake can have adverse health effects.Thus,consumers often look for alternative,low-fat ice cream options,but decreased fat content in ice cream can affect the taste and quality.Therefore,this study investigated the functional and physiochemical properties of debranched waxy rice(DBWR)starches as a fat substitute in ice cream.We found that after debranching,the molecular weight of DBWR starch changed from 17.03×10^(6) g/mol to 9.18×10^(4) g/mol.Additionally,the short-chain amylose content and dextrose equivalence value increased as the debranching degree increased.Furthermore,the particle size of the ice cream mixture gradually decreased as the degree of debranching increased,stabilizing after 4 h of debranching(1.356±0.364μm);the ice cream slurry also had a high Zeta potential(over-30 mV)and improved emulsion stability.Compared to low-fat ice cream without fat substitutes,adding DBWR starches also increased the viscosity and consistency coefficient of the mixture,reduced the amount of ice and free water,increased the amount of bound water,positively affected the glass transition temperature,and improved the melting resistance of ice cream owing to the strong interactions among short-chain amylose molecules.Specifically,2 and 4 h of debranching had the best substitution effects.The low-fat ice cream mixtures with DBWR-2 and DBWR-4 had similar sensory properties as medium-fat ice cream mixtures.This study demonstrates that DBWR starch could be a suitable fat substitute that retains the quality and consistency of low-fat ice cream.展开更多
基金supported by the Speical Support for Post-doc Creative Funding in Shandong Province(NO.2020003072)Jiangsu Agricultural Science and Technology Innovation Fund(CX(17)2022)+1 种基金the Science&Technology Pillar Program of Jiangsu Province(BE2018304)Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment&Technology(FM-201904).
文摘Amylose content has a profound impact on the contents of slowly digestible starch and resistant starch.Enzymatic debranching is a safe method to increase the amylose content,however,the lower substrate concentration and high viscosity of fully gelatinized starch limit the efficiency and yield of this method.This paper aims to explore the effects of extrusion and enzymatic debranching on increasing the amylose content thereby increasing slowly digestible starch and resistant starch contents.Different starch concentrations (10%,15%,and 20%) of extruded corn starch (ECS) and extruded potato starch (EPS) were used to debranch.Both debranched ECS and debranched EPS showed high amylose content of approximately 90%,indicating that all samples with different starch concentrations achieved high-efficiency enzymatic debranching.The high-performance liquid chromatograph results indicated that the samples were mainly short amylose.The samples exhibit a typical B-type crystalline structure and the relative crystallinity of them exceeds 37%.The short amylose exhibited rapid rearrangement ability,with the gelatinization temperature range of rescanning determined as 80–125℃,this will facilitate the formation of slowly digestible starch and resistant starch.The slowly digestible starch and resistant starch contents of the samples (debranched ECS and debranched EPS) were between 23% and 30% and between 31% and 37%,respectively.These results indicate that the extrusion and enzymatic debranching of a high substrate concentration can efficiently increase the amylose content,thereby significantly reducing the digestibility of starch,and has broad prospects of the actual production of slowly digestible starch and resistant starch.
文摘Dynamic changes of starch, amylose, sucrose contents and the activities of starch synthesis enzymes under shading treatments alter flowering were studied using two rice varieties IR72 （indica） and Nipponbare （japonica） as materials. Under shading treatments, the starch, amylose and sucrose contents decreased, while ADP-glucose pyrophosphorylase （ADPGPPase） activity only changed a little, soluble starch synthase activity and granule bound starch synthase activity decreased, soluble starch branching enzyme （SSBE, Q-enzyme） activity and granule bound starch branching enzyme （GBSBE, Q-enzyme） activity increased, and starch debranching enzyme （DBE, R-enzyme） activity varied with varieties. Correlation analyses showed that the changes of starch content were positively and significantly correlated with the changes of sucrose content in the weak light. Both ADPGPPase activity and SSBE activity were positively and significantly correlated with starch accumulation rate. It was implied that the decline of starch synthase activities was related to the decrease of starch content and the increase of the activity of starch branching enzyme played an important role in the decrease of the ratio of amylose to the total starch under the weak light.
基金the National Key Research and Development Program of China(GrantNo.G199810100)
文摘The dynamic changes of the activities of enzymes involving in starch biosynthesis,including ADP-glucose pyrophosphorylase(AGPase),soluble starch synthases(SSS),starch branching enzyme(SBE)and starch debranching enzymes(DBE)were studied,and changes of fine structure of amy-lopectin were characterized by isoamylase treatment during rice grain development,using trans anti-waxy gene rice plants.The relationships between the activities of those key enzymes were also analyzed.The amylose synthesis was significantly inhibited in transgenic Wanjing 9522,but the total starch content and final grain weight were less affected as compared with those of non-transgenic Wanjing 9522 rice cultivar.Analyses on the changes of activities of enzymes involving in starch bio-synthesis showed that different enzyme activities were expressed differently during rice endosperm development.Soluble starch synthase is relatively highly expressed in earlier stage of endosperm de-velopment,whilst maximal expression of granule-bound starch synthase(GBSS)occurred in mid-stage of endosperm development.No obvious differences in changes of the activities of AGPase and SBE between two rice cultivars investigated,except the DBEs.Distribution patterns of branches of amy-lopectin changed continually during the development of rice grains and varied between two rice culti-vars.It was suggested that amylopectin synthesis be prior to the synthesis of amylose and different enzymes have different roles in controlling syntheses of branches of amylopectin.
基金the National Key R&D Program of China(No.2021YFC2103500)the Tianjin Synthetic Biotechnology Innovation Capacity Improvement Project(No.TSBICIP-KJGG-009-02 and No.TSBICIP-CXRC-003).
文摘Starch,a semi-crystalline energy storage form primarily found in plant plastids plays a crucial role in various food or no-food applications.Despite the starch biosynthetic pathway’s main enzymes have been characterized,their origin and evolution remained a subject of debate.In this study,we conducted the comprehensive phylogenetic and structural analysis of three types of starch biosynthetic enzymes:starch synthase(SS),starch branching enzyme(SBE)and isoamylase-type debranching enzyme(ISA)from 51,151 annotated genomes.Our findings provide valuable insights into the possible scenario for the origin and evolution of the starch biosynthetic pathway.Initially,the ancestor of SBE can be traced back to an unidentified bacterium that existed before the formation of the last eukaryotic common ancestor(LECA)via horizontal gene transfer(HGT).This transfer event likely provided the eukaryote ancestor with the ability to synthesize glycogen.Furthermore,during the emergence of Archaeplastida,one clade of SS was transferred from Deltaproteobacteria by HGT,while ISA and the other clade of SS originated from Chlamydiae through endosymbiosis gene transfer(EGT).Both these transfer events collectively contributed to the establishment of the original starch biosynthetic pathway.Subsequently,after the divergence of Viridiplantae from Rhodophyta,all three enzymes underwent multiple duplications and N-terminus extension domain modifications,resulting in the formation of functionally specialized isoforms and ultimately leading to the complete starch biosynthetic pathway.By shedding light on the evolutionary origins of key enzymes involved in the starch biosynthetic pathway,this study provides important insights into the evolutionary events of plants.
文摘Starch nanoparticles(SNPs)are attracting attention due to their novel attributes beneficial to certain applications;their fabrication technique and physicochemical attributes have yet to be systematically investigated.In this study,starch nanoparticles were fabricated from the debranched rice starches of three rice lines employing the mono-modification by annealing treatments for one and five days and the dual-modification by the combined annealing and heat-moisture treatments,and their physicochemical properties were characterized.The highest percent recovery of crystalline SNPs was obtained by the dual-modification treatments(32.6-45.6%),followed by the five-day annealing treatment(23.8-28.7%),and then the one-day annealing treatment(11.7-15.8%).The modified starches showed significant increases in oil absorption capacity,water holding capacity,and solubility and decreases in swelling power and volume fraction compared to their native counterparts.The crystal types were changed from A-type to B-type polymorphs by mono-modification treatment and to CA-type polymorphs by the dual-modification treatment with significant increases in relative crystallinity.The dual-modification treatment resulted in the highest increases in 1047/1022 cm^(-1),995/1022 cm^(-1),and 1047/1035 cm^(-1)band ratios and the highest melting temperatures and enthalpies.The resistant starch contents of the modified starches were markedly increased and strongly related to the percent recovery and the short-and long-range ordered structures.The results suggest that the dual-modified starches comprised the rigid and densely packing of nanoaggregates with superior oil/water absorption performance and water dispersibility,and high enzymatic resistance,which could be the contributing factors for their utilizations as novel ingredients in food-related applications.
基金supported by National Natural Science Foundation of China(22276078,32302066)China Postdoctoral Science Foundation(341192)National Key R&D Program for the 14th Five Year Plan(2023YFD1000600-023YFD1000602).
文摘Excessive fat intake can have adverse health effects.Thus,consumers often look for alternative,low-fat ice cream options,but decreased fat content in ice cream can affect the taste and quality.Therefore,this study investigated the functional and physiochemical properties of debranched waxy rice(DBWR)starches as a fat substitute in ice cream.We found that after debranching,the molecular weight of DBWR starch changed from 17.03×10^(6) g/mol to 9.18×10^(4) g/mol.Additionally,the short-chain amylose content and dextrose equivalence value increased as the debranching degree increased.Furthermore,the particle size of the ice cream mixture gradually decreased as the degree of debranching increased,stabilizing after 4 h of debranching(1.356±0.364μm);the ice cream slurry also had a high Zeta potential(over-30 mV)and improved emulsion stability.Compared to low-fat ice cream without fat substitutes,adding DBWR starches also increased the viscosity and consistency coefficient of the mixture,reduced the amount of ice and free water,increased the amount of bound water,positively affected the glass transition temperature,and improved the melting resistance of ice cream owing to the strong interactions among short-chain amylose molecules.Specifically,2 and 4 h of debranching had the best substitution effects.The low-fat ice cream mixtures with DBWR-2 and DBWR-4 had similar sensory properties as medium-fat ice cream mixtures.This study demonstrates that DBWR starch could be a suitable fat substitute that retains the quality and consistency of low-fat ice cream.
