Browsing by Subject "oligosakkaridit"

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  • Niklander, Katariina (Helsingin yliopisto, 2021)
    Enzyme treatments have been able to reduce the amount of oligosaccharides and phytates in legumes. Enzyme treatment has the potential to improve the sensory properties of the product and reduce the stomach symptoms they cause. The aim of the study was to find out how enzyme treatment affects to the sensory properties of spoonable yogurt-like faba bean and pea-based snack samples. In addition, an online survey was made to map stomach symptoms caused by legumes and to study their effect on the use of legumes and legume foods. The methods used in the study were generic descriptive analysis with a trained panel (11 panelists) and an online survey made with E-lomake (227 respondents). In addition, the benefit data from the second study of the project for pea snacks were used (27 evaluators). In the generic descriptive analysis, there were a total of 6 spoonable snack samples to be examined (3 faba bean samples and 3 pea samples). Both raw materials had a control sample (no enzyme treatment) and two differently enzyme treated samples. In the generic descriptive analysis, the panel evaluated 12 properties from the samples: color, fruity and legume-like odor, runniness, grainy, powderiness, thickness, sweet, bitter, legume-like, bitter aftertaste and total intensity of aftertaste. Enzyme treatment had an effect on texture and mouthfeel properties, but not on taste, color, or odor. As a result of the enzyme treatment, the structure thickened and became smoother. The raw material had an effect on all the properties to be evaluated, except for the legume-like flavor. Enzyme treatment had no effect on the pleasantness of spoonable pea snacks. According to the survey, the most common symptoms caused by legumes were flatulence and bloating. Of the legumes and legume foods, chickpeas and pea soup were the most common foods to cause symptoms. More than half (about 65 %) of the respondents stated that they would definitely or probably eat more legumes if they did not cause stomach symptoms. More than half (67 %) would also be absolutely or probably willing to try enzyme-treated legume foods. Based on the results, it is worth further investigating the effects of enzyme treatment on sensory properties, especially in terms of structure / mouthfeel. In addition, the effect of fermentation on the sensory properties of pea and faba bean spoonable snacks should also be studied, as fermentation has been found to improve the sensory properties and nutritional value of plant-based spoonable snacks. Based on the responses to the survey, there seems to be a demand for legume products that cause less stomach symptoms.
  • Pehkonen, Teresa (Helsingfors universitet, 2010)
    Biologisesti aktiivisilla oligosakkarideilla on vaikutuksia kasvin kasvuun ja kehittymiseen. Tietyn tyyppiset oligosakkaridit voivat myös indusoida puolustusreaktion valikoivasti oligosakkaridista riippuen. Useat biologisesti aktiiviset oligosakkaridit on löydetty kasvien soluseinää keinotekoisesti hajottamalla. Pro gradu -tutkielman tarkoituksena oli karakterisoida kuusen (Picea abies) solukkolinjan A3/85 solususpensiokasvatukseen erittämiä oligosakkarideja. Kuusisolukko A3/85 on otollinen kandidaatti tutkimukseen, sillä sen on todettu erittävän solunulkoista ligniiniä suspensioliuokseen. Oligosakkarideja karakterisoitiin yhden ja neljän vuorokauden kasvatuksista. Alustan sokeripitoisuutta alennettiin neljän vuorokauden kasvatuksissa karakterisoinnin helpottamiseksi. Oligosakkaridien pitoisuudet voivat olla hyvin alhaisia, joten solujen tuottamia yhdisteitä seurattiin myös radioaktiivisen D-[U-14C]-glukoosin avulla. Kasvien soluseinässä yleiset glukuronihappo, galakturonihappo, ksyloosi, arabinoosi ja apioosi valmistetaan glukoosi-6-fosfaatista, joko myo-inositolihapetusreitin tai sokerihapetusreitin kautta. Lisäksi tutkittiin, muuttuuko radioaktiivisen leiman jakautuminen näytteissä, kun kasvatusliuoksessa on tai ei ole myo-inositolia. Kasvatusliuos fraktioitiin geelisuodatuskromatografialla. Fraktioiden sisältämät yhdisteet eroteltiin paperikromatografialla ja värjättiin hopeanitraatilla, aniliinivetyftalaatilla tai ninhydriinillä. Hopeanitraatti on hyödyllinen monosakkaridien, oligosakkaridien ja alditolien värjäyksessä. Radioaktiivisuuden kertymistä yhdisteisiin seurattiin nestetuikelaskimella ja autoradiografialla. Paperikromatografialla erotelluista yhdisteistä valittiin mielenkiintoiseksi koetut yhdisteet, jotka eristettiin preparatiivisella paperikromatografialla. Eristetyille yhdisteille tehtiin happohydrolysointi, borohydridikäsittely tai entsymaattinen Driselaasi -käsittely. Happohydrolysointi avaa sokeriyksiköiden väliset glykosidiset sidokset. Natriumborohydridipelkistys muuttaa oligosakkaridiketjun pelkistävän sokerin sokerialkoholiksi ja Driselaasi -käsittely avaa isoprimeveroosin Xyl-α-(1 –> 6)-Glc -sidosta lukuun ottamatta muut glykosidiset sidokset. 14C-leima on jakautunut myo-inositolin kanssa kasvatetun näytteen fraktioinnissa vahvemmin suurimolekyylisiin yhdisteisiin, kun taas ilman myo-inositolia kasvatetussa näytteessä suurin aktiivisuus D-[U-14C]-glukoosin jälkeen on trisakkaridien alueella. Suspensioliuoksista analysoitiin useita oligosakkarideja polymerisaatioasteella 1-4. Analysoiduista yhdisteistä kolme sisälsivät ksyloosia, jota solut voivat syntetoida joko myo-inositolin hapetusreitin tai glukoosin hapetusreitin kautta. Myo-inositolin puuttuminen alustasta lisäsi näiden leimattujen yhdisteiden pitoisuutta. Alustan myo-inositoli ei ole radioaktiivista, joten myo-inositolihapetusreitin kautta valmistetut monosakkaridit eivät näy autoradiografiassa. Vaikuttaisi siis siltä, että myo-inositolihapetusreitti on aktiivinen ainakin, jos solukolle tarjotaan myo-inositolia. Lisätty myo-inositoli vähentää sokerihapetusreitin aktiivisuutta. Työn aikana onnistuttiin eristämään ja osittain tunnistamaan useita kuusen suspensioliuoksen yhdisteitä. Myo-inositolihapetusreitti todettiin aktiiviseksi solukkokasvatuksessa, kun ravintoalustassa on myo-inositolia.
  • Juvonen, Minna (Helsingfors universitet, 2011)
    The aim of the present study was to implement a tandem mass spectrometry (MS/MS) method for determining glycosidic bond linkage positions of neutral isomeric glucooligosaccharides. The methods for structural analysis and the fragmentation mechanisms of oligosaccharides in MS/MS-analysis was reviewed. The MS/MS-spectra of oligosaccharide contains glycosidic bond and cross ring cleavage fragment ions. The linkage position can be determined by cross ring cleavage fragment ions of cationized or anionized oligosaccharides. The study started by analyzing the typical MS/MS-spectra of model isomeric disaccharides with different linkage positions. The data was then used to assess the MS/MS-spectra of model tri- and tetrasaccharides. The similarity of MS/MS fragmentation patterns of the model disaccharides and the tri- and tetrasaccharides would enable the linkage position analysis by the applied MS/MS method. The MS/MS-analyses were carried out by using electron spray ionization with ion trap mass spectrometer in both positive and negative mode. In positive mode the oligosaccharides were analyzed as sodium and lithium adduct ions while chloride adduct ions were used in negative mode analysis. The different linkage positions of disaccharides were characterized by the different MS/MS fragmentation profiles in positive and negative ionization methods. The reducing end linkage positions of tri- and tetrasaccharides were easily identified by comparing their MS/MS fragmentation patterns with the MS/MS-spectra of model disaccharides. The other linkages in the tri- and tetrasaccharide were identified by using negative mode. In positive mode the identification of other linkages was not possible because the cross ring cleavage fragment ions were formed mostly from the reducing end. The linkages of tri- and tetrasaccharides could not be identified by MS3-analysis due to formation of isomeric glycosidic bond fragment ions as the charge can be retained in the reducing or non-reducing end. The results indicated that the applied MS/MS method was suitable for determing the glycosidic bond linkages of oligosaccharides in negative mode. In positive mode only the reducing end linkage can be determined.