Maatalous-metsätieteellinen tiedekunta

 

Recent Submissions

  • Anni, Silvennoinen (Helsingin yliopisto, 2019)
    A common quality issue in fresh-cut vegetables is enzymatic browning. Anti-browning agents regulated by (EU) N:o 1129/2011 can be used in processing and vegetables are usually treated with compounds after washing and cutting. Polyphenol oxidase enzyme (PPO) in vegetables ox-idises phenolic compounds to quinones and brown melanin pigments are formed when reactive quinones polymerize. The literature review focused on phenolic compounds of apples, the mech-anism of action and inhibition of PPO. In addition, the review covered anti-browning agents in-vestigated in previous studies and physical inhibition methods for enzymatic browning. The aim of the experimental study was to find a mixture of anti-browning agents classified as a processing aid for fresh-cut apple with the help of the experimental design. In addition, apples treated with three different concentrations of calcium ascorbate were also investigated. The colour of the treated apples was measured using a colorimeter, the activity of PPO was determined spec-trophotometrically and the concentrations of the most common phenolic compounds of Granny Smith were determined by Ultra-High Performance Liquid Chromatography (UHPLC). The concentrations of anti-browning agents of the mixtures in PLSR model did not have a statis-tically significant effect on colour and the coefficient of determination was satisfactory. The ap-ples from the experimental design maintained their colour over one but less than five days and the apples treated with calcium ascorbate maintained their colour for one week which was the targeted shelf life. The PPO activity of the samples from the experimental design increased during the storage but activity of the samples treated with calcium ascorbate was zero all the time. The standard deviations of concentrations of phenolic compounds were high and no clear trend re-garding the change of concentrations and browning was noticed. The three major phenolic com-pounds of Granny Smith were (-)-epicatechin, (+)-catechin and chlorogenic acid. The concentra-tions of catechins were higher in the peel than in the flesh but for chlorogenic acid it was the opposite. The shelf life of one week was not achieved with the mixtures of the experimental design but calcium ascorbate acted effectively. Also compounds in the mixtures had the ability to inhibit the PPO because the apples did not start to brown immediately as the control samples treated with water. The results confirmed previous results from the literature that calcium ascorbate is an effective anti-browning agent and therefore it is one of the most common anti-browning agents in the fresh-cut industry.
  • Narinen, Lauri; Narinen, Lauri (Helsingin yliopisto, 2019)
    Controlling crystallization is an important factor in the production of food, whether it is preventing crystallization or enabling it, depending on the food product. To control crystallization, one must understand the theory behind crystallization and the components in food that affect crystallization. In sugar icing the most obvious components are sugars and water that affect crystallization. Also, the frozen storage has an important role concerning shelf-life of the sugar icing. The aim of this study was to prolong the shelf-life of the sugar icing on top of the donuts and to understand the phenomena that have an influence on the quality of the sugar icing during freezer storage. The experimental part of the study was divided into two parts. Preliminary tests were conducted in the first part. In these preliminary tests the aim was to measure the temperature and relative humidity during the melting of donuts in its packaging and to evaluate the applicability of ultracentrifuge and Karl Fischer titration in the measurement of the sugar icings properties. In the main experiment part, the water activity was measured from the different parts of the donut, the freezing of the sugar icing as well as its viscosity were evaluated and the shelf-life of the sugar icing on top of the donuts was evaluated. Karl Fischer titration was found to be a suitable method for measurement of water content of sugar icings. Also, the ultracentrifuge was found to be a suitable method to measure the liquid phase of the sugar icing. In the measurement of the conditions during the melting of the donuts it was detected that the conditions in the package that was open during the melting of the products, balanced with the conditions surrounding the packaging rather quickly. At the same in the closed package the conditions remained same during melting even though the melting was done in different surrounding conditions. The shelf-life of the donuts was found to be shortest in those icings that had less water or if the water was less free in the icing. The longest shelf-life was found to be in the coated sugar icings. Methods to prolong the shelf-life of the sugar icing on top of the donut were found in this study. Also, the phenomena affecting the quality of the sugar icing during frozen storage were discovered to some extent but to understand them even further requires more research.
  • Rauta, Janne (Helsingin yliopisto, 2019)
    Extrusion is a versatile thermomechanical food processing technology, and cereal based snack products made with extrusion are one of the most significant ready-to-eat products. The literature review covered extrusion process in general while the effect of different components of grain and milk powders in extrusion was examined more closely, and also different methods to evaluate the properties and the quality of extrusion products were examined. The objective of the experimental study was to study the effects of sugar content and composition as well as the effects of different milk protein and water contents of the mass on the properties (water content, expansion and hardness) and organoleptic quality of extrudates. Experiments were carried out by using twin-screw extruder and the main component of extrudates was a mixture of oat flour and waxy maize starch. Three different milk powders were used (one lactose-containing and two lactose-free skimmed milk powders) in experiments, so that the milk protein content of mass was 8, 10 and 12 % (from solids) and water content 14, 16 and 18 %. The effect of sugar composition (lactose vs. glucose/galactose mixture) and sugar content (lowering the milk sugar content to about 60 % from solids) in extrusion was also examined. The water content, hardness and expansion of extrudates were measured. In sensory analysis (n=6) the effect of different milk powders and water contents on extrudates were evaluated. More expanded and less hard extrudates were obtained by adding milk powder that contained lactose compared to lactose-free milk powders. Lowering the sugar content did not affect the properties of extrudates significantly. Increasing the milk protein content of the mass increased the typical positive features of extrudates when lactose-containing milk powder was used, but when lactose-free milk powders were used the effect was the opposite. Increasing the water content of the mass decreased the expansion and increased the hardness of extrudates. In sensory analysis the major differences were observed in the darkness of color and the diameter of the extrudates. According to the results of the present study it is possible to obtain extrudates with good structure using lactose-containing milk powder as well as lactose-free milk powder. However, lactose-containing milk powder may be a better alternative in extrusion compared to the lactose-free milk powder. It may be possible, to some extent, to lower the sugar content of the extrudates that contain lactose-free milk powders without compromising the structural and organoleptical quality of the extrudates.
  • Amoah, Samuel (Helsingin yliopisto, 2019)
    Tiivistelmä/Referat – Abstract Biochars, made from biomass heated in limited oxygen, have been suggested as a sustainable means of increasing crop productivity. Two of the most commonly reported benefits of biochars are improved soil water availability and nutrient status, due of which also yield increases have been reported. Most studies so far have focused on subtropical soils that are low in initial carbon content, and cereals have been the main crops studied. There is also lack of knowledge of the effects of biochar in longer term than five years on the yield formation of grain legumes like peas. A long-term field experiment was conducted in Helsinki, Finland to investigate the effects of softwood biochar on the soil properties and on the yield formation of peas. Three levels of biochar rates were used: 0 ton/ha, 5 ton/ha and 10 ton/ha in conjunction with 3 NPK fertilizer levels of 30, 65, and 100 percent of the recommended levels. The addition of biochar was tied to slightly elevated levels of soil moisture at the upper soil layers (0 – 18 cm). This increase was however not significant (p > 0.05). Changes in biochar porosity over the years may have led to decreased water holding capacity of the soil and hence low moisture content. The soil nutrient status was also not significantly affected by biochar additions, except for sulphur levels which recorded a marginal significance of p < 0.1. Changes in biochar properties over time could also be responsible for the lack of effects on soil nutrients. The soil used was relatively fertile (3.5 % C), hence the effects of biochar were insignificant. Fertilizer effects were also not significant, except for significant levels of such nutrient as P, Ca, P and S. The lack of fertilizer effects could be due to the relatively fertile nature of the Luvic Stagnosol soil. The lack of effects of biochar on soil properties resulted in non-significant results for yield components of peas. The relatively dry weather during the growing season could also be responsible for the vast lack of significance recorded.
  • Nguemgne Fotso, Rostandine (Helsingin yliopisto, 2019)
    Cameroon is a country located in Central Africa. The country has an export-led economy, which means that the country highly depends on exports to ensure its population well-being. Sawnwood exports represent 14% of Cameroon’s total exports. Sawnwood is therefore one of the most important export products for Cameroon. Since Cameroon signed the EU-Cameroon voluntary partnership agreement policy in 2010, Cameroon’s sawnwood exports were impacted. The aim of this study is therefore, to examine the export competitive performance of Cameroon’s sawnwood industry from 2001 to 2017. Based on the literature, a set of three methods analyzing the competitiveness of Cameroon’s sawnwood exports were chosen. These methods are: The Revealed Comparative Advantage Index (RCA) and RSCA index which were used to analyze the competitiveness and international specialization of Cameroon in exporting sawnwood. The Spearman Rank Correlation was used to study the export competitive performance of Cameroon’s sawnwood across years and to analyze the level of competition between Cameroon, Finland, China and Ghana. Lastly, the Constant Market Share Analysis was used to explain the drivers of Cameroon’s sawnwood export competitiveness. This study also compiles information on forest in Cameroon and provides an overview of Cameroon sawnwood industry, it can therefore serve as a base for further studies on sawnwood in Cameroon. Results show that Cameroon has a competitive advantage and is the highest specialized in exporting sawnwood compared to Finland, China and Ghana. Nevertheless, the export competitive performance of Cameroon across years is not continuous and highly depends on external factors. Results also show that Cameroon has reduced its exports to EU and has diversified its importers portfolio by redirecting its exports trade flows towards Asia, especially China which has less stringent imports policies compared to EU. Cameroon will need to improve its production technologies and management practices to ensure a long run competitiveness on the global sawnwood market.
  • Heikkilä, Andreas (Helsingin yliopisto, 2019)
    From the beginning of 2013, the European Commission restricted the use of neonicotinoid based insecticides on honeybee attracting plants, such as Brassica oilseeds. This was done because neonicotinoids were believed to cause the death of honeybees. The initiative for this study came from the need to adapt to the change in insecticide use on oilseed crops. Adaptation had to happen at a time when the environmental effects of chemical control agents are evaluated from all sides. The aim of the study was to investigate if there was a correlation between seedling stage trichome abundance, or seed glucosinolate content, and flea beetle damage in Brassica rapa subsp. oleifera. The usability of trichomes and seed glucosinolates in increasing plant resistance against flea beetles was evaluated according to the results. The significance of seedling stage trichome density on the amount of flea beetle damage was investigated in field assays at Jokioinen 2015, and Loimaa 2016. Total glucosinolate content of different lines was determined from crushed seeds. Leaf trichome density, or seed total glucosinolate content, didn´t have a statistically significant effect on the formation of flea beetle damage. However, there is a multitude of scientific literature repeatedly suggesting that leaf trichomes can decrease flea beetle damage. This raises a question about the purposefulness of the methods used in exploring the phenomenon. Despite of this, the study revealed lines which suffered little beetle damage, because of an unknown reason. In the case of future research focus should be aimed at determining the resistance mechanisms in these lines. The role of glucosinolates, and their various hydrolysis products, as flea beetle repelling agents should be examined one compound at a time. This is because of their varied effects on flea beetle behaviour. Repelling substances are needed especially at the early seedling stage, because plants are most vulnerable to flea beetle damage at this growth stage. To maintain good nutritional and feed value, glucosinolates appearing in the seed should be avoided.
  • Lappalainen, Inka (Helsingin yliopisto, 2019)
    Tämän tutkimuksen tavoitteena oli selvittää luomumaatalousyrittäjien riskiasenteita, riskienhallinnan keinoja ja riskin lähteitä. Erityisenä tutkimuskohteena oli se, miten tavanomaisessa tuotannossa olevien maatalousyrittäjien ja luomuyrittäjien riskiasenteet ja riskienhallinnan keinot eroavat toisistaan. Tutkimusaineistona käytettiin MTT:n (nyk. Luonnonvarakeskus) vuonna 2012 At Risk- hankkeen yhteydessä keräämää aineistoa. Kysely lähetettiin 5000 tilalle, ja siihen vastasi 1170 maatalousyrittäjää, joista luomutuotantoa harjoitti 86 viljelijää. Tutkimusaineisto analysoitiin kvantitatiivisin tutkimusmenetelmin. Työkaluina tutkimuksessa käytettiin Excel-taulukkolaskentaohjelmaa ja SPSS-tilasto-ohjelmaa. Riskien lähteitä ja riskien vähentämiskeinoja tutkittiin keskiarvojen, keskihajontojen ja tilastollisten merkitsevyyksien selvittämisen keinoin. Tutkimustulokset havainnollistettiin kaavioin ja taulukoin. Riskiasenteita tutkittiin mm. viiden riskiasenneväittämän avulla, joista muodostettiin faktorianalyysillä riskiasennefaktori. Lineaarisella regressioanalyysillä tutkittiin muuttujien ikä, sukupuoli, koulutus ja tuotantotapa vaikutusta faktorianalyysin avulla löydettyyn riskiasennefaktoriin. Tutkimustulosten perusteella voidaan todeta, että luomuyrittäjien ja tavanomaisesti tuottavien maatalousyrittäjien riskien vähentämiskeinoissa on jonkin verran eroja. Sen sijaan riskin lähteet ovat kummassakin tuotantotavassa samankaltaisia. Vastaajien mukaan suurimmat riskin lähteet olivat sääilmiöistä johtuva satovaihtelu, tuotteiden ja tuotantopanosten hintavaihtelu sekä politiikan muutokset. Tulosten perusteella luomuyrittäjien ja tavanomaisesti tuottavien riskiasenteet eroavat toisistaan jonkin verran. Luomuyrittäjät olivat vähemmän riskiä välttäviä kuin tavanomaisesti tuottavat.
  • Chambers, Philip (Helsingin yliopisto, 2019)
    Forestry is a hazardous industry globally. Physical conditions, legal frameworks and cultural norms can vary from country to country leading to different approaches to site safety management. There are international, national and regional legislation and guidelines which outline normative approaches land managers can utilise to protect forestry machine operators and the public from accident or injury. In this study, the approaches the health and safety management in forestry operations are assessed in two countries within the European Union –Scotland (as part of the UK member state) and Finland. While both countries practice sustainable forest management, it is shown that this is carried out under different legal frameworks leading to differences in approach to site safety planning. Other factors are shown to have an effect including cultural factors and land ownership patterns.
  • Ryytty, Satu (Helsingin yliopisto, 2019)
    Pitkä rannikkoalue Itämerelle sekä lukuisat järvet ja joet muodostavat Suomen runsaat vesivarat. Näitä vesivaroja hyödynnetään useissa liiketoimissa ja viime vuosina näiden toimialojen merkitys on noussut esille. Tämä pro gradu -tutkielma on osa BlueAdapt-hanketta, joka tavoittelee vesivaroihin perustuvan kestävän taloudellisen kasvun edistämiseksi innovatiivisia keinoja. Hanke on alkanut vuoden 2018 alussa ja tämä tutkimus on tehty hankkeen tulevien tutkimusten tueksi ja taustamateriaaliksi. Hankkeeseen lukeutuvien toimialojen (ruoantuotanto, energiantuotanto ja matkailu) keskinäinen riippuvuussuhde on vahva (Maa- ja metsätalousministeriö, 2018). Tämän tutkimuksen tavoitteena oli selvittää kuinka sinisen talouden toimijat kalatalouden, energiantuotannon ja matkailun aloilta kokevat ja käsittävät taloudellisen tilanteensa, miten he määrittelevät vaikutuksensa ympäristöön ja kuinka ympäristölliset piirteet vaikuttavat toimialan kehitykseen. Politiikan piirteiden arvioinnissa mitattiin nykyisen sinisen talouden politiikan viitekehyksen onnistumista. Kaikki teemat käsittivät aikajänteen nyt ja tulevaisuudessa. Tutkimuksen aineiston keräsi Taloustutkimus Oy tekemällämme sähköisellä kyselylomakkeella vuoden 2018 marraskuun ja joulukuun aikana. Vastauksia saatiin yhteensä 150, joista 57 vastausta olivat kalataloudesta, 40 energiantuotannosta ja 53 matkailualalta. Tutkimuksen tulokset analysoitiin tarkastelemalla selittävien vastausten vaikutusta. Teoreettisena viitekehyksenä toimi kvantitatiivisen tutkimuksen teoria. Tulokset osoittivat, että talouden osalta kannattavuuden odotukset olivat kaikilla toimialoilla hyvät. Ympäristöön liittyvissä arvioinneissa esille nousivat toimialojen eroavat näkemykset ympäristöllisten piirteiden tärkeydestä. Sinisen talouden politiikan piirteitä arvioitaessa toimialoilta löytyi yhteneväisiä kehitysideoita.
  • Jaatinen, Henri (Helsingin yliopisto, 2019)
    The aim of this research was to study the effect of air current speed on yield of basil (Ocimum basilicum L. cv. ‘Marian’) in vertical farming. A fan system was built to form an air current gradient inside the culture layer. Environmental conditions (air current speed, temperature, relative humidity, light) were measured before and during the experiment. The experiment was conducted at a vertical farm owned by Novarbo Oy in Säkylä, Finland, which is a showroom and research facility for Novarbo Vertical Farm Concept. The cultivation was performed with LED-lights (Valoya, Finland) without sunlight and fertigation was done by NFT-technique in gutters with mineral fertilizers. Climate control of the facility was managed with Novarbo Vertical Farming droplet curtain. Basil plants were grown for 29 days between January and February of 2019. The plants were grown for 21 days before transplanting to the vertical farm. The experiment was conducted in one layer with three different air currents grouped by 0 m/s, 0,5 m/s and 1,2 m/s. Air temperature of the area averaged 22 °C with 76,5 % of relative humidity and light intensity of 200 µmol/m2/s was maintained during the experiment. Results of the experiment were contrary to expectations based on the literature and previous studies in vertical farming. The highest biomass formation was achieved by a group of plants grown under the lowest (0 m/s) air current speed. A group that was grown under the highest air current speed (1,2 m/s) yielded the lowest biomass as expected. According to the results, it can be said that air current speed has an impact on the yield in basil cultivation. However, no recommendations can be made for optimal levels of air current speed due to the sources of error. Plant material of commercial quality that was used in this experiment was not suitable for accurate interpretation of the results. It could be advisable to do further research focusing on air current speed of 0,1 – 0,5 m/s to find optimal level for efficient yield formation.
  • Alakotila, Anni (Helsingin yliopisto, 2019)
    The literature section of this Master's Thesis focuses on cheese making process from milk composition to cheese ripening. In addition, the thesis investigates the effect of lactose standardization on lactic acid fermentation, sensory characteristics of the cheese and what biochemical changes the standardization causes during cheese ripening. The aim of the experimental part was to investigate the effect of standardization of the lactose content of cheese milk and how it will affect the ripening and final quality of Swiss -type cheeses. The effect of lactose content of the cheese milk, protein fraction used, pre-ripening time and ripening temperature was studied using statistical design of experiments (DOE). 16 test batches were manufactured according to factorial screening design. Water, cream and protein fraction were used to standardize the lactose content of the cheese milk. In addition, two center point experiments were performed with third protein fraction. The fat and protein content, dry matter, moisture of non-fat substance, fat in dry mater, lactose, lactic acid, acetic acid, propionic acid, butyric acid and the level of volatile organic acids and titrated free amino acids of cheese were analyzed during manufacturing and ripening. The lactose and lactic acid content of the cheese milk can be lowered by standardization of the lactose concentration. If set too low however, it is no longer beneficial for the lactic and propionic acid fermentation processes or to the quality of the cheese, as flaws in the fermentation process will start to occur. With lower levels of lactose content, less lactic acid and more propionic acid will form in the cheese. Pre-ripening creates beneficial environment for propionic acids and that can prevent cracking of the cheese. Cheese that has been ripened for too long in temperatures too high will have flaws in the fermentation process. Moreover, the statistical centre point tests show that the standardization of the protein level in the cheese milk is best to be done by using protein fraction U. Fraction U gave best results on average in the sensory evaluation.
  • Veirto, Timo (Helsingin yliopisto, 2019)
    Tämän tutkielman tarkoitus on selvittää, että voiko teknisen analyysin sijoitusstrategialla päästä markkinatuottoa parempiin tuottoihin sijoitettaessa metsäteollisuusosakkeisiin noususuhdanteen aikana. Samalla testataan tehokkaiden markkinoiden teoriaa. Tehokkaiden markkinoiden teorian heikko ehto ei toteudu, mikäli teknisen analyysin avulla voidaan ylittää osta ja pidä –strategian tuotot. Tutkielmassa vertaillaan erilaisia teknisen analyysin menetelmävariaatioita, jotka koostuvat yksinkertaisista liukuvista keskiarvoista sekä RSI:stä. Tutkimus toteutettiin empiirisesti strategioita jälkitestaten UPM-Kymmenen ja Stora Enson osakkeisiin sekä iSharesin WOOD etf rahastoon. Empiirisen testauksen aikavälinä käytettiin vuosia 2009–2018. Tulokset laskettiin teoreettisessa skenaariossa, sekä reaalimaailman skenaariossa, jossa huomioitiin verotus, kaupankäyntikulut, osingot ja hallinnointipalkkiot. Tulosten perusteella teknisestä analyysistä ei ole hyötyä sijoitettaessa suoraan osakkeisiin, mutta ETF rahaston kohdalla ylituottoa olisi syntynyt. Osakkeiden kohdalla verotuksen vaikutus suurimpana tekijänä teki teknisen analyysin strategiasta kannattamattoman. Osakkeiden vahva osinkotuotto myös tuki enemmän osakkeiden osta ja pidä -strategiaa. Tämä tukee osittain aikaisempaa tutkimusta teknisestä analyysistä. Johtopäätös on, että yksinkertaisesta teknisestä analyysistä ei ole hyötyä sijoitettaessa noususuhdanteessa yksittäisiin osakkeisiin, joilla on vahva osinkotuotto. Tutkimuksessa jää epäselväksi, että minkälainen yksinkertaisen liukuvan keskiarvon ja RSI:n menetelmävariaatio olisi tehokkain.
  • Ma, Kaiyue (Helsingin yliopisto, 2019)
    The literature review deals with coeliac disease and wheat, rye and barley prolamins. The characteristics and analysis methods of the prolamins were discussed. Furthermore, the ELISA types, antibodies and reference material in ELISA were introduced in literature review. The aim of this master thesis study was to determine the feasibility of barley C-hordein as reference material in the quantification of wheat gluten in a sandwich ELISA method based on R5 antibody. RP-HPLC was used to determine the compositions of wheat prolamins from 27 wheat cultivars. SDS-PAGE was used for wheat prolamin subgroups identification. The R5 antibody reactivity of prolamins and the same prolamin group from different cultivars were tested. By comparing the R5 reactivity of total gluten of the 27 wheat cultivars, 10% barley C-hordein was used to calibrate the gluten content in spiking test of oat flour and oat biscuits. Omega 1,2-gliadin (Km 13) and γ-gliadin (Km 21) showed rather strong R5 reactivity while ω 5-gliadin (Km 203) and LMW glutenin subunits (Km 523) showed almost no reactivity against R5 antibody. However, the subgroup R5 reactivity differences between cultivars were not significant. The reactivity of total gluten from 27 cultivar varied from Km 14 to 192, with a logarithmic average Km 53. Thus, 10% C-hordein (Km 49) had similar reactivity of the average of all cultivars. In flour spiking test, the recoveries calibrated with PWG gliadin were 57-187%, comparing to 30-115% with 10% C-hordein calibration. In biscuit spiking test, the recoveries calibrated with PWG gliadin and 10% C-hordein were 84-145% and 44-76%.
  • Ignatius, Heikki (Helsingin yliopisto, 2019)
    The structural changes concerning the forest industry sector will stimulate the incumbents in the sector to develop new product areas for the replacement of the old, declining core products. Wood-based biochemicals are considered as one of the major product areas able to compensate the decline in revenues caused by diminishing demand for graphic papers. There is already existing demand for biochemicals from the owners of major product brands who seek to replace fossil-based raw materials with more sustainable alternatives. New wood-based product areas respond to the changing operating environment of the sector but also require new types of business models and strategies as well as development of expertise from different fields. This work examines the systemic weaknesses and strengths of the development of the Finnish wood-based biochemical sector as well as the policy tools facilitating the development and diffusion of the sector. This study was carried out as a qualitative study where literature review was complemented with eight semi-structured expert interviews. The conceptual basis for analyzing the material were based on innovation theories, enabling the identification of the weaknesses and strengths of the system. The results revealed several drivers for the further progression of the system but specifically two internal functions of the system were identified which can be recognized to hinder the optimal development of the entire system. The development and diffusion of knowledge as well as the differing expectations and visions between system actors were identified as barriers to the further development of the system, necessitating more effective policy measures. As this study addressed specifically the systemic weaknesses and strengths, it would be important for the future studies to address more detailed policy measures in order to enhance the further promotion of the sector. This approach should also consider the relationship of the wood-based biochemicals as a part of the whole biochemical sector and its development.
  • Stolze, Markus (Helsingin yliopisto, 2019)
    The purpose of this master’s thesis is to evaluate the reliability of forest products forecast information produced by United Nations Economic Commission for Europe member States. The study also aims to answer which dimensions of data quality are the most important when producing these predictions This study is carried out as quantitative research and it focuses on the predictions made by the 27 member States, produced between 2002 and 2017. This research aims to find out what methods are used by different member States and which methods produce the most reliable results. This research also aims to find out if there are any differences in reliability when assessing different product flows (removals, production, exports or imports) of the various products analyzed. There were clear differences visible between different products in the results of this research. In some products, almost all member States had managed to produce reliable predictions, while for others majority of member States didn’t manage that. There were also differences between member States and some were clearly more reliable than others. The biggest factor affecting reliability was volume: for most parts, bigger volumes meant more reliable predictions. Production and removals were more reliable product flow than imports or exports. This is due to the nature of imports and exports, as they are more easily affected by outside impacts. Although all member States were able to be sorted into four groups based on how different product flows looked like, no clear patterns were visible when observing how different member States produce predictions. Almost all of the interviewed representatives of member States reported that they were using almost or exactly the same methods to produce predictions.
  • Helander, Riina (Helsingin yliopisto, 2019)
    Ruokaturvallisuuden merkitys korostuu tulevaisuudessa muun muassa ilmastonmuutoksen, kuluttajan toiveiden ja globalisaation myötä. Ammattikeittiöissä ruokaturvallisuus painottuu elintarvikehygieniaan ja sitä toteutetaan omavalvonnalla. Omavalvonnan kirjauksia, kuten lämpötilahallintaa, on perinteisesti tehty käsin paperille ja valvonnan mittaukset ovat olleet näytemittauksia jatkuvan valvonnan sijasta. Suomalaisissa ammattikeittiöissä omavalvonta toteutuu pääasiassa hyvin, mutta lainsäädännön tulkinta, resursointi ja epäyhtenäiset toimintatavat saattavat aiheuttaa haasteita. Ihmisen rooli ruokaturvallisuudessa on merkittävä. Tänä päivänä teknologian hyödyntäminen ruokaturvallisuudessa yleistyy ja uusia innovaatioita siihen kehitetään jatkuvasti. Omavalvonta voidaan digitalisoida ja automatisoida. Tämän tutkimuksen tavoitteena oli kehittää digitaalista omavalvonnan palvelua ruokaturvallisuutta edistävästi. Tutkimus oli laadullinen tutkimus, jossa menetelminä käytettiin puolistrukturoitua teemahaastattelua ja lyhyempää kyselyhaastattelua. Teemahaastattelujen haastateltavat olivat ammattikeittiöiden keittiöpäälliköitä tai ylemmän tason esimiehiä ja kyselyhaastatteluihin vastasi keittiöiden työntekijät ja kokit. Lisäksi haastateltiin neljää valvontaviranomaista. Teemahaastattelun teemoja olivat omavalvonnan merkitys, haasteet ja ajankäyttö, digitaalisen omavalvonnan vahvuudet, heikkoudet ja kehittäminen, palveluntarjoajan rooli sekä digitaalisen omavalvonnan vaikutus ruokaturvallisuuteen. Valvontaviranomaisilla teemana oli myös valvontakäynnit. Nauhoitetut aineistot litteroitiin ja analysoitiin sisällönanalyysilla teemoitellen. Haasteita omavalvonnassa tuottivat resursointi, lainsäädännön tulkinta sekä eri tasoinen osaaminen niin ruokaturvallisuudesta kuin digitaalisista työvälineistä. Digitaalinen omavalvonta lisäsi haastateltavien mielestä ruokaturvallisuutta automaattisen lämpötilaseurannan, läpinäkyvyyden ja sitouttamisen myötä. Digitaalista omavalvontaa tulisi kehittää kahdesta näkökulmasta. Ensinnäkin, digitaalisten työvälineiden tulisi ohjata käyttäjää tekemään ruokaturvallisia ratkaisuja, perehdyttää, motivoida ja sitä kautta sitouttaa paremmin omavalvonnan tekemiseen. Toiseksi, teknologian ratkaisuja ja automatisointia tulisi lisätä laajemmin koko omavalvontaan. Eri keittiöiden eri prosessit ja sitä kautta omavalvonnan toimintamallit tulee huomioida kehityksessä.
  • Sainio, Taru (Helsingin yliopisto, 2019)
    Availability of plant-based food products and snack products has increased during the last years. In Finland, especially oat-based food products have been popular. Milk-based yogurts have been accompanied by fermented oat-based snack products, ‘oatgurts’. The aim of this study was to investigate texture and mouthfeel properties of commercial oatgurts and milk-based yogurts. Pleasantness of the mouthfeel and overall pleasantness were also studied. In addition, structure properties of the products were measured with instrumental methods. Sensory study of the products was conducted as a consumer study (n = 87) using a time-dependent method called Temporal Dominance of Sensations, TDS. TDS was used to study dominant sensations of mouthfeel properties (creamy, foamy, thick, thin, sticky and watery) during eating. Two milk-based yogurts with 2,5 % and 4,0 % of fat and five oat-based gurts were used as samples. Overall pleasantness and pleasantness of the mouthfeel were evaluated with a 7-point hedonic scale. Assessor’s demographic factors, innovativeness and usage frequency of plant-based yogurts were studied with the sensory study. With instrumental methods viscosities during steady state shear rates 10 s-1 and 50 s-1 were measured. In addition, flow curves, amplitude sweeps, frequency sweeps were conducted, and particle sizes of the products were measured. According to the results, milk-based products were scored more pleasant in the overall pleasantness and in the mouthfeel pleasantness. However, one of the gurts was statistically as pleasant in the mouthfeel as the milk-based yogurt with lower fat content (2,5 % of fat). Ethnic background of the assessors had an impact to the hedonic ratings of the gurts. Assessors with Finnish background (n = 68) evaluated the gurts more pleasant in the overall pleasantness and in the pleasantness of the mouthfeel. Innovativeness of the assessors had an impact to the overall pleasantness of the gurts but not to the pleasantness of the mouthfeel. According to TDS results, creaminess and thickness improved the hedonic ratings whereas wateriness and thinness had a negative effect on the hedonic ratings. According to the instrumental measurements, structures of the products were different. One of the gurts showed rheopectic behavior which is less common among food products. Other products were thixotropic. From the results it can be concluded that high viscosity of the products correlated positively with dominance ratings of thickness. To find reliable connections between sensory properties and instrumental measurements, more research must be done. There were differences in the mouthfeel properties of the milk- and oat-based products. Oatgurts and their mouthfeel properties have lot to be improved that their pleasantness would be equal to milk-based yogurts. In a future research, it would be good idea to find out what kind of qualities consumers want for oatgurts and whether milk-based yogurts are good reference products for oatgurts.
  • Peltomäki, Katja (Helsingin yliopisto, 2019)
    The literature part of the study dealt with frying methods, frying fats and oils, chemical and physical changes of frying fats and oils during the frying and analyse methods of frying fats and oils. The aim of the experimental part was to study changes in rapeseed oil quality during continuous frying process during three different frying periods. Especially the effect of day without production during the frying period was studied. Samples, frying oils, were taken every day during the different frying periods. In period one and two there was one day without production. Oils were stored in storage tanks during that time. In third period, there was production on every day. All samples were inspected for colour, odour, viscosity and clearness by visual methods. Also viscosity by rotation viscometer, smoking point, free fatty acids by titration method, fatty acid content and water content of samples was analysed. Based on sensory evaluation, the quality of oil deteriorated over thedays of use. Colour was darker, viscosity was higher and off-odours were sensed. Instrumental analyses indicate same kind of changes; viscosity and free fatty acid were increased and smoking point and amount of unsaturated fatty acid were decreased while frying time was increasing. In literature, also same changes were mentioned. There was changes in fatty acid content during the frying periods. More fatty acids characteristic to meat was detected in oils at the end of period than in fresh oils. Based on these results, oil quality remained acceptable in everyday use for a typical frying period of one week. Difference between fresh oil and used oils was clear but still acceptable. The amount of free fatty acids, and the level of viscosity and smoking points were under the limits applied in Finland. The day without production deteriorated oils quality substantially Reducing the amount of oil in process and having shorter frying periods or more efficient filtering of oils can help to keep the quality of frying oil better.
  • Karjalainen, Satu (Helsingin yliopisto, 2019)
    Sphagnum moss could be used as a substitute for Sphagnum peat as a growing medium. It has the same positive physical properties as peat and it is also a more sustainable option. However, there are some indications that Sphagnum moss may have some inhibitory effects on vascular plant seed germination and seedling development. The aim of this study was to find out whether this is true and due to the low pH of different Sphagnum moss species. The tested moss species were Sphagnum fallax, Sphagnum medium, Sphagnum rubellum and Sphagnum spp. The seed germination on Sphagnum moss substrate was tested with lettuce, radish, basil, pine and ryegrass. Also, two additional seed germination experiments were done with lettuce. Seedling growth experiment on Sphagnum substrate was tested with lettuce. The first germination experiments indicated that the dicotyledon species basil, radish and lettuce are sensitive to the allelopathic effect caused by Sphagnum moss. In the case of ryegrass and pine no indication of seed germination inhibition was found. The two additional germination experiments confirmed that Sphagnum moss and white peat substrates and Sphagnum moss and white peat organic matter/water extracts were inhibiting lettuce seed germination. Added lime didn’t conclusively explain the inhibition in germination percentages of Sphagnum moss substrate when compared to control treatment gauze. Only in the case of radish the raised pH had positive effect on the germination percentage. Therefor it was concluded that the low germination percentage is not explained only by the naturally low pH of Sphagnum mosses and Sphagnum mosses’ other characteristics should be investigated in the future. In the seedling growth experiment done with lettuce on Sphagnum medium growing medium there was no indication of allelopathic effect on seed germination or seedling development. The allelopathic compounds were thought to have been lost in this experiment through leaching when the substrates were watered.
  • Vaatmann, Mari-Liis (Helsingin yliopisto, 2019)
    Yhteisöllisyys on saanut uusia muotoja ja modernisaatio on muuttanut ihmisten välisiä suhteita monimutkaisemmaksi ja monimuotoisemmaksi. Informaatioteknologian kehittyminen ja sosiaalisen median kanavien tuleminen on edes auttanut uusien yhteisöjen syntymistä. Tällaiset Facebookiin perustetut virtuaaliyhteisöt ovat hyödyllisiä ja edullisia yrityksille sekä lisäksi tarjoavat valtavasti tietoa kuluttajista. Yritykset voivat saada ajankohtaista tietoa liittyen yritykseen tai tuotteisiin. Parhaimmassa tapauksessa yritykset voivat saada selkeätä kilpailuetoa kilpailijoihin nähden. Tämän maisterintutkielman tavoitteena oli selvittää, mitä ominaispiirteitä liittyy virtuaaliseen yhteisöön ja minkälaiset motiivit ja ajurit sitouttavat kuluttajia virtuaaliseen yhteisöön. Tutkimusongelmaa lähestyttiin yhdistämällä kuluttaja- ja brändiyhteisöön liittyvää teoriaa, määrittelemällä brändiyhteisöön liittyvät ominaispiirteet sekä kuluttajan sitoutumiseen liittyviä motiiveja ja ajureita perustuen aikaisempiin tutkimuksiin. Teoriaosuus käsittelee myös sosiaalista mediaa ja Facebookia. Tutkimuksen empiirinen osuus toteutettiin käyttäen kahta tutkimusmenetelmää, netnografiaa sekä teemahaastattelua. Tutkimus toteutettiin tapaustutkimuksena, jossa tutkija havainnoi syksyn 2018 aikana muutos-heimo Facebook –yhteisöä sekä haastatteli helmikuussa 2019 yhdeksää yhteisön jäsentä. Tarkastelun kohteena oleva Facebook –yhteisö toimii tukena muutos.net verkossa tapahtuvalle hyvinvointivalmennukselle. Kaikki elämäntapamuutosvalmennuksen ostaneet henkilöt liitetään Facebook –yhteisöön, jossa valmennuksessa mukana olevat voivat vapaasti keskustella keskenään sekä tarvittaessa esittää kysymyksiä valmentajille. Tavoitteena oli ymmärtää tutkimuskohdetta havaintojen sekä haastatteluiden kautta. Aineistoa tarkasteltaessa huomiota kiinnitettiin mm. keskusteluiden sisältöön, kuviin, kommentteihin ja yhteisön ilmapiiriin. Haastattelujen tavoitteena oli ymmärtää kuluttajien motiiveja ja sitoutumiseen liittyviä ajureita. Tutkimuksessa tarkasteltiin aikaisemmissa tutkimuksissa havaittuja yhteisöjen ominaispiirteitä. Ominaispiirteillä on vaikutusta yhteisössä tapahtuvaan jokapäiväiseen vuorovaikutukseen ja toimintaan. Lisäksi tarkasteltiin viittä sitoutumiseen liittyvää ajuria kuten informaatiota, viihdettä, hyötyä, sosiaalista vuorovaikusta ja saavutuksia. Kuluttajien sitoutumiseen vaikuttaa useita tekijöitä. Yhteisöön liittymisen taustalla on kuluttajan henkilökohtainen motiivi liittyä yhteisöön ja usein yhteisössä olevia kuluttajia yhdistää kiinnostus tuotetta tai palvelua kohtaan. Tässä tutkimuksessa kuluttajia yhdisti halu tehdä elämäntapamuutos. Yhteisön ominaispiirteissä oli havaittavissa erovaisuuksia verrattuna aikaisempiin tutkimuksiin. Kaikki edellä mainitut ajurit korostuivat tutkittavassa yhteisössä tavalla tai toisella.

View more