Maatalous- metsätieteellinen tiedekunta


Recent Submissions

  • Assmuth, Aino (University of Helsinki, 2015)
    This study applies two novel forest economic models to analyze the effect of optimal carbon storage on the choice between clearcuts and continuous cover forestry. Unlike previous studies, we determine the economically optimal management regime endogenously, by optimization. We study a policy where the society pays forest owners a Pigouvian subsidy for the carbon that is sequestered by the stand as it grows. The focus of our analysis is a subsidy system that also takes into account the carbon both stored in and released from wood products. In the first part of the thesis, the question of optimal carbon storage is studied using a continuous time biomass model that does not include any a priori assumptions on clearcuts vs. continuous cover forestry. We show analytically that subsidized carbon sequestration postpones thinning and increases optimal stand volume along the rotation. With high carbon price the shadow value of stand volume becomes negative. Numerical results show that carbon prices within a realistic range may switch the optimal management regime from clearcuts to continuous cover management. A higher interest rate can lead to a higher stand volume and a longer optimal rotation, which contrasts the results of the classic Faustmann model. Next, the question is studied applying a more detailed size-structured transition matrix model based on empirically estimated Scandinavian growth data. This approach produces a more accurate description of the complex dynamics of uneven-aged stands and optimization of harvesting activities. According to numerical results, thinning is invariably carried out from above, and the size of the harvested trees increases with carbon price. Optimal rotation age increases with carbon price, and moderate carbon pricing is sufficient to switch the management regime to continuous cover management. Optimal rotation age also increases with interest rate. Clearcut management is the more competitive, the more productive is the site type. Both models suggest that carbon storage has a significant effect on optimal forest management, and that it typically favors continuous cover forestry. Similar analysis on optimal carbon storage in forestry has not been presented before. We also discuss various carbon subsidy systems in the context of developing climate policy.
  • Lemmetyinen, Juho (Helsingin yliopisto, 2015)
    Metabolista oireyhtymää (MBO) pidetään merkittävänä sydän- ja verisuonisairauksien sekä tyypin 2 diabeteksen (T2D) riskitekijänä. Ruokavalion laatua voidaan tutkia ruokavalioindekseillä. Indekseillä mitatun ruokavalion laa-dun ja MBO:n riskin välistä yhteyttä on kuitenkin tutkittu vähän. Tämän tutkimuksen tavoitteena oli tutkia ruoka-valion laadun ja MBO:n välistä yhteyttä kuuden vuoden seurantatutkimuksessa. Tutkimus perustui PPP-Botnia -tutkimuksen aineistoon. Tutkittavat olivat 18–75-vuotiaita pohjanmaalaisia (n=3053; naisia 53,7 %). Botnia-ruokavalioindeksi perustui suomalaisiin vuoden 2014 ravitsemussuosituksiin, ja sillä tutkittiin ruokavalion laatua tässä tutkimuksessa. Metabolinen oireyhtymä määriteltiin NCEP-ATP III (Nati-onal Cholesterol Education Program Adult Treatment Panel III) - määritelmän mukaisesti. Ruokavalion laadun ja MBO:n seurannan aikaista kehittymistä tai paranemista tutkittiin logistisella regressioanalyysillä laskettujen vedon-lyöntisuhteiden (OR) sekä 95 % -luottamusvälien (LV) perusteella. Lähtötilanteen ruokavalion laatu ei ollut yhteydessä MBO:n paranemiseen tai kehittymiseen. Ruokavalion laadun paraneminen seurannan aikana oli yhteydessä alhaisempaan MBO:sta paranemisen todennäköisyyteen yli 39-vuoti-ailla (OR=0,40; LV=0,18–0,93) sekä lihavilla ja ylipainoisilla tutkittavilla (OR=0,41; LV=0,18–0,91). Terveellistä ruokavaliota noudattaneiden muutkin elämäntavat olivat terveellisemmät, mutta terveydentila huo-nompi, kuin epäterveellistä ruokavaliota noudattaneiden. Sama tulos saatiin myös kun ikä huomioitiin mallissa. Mahdol-lisesti ikääntymisen ja T2D:n perhehistoria ovat voineet motivoida tutkittavia muuttamaan elämäntapojaan terveel-lisemmäksi, minkä vuoksi tutkimuksessa havaittiin yhteys terveellisten elämäntapojen ja korkeamman MBO:n esiintyvyyden välillä.
  • Arnkil, Nora (University of Helsinki, 2015)
    The boreal forest is one of the largest biomes in the world, maintaining natural disturbances such as forest fires and insect outbreaks, still occurring widely at their full scale, frequencies and patterns. However, the knowledge of natural forest dynamics, disturbance factors other than fire and post-disturbance development is still inadequate; this is partly due to the lack of accurate, repetitive measurements with adequate temporal resolution. The aim of this study was to examine the structural change and development of natural, Abies balsamea (L.) Mill. dominated forest stands following an insect outbreak of late-1970s to early 1980s. The focus was on annual tree basal area and species composition change at the stand level during the recent decades. The post-disturbance stand development was studied to see whether the stands were following the development model of steady state and quasi-equilibrium. Additionally, the size and age structure of the stands were studied. The objectives were achieved by using dendrochronological methods with tree-ring analyses, in which the forest characteristics were reconstructed at an annual resolution. The study was carried out in the province of Quebec in Eastern Canada, in the North Shore region (Côte-Nord) of St. Lawrence River. Nine sites of a size of 32 m x 32 m were chosen for data collection. The results showed that the tree species composition of the studied stands had clearly changed from the pre-episode to the current state: the composition of A.balsamea, Picea mariana (Mill.) BSP and Betula papyrifera Marsh. in 1975 had changed towards the abundance of A. balsamea, with notably less of P. mariana and B. papyrifera in 2013. Particularly B. papyrifera seems to disappearing from the studied stands. On average, the shape of the live tree diameter distribution for the whole study area was close to a reverse-J, whereas the dead tree diameter distribution resembled rotated sigmoid, with a plateau in the middle. The trees were of all age, mean age for live A. balsamea, P. mariana and B. papyrifera trees was 91 years (SD ± 32 years), 135 years (SD ± 48 years) and 180 years (SD ± 24 years), respectively. The examination of the development of total basal area showed apparent changes during the four decades from 1975 to 2013. The average stand development of total basal area for the whole study area was modest decline after a dramatic post-outbreak drop: the basal area was 33.8 m2 ha-1 (SD ± 4.5 m2 ha-1) in 1975 and 20.7 m2 ha-1 (SD ± 6.0 m2 ha-1) in 2013. Stands showed different types of development: for some of the stands basal area had dropped throughout the observation period, for some the total basal area had started to recover after a decline, and some stands had fairly stable development throughout the observation period. The development of basal area in the past fifteen years has been negative in over half of the studied stands; it seems that the stands are not following the expected post-disturbance development, where the biomass of the forest recovers to the pre-outbreak level and over it, at these time scales of 30-years of observation. Results suggest that the studied forest stands have reached a state where the basal area is yet to be recovered from the decline following the spruce budworm outbreak in the late-1970s to early 1980s. There is a new, on-going defoliation of spruce budworm – that already has heavily affected particularly A. balsamea – in the study area, and therefore the basal area of the forest stands might be expected to furthermore decline in the future.
  • Åhlgren, Johanna (University of Helsinki, 2015)
    Hovawart is an old German working dog breed. Few hundred dogs are registered annually in Finland. Hovawarts can be seen in working trials as well as a family pet. In Hovawart breeding program (JTO) hypothyroidism is mentioned as a one of the most common hereditary diseases and is usually caused by lymphocytic thyroiditis. Lymphocytic thyroiditis is an autoimmune disease which destroys the thyroid gland. Hypothyroidism is treated medically by substituting natural hormone production with medical hormones. The aim of this study was to estimate the heritability of the hypothyroidism in Finnish Hovawart population. Research material was provided by Finnish Kennel Club and Finnish Hovawart Club. Dogs born between 1990 and 2010 were included in the study. The influence of gendre, birth year and month, size of the birth litter, breeders living area, colour and inbreeding were studied. Data was delimited in two different ways. Data 1 consisted 4953 dogs, where 107 were hypothyroid and 4846 were assumed to be healthy. In data 2, hypothyroid dogs were the same as in data 1 but only dogs used for breeding were considered as healthy (739 dogs). The χ2 test was used to evaluate the influence of individual factors. The influence of fixed effects and covariate were tested with a generalized linear model. Fixed effects were chosen by using the backward method and the applicable model was chosen by using e.g. Akaike’s information criterion, AIC. The animal model and the REML method was used in variance component analyses. Since hypothyroidism is a binary factor logit and probit models were used. For comparison, heritability was also estimated with a linear model. In data 1 colour and birth litter size were significant. In data 2 colour, birth litter size and gender were significant. Estimated heritability by logit model was 0.65 in data1 and 0.54 in data 2. When transformed to the underlying liability scale the corresponding values were 0.36 and 0.26, respectively. Heritabilities by probit model were 0.24 and 0.23 and by linear model 0.21 and 0.44 for data 1 and 2, respectively. Heritability of hypothyroidism is moderate and can be considered even as high, hence the prevalence of hypothyroidism can be decreased by breeding. However, it is not possible to exclude all hypothyroid dogs and their close relatives from breeding. Hypothyroidism can be diagnosed later when the dog has already been used for breeding. To decrease the prevalence of hypothyroidism there is a need for an appropriate tool to support breeders’ choices. Efficiency requires openness within breed and collecting and offering the data to public use.
  • Kämäräinen, Helena (Helsingin yliopisto, 2015)
    Palkokasvien käyttö säilörehun raaka-aineena on yleistynyt lannoitekustannusten nousun myötä. Palkokasvit kykenevät sitomaan typpeä ilmasta juurinystyräbakteerien avulla kas-vin tarpeisiin. Suomessa on puna-apilan käytön rinnalle noussut alsikeapila, joka on kestä-vämpi kuin puna-apila kosteissa olosuhteissa ja happamilla mailla. Herne ja härkäpapu ovat lisänneet suosiotaan kokoviljasäilörehujen raaka-aineena tuomaan valkuaista re-huseokseen. Puna-apilalla on useiden tutkimusten mukaan vaikutusta sekä maidon että lihan rasvahappokoostumukseen ihmisen ravitsemuksen kannalta edulliseen suuntaan: n-6/n-3 –rasvahappojen suhde pienenee sekä tyydyttyneiden rasvahappojen osuus vähenee. Alsikeapilan sekä herneen ja härkäpavun koko kasvuston vaikutusta maidon ja lihan rasva-happoihin on tutkittu hyvin vähän. Tässä tutkimuksessa verrattiin timotei- ja alsikeapilasäilörehun (koe 1) ja timotei-, herne-vehnä- ja härkäpapuvehnäsäilörehujen (koe 2) vaikutusta lihan syöntilaatuun ja lihan sisäi-sen rasvan rasvahappokoostumukseen sekä kahta Suomessa yleistä nautarotua: aberdeen angus (ab) –liharotua ja ayrshire (ay)-maitorotua. Alsikeapilasäilörehu lisäsi alfa-linoleenihapon ja margariinihapon osuutta ja vähensi transpalmitoleiinihapon osuutta li-haksen sisäisessä rasvassa verrattuna timoteisäilörehuun. Herne- ja härkäpapuvehnäsäilö-rehut vähensivät transpalmitoleiini-, heptadekeeni-, eikosadieeni- ja dokosaanihappojen osuutta ja lisäsivät margariinihapon osuutta timoteisäilörehuun verrattuna. Alsikeapila-, hernevehnä- ja härkäpapuvehnäsäilörehu eivät vaikuttaneet n-6/n-3 –rasvahappojen suh-teeseen eikä tyydyttyneiden rasvahappojen määrään toisin kuin rotu. Ab–rotuisten lihan rasvassa oli pienempi n-6/n-3 –rasvahappojen suhde ja niissä oli enemmän tyydyttynyttä rasvaa kuin ay-rotuisissa. Naudanlihan syöntilaatuun vaikuttaa mm. rotu, ruokinta, eläimen temperamentti ja käsit-tely ennen teurastusta. Ab-rotuisten liha oli marmoroituneempaa, punaisempaa ja keltai-sempaa ja lihan pH oli matalampi kuin ay-rotuisten. Leikkuuvaste oli pienempi ja aistinva-raisen arvion yhteispisteet olivat suuremmat sekä valuma pienempi ab-rotuisilla kuin ay-rotuisilla. Herne- ja härkäpapuvehnäsäilörehua saaneiden eläinten lihan pH oli matalampi kuin timoteisäilörehua saaneiden. Tässä kokeessa rotu vaikutti enemmän kuin ruokinta lihan syöntilaatuun ja lihaksen sisäisen rasvan rasvahappokoostumukseen.
  • Zhang, Teng (University of Helsinki, 2015)
    The architecture of inflorescence refers to the spatio-temporal arrangement of flowers on the reproductive branches. Flowering plants have evolved great diversity in such branching systems. Among which, the showy capitulum type inflorescence in the large Compositae (Asteraceae) species is regarded as a prerequisite factor for their wide spreading around the world. Different from the simple raceme and cyme, capitulum compresses hundreds of individual florets on its receptacle, but overall resembles a single, solitary flower. The ontogeny of capitulum also bears resemblance to a single flower, with regard to the meristem determinacy, floral sequence and histological configurations. Recent molecular studies have revealed that a plant specific transcription factor LEAFY (LFY), is required for both the floral initiation and floral patterning, the two essential steps to form an inflorescence. The thesis elaborates Gerbera hybrida as a model to elucidate functions of the LFY ortholog during the development of inflorescence/flower in a capitulum background. In addition to the conserved functions in regulating floral meristem identity and floral patterning, three specified functions were revealed by transgenic Gerbera with down-regulated expression of GhLFY. Firstly, GhLFY is involved in the regulating the floral initiation of marginal ray florets. Down regulation of GhLFY resulted the marginal ray florets revert into a branching patterm that shown on the capitulum of Calyceraceae, the close relatives of Asteraceae. Secondly, the determinacy of IM is disrupted when GhLFY loses its functions, suggesting that GhLFY may function at both the flower and inflorescence interfaces. Thirdly, different flower types show specific responses to GhLFY down-regulation in floral patterning, indicating that there exist a potential genetic gradient among different flower types. At protein level, the LFY functions are specified by formation of versatile protein complexes with its transcriptional co-regulators. In Gerbera, GhLFY proteins tend to form homodimers and they were also capable to interact with a conserved transcriptional co-regulator, the UNUSUAL FLORAL ORGANS (UFO) ortholog GhUFO. Taken advantage of the forward Y2H library screening, 6 additional proteins were identified to interact with GhLFY, including several novel potential co-regulators of LFY that has not yet been identified in other species. Additionally, a bimolecular fluorescence complementation assay (BiFC) was optimized to verify the GhLFY self-interaction in planta.
  • Christersson, Jenni (Helsingin yliopisto, 2015)
    This case study sheds new light on rural water use and related social, aconomic and environmental dimensions and proposes government intervention in order to ensure water rights and protect public value of fairness. The aim is to highlight farmers’ perspectives on irrigation water use and related obstacles, and specifically distinguish if views are connected to farmers’ underlying socioeconomic or agro-ecologic factors. For further considerations adaptive capacity of community for irrigation water fees is explored. The research material consists of semi-structured interviews for farmers (n=63), government organizations (n=3) and agricultural enterprises (n=2). Economic groups were formed via analysis of asset-based economic status. Grouping based on agricultural water use was conducted through categorization. Costs and lack of knowledge were identified as the main barriers for adopting advanced irrigation technology. The study showed prevailing allocation system is in need of reformation. When designing rural policy, farmers’ perceptions should be respected. Water allocation is considered unfair community-wide and social conflicts are largely faced. Those who do not suffer from conflicts are most commonly rich. Technology transfer offer potential benefits, but community needs to be mobilized. Grouping based on irrigation water usage may be used for targeting policies. Economic grouping may be used for distinguishing farmers’ behavior when designing change in economic conditions or conflict resolution strategy. The complementary role of this study is to bring out special focus on development for institutional capacity-building; strengthening the forcing nature of laws and user rights. This may reduce the attractiveness for corruption in the process. Under these conditions, the greatest benefits may be obtained by giving top priority instead of irrigation improvement, but conflict mediation and establishment of water markets.
  • Liu, Lingdai (University of Helsinki, 2015)
    The literature review introduced properties of native cellulose and common water-soluble cellulose derivatives, pathways to develop antimicrobial packaging from cellulosic materials, mechanisms of existing antimicrobial packaging systems and characterization of antimicrobial films. Special emphasis was given to potential of cellulose betainates (CB) as inherently antimicrobial, low-toxic materials for development of antimicrobial films. The aim of this study was to investigate overall potential of CB as antimicrobial films. CB together with commercial cationic starch (CS) and chitosan (CH) added with different amounts of sorbitol were prepared into films by solution casting. Mechanical properties, moisture and oxygen barrier attributes, and microscopic characteristics of aforementioned films were determined. In addition, antimicrobial potential of CB were tested against Listeria innocua and Escherichia coli compared to CS and CH by agar diffusion assay for films and measurements on optical density at 600nm for aqueous polysaccharide solutions. CB forms self-standing films with relatively low mechanical strength and stiffness while possessing good flexibility and medium barrier properties against water vapor and oxygen. CB films is antimicrobial against E. coli but not against L. innocua according to agar diffusion assay. Based on growth inhibition ratio (GIR%) from solution-phase tests, L. innocua was also more resistant than E. coli against CB at concentrations below 512 µg/ml. CB exhibited similar antimicrobial activity to that of CH within 512–1280 µg/ml. However, an increase in viscosity of CB solution at higher concentration (2560 µg/ml) as well as excessive microorganism (~108cfu/ml) in initial inoculum led to decrease in their antimicrobial efficacy. In conclusion, CB is antimicrobial against E. coli in film, and potential to exert similar antimicrobial potency as that of chitosan in solution with adequate quantities. Therefore, CB is a promising candidate as for fabrication of antimicrobial films. However, the antimicrobial mechanism, antimicrobial spectrum of CB and the applicability of CB films require further explorations.
  • Jiang, Xinyu (University of Helsinki, 2015)
    Biofilms constitute a successful protection mechanism for planktonic bacterial cells to survive in hostile environments. To date, biofilm-associated infections in medical devices represent a major cause of morbidity and mortality among patients. As a potential candidate for anti-biofilm therapy, fungal hydrophobins provide new solutions to manipulate the physical and chemical properties of surfaces, which in turn may give protection against bacterial colonization. However, in practice, native hydrophobin coatings generally have no impact on bacterial surface colonization, because of the lack of being antibacterial by these fungal proteins themselves. The aim of this study was to explore the feasibility of using recombinant fusion hydrophobins to control bacterial growth. In this study, the class I hydrophobin hgfI gene isolated from the edible mushroom Grifola frondosa was in frame fused with two antimicrobial peptide genes (bac8c and p11-5), respectively, and subsequently cloned into the corresponding expression vectors with a view to obtain two recombinant fusion hydrophobins, Bac8c-HGFI and P11-5-linker-HGFI. These two chimeric genes were separately expressed in Pichia pastoris under the regulation of alcohol oxidase 1 promoter. SDS-PAGE and immunoblot analyses confirmed that these two fusion proteins were successfully expressed and secreted into the culture medium. Minimum inhibitory concentration (MIC) test demonstrated that the highly active antimicrobial peptide Bac8c became inactivated when it was fused with the hydrophobin HGFI. Interestingly, the hydrophobin HGFI gained an acquired antibacterial nature when it was fused with the antimicrobial peptide P11-5 through a 10-mer flexible polypeptide linker, with the MIC of 100 μg/ml against Escherichia coli. To the best of my knowledge, this study presents the first heterologous expression of an antibacterial fusion hydrophobin in P. pastoris. This finding in combination with surface modification mediated by hydrophobin may broaden the current approaches used for anti-biofilm therapies.
  • Suutarla, Heli (University of Helsinki, 2015)
    Proteins contribute to network structures in foods not only when soluble as monomers but as various meso-scaled structures. The aim of the work was firstly to investigate the effects of heating and high pressure homogenization on colloidal properties and stability of plant protein dispersions, in particular soy and oat proteins. Secondly, aim was to test gelation properties of soy and oat proteins by fermentation using lactic acid bacteria. Results showed that when dispersed in milk permeate, soy protein isolate and oat protein concentrate powders were sedimenting fastly unless high pressure homogenization was applied. Particle size measurement also showed starch granules (average size 5 μm) existed in oat protein concentrate. In gelation study, gelation point varied from pH 6.0 to 5.5 depending on the soy protein content in the milk-soy mixture. As casein has lowest isoelectric point (compared to ~5.5 of oat globulin and soy), gelation takes place at lower pH value in milk-only gels. Confocal Laser Scanning Microscope (CLSM) pictures demonstrated a difference in gel network; the higher the soy protein content, the denser the protein network was. Texture analysis showed no significant (p<0.05) difference in firmness of soy or milk gels. However, soy- skim milk 75:25 and 50:50 mixtures were slightly weaker. Oat protein in ratio of 50:50 (oat-milk) could not form a gel and even with 25:75 ratio, the gel was considerably weak. The storage experiment showed that water retention was improved by addition of soy protein. Firmness of soy protein gels also increased in storage. The panelists in the sensory panel had very scattered opinions on the given samples but found sample with soy- skim milk 50:50 most generally appealing. In conclusion soy proteins formed a denser gel network compared to milk proteins when fermented with lactic acid bacteria. Mixing soy protein isolate with skim milk improved water retention in fermented gels during storage. Sensory wise addition of 50 % soy protein to the product was found generally appealing even when comparing to the skim milk sample. Oat protein formed a gel when added 25 % only. The effect of other compounds (for example starch in oat) could be one of the structure weakening factors.
  • Tuomi, Ilona (University of Helsinki, 2015)
    The aim of this thesis was to validate the AOAC integrated total dietary fibre method (2011.25) for tomato. Additional purpose of this study was to update dietary fibre values in Finnish food composition database Fineli. The literature review focused on the background of dietary fibre analysis, method development and dietary fibre composition of vegetables. The method measures separately insoluble dietary fibre (IDF), dietary fibre soluble in water but precipitated in ethanol (SDFP) and dietary fibre soluble in water and not precipitated in ethanol (SDFS; oligosaccharides). The method includes a 16 hour starch hydrolyzing incubation that was presumed to stimulate enzyme activity in tomato. The effect of endogenous enzyme activity was examined with preliminary experiments, which included keeping the sample at room temperature before analysis, inactivation of enzymes with heat treatment and performing the analysis without incubation. Repeatability and reproducibility of the method were determined by analysing a pooled sample consisting of Finnish tomatoes. The amount of IDF was highest in samples prepared without incubation. In incubated and heat treated samples, and in samples kept at room temperature the amount of IDF was lower and the amount of SDFP was higher compared to the samples prepared without incubation. This was propably due to pectin depolymerisation and solubilisation by enzymes. Validation sample was prepared without heat treatment. Validation was performed with incubated samples, because standard deviation for non-incubated samples was markedly higher. The amount of TDF (total dietary fibre) in digested samples was 1.3 % (1.1 % IDF and 0.2 % SDFP). Oligosaccharides were found only in trace amounts. Repeatability of the method was 11 % (TDF), 13 % (IDF) and 23 % (SDFP). Reproducibility was 11 % (TDF), 12 % (IDF) and 17 % (SDFP). Repeatability and reproducibility were propably impaired by the inhomogeneity of the sample matrix. Uncertainty of the method was 26 %. The method was validated and proven to be fit for purpose.
  • Oksanen, Marja (University of Helsinki, 2015)
    Tämän tutkimuksen tarkoituksena oli selvittää sitä, miten virvoitusjuoma-alan makroympäristön eri tekijät vaikuttavat yritysten toimintaan ja kilpailuetuun. Makroympäristön tekijöistä tarkempaan arviointiin nostettiin poliittisiin tekijöihin kuuluva virvoitusjuomavero. Makroympäristöanalyysi toteutettiin PESTEL-analyysin avulla. Tutkimuksen teoreettinen viitekehys rakentui yrityksen toimintaympäristöstä, sekä strategian rakentamisesta kilpailuedun luomiseksi. Viitekehyksen avulla pyrittiin kuvaamaan, miten tutkimuksen teoriat kytkeytyvät toisiinsa. Tutkimuksen ote oli kvalitatiivinen ja tutkimusmenetelmänä käytettiin teemahaastattelua. Tutkimuksessa haastateltiin yhteensä kahdeksaa virvoitusjuoma-alan edustajaa. Teemahaastattelu valittiin tutkimusmenetelmäksi, koska aiheesta haluttiin saada syvempää ymmärrystä. Teemahaastattelujen avulla oli mahdollista antaa haastateltavien nostaa esiin itse tärkeimmiksi makroympäristön tekijöiksi kokemiaan asioita. Virvoitusjuoma-alan makroympäristön tekijöistä tärkeimpinä nähtiin omien merkkien osuuden kasvaminen, terveystrendin vahvistuminen, sekä sokeriin kohdistuvan kritiikin voimistuminen. Näillä tekijöillä nähtiin olevan vaikutusta alan markkinarakenteeseen ja kehitykseen tulevaisuudessa. Kilpailuetua yritykset pyrkivät luomaan panostamalla edelleen tuotekehitykseen ja vastaamalla kuluttajatrendeihin. Myös vahvojen brändien rakentaminen nähtiin mahdollisuutena luoda kilpailuetua, vaikka markkinarakenne muuttuisikin. Virvoitusjuomaveroon ja sen korotuksiin suhtauduttiin melko negatiivisesti. Kritiikki ei kohdistunut verotukseen sinänsä, vaan veromalliin, joka kohtelee substituuttituotteita epätasa-arvoisesti ja kohdistuu ainoastaan tiettyihin toimialoihin ja toimijoihin. Verolla koettiin olevan huonoja vaikutuksia alan investointeihin, työllisyyteen ja kehitykseen. Veron terveysperusteet koettiin heikoiksi. Arvonlisäveroa pidettiin oikeudenmukaisempana verotusmallina, jota olisi myös helpompi hallita.
  • Pasupulate, Avinash (University of Helsinki, 2015)
    The aim of this study was to develop and apply a high throughput and cost effective method for screening food samples for antibiotic contamination. This method can be used to reduce the number of samples that have to be analysed using expensive chemical methods that are at currently being used for determining antibiotic concentrations. The primary objective of this study involved the construction of a macrolide sensitive bacterial bioreporter, which can be used to detect the levels of macrolide antibiotics in meat samples. The bioreporter was constructed by merging a macrolide promoter region to a bioluminescent signalling gene like the lux operon, this fused segment was then cloned into a suitable vector and transformed to a host E. coli along with the repressor (producing) plasmid. The bioreporter works in the presence of macrolides, when the repressor protein is released from the promoter region, resulting in the expression of the lux operon, which produces light. This light signal can be used for the detection and estimation of macrolide antibiotics using a luminometer. The secondary objective was to use the macrolide bioreporter along with a previously constructed tetracycline bioreporter to measure antibiotic concentrations in bovine meat samples acquired from EVIRA (Finnish Food Safety Authority). On analysis of the resulting luminescence data, calculated concentrations of oxytetracycline were found to be in correlation to the data acquired from EVIRA and also using solid meat samples in assays, instead of extracted muscle fluid produced more accurate results. This shows the usability of bioreporters in the detection of antibiotics in animal-based foods from different sources. The resulting data can also be used to monitor and control the spread of antibiotic resistance through animal farms.
  • Han, Li (Helsingin yliopisto, 2015)
    Trichothecenes, as a dominant group of Fusarium mycotoxins, have received lots of scientific attention due to their wide contamination of human food and animal feed. Besides native trichothecenes, their conjugated forms the so-called masked mycotoxins, have also been somewhat studied in recent years due to their potential harmful impact. Beer, as one cereal-derived beverage, encounters the threat of trichothecene contamination. During beer fermentation, trichothecenes may be biotransformed into metabolites, which could potentially exert toxicological implications on beer consumers. The aim of this study was to investigate the metabolic fate of several major trichothecenes, including T-2 toxin (T-2), HT-2 toxin (HT-2), deoxynivalenol (DON) and its masked form deoxynivalenol-3-glucoside (D3G) during beer fermentation by lager yeast. A four-day fermentation experiment was conducted with four analytes inoculated in 11.5°Plato wort at the initial stage of fermentation individually or as a mixture with various concentrations. A reliable and efficient method was developed for the kinetic study of trichothecenes by liquid chromatography-triple quadrupole-mass spectrometry (LC-TQ-MS). After four-day fermentation, an approximate 10-40% decrease of all analytes was observed. The missing trichothecenes were very likely bound with yeast cell wall or biotransformed to their masked forms metabolic reactions. Further identification of the masked metabolites was fulfilled by analysing concentrated samples with liquid chromatography-quadrupole-time of flight-mass spectrometry (LC-Q-Tof-MS). Several putative masked metabolites were annotated, including D3G and acetyl-DON in DON-dosed samples, acetyl-T-2 and HT-2 in T-2-dosed samples and T-2/3-acetyl-HT-2 in HT-2 samples. The stability of D3G during fermentation was for the first time investigated and was found stable under brewing fermentation conditions.
  • Kaila, Lotta (Helsingin yliopisto, 2015)
    The mission of International Potato Centre (CIP) is to achieve food security for developing countries. Late blight is one of the most serious diseases of potato, and efficient control of the disease is needed to get proper yield. Chemical plant protection and resistant cultivars are the main keys in controlling late blight. CIP improves the food security by breeding late blight resistant genotypes, which are further tested in developing countries. In this research CIP’s breeding population B3 was studied for the inheritance and stability of late blight resistance. Inheritance of resistance was analysed by comparing the level of resistance in two consecutive cycles of recurrent selection (C2 and C3). The stability of resistance was analysed by comparing historical data of population B3 in nine different environments in years 2001–2006. Results showed that the fourth cycle of recombination will improve late blight resistance in the population and the resistance is mainly caused by genetic factors. The research also revealed 78 genotypes that had stable late blight resistance in studied environments. In addition, the study suggests that the population contains some still unidentified R genes. Population B3 has already high late blight resistance, which the fourth cycle of recombination will further improve. In addition, the population contains genotypes with stable and extremely high late blight resistance. Thus, the population serves as a strong material for further late blight resistance breeding and as trial genotypes for tropical highlands. However, the still unidentified R genes should be studied further at molecular level to get best out of the population.