| 1. |
- Bannak Gedara, Shishanthi Jayarathna, et al.
(författare)
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High fructan barley lines produced by selective breeding may alter beta-glucan and amylopectin molecular structure
- 2023
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Ingår i: Carbohydrate Polymers. - 0144-8617. ; 316
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Tidskriftsartikel (refereegranskat)abstract
- Six cross-bred barley lines developed by a breeding strategy with the target to enhance the fructan synthesis activity and reduce the fructan hydrolysis activity were analyzed together with their parental lines, and a reference line (Gustav) to determine whether the breeding strategy also affected the content and molecular structure of amylopectin and beta-glucan. The highest fructan and beta-glucan content achieved in the novel barley lines was 8.6 % and 12 %, respectively (12.3-fold and 3.2-fold higher than in Gustav). The lines with low fructan synthesis activity had higher starch content, smaller building blocks in amylopectin, and smaller structural units of beta-glucans than the lines with high-fructan synthesis activity. Correlation analysis confirmed that low starch content was associated with high amylose, fructan, and beta-glucan content, and larger building blocks in amylopectin.
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| 2. |
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| 3. |
- Andersson, Annica, et al.
(författare)
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Lignin is the main determinant of total dietary fiber differences between date fruit (Phoenix dactylifera L.) varieties
- 2020
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Ingår i: NFS Journal. - : Elsevier BV. - 2352-3646. ; 21, s. 16-21
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Tidskriftsartikel (refereegranskat)abstract
- Date fruits (Phoenix dactylifera) of ten varieties, collected in the United Arab Emirates, were studied to determine their dietary fiber content and composition. Fourier transform infrared (FTIR) spectroscopy indicated that the dietary fiber components in all the date fruit varieties was similar. The major dietary fiber components, including cellulose, hemicellulosic components, lignin, and pectin, were analyzed by the Uppsala method. The total dietary fiber content in the date fruits analyzed (5.2%–8.3%) is comparable to commonly consumed dried fruits and is correlated with the content of lignin. The lignin was the main determinant of the total dietary fiber content in dates and its content was higher in semi-hard and hard fruit varieties.
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| 4. |
- Andersson, Mariette, et al.
(författare)
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A simplified method of determining the internal structure of amylopectin from barley starch without amylopectin isolation
- 2021
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Ingår i: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617. ; 255
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Tidskriftsartikel (refereegranskat)abstract
- To determine the internal structure of barley starch without amylopectin isolation, whole starch was hydrolyzed using beta-amylase to remove the linear amylose and obtain beta-limit dextrins (beta-LDs). The beta-LDs were treated with extensive a-amylase to prepare alpha-limit dextrins (alpha-LDs), and the alpha-LDs were further hydrolyzed with beta-amylase into building blocks. The chain-length distribution of beta-LD and building block composition were analyzed by sizeexclusion chromatography and anion-exchange chromatography. The internal structure of the barley whole starches had similar pattern to barley amylopectins analyzed by conventional methods. The starch of barley amol-mutated varieties contained more short internal B-chains and less long internal B-chains than that of other varieties. The starch from amol-mutated varieties had more large building blocks than that from waxy varieties. The simplified method presented in this study can effectively characterize starch internal structure that relates to physicochemical properties of starch, although some details of amylopectin structure are not assessable.
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| 5. |
- Bannak Gedara, Shishanthi Jayarathna, et al.
(författare)
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Recent Advances in Starch-Based Blends and Composites for Bioplastics Applications
- 2022
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Ingår i: Polymers. - : MDPI AG. - 2073-4360. ; 14
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Forskningsöversikt (refereegranskat)abstract
- Environmental pollution by synthetic polymers is a global problem and investigating substitutes for synthetic polymers is a major research area. Starch can be used in formulating bioplastic materials, mainly as blends or composites with other polymers. The major drawbacks of using starch in such applications are water sensitivity and poor mechanical properties. Attempts have been made to improve the mechanical properties of starch-based blends and composites, by e.g., starch modification or plasticization, matrix reinforcement, and polymer blending. Polymer blending can bring synergetic benefits to blends and composites, but necessary precautions must be taken to ensure the compatibility of hydrophobic polymers and hydrophilic starch. Genetic engineering offers new possibilities to modify starch inplanta in a manner favorable for bioplastics applications, while the incorporation of antibacterial and/or antioxidant agents into starch-based food packaging materials brings additional advantages. In conclusion, starch is a promising material for bioplastic production, with great potential for further improvements. This review summarizes the recent advances in starch-based blends and composites and highlights the potential strategies for overcoming the major drawbacks of using starch in bioplastics applications.
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| 6. |
- Fei, Mingliang, et al.
(författare)
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Achieving of high-diet-fiber barley via managing fructan hydrolysis
- 2022
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- High fructan content in the grain of cereals is an important trait in agriculture such as environmental resilience and dietary fiber food production. To understand the mechanism in determining final grain fructan content and achieve high fructan cereal, a cross breeding strategy based on fructan synthesis and hydrolysis activities was set up and have achieved barley lines with 11.8% storage fructan in the harvested grain. Our study discovered that high activity of fructan hydrolysis at later grain developmental stage leads to the low fructan content in mature seeds, simultaneously increasing fructan synthesis at early stage and decreasing fructan hydrolysis at later stage through crossing breeding is an efficient way to elevate grain diet-fiber content. A good correlation between fructan and beta glucans was also discovered with obvious interest. Field trials showed that the achieved high fructan barley produced over seven folds higher fructan content than control barley and pull carbon-flux to fructan through decreasing fructan hydrolysis without disruption starch synthesis will probably not bring yield deficiency.
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| 7. |
- Jayarathna, Shishanthi, et al.
(författare)
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GBSS mutations in an SBE mutated background restore the potato starch granule morphology and produce ordered granules despite differences to native molecular structure
- 2024
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Ingår i: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617 .- 1879-1344. ; 331
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Tidskriftsartikel (refereegranskat)abstract
- Potato starch with mutations in starch branching enzyme genes (SBEI, SBEII) and granule-bound starch synthase gene (GBSS) was characterized for molecular and thermal properties. Mutations in GBSS were here stacked to a previously developed SBEI and SBEII mutation line. Additionally, mutations in the GBSS gene alone were induced in the wild-type variety for comparison. The parental line with mutations in the SBE genes showed a ∼ 40 % increase in amylose content compared with the wild-type. Mutations in GBSS-SBEI-SBEII produced non-waxy, low-amylose lines compared with the wild-type. An exception was a line with one remaining GBSS wild-type allele, which displayed ∼80 % higher amylose content than wild-type. Stacked mutations in GBSS in the SBEI-SBEII parental line caused alterations in amylopectin chain length distribution and building block size categories of whole starch. Correlations between size categories of building blocks and unit chains of amylopectin were observed. Starch in GBSS-SBEI-SBEII mutational lines had elevated peak temperature of gelatinization, which was positively correlated with large building blocks.
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| 8. |
- Jensen Wolfhechel, Ola, 1965-, et al.
(författare)
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Norrlands vattenanknutna kulturmiljöer – en förstudie : rapport från ett FoU-projekt
- 2022
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Syftet med föreliggande förstudie har varit att ta fram ett underlag inför ett kommande tvärvetenskapligt forsknings- och digitaliseringsprojekt. Bakgrunden är att Riksantikvarieämbetet under 1940-1980-talen genomförde omfattande arkeologiska, men även naturvetenskapliga och etnologiska, undersökningar vid Norrlands älvar och sjöar som ett led i vattenkraftsutbyggnaden. Materialet kom under 1960-1980-talen att bearbetas tillsammans med Stockholms universitet inom ramen för det tvärvetenskapliga projektet Norrlands Tidiga Bebyggelse. Insatserna resulterade i ett rikt material som idag förvaras i Riksantikvarieämbetets arkiv. Då stora delar av Norrland alltjämt är antikvariskt eftersatta utgör det ett mycket viktigt källmaterial för både forskning och förvaltning av dess kulturmiljöer.Det långsiktiga målet med förstudien och det kommande projektet är att skapa ett kunskapsunderlag för forskning och redskap för landskapsanalyser som leder till ett hållbart bevarande och förvaltning av Norrlands vattenanknutna kulturmiljöer. Inom förstudien har en rad viktiga forsknings- och förvaltningsområden identifierats. För att ta fram ett adekvat underlag inför ansökan har den bland annat mynnat ut i olika förslag på strategier för det kommande projektets genomförande och finansiering, en fördjupning av frågor som rör förvaltning av vattenanknutna kulturmiljöer, utvecklat tvärvetenskapliga forskningsfrågor, tagit fram en digitaliseringsstrategi, formaliserat ett nätverk och en referensgrupp, genomfört en behovsanalys samt en inventering för att identifiera relevant arkivmaterial inom projektdeltagarnas respektive institutioner. Med förstudien har vi således lagt grunden till ett tvärvetenskapligt forsknings- och digitaliseringsprojekt som inkluderar kulturmiljöförvaltning, arkeologi, etnologi, sociologi och naturveten-skapliga ämnen, däribland miljö- och klimatforskning.
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| 9. |
- Kamal-Eldin, Afaf, et al.
(författare)
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Dietary fiber components, microstructure, and texture of date fruits (Phoenix dactylifera, L.)
- 2020
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 10:1, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- Date fruits vary widely in the hardness of their edible parts and they are classified accordingly into soft, semi-dry, and dry varieties. Fruit texture, a significant parameter in determining consumer acceptance, is related to the tissue structure and chemical composition of the fruit, mainly the ratio of sucrose to reducing sugars. This study aimed to understand the relationship between the chemical composition, microstructure, and texture profile of 10 major Emirati date fruits. The soluble sugars, glucose and fructose, represent ca 80 g/100 g of the fruits on the basis of dry weight (DW) while the dietary fiber contents varied 5.2-7.4 g/100 dg D.W. with lignin being the main determinant of the variability. The textures of the samples were studied using instrumental texture profile analysis. While no correlation was found between the soluble sugar and texture parameters in this study, the different fiber constituents correlated variably with the different parameters of date fruit texture. Lignin, arabinoxylan, galactomannan, and pectin were found to correlate significantly with fruit hardness and the related parameters, gumminess and chewiness. Both lignin and arabinoxylan correlated with resilience, and arabinoxylan exhibited a strong correlation with cohesiveness.
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| 10. |
- Zhao, Xue, et al.
(författare)
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Amylose starch with no detectable branching developed through DNA-free CRISPR-Cas9 mediated mutagenesis of two starch branching enzymes in potato
- 2021
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- DNA-free genome editing was used to induce mutations in one or two branching enzyme genes (Sbe) in tetraploid potato to develop starch with an increased amylose ratio and elongated amylopectin chains. By using ribonucleoprotein (RNP) transfection of potato protoplasts, a mutation frequency up to 72% was achieved. The large variation of mutations was grouped as follows: Group 1 lines with all alleles of Sbe1 mutated, Group 2 lines with all alleles of Sbe1 as well as two to three alleles of Sbe2 mutated and Group 3 lines having all alleles of both genes mutated. Starch from lines in Group 3 was found to be essentially free of amylopectin with no detectable branching and a chain length (CL) distribution where not only the major amylopectin fraction but also the shortest amylose chains were lost. Surprisingly, the starch still formed granules in a low-ordered crystalline structure. Starch from lines of Group 2 had an increased CL with a higher proportion of intermediate-sized chains, an altered granule phenotype but a crystalline structure in the granules similar to wild-type starch. Minor changes in CL could also be detected for the Group 1 starches when studied at a higher resolution.
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