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  • Xue, Yaxin (Helsingin yliopisto, 2016)
    Previous research has demonstrated that biochar added to soil improves plant performance. When widely used, biochar can help reduce the consumption of chemical pesticides and fertilizers. The aim of this study is to explore whether biochar can help strawberry (Fragaria × ananassa) plants in greenhouse to fight against foliar disease, gray mold caused by Botrytis cinerea. Disease progress was estimated after infection. Nine days after inoculation, the biomass of leaves and root were quantified to reflect the plant growth during inflection. In 2013, three types of birch biochar with different chemical compositions were tested. The best performing of biochar were selected for 2014 assay at the rate of 5.4%. Based on data obtained in 2013 and 2014, both 3% and 5.4% birch biochar amendment are able to retard gray mold development in the beginning of the infection, but disease severity finally reaches the same level on the ninth day after Botrytis cinerea inoculation. We also found that 5.4% birch biochar results in significantly increased electrical conductivity and less water consumption in peat soil. Finally, we propose that higher concentrations of biochar might more benefit the plant growth rather than contributing to plant defense. However, evidence at the molecular level is still needed to support our hypothesis.
  • Kuusisto, Katja (Helsingin yliopisto, 2015)
    The aim of this study was to investigate the ensilability of field pea and faba bean bi-crop with spring wheat when ensiled as whole-crop with different additives. In this study we attempted to clarify use of pea – wheat and faba bean – wheat bi-crop in organic farming. Forages was sown at 4th to 7th of June in Luonnonvarakeskus (Luke) Ruukki and forages were ensiled in laboratory silos at 26th of August 2013. Silages were ensiled without additive (PR), with formic acid (MH) and with two different heterofermentative inoculants (B1 and B2) as additive. Each treatment were made three replicants. Silos were opened after 106 ensiling days at 9th of December in Luke Jokioinen. Chemical and microbiological compositions were determined from samples of herbage. From silage samples were analysed fermentation quality, microbiological composition and aerobic stability. All samples were wet. Faba bean – wheat bi-crop was a little wetter than field pea – wheat bi-crop. Field pea – wheat forage contained more crude protein, water-soluble carbohydrates, starch and had stronger buffering capacity than faba bean – wheat. Faba bean – wheat bi-crop contained more neutral-detergent fiber (NDF) and had also lower digestibility. Both of crops were easy to ensile and growth stage were different between crops. All samples included lot of micro-organism especially yeast, moulds and epiphytic lactic acid bacteria. Field pea – wheat silage contained more fermentation products than faba bean – wheat silage. MH- treated silages had better fermentation quality than other silages although there were higher pH values in MH silages. MH silages contained less lactic and acetic acids and ammonium nitro-gen. Inoculant treated silages mostly did not differ from PR treatment in fermentation parameters. That is probably due to high epiphytic lactic acid bacteria account in herbage. Silages contained only a little butyric acid. Microbiological quality of silages predisposed them to aerobic deteriora-tion because there were considerable high amounts of yeasts and moulds. Field pea –wheat silages were more aerobically stable than faba bean - wheat. This is probably due to higher concentration of fermentation acids in field pea-wheat silages. MH treatment was the most aerobically stable of field pea – wheat silages. B2 treatment was the most stable of field pea – wheat silages. Mixed ration of these silages were more prone to aerobically deterioration than silages.
  • Suutarla, Heli (Helsingin yliopisto, 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.
  • Malkamäki, Arttu J. (Helsingin yliopisto, 2015)
    This thesis aims to assess the state and development of beekeeping in Uruguay. Uruguay exports more than 90% of its honey and supplies regularly to the demanding markets in the EU and the US. As marginalized actors in the global honey chain, the beekeepers' livelihoods are largely dependent on the shifts of globalization, predominantly on the patterns of global economy. Proliferation of voluntary certification schemes such as Fairtrade International and European Union Organic Farming have become evident features of these patterns. Adoption of voluntary certification schemes has impacted particularly the development trajectories of smallholders, which is why particular attention in this thesis was laid on them. It was, however, quickly understood the development is dependent on several factors on different levels. To conceptualize these levels, value chain governance and voluntary certification schemes in them were seen shaping the livelihood outcomes of the smallholders. Combining governance and horizontal livelihood approaches, which represents the main innovation of this thesis, was used to identify action points and upgrading strategies feasible for the beekeepers as actors engaged in the global honey chain. In addition, this thesis further highlights the context of beekeeping as a livelihood, honey as a commodity with certain features and market dynamics, as well as Uruguay as the main geographical scope. Research methods were qualitative. Semi-structured interviews were conducted in 2014 with four different respondent groups along the global honey chain: importers of honey in the EU; representatives of local institutions and export agencies in Uruguay; and the beekeepers themselves, which of some were organized in cooperatives. From the collected data, the development trajectories were analyzed deductively to identify the viable strategies to improve sustainable livelihood outcomes. Based on results, the global honey chain was found buyer-driven since the buyers bear the most powerful role. The structure replicates features of market and captive types of governance, suggesting there is a high degree of power asymmetry and coordination. Higher coordination, however, favors successful upgrading. By identifying the activities performed by actors in the chain, the action point was found in the production node due to the recent increase in activities. High costs of inputs and low margins throughout the chain were observed, particularly in the export node. Beekeepers' baseline conditions were determined as access to livelihood assets, which were found generally weak. State of the fundamental aspect of beekeeping, access to natural assets, was found alarming. The decreased floral resources in Uruguay are due to the rapid proliferation of changes in land use, accelerated by the main vulnerability causing shocks in production and with implications on prices: the climate variability. A key finding, however, was that the proliferation of Eucalyptus grandis in Uruguay has created a dependency by compensating the losses in production based on other flowerings. Furthermore, the emergence of pests has brought risk of losing colonies and increasing costs in treatment and prevention. Natural assets set the main constraint over sustainability of beekeeping in Uruguay, but possibilities to compensate smallholders was found among social assets, which clearly were not optimized at their current levels. This notion largely represents the main conclusion in this thesis: horizontal contractualization of the beekeepers through collective action is the only strategy with a reasonable balance between revenues and risks. In all other scenarios, the risks are likely to become unbearable, unless an external agent would be willing to guarantee the risks up to some point to initiate the process. Collective action was found as a precondition of vertical contractualization, which could include affiliation in voluntary certification schemes. Fairtrade International was predominantly found as a more attractive scheme, but could in this context benefit only a large cooperative with already good resources. Affiliation in a certification scheme, however, would not remove the main constraints faced by the sector in Uruguay, which are the decreasing production per hive and the costs running relatively faster than the prices received, resulting in a decreasing profitability. Whereas more beekeepers are excluded from the chain, the ones remaining practice beekeeping largely based on love and tradition. Future research is suggested to take a more sophisticated approach to cost-benefit analyses to support further decision-making on the level of the beekeepers, as well as on the level of policy-makers. In addition, prospective approaches to develop and assess the potential of systems such as payments for ecosystem services in the context of beekeeping are highly recommended.
  • Ilonen, Iikka- Santeri (Helsingin yliopisto, 2015)
    Since 1980s the major global forest industry enterprises have been renounced their forest holdings in Northern- America and sold them for the public and private institutions as well as for the private investors. Since 1990s until 2010s corresponding renouncement have been distinguished also in Europe. Especially because of the quarterly reporting the trend between major global forest industry enterprises have been towards renouncing fixed capital in desire to satisfy the needs of investors. In the beginning of the millennium the global forest products companies have been transposing manufacturing into emerging markets. The predicted growth opportunities and demand expectations in regard to forest based products are cut out for induce the global forest industry enterprises to invest in forest holdings in emerging markets. The increasing competition of bare land in emerging markets has been a major driver to switch the strategy of global forest industry enterprises back into vertical integration in lieu of buying the raw material from the markets. This Master’s Thesis takes a look at the relationship between timberland ownership (vertical integration) and financial performance of a forest industry enterprise. In addition this thesis aspires to substantiate whether there exists a relationship between timberland ownership and the geographical location of operations of a global forest industry enterprise. The material covers review of literature, the theories of industrial economics, annual reports of forest industry enterprises and the survey of TOP 100 global forest, paper and packaging industries. (PricewaterhouseCoopers 2007; 2012). Statistical hypothesis test and descriptive statistics are utilized to analyze the results received from the annual reports and the surveys of TOP 100 global forest paper and packaging industries. Conclusions regarding the relationship between timberland ownership and financial performance are drawn from the results received. In addition the results produce information on the current state of the timberland holdings between the TOP 100 major global forest industry enterprises. Quantitative data behind this study has been collected from years 2007 and 2012. The findings of this study verifies the trend towards timberland ownership between major forest industry enterprises. Regarding on the results attained from the statistical test there exists a positive correlation between timberland ownership and financial performance. In the future especially the prices of raw material, prices of bare land and prices of end- product will continue to play a crucial role for the profitability of global forest industry enterprises. Finally, it is interesting to see in the future how the green economics will shape the Forest Industry and what kind of an impact it will have for the profitability and forest ownership of global forest industry enterprises.
  • Kraama, Mikko (Helsingin yliopisto, 2015)
    The study examines views of the family forest owners on the profitability of forestry, profitability factors related service needs, and possibilities to improve profitability. The data were collected by interviewing 19 forest owners who are members of the Forest Management Association Päijät-Häme. The employed method was semi-structured interview. In addition, structured questionnaires were used to collect information on the forest ownership objectives. The results consist of the conceptualization of forest owners’ attitudes in terms of forestry profitability, typology of the forest owners’ profitability views, types of forest owners’ information service needs and classification of attitudes towards the profitability of information services. Forest owners had various views on profitability. They were mainly interested in utilizing their forests. However, forest owners' knowledge and abilities to utilize the profitability concepts were incomplete. The economic information services could provide a solution to this problem. Services for forest owners could indicate the potential total economic value of forests. The forest owners could be encouraged to implement actions to improve profitability by showing and digesting the gap between their current and the potential situation. Profitability services could be implemented in interaction with the forest owners, information and personal advice. The government could influence the profitability of the non-industrial forestry by providing incentives to build up and utilize the services.
  • Jauhiainen, Samuli (Helsingin yliopisto, 2015)
    This study focuses on machinery and equipment failures in agriculture. For example, unreliable operations, or breakages and obstructions are common failures. Usually failures interrupt the work, either temporarily or for a longer period of time. Sometimes it is possible to continue working despite the failure. On the other hand failures can cause delaying or financial losses. Repairs can cause dangerous situations for farmers. Maintenance and repair works on farms are causing the most of the work-related accidents. The main targets of the study were to determine the most common failures on agricultural machinery and equip-ment, find the main reasons for the failures and find the ways to prevent failures and accidents caused by failures. The study was intended to serve as a basis of the newsletter to be made for farmers. The study was conducted 1.5 years lasting follow-up study. This study was finally included 21 farmers from all over the Finland. Farmers reported their machinery and equipment failures according to a pre-defined form. According to the results most machinery and equipment faults occurs with tractors. That is because tractors have a lot of places for failures and they are widely used on farms. Also harvesting machines seems to have a lot of failures. Machine failures were mainly on the frame and on the mechanical parts of power transmission. About one-fifth of all were electrical failures. Around two times out of three the failure interrupts working. According to farmers most of the failures were age-related and result from a "normal" wear. The remaining causes for failures were divided almost evenly between operating environment, machinery and equipment poor quality and factors resulting from the users. A significant result is that many failures can be prevented. For farmers it is almost impossible to avoid the machine and equipment failures. This study and the earlier stud-ies show that many of failures can be prevented and farmers should prepare better for failures. According to study the most important ways to prevent failures are proactive maintenance, careful reading of the operation manual, in-vesting to good quality machinery and equipment and by focusing to the work they are doing. Machinery mainte-nance and failure solving is safe when maintenance facilities are decent, using high quality tools and protective clothes, and when using the correct methods of work and not taking extra risks. It is also important to remember that the most demanding repair work should be left to professionals. The main goals of the study were achieved. TTS has published a newsletter for farmers, "Agricultural machinery and equipment failures - prevention methods and guidelines" based on the results of this study.
  • Leminen, Mikko (Helsingin yliopisto, 2015)
    Tutkielman tavoitteena oli selvittää kirjallisuustutkimuksena ISOBUS-väylän hyödyntämismahdollisuuksia. Hyödyntämismahdollisuuksia etsittiin sekä peltotöidenteon aikaisista hyödyistä, että jälkikäteen työn analysoinnin hyödyistä sekä hyödyistä valmistauduttaessa seuraavaan työtapahtumaan ja seuraaviin vuosiin. Työn aikaiset hyödyt jakautuvat kahteen eri luokkaan. Sellaisiin, mistä on apua viljelijälle sekä työkoneen ja traktorin autonomisen toiminnan lisäämisen hyötyihin. Viljelijälle apua on mm. polttoaineenkulutusmittarista, joka näyttää reaaliaikaista polttoaineenkulutusta myös hehtaaria kohti, työkoneen toimintaa mittaavista anturitiedoista tai pienestä mutta tärkeästä asiasta eli työkoneen työtuntilaskuriin perustuvasta huoltomuistutuksista. Työkoneen ja traktorin autonomisuuden lisäämisellä on mahdollista tehdä jopa täysin ilman ihmistä toimiva traktori. Väylän avulla työkone voi ohjata traktoria mm. muuttamaan työnopeutta tai työsyvyyttä ja kun väylälle lisätään vielä GPS-ajouraopastin niin traktori osaa myös ohjata itseään pellon sisällä gps-paikkatiedon perusteella. Työn analysoinnissa väylän isoimmat hyödyt ovat tietojen siirtäminen suoraan tietokoneelle viljelykirjanpitoon, jolloin viljelijän ei tarvitse pitää paperisia muistiinpanoja työsuorituksista sekä analysoitavien tietojen määrän runsas kasvu. Viljelijä pystyy runsaan tietomäärän avulla kotonaan etsimään pellolta ongelmakohtia ja selvittämään johtuuko pellon vajavainen kasvu pellon huonosta kasvukunnosta vai viljelytoimenpiteistä. Tietokoneella pystyy myös valmistelemaan työtä tekemällä esimerkiksi paikkakohtaisen lannoituskartan esimerkiksi satokartan avulla tai määrittämällä ajourat pellolle niin, että pelto saadaan työstettyä mahdollisimman nopeasti ja tehokkaasti ilman päällekkäisajoa. Tietoja voi siirtää tietokoneelle ja sieltä takaisin väylälle joko reaaliaikaisesti mobiilidatan tai langattoman internetin avulla tai määräajoin laittamalla muistitikun väylälle ja siirtämällä tiedot sen avulla tietokoneelle. Väylän standardisointi on vielä kesken, mutta joka tapauksessa se mahdollistaa monipuolisen teknologian käytön ja hyödyt viljelyssä.
  • Halonen, Jussi (Helsingin yliopisto, 2015)
    Tämän tutkielman tavoitteena oli selvittää millaista ruokahävikkikäyttäytyminen kotitalouksissa on ja minkälaiset asenteet vaikuttavat kotitalouksissa tapahtuvaan ruokahävikin syntyyn. Lisäksi tutkittavana oli tiedon rooli ja kuinka se vaikuttaa toisaalta asenteisiin ja toisaalta suoraan hävikkikäytökseen. Myös tärkeimmät hävikkikäyttäytymiseen liittyvät taustamuuttujat kartoitettiin, jolloin niiden avulla voidaan selittää osa ilmiöstä. Tutkimus suoritettiin kvantitatiivisena kyselytutkimuksena strukturoidulla lomakkeella ja aineisto kerättiin opiskelijoista sähköpostilistojen avulla. Tutkimuksen kirjallisuusosiossa selvitettiin asenteiden ja käytöksen välistä yhteyttä, ruokahävikkiin liittyviä asenteita sekä ruokahävikkikäyttäytymistä. Kirjallisen aineistosta etsittiin merkittävimmät ruokahävikkiin liittyvät asenteet, joita olivat ympäristöystävällisyys, ruokaturvallisuus, säästäväisyys sekä ruoan arvo. Ruokahävikkiin liittyvä tieto jaettiin yleiseen tietoon sekä omaan käytökseen liittyvään tietoon. Kirjallisuuden pohjalta määritettiin myös ruokahävikkikäyttäytyminen, johon löydettiin kolme tärkeintä syntykohtaa. Nämä olivat varastointi, ruoanlaitto ja ruokailu. Tutkittavat asenteet olivat varsin positiivisia lähes kaikkien tutkimuksessa mukana olleiden asenteiden kohdalla. Tämän vuoksi lineaarista korrelaatiota asenteiden ja muiden tekijöiden välillä ei ollut merkittävällä tasolla löydettävissä. Asenteista keskenään eniten korreloivat hävikki- sekä ympäristöasenteet. Tiedot jaettiin kahteen klusteriin, joista toisessa oli korkean tiedon omaavat yksilöt ja toisessa matalamman tiedon omaavat. Korkeamman tiedon omaavilla vastaajilla oli korkeammat arvot myös ympäristöasenteissa, ruoan arvostuksessa sekä hävikkiasenteissa. Vastaajat jaettiin käytöksen mukaan myös kahteen klusteriin, joista toiseen kuuluvilla oli suhteessa enemmän hävikkiä ehkäiseviä käytöksiä ja toiseen kuuluvilla suhteessa enemmän hävikkiä tuottavia käytöksiä. Asenteista oli löydettävissä yhteys näihin ryhmiin ja asenteissa säästäväisyyteen, ruoan arvoon sekä hävikkiin olikin eroja ryhmien välillä. Vähemmän hävikkiä tuottavalla ryhmällä asenteet olivat näiden osalta positiivisempia. Myös tiedon määrä oli tärkeässä osassa ja vähemmän hävikkiä tuottavassa ryhmässä tieto oli suurelta osin parempaa. Tuoteryhmien poisheittoa tutkittaessa nousivat esiin myös asenteet ruokaturvallisuutta kohtaan. Myös korkean tiedon omaavat yksilöt saattoivat käyttäytyä enemmän hävikkiä tuottavalla tavalla, mikäli ruokaturvallisuus oli uhattuna.
  • Tasiyana, Diana Tendai (Helsingin yliopisto, 2015)
    The shelf life of ESL milks and pasteurized creams is limited by bacterial spoilage. The current state of knowledge with respect to the diversity and activities of the spoilage microflora in these products is still limited. To date, studies on this subject are yet to be carried out in Finland. The aim of this study was to characterize the spoilage microorganisms found in ESL milks and pasteurised creams mainly produced in Finland. 10 ESL milks and 8 pasteurised cream packages were obtained from the Finnish retail market and were stored at 8?C, 15?C, room temperature and 30?C, respectively, until expiration. Total bacterial counts were evaluated and 31 bacterial isolates were selected. An attempt was made to characterize the bacterial isolates using rpoB and 16S rRNA partial gene sequence analyses. Psychrotrophic, spore-forming and spoilage features were also determined. Strain diversity was determined by rep-PCR profiling. Five selected isolates were subjected to metabolic profiling using the API50 CHB test. When growth was detected, total bacterial counts ranged from 2.67 to 3.74 and 2.54 to 8.98 log units in cream and ESL milk samples, respectively. Both ESL milks and cream samples were dominated by heat-resistant, spore-forming species of the Bacillus genera: the isolates were related to B. licheniformis. B. weihenstephanensis, B. safensis, B. kochii, B. pumilus, B. subtilis and B. anthracis. Intraspecies and intrasample strain diversity was very high. Isolates mainly displayed proteolytic and lipolytic activity. Psychrotrophic activity was high in the cream samples while most ESL milk isolates were mostly mesophilic. Tested isolates were non-lactose fermenters and had varying metabolic profiles. The study revealed that Finnish ESL milks and pasteurized creams are prone to spoilage by species of the Bacillus genera that have potential for lipolytic and proteolytic spoilage and some of which are considered toxigenic. There is wide intraspecies strain diversity responsible for the wide variability in metabolic, psychrotrophic and spoilage features. Phenotypic tests based on API50 CHB cannot be relied upon to make conclusions on taxonomy. Combining various methods is important for the comprehensive characterization of the bacterial isolates. Strategies to eliminate bacterial species of the Bacillus genera are important to prolong shelf life. However, intervention should be strain-specific to be effective. Large scale studies are required to confirm findings from this study.
  • Kangas, Jaakko (Helsingin yliopisto, 2015)
    New primary tillage methods have appeared alongside traditional ploughing. Objectives of primary tillage can nowadays be achieved with other methods such as by exploiting nature’s own processes or with chemical weed control. The endeavor of farmers to save time and money has caused conservation tillage to become more common. Different methods of conservation tillage and no-tillage has been replacing traditional ploughing. Conservation tillage has had various kinds of effects to achieved yields. Some international studies reported that conservation tillage had reduced yields. On the other hand, the rest of the studies point out that either the yield remained at the same level or at times, yield levels rose with reduced tillage. The aim of this study was to determine the profitability of different tillage methods. The profitability of three different primary tillage methods were compared at three farm sizes (50, 100 and 200 ha). Retail prices of farming machinery and Luke’s on-going field experiments on clay soil in Jokioinen were drawn on for data used in this study. Luke has been running no-tillage field experiments in Jokioinen since 2000. Yield data of spring barley from Jokioinen field experiment was used in this study. No-tillage was the most profitable tillage method on every farm size. The costs of no-tillage was 145?279 €/hectare lower than the costs with ploughing and 111?234 €/hectare lower than the costs with cultivation. The surplus of no-tillage was 93–226 €/hectare greater than surplus with ploughing and 69?192 €/hectare bigger than the surplus achieved with cultivation as a primary tillage. The profitability of cultivation was 16–34 €/hectare bigger than the surplus acquired through ploughing. No-tillage was more economically beneficial on a field which had less clay in its texture. The no-tillage’s surplus was 183?317 €/hectare bigger than the ploughing’s surplus and it was 161?284 €/hectare bigger than the cultivation’s surplus. Fields of similar size were used when analyzing the difference of profitability between ploughing and cultivation. This study asserts that the profitability of primary tillage method depends on machinery, weather conditions, soil type and the size of the farm. In this study, no-tillage was more profitable even though the yields produced were less than with traditional primary tillage. The profitability of the different primary tillage methods varied erratically between farms and for this reason, an unambiguous answer for profitability cannot be given.
  • Seyed Hameed, Ahkam Saddam (Helsingin yliopisto, 2015)
    Increased consumption of raw milk has been observed among the urban population in Europe along with an increasing consumer interest in foods that are less processed and locally produced. Raw milk and raw milk products have been associated with listeriosis caused by Listeria monocytogenes. These new trends in consumer behavior increase the need for more effective surveillance methods for L. monocytogenes at farm level. In Finland, raw milk sales are allowed directly from the farms to the consumer. The renewed Finnish national legislation stipulates that screening of L. monocytogenes on farms that sell raw milk includes five replicates of 25-ml bulk tank milk (BTM) samples. Due to dilution to the high volume of BTM, it is unlikely to detect low levels of bacterial contamination from the milk samples. Testing milk samples is also expensive and logistically difficult for continuous monitoring of L. monocytogenes at the farms. An alternative approach could be the testing of milk filters. Theoretically, milk filters may be more sensitive than BTM as a sampling material since all of the milk in the bulk tank has to pass through the filter. The objective of this longitudinal study is to compare milk filters and BTM for the best sampling material suitable for routine monitoring of L. monocytogenes in the dairy farms selling raw milk. Five BTM samples and a milk filter sample from two farms were tested for L. monocytogenes each week, for a period of 10 months, using NMLK 136:2010, ISO 11290-1:1996 and ISO 11290-2:1998 methods. The isolation of L. monocytogenes and other Listeria species were identified by API biochemical assay and multiplex PCR. The results indicate that milk filters are ideal as a sampling material in detecting L. monocytogenes than BTM samples. However, the presence of L. monocytogenes in milk filters was not associated to the presence of L. monocytogenes in BTM. Thus, milk filters could be used as indicators of the farm’s contamination status. Along with these findings, seasonal variation in detection, and advantages of identification methods were also discussed in this thesis.
  • Zhang, Xusheng (Helsingin yliopisto, 2015)
    Sterols and their conjugates are minor natural constituents in oils and fats. Plant sterols are also enriched in functional foods because of their known ability to lower serum cholesterol levels. Like other unsaturated lipids, sterols are prone to oxidize. In the literature review, thermo-oxidation reactions of free and esterified sterols were introduced and methods for the analysis of the formed products were summarized. The aim of the experimental research was to study the oxidation reactions of steryl esters. The oxidation reactions were studied at two temperatures, at 100 ºC and 180 ºC, by following the changes in the profiles of oxidation products varying in polarity and molecular size. The effects of esterification, unsaturation level of the acyl moiety in the sterol structure and temperature were studied. Solid-phase extraction (SiOH-SPE) and size-exclusion chromatography (SEC-RI) were applied for the separation and quantification of monomeric and oligomeric oxidation products. Silver coordination ion spray mass spectrometry (Ag+-CIS-MS) was applied to indicate mass ranges of the formed oxidation products. In the oxidation, sterol molecules first reacted with oxygen and then the formed monomeric oxidation products began to link with each other forming oligomers. Oligomers contributed to 17-90% and 23-78% of the oxidation products of steryl esters after 3 days and 2 hours of heating at 100 ºC and 180 ºC, respectively. Polar oligomers were the most abundant fraction at both temperatures. Non-polar oligomers were not formed in the oxidation of steryl esters. Increased unsaturation of the acyl moiety increased polymerization. Increased temperature changed the oxidation reactions and mid-polar oligomers became more dominant. Thermal reactions led to the loss of hydroxyl groups and hence the polarity of oligomers decreased. The molecular weight ranges of the most abundant oligomers and their fragments were m/z 900-1100 and 1300-1500 at 100 ºC. In conclusion, the oxidation of steryl esters begins by reactions with molecular oxygen after which the formed oxidation products begin to polymerize. This occurs both at auto-oxidation and thermo-oxidation conditions; i.e., at cooking and frying temperatures.
  • Vilkkilä, Asta (Helsingin yliopisto, 2015)
    Tutkielmassa tarkastellaan alle kymmenenvuotiaiden lasten tavarasuhdetta. Tarkoituksena on selvittää lasten suhtautumista ympärillä olevaan tavaramaailmaan. Tutkimuksessa tarkastellaan myös sitä, millaisia erilaisia merkityksiä lapset tavaroille antavat. Lasten näkökulman lisäksi tutkimuksessa on tarkasteltu vanhempien käsityksiä lastensa tavarasuhteesta ja sitä, kuinka he kasvattajina kokevat lapsen ja tavaran välisen suhteen. Tutkimuksen empiirinen osa koostuu 10 teemahaastattelusta. Haastatteluun osallistui viisi 4–9-vuotiasta lasta ja viisi heidän vanhempansa. Laadullisen tutkimuksen analyysissä tulkintateoreettisena kehyksenä on käytetty sisällönanalyysiä. Tavarat eivät ole lapsille pelkästään välineitä, joiden avulla he tekevät asioita vaan ne pitävät sisällään monia erilaisia merkityksiä. Tutkimuksen mukaan lapsen suhde tavaraan ei ole yksiselitteinen, vaan annetut merkitykset ovat moninaisia ja tilannesidonnaisia. Tavarat näyttäytyvät lapselle pääasiassa leluina. Lelut eivät määrity kuitenkaan pelkästään suhteessa leikkiin. Lelujen avulla lapset luovat ja vahvistavat sosiaalisia suhteita esimerkiksi omiin sisaruksiin ja ikätovereihin. Uutuudet ja muoti vaikuttavat lasten lelumieltymyksiin, mutta kaikista kallisarvoisimpia ovat lelut, joihin lapsi luo emotionaalisen suhteen. Suhde kallisarvoisiin leluihin on verrattavissa ihmisten välisiin suhteisiin. Lapset antavat tavaroille myös sosiaalisia merkityksiä. Niiden avulla vahvistetaan suhteita perheenjäsenten kanssa. Tavarat toimivat näin yhteenkuuluvuuden symboleina. Tavaroiden avulla lapset hahmottavat myös menneisyyttä, nykyisyyttä ja tulevaa. Lasten tavarasuhteissa on kyse muustakin kuin vain uuden haluamisesta. Tavarat toimivat välineinä erilaisille tavoille olla yhdessä toisten kanssa. Vanhempien suhtautuminen lasten tavaramaailmaan on kontekstisidonnaista, ja tilanteesta riippuen samat esineet voidaan nähdä sekä hyvinä että huonoina lapselle. Vanhemmat antavat tavaroille merkityksiä siinä missä lapsetkin. Nämä merkitykset määrittelevät vanhempien suhtautumista lasten esineisiin. Nykypäivän vanhemmuutta voi nimittää neuvottelevaksi vanhemmuudeksi, koska lasten mielipiteitä kuunnellaan kulutukseen liittyvissä päätöksissä. Vaikka tutkimuksen perusteella tavaroilla on suuri rooli lasten elämässä, ne eivät korvaa kuitenkaan lasten ja heidän vanhempiensa yhdessä viettämää aikaa.
  • Mattila, Katariina (Helsingin yliopisto, 2015)
    Tutkielman tavoitteena oli tarkastella rukiin alkuperän vaikutusta kuluttajan ruisleivän valintaan ja peilata sitä muihin ostopäätökseen vaikuttaviin tekijöihin. Tutkimuksen lähestymistavaksi valittiin kvalitatiivinen tutkimusote ja tutkimusmenetelmänä käytettiin puolistrukturoitua teemahaastattelua. Haastattelujen tavoitteena oli syventää tietoa ja lisätä ymmärrystä kuluttajien rukiin alkuperään ja kotimaisuuteen liittyvistä mielikuvista sekä suhtautumistavoista. Tarkoituksena oli selvittää myös, minkä tekijöiden perusteella kuluttajat mieltävät tuotteen kotimaiseksi ja miten ruisraaka-aineen alkuperästä tulisi viestiä, jotta alkuperätieto olisi mahdollisimman hyvin kuluttajien saatavilla. Tutkimuksessa haastateltiin yhteensä 16 kuluttajaa eri puolella eteläistä Suomea. Tutkimuksen teoreettinen viitekehys rakentui kuluttajakäyttäytymistä ja ostopäätösprosessia sekä alkuperämaata käsittelevien teorioiden ympärille. Lisäksi käsiteltiin ruoan valintaprosessin erityispiirteitä sekä sen taustalla vaikuttavia tekijöitä. Rukiin alkuperämaan vaikutus ruisleivän valintaan näyttää olevan tilanne- ja kontekstisidonnainen sekä riippuvan kuluttajan arvoista ja asenteista, ympäristön vaikutuksesta sekä mielenkiinnosta ruokaa ja ruoantuotantoa kohtaan. Myös tietoisuus tuontirukiin käytöstä vaikuttaa siihen, mikä rooli alkuperätiedolle annetaan. Tutkimuksen perusteella rukiin kotimaisuutta sekä pyrkimystä omavaraisuuteen pidetään tärkeänä ja viljelijöitä halutaan kannustaa rukiin tuotantoon. Leivontamaahan kiinnitetään kuitenkin enemmän huomiota kuin pääraaka-aineen alkuperämaahan. Lisäksi leivontamaan/valmistusmaan ja alkuperämaan käsitteet sekoitetaan usein toisiinsa. Osa kuluttajista ei tiedä, ettei kotimainen ruis riitä teollisuuden tarpeisiin ja että osa Suomessa käytetystä rukiista tuodaan ulkomailta. Näin ollen ruisraaka-aineen alkuperään ei ole osattu kiinnittää huomiota. Tutkimuksessa haastatellut kuluttajat suhtautuivat myönteisesti siihen, että pakollinen pääraaka-aineen alkuperämerkintä laajenisi koskemaan myös viljatuotteita. Kuluttajat peräänkuuluttivat tuotantoketjun läpinäkyvyyttä. Kotimaisesta rukiista leivotun leivän tunnistaminen pitäisi tehdä mahdollisimman helpoksi. Selkeä teksti tuotepakkauksen etupuolella on tutkimuksen mukaan paras tapa viestiä tuotteen alkuperästä ja kotimaisuudesta. Tekstin tukena voitaisiin käyttää luotettavaa alkuperämerkkiä. Tutkimuksen mukaan kuluttajat eivät ole halukkaita selvittämään raaka-aineen alkuperää muualta kuin tuotepakkauksesta. Kotimaisuuskampanjointiin ja alkuperätiedon hyödyntämiseen markkinoinnissa suhtaudutaan nyt tehdyn tutkimuksen perusteella positiivisesti.
  • Carlson, Paul (Helsingin yliopisto, 2015)
    Efficient utilization of renewable plant and crop based biomass is one of the main areas of study in industrial biotechnology. Roughly 20-30 % of all plant biomass consists of hemicellulose, a polymer composed of six carbon (hexose) and five carbon (pentose) sugars. This proves a challenge in utilizing all available plant biomass efficiently, since many micro-organisms, which for instance readily ferment glucose (a hexose) into ethanol, will not do so for pentose sugars. Alternative pathways for utilization of pentose sugars are being looked for. Characterization of the Caulobacter crescentus D-xylonate dehydratase (Cc XyDHT) was the aim of this study. Cc XyDHT belongs to the ILVD/EDD protein family, whose members incorporate an iron-sulfur (FeS) cluster into their protein structure coordinated by two to four cysteine amino acids. Removal of the cysteine ligands should disrupt the incorporation of the FeS cluster, and thus presumably the activity of the enzyme. Three cysteines in Cc XyDHT which could act as ligands for the FeS cluster had previously been identified by sequence alignment among the ILVD/EDD family. Accordingly, four single cysteine-to-serine mutants of the Cc XyDHT as expression plasmid constructs were designed, with a non-conserved cysteine residue selected as a control. The wild type and mutated Cc XyDHTs were produced in Escherichia coli and purified with affinity chromatography using Strep-tag. SDS-page and Western blotting with an anti-Strep-tag antibody were used to confirm that the expressed proteins were Cc XyDHTs. The mutations’ effects on the protein fold and to the presence of the FeS cluster were investigated with UV and circular dichroism spectroscopy. Cc XyDHT catalyzes the conversion of D-xylonate into 2-keto-3-deoxy-xylonate. A colorimetric assay using thiobarbituric acid (TBA) as the reactant was used to measure enzymatic activity. The pH and temperature optima, substrate specificity, and enzyme kinetics of the wild type Cc XyDHT were determined. For the two best substrates, kcat/Km = 1220 mM/min for D-xylonate and kcat/Km = 1160 mM/min for D-gluconate were found. All three conserved mutations were found to reduce enzymatic activity more than 99 % with these substrates. Depending on which cysteine was disrupted, differences in the kinetic constants between D-xylonate and D-gluconate were found. The non-conserved mutation reduced activity by approx. 40 %. The spectroscopic results indicate that the three conserved mutants lacked the FeS cluster, while the non-conserved mutant still incorporated it. It can be concluded that the three conserved cysteines are involved in coordinating the FeS cluster, which itself plays an important role in the catalytic activity of Cc XyDHT. These findings should be helpful for follow-up studies in biotechnological application of pentose sugars acids and their derivatives.
  • Annala, Marja-Leena (Helsingin yliopisto, 2015)
    The goal of the research was to find out genetic gain and correlation of stem growth and quality traits in progeny trials of birch. Measurements and observation s of many traits are slow and expensive work. The costs could be decrease if some of the traits could be leaved unmeasured based on sufficient correlation between different traits. It’s very important to know association between different traits. Association can be even harmful. While some important trait becomes better some other can become worse. The internal and the external quality traits have a great importance for wood processing industry. The material of the research consists of eleven progeny trials established by The Finnish Forest Research Institute. Growth and quality trait were measured or observed. Measurements and observations were made at the age between 9-20 years. Change in mean of improved trait represents progress in tree improvement. This change is called genetic gain and it’s impressed usually as a relative value compared with mean of unimproved reference material. Reference material can even be other genetically improved material of different degree. Association between different traits was impressed with Spearman’s rank correlation coefficient. Nonparametric method was chosen because some traits were observed in rank order scales. Inconvenient for tree improvement is when association between growth and important quality traits is harmful. In this study was mainly found out remarkably genetic gain as well in growth as in quality traits in comparison with unimproved natural stand origins and even partly with earlier produced improved breeding material of different breeding degree. Correlation between stem volume and diameter at breast height were higher than between stem volume and height. There were several positive statistically significant correlations between growth and stem quality traits. Harmful correlation was found out between diameter at breast height and branch quality. Correlation between number of limbs and ramicorns had harmful correlation in some trials but correlations were quite weak. Ocular estimated general quality correlated well between its different factors. The costs of the practical forest tree breeding can be decreased by measuring fewer traits. Diameter at breast height is easy and quick trait to measure and correlate well between stem height and stem volume. Stem height could be leaved unmeasured. Because general quality correlates well between its different factors, other factors are not necessary to measure observe. Further research is needed within the reliability of the ocular observation. Differences in scaling within different person are important for reliability. Also the appropriate number of scales should be researched.
  • Viinikka, Joonas (Helsingin yliopisto, 2015)
    Työn tavoitteena on selvittää, miten valittujen sekajätteen käsittelyvaihtoehtojen yksikkö- ja nettoyksikkökustannukset käyttäytyvät laitoskapasiteetin suhteen. Lisäksi selvitetään, miten mahdollisesti tulevaisuudessa asetettava jätteenpolttovero voisi vaikuttaa käsittelyvaihtoehtojen kannattavuuteen. Keskeisenä tavoitteena on myös tuottaa yleisemmällä tasolla tietoa sekajätteen laitosmaisesta käsittelystä sekä eri vaihtoehtojen kustannuksista ja tuloista. Työssä tarkasteltavat käsittelyvaihtoehdot ovat arinapoltto, leijupetipoltto, mekaaninen käsittely ja kompostointi sekä mekaaninen käsittely ja mädätys. Työssä muodostetut yksikkö- ja nettoyksikkökustannuskuvaajat noudattelevat pääosin kasvavien skaalatuottojen mukaista muotoa. Vaihtoehdoille lasketut yksikkö- ja nettoyksikkökustannukset pienenevät laitoskapasiteetin kasvaessa. Poikkeuksena on arinapoltto, jonka yksikkö- ja nettoyksikkökustannukset lähtevät loivaan nousuun suurimmissa kapasiteettiluokissa noin 240 000 t/a jälkeen. Tulokset osoittavat, että jätteenpolttovaihtoehdot ovat nettoyksikkökustannuksiltaan noin 40 euroa mekaanis-biologisia käsittelyvaihtoehtoja edullisempia. Sekä jätteenpolttovaihtoehdot että mekaanisbiologiset vaihtoehdot ovat yksikkö- ja nettoyksikkökustannuksiltaan keskenään hyvin samansuuruisia. Herkkyystarkastelussa tehdyt muutokset eivät vaikuta merkittävästi tuloksiin. Jätteenpolttoveron vaikutusta tutkitaan työssä lisäämällä arinapoltto- ja leijupetipolttovaihtoehdoille lisäkustannuksiksi eri veron tasoja (6,6 e/t; 11,6 e/t; 55 e/t). Polttovero nostaa jätteenpolttovaihtoehtojen nettoyksikkökustannuksia, jolloin mekaanis-biologisten käsittelyvaihtoehtojen kilpailukyky paranee. Jätteenpolttoveron oletetut alemmat tasot (6,6 e/t ja 11,6 e/t) eivät vaikuta juurikaan tarkasteltavien vaihtoehtojen keskinäiseen järjestykseen. Korkein verontaso 55 e/t sen sijaan nostaa jätteenpolttovaihtoehdot nettoyksikkökustannuksiltaan mekaanis-biologisia vaihtoehtoja hieman kalliimmiksi. Kyseisellä veron tasolla on siis mahdollista, että sekajätteen käsittelyssä siirryttäisiin suosimaan mekaanis-biologisia vaihtoehtoja. Työn tulokset kuvaavat keskimääräisiä nettokustannuksia nimenomaisilla käsittelyvaihtoehdoilla. Jätehuollon ratkaisut ovat kuitenkin aina yksilöllisiä. Tästä syystä tuloksia ei voida yksinomaan käyttää harkittaessa jätehuollon ratkaisuja. Yhteiskunnallisesti optimaalista jätehuoltoa suunniteltaessa olisi huomioitava työn näkökulmaa laajemmin koko jätehuoltoketjun kustannukset sekä ulkoisvaikutukset.
  • Ojala, Vilma-Riikka (Helsingin yliopisto, 2015)
    During early lactation diet is usually rich in protein to stimulate and support milk production. Increased milk production has been connected with negative energy balance and impaired fertility. The aim of this study was to investigate the effects of concentrate crude protein (CP) level to dairy cow silage intake, milk production and energy balance in early lactation. The study was conducted in the experimental barn of MTT Agrifood Research Finland in Maaninka. The experiment started at October 2013 and finished at April 2014. The experiment lasted 70 days starting from parturition day. Fifty-five primiparous or multiparous Holstein and Ayrshire cows were allocated to one of three different CP levels in concentrate (149, 179 or 200 g/kg DM) after parturition. Concentrate allowance was 9 or 13 kg. Silage was fed ad libitum through an individual feeding system. Animals were weighed daily. Body condition score (BCS) was determined when blood samples were taken at 10 days before parturition and 7, 21, 42 and 63 days after parturition. The data were subjected to analysis of variance using the SAS MIXED procedure. Concentrate CP level did not affect silage intake or energy balance. Amino acids digestible from small intestine increased when CP level increased. Increasing CP content of concentrate tended to increase milk and protein yields suggestively. Milk protein yield and milk urea increased when concentrate CP level increased. Concentrate CP level had no significant effect on blood NEFA, BHBA, 3-MH or glucose concentration. There were no significant effects on live weight or BCS change throughout the experiment. Results of this experiment indicate that increasing concentrate CP level improves milk and protein yield in early lactation. In this experiment concentrate CP level did not affect silage intake or energy balance.
  • Innanen, Laura (Helsingin yliopisto, 2015)
    The aim of the study was to optimize growth media and its composition for one Lactobacillus strain. The purposes of the optimized culture media for fermentation were to maximize cell count and amount of viable cells during processing. The raw materials for growth media had to be suitable for industrial use. The study was performed by Bioscreen and fermentation tests in different growth media. At first ability of the strain to grow was tested by Bioscreen C with different raw materials and their compositions. According to literature, six carbon, four nitrogen sources and three other raw material were chosen to Bioscreen tests. Bioscreen C measured turbidity (OD value) of cultivation. According to the results from Bioscreen tests, optimal raw materials were chosen to the fermentation tests. The optimal carbon sources were whey permeate powder and glucose, the optimal nitrogen sources casein peptone and yeast extract and other raw materials manganesulfate, magnesiumsulfate and yeast extract. The cultivations were made in a bioreactor (Biostat Q). The starter strains were concentrated and freeze-dried. Samples from cultivated, concentrated and freeze-dried starter strain were analyzed (cell counts, optical density, growth rate, base consumption and survival-%). Results were compared to those obtained using control medium that is known to support the growth of the Lactobacillus strain. Lactobacillus strain was able to grow in different growth media. In Bioscreen tests compositions of growth media have major effect on lactobacilli growth. Bioscreen experiments revealed that in most cases the Lactobacillus strain grew to higher OD values in the composed media compared to control medium. In Bioscreen tests the sugar based growth media required more added minerals and yeast extract than whey permeate based media. Yeast extract was found to promote Lactobacillus growth in Bioscreen tests. In fermentation tests cells grew on growth media equally as on control media. Suitable alternative options for growth media were found from tests for further studies. Further studies can research functionality of the raw materials in production scale and preservation of the cell concentration during storage.