Faculty of Agriculture and Forestry


Recent Submissions

  • Arjama, Mariliina (2022)
    Melanoma observed at an early stage can often be treated with surgery, but the prognosis is significantly worsened if the tumor is invasive or has sent metastases. Membrane-type matrix metalloproteinases (MT-MMP), often associated with cancer invasiveness, have been extensively studied, but their individual roles in melanoma are still unclear. In melanoma, MT3-MMP is often expressed in the most aggressive nodular type of tumors. MT1-MMP, on the other hand, promotes invasive cell movement between basement membrane and type I collagen tissues. Here MT3-MMP expression was examined by quantitative PCR (qPCR) from lymph node metastases and metastatic cell lines. The functions of MT1-MMP and MT3-MMP in cell invasiveness were studied by siRNA silencing and invasion assay in fibrin and collagen. MT3-MMP appeared to inhibit MT1-MMP-directed melanoma cell invasion in three-dimensional collagen, but in conjunction caused an MT1-MMP-dependent increase in invasive growth in the fibrin matrix and caused nodular-type cell colonies to form. MT3-MMP overexpression was also significantly visible in human melanoma metastasis specimens. In cell lines, silencing MT3-MMP increased invasiveness to collagen. The results demonstrate the ability of MT3-MMP to modify cancer cell functions during the progression of invasive melanoma. Treatment options for patients with metastatic melanoma (MM), including immunotherapy, checkpoint inhibitors, and BRAF inhibitors, have increased over the past decade. Yet many patients do not receive effective medication after failed standard treatments or the development of drug resistance. It is therefore important to develop methods for advancing personalized and translational medicine. The patient's own cells are closer to the in vivo conditions for this purpose than commercial cell lines. In this study, different cell types from patient-derived melanoma samples were isolated from each other and validated. We compared patient-derived normal cells (NFs), activated fibroblasts (CAFs), and cancer cells (PDC) from an NRAS Q61-positive MM patient and evaluated the response of these patient-derived cells and two commercial NRAS-positive and two BRAF-positive cell lines in a 527- oncology drug panel for drug sensitivity and resistance. Healthy bone marrow and patient-derived fibroblasts were used as controls. The function of normal cells and CAFs as control cells were compared with normally used bone marrow control. Preoperative medication and culturing stromal-based cells made isolation more complicated. From six melanoma samples, we succeeded in creating three melanoma patient-derived primary cell lines and three patient-derived fibroblast cell lines for further studies. Drug Sensitivity Assay NRAS Q61- positive PDCs and cell lines showed a strong response to MEK, ERK, and RAF inhibitors. In addition, PI3K/mTOR, mTOR, and PLK1 inhibitors had a drug response in cell lines as well as PDC. The application of a patient’s own cancer cells and fibroblasts to ex vivo medical testing allows for the identification of effective patient-specific drugs and can improve treatment outcomes for individual MM patients while reducing side effects caused by ineffective treatments. DSRT can help find individualized treatment planning for patients with metastatic melanoma whom conventional therapies have failed.
  • Savonen, Outi (2020)
    Novel fibrous feeds for ruminants The objective of this licentiate thesis was to study the effects of novel fibrous feeds on feed intake, digestibility, rumen fermentation and milk production of lactating dairy cows. The novel feeds used in the milk production trials were silage solid fraction originated from a green biorefinery process (solid fraction) and microcrystalline cellulose (MCC) from coniferous trees. Solid fraction replaced unprocessed grass silage whereas MCC replaced barley in the diet as concentrate. The idea behind this thesis was a need to examine ruminant feeds unsuitable for human food. The need of more efficient food production will increase significantly due to the global population growth. Novel feeds for ruminants could form a part of a sustainable food system because the use of grass solid fraction would intensify the use of natural resources. The use of wood-based products would release arable land for producing human food. Enhancing the efficiency of grassland management in Finland might help to answer many problems caused by climate change. Furthermore, the processing of grass based biomaterials would contribute to the overall benefits from grasslands. In the first experiment (Exp. I), grass silage was fractionated using a farm scale twin-screw press. Due to the separation of liquid fraction the concentration of both dry matter and neutral detergent fibre (NDF) increased whereas the crude protein concentration was reduced in the solid fraction compared to the unprocessed silage. In the feeding trial, solid fraction replaced 0, 0.25 or 0.5 of the portion of forage. The cows were able to increase their feed intake when the proportion of solid fraction increased to 0.25. However, at the point where the proportion of solid fraction reached 0.5 the cows could not increase feed intake further. The digestibility of crude protein decreased linearly whereas the digestibility of NDF tended to increase with the increase in the NDF content of the diet. The pH or the content of ammonia in the rumen fluid did not change when silage was replaced with the solid fraction. There was also no difference in the amount of total volatile fatty acids in the rumen fluid but the proportion of acetic acid increased with the increased proportion of solid fraction. Due to the increase in NDF content, the intake of metabolizable energy decreased quadratically and the amount of energy corrected milk tended to decrease. The separation process probably mechanically crushed the plant structure thus enhancing its rumen digestibility. This might explain the increase in feed intake and prevent the energy corrected milk production from declining when the portion of solid fraction was 0.25. In the second experiment (Exp. II), the effects of microcrystalline cellulose manufactured from coniferous wood pulp using a method developed at Aalto university (AaltoCell TM) was studied on dairy cows. In the feeding trial on lactating dairy cows MCC replaced barley in the concentrate. The proportion of MCC in diet dry matter was 0, 0.01 or 0.1. Microcrystalline cellulose has a very tight structure because the crystalline regions of the cellulose chains are strengthened by numerous inter- and intramolecular hydrogen bonds. The increase in MCC concentration did not affect dry matter intake. However, the digestibility of NDF improved with the increase in NDF content of the diet. Despite of increased intake of metabolizable energy, energy corrected milk production decreased linearly with the increase of MCC. The methods used in this study could not reveal the cause of the reduction in milk production. The increase in fibre digestibility can probably be explained by the better digestibility of MCC fibre compared to other fibres in the diet. Due to the small particle size of MCC, there is more surface area for microbial fermentation which may enhance the rumen digestibility. The cows were able to use the novel fibrous feeds examined in both experiments. The improvements in fibre digestibility compensated the increased fibre concentration in both experiments and there was only a minor reduction in milk production. The low concentration of crude protein in solid fraction improved the nitrogen use efficiency in milk production. The usage of MCC might also increase nitrogen use efficiency because it does not contain any nitrogen. The use of novel fibrous feeds in ruminant nutrition would help to enhance the use of natural resources and release arable land for human food production Grass cultivation as well as the usage of grass based biomaterials would be more efficient if the fractionation of grass would be more widely used.
  • Hakala, Kati P. (2020)
    Fungal disease late blight (Phytophthora infestans) causes considerable damage to potato crops worldwide. Fluazinam is a widely used pesticide employed against the late blight in potato cultivation. It ends up into soil during spraying and at the end of the growing season when potato foliage is incorporated into the soil. Nevertheless, there is very little literature about behaviour of fluazinam in soil, especially in the conditions that exist in Finland. Therefore, in the preparation of user guidelines, studies made elsewhere are used. From the environmental risks point of view, behaviour of fluazinam in Finnish conditions should be known better. Soils in the boreal zone are characterised by low pH and low temperatures that delay microbiological decomposition and they are typically high in organic matter and saturated by water for long periods in autumn, winter and spring. A prerequisite for assessing the environmental risk of fluazinam is knowledge of its sorption and desorption tendency as well as its degradation rate in boreal conditions. This information is needed, because more aggressive strains of Phytophthora infestans have spread to northern latitudes, increasing the need to use fungicides. In this study, a specific and repeatable high-performance liquid chromatography method utilizing a diode array detector was developed to determine the presence of fluazinam in soil. This method differs from most of the methods found in the literature, which used gas chromatography or gas chromatography-mass spectrometry as an instrument for analysing fluazinam. The method consists of acetonitrile extraction, clean-up with solid-phase extraction and separation using a mobile phase consisting of 70% acetonitrile and 30% water (v v-1), including 0.02% acetic acid. The method was successfully applied to various laboratory experiments and to soil samples collected from potato fields in which fluazinam had been used. In the systematic experiments carried out in controlled conditions, performed with both the fluazinam standard and the commercial product Shirlan®, the effect of soil organic matter on the fluazinam degradation was tested, as well as the persistence of fluazinam in the boreal zone soils for a maximum of one year. The major outcomes of the laboratory experiments were that fluazinam degradation was enhanced by the presence of soil organic matter and even after one year of incubation, more than half of the added fluazinam was recovered. Additionally, soil samples were collected from intensively cultivated potato fields. Over half of these field samples contained varying concentrations of fluazinam, but no substantial accumulation of fluazinam was detected.
  • Kinnarinen, Anneli (2019)
    Room attendants’ tasks at hotels consist of daily cleaning of the hotel guest rooms, making beds, handling materials, taking care of guest room facilities, and maintenance of the working areas. Surveys conducted (interviews and questionnaires) on hotel guestroom cleaning have shown that room attendants’ tasks involve a high amount of physical work, they work under time pressure and experience discomfort in different parts of the body. There were no objectively measured data available about the amount of the physical workload. The main objective of this case study research was to quantify the level of energetic workload in guest room cleaning. The second objective of the study was to discover the key features impacting on the room attendants’ physical work load. The field study was conducted at five hotels from same hotel chain. Aerobic capacity of the room attendants was assessed with a submaximal cycle ergometer test. Work operations throughout the work shift were video-taped with direct measuring of the heart rate (HR). Also physical conditions (°C, % RH) and number of steps taken were measured during the work operations. Perceived workload was assessed in these actual work situations on the Borg scale RPE (6–20). Load factors of the work system and working environment were discovered through group interviews. Furthermore, additional measurements were carried out in the working areas. Changes in working conditions and technology were identified 17 years afterwards by interviewing cleaning managers at those the hotels that still had an in-house cleaning organization. Room temperature exceeded the recommended limits for physical cleaning work. Functionality of the tools sometimes mismatched with the working environment. Heavy hotel trolleys, heavy textiles, lack of space to do the cleaning work, and furnishings and fittings of the guest rooms caused additional effort during the cleaning work. Work pace (rooms/hour) increased towards the end of the work shift. Approximately 23.4 (SD ±4.3) rooms were cleaned per work shift. Time spent on guest room cleaning cycles covered approximately 76.3% of an entire work shift. During guest room cleaning cycles, estimated oxygen consumption was approximately 35.5% VO2max and energy expenditure approximately over 270 W. In terms of heart rate response, over half of the whole work shift was moderate work and over one third heavy work for the women participating this study (age ≤ 45 years). Rating of perceived exertion (RPE) at the end of the workshift was almost at the same level as it was at the end of the submaximal cycle ergometer test (heavy work). The WHO (World Health Organization) has accepted the classification of work by its demand for energy (W·kg-1). According to this classification, room attendants’ workload is moderate for women aged 20–45 years. As a complement to the results, the foremen were also interviewed. Development in information technology, redesigned work procedures and the furnishings and fittings of the guest rooms have on the one hand lightened room attendants’ workload, but on the other hand the demand for output (rooms/hour) has increased. Notwithstanding its limitations, this study suggests that the results can be used to improve both the job design of hotel guest room cleaning and the space and interior design of hotel rooms, in order to decrease the physical workload and whole body work performed under time pressure. Space and interior planning has a major impact on creating possibilities for accessible cleaning and accessible housing, both at hotels and other companies or public institutions providing accommodation. However, lightening the work-load also increases both the speed of the work and the risk of work overload, especially in team work. Therefore, future research could be directed to re-assess the productivity norms used especially in service organizations so as to avoid unexpected outcomes.
  • Raisio, Juha (Helsingin yliopisto, 2016)
    The phenology and flowering of the pedunculate oak (Quercus robur L.) in Southern Finland was monitored during 1999-2006, in the Framnäs and Lenholm oak forests, which are mixed with hazels, birches, aspens, rowans, lindens, junipers, spruces, pines. Both stands are about 20 ha and located by the northern limit of natural distribution of oaks. The distance between the groves is about 60 km. A long-term pasture of about 150 years, on both islands has reduced the oak stands, however in recent decades selective cuttings have been made to help the oaks. In the south-western coastal areas degree days ranged from 1405,7 to 1737,7 d.d. in 1999-2006, indicating higher cumulating heat sums than on average over the normal period for the years 1981-2000. A total of 20 oaks × 3 branches /each tree sits in both stands, which equals 120 branches that were surveyed. The cork oak flowering model was modified to common oaks. Phases: 0-7 in male flowering were specified: from the dormant period (0) to swelling of the buds, from the onset of flowering to withering of the inflorescences (6). During the female flowering similar phases were found - from the rest period of apex buds (0) to the development of auxiliary buds on same year shoots. Further from the onset of first tiny female flowers to the withering of stigmas on the latest ones (6). The common oak flowering model was accurate enough and easy to apply in the survey. Male flowering began in 1999-2006 between 17th May and 6th June. Anthesis followed a few days later, when most of the staminate inflorescences had ripened. The catkins in the full length turned from green to bright yellow just before pollen release. Ripening was equal to phase 5 in the model of staminate flowering. Onset of the first female flowers began when the phase for stamens was about 3-4. Pollen receptivity of the first glossy reddish stigmas began when male flowering was about 5-5,5. The peak for female flowering took place a few days later than the anthesis, indicating protandry in common oak flowering. The period from pollination to fertilization is still a competition sequence for the pollen tubes. The stigmas, the developing female flower organs in gynoecium and the pollen tube cell tissue interact at the cell level. The self-incompatibility system acts on preventing selfing. Hence the loss of female flowers is huge, in some trees and in some years about 50% of the flowers fall down by the time of fertilization. Only 0-7,5% of the female flowers of the peak blossom period developed into acorns, which was less than in many other investigations. The suitable period for the common oak reproduction is very limited in the northernmost parts of its natural distribution. If the onset of the male flowering was delayed to early June, the number of female flowers was consequently low (years 1999, 2003, 2005). The detected linear regression is a topic for further studies. It remains unclear in this current scrutiny how the regulatory process acts on limiting the seed set and preventing extra ecological costs of any failing reproduction. In 2004-2006 a new potential pest, the black-dotted groundling, Stenolechia gemmella L. attacked the common oaks in many parts of Southern Finland. The moth larvae hollowed out new, same year shoots by length of few centimeters. Slightly afterwards shoots with their leaves and flowers turned brown. In July 2005 hundreds of withering shoots appeared in large oak crowns and of the monitored 1500 shoots in Framnäs 249 were infested by the moth larvae. Larvae and pupae are present in shoots in July, the adults emerge later in August or September.
  • Salo (os. Muurinen), Kirsti (Helsingin yliopisto, 2016)
    The history of Finnish school system has mutual interest with agricultural club established in USA in the beginning of 1900. Learning by doing was the motto for 4H-work and experiential learning was valued at school as well. The Evergreen Model of Environmental Education action plan describes the use of the outdoors as an expanded learning environment and to develop sustainability education at modern school. The model was initiated by a local 4H-association in collaboration with the local municipality and the schools. The intention according to the schools curricula and learning goals was to fulfill experiential learning out of doors and to realize a holistic vision of a sustainable learning environment. The development of the model started in 2003 with four pilot schools and by 2010 all 16 primary schools of the municipality were involved - from small village schools (32 96 students, grades 1 6) to large comprehensive schools (370 583 students, grades 1 9). Within seven years school gardens were built, active learning in nearby farms was conducted, and learning sessions were organized in the nearby forests and in special nature resorts. Research questions were: What were the reasons to start the collaboration to develop new methods and places for learning outdoors? How did the teachers experience garden activities and learning outdoors? What were hindrances and promoting factors for learning outdoors and gardening in school every day? The Evergreen Model of Environmental Education has shown positive results and could be at least partly applied in all schools. Action plans need to be developed depending on each school s own possibilities and surroundings. Schools possess limited resources and teachers need to feel starting a program and teaching outdoors is easy. Collaboration with specialists like farmers or gardeners is important while establishing outdoor education in addition to everyday school work. The size of a school was not a hindrance for outdoor learning but larger groups did require extra adults and more complex organizing efforts to have successful sessions.
  • Birge, Traci (Helsingin yliopisto, 2015)
    ABSTRACT Traditional rural biotopes are high nature value (HNV) farmlands that include grazed forests, woodlands, and semi-natural meadows formed through traditional agricultural practices. Agricultural intensification and associated changes in demographics and land use have resulted in a decline in traditional rural biotopes throughout Europe. Despite the downward trend, some farmers still do manage traditional rural biotopes. Literature in farmer behavior variously suggests that agency and structural factors determine farmer decision-making and conservation behavior, and that farmers engage in farming styles according to their own values. The objectives of this research are to 1) understand what motivates farmers and landowners to manage traditional rural biotopes, 2) test whether managers differ in motivation, knowledge or structural factors according to whether the traditional rural biotopes are used in the farming system or managed separately from it as conservation sites or landscape elements, and 3) explore conservation tools and frameworks that might be used to improve policy and agri-extension services for conservation and management of traditional rural biotopes. The purpose of this thesis is to provide support to traditional rural biotope conservation in agriculture by furthering knowledge about manager behavior and motivations and to add to the literature on farmer conservation behavior more broadly with management of traditional rural biotopes as a focus for understanding farmer conservation related decision-making. The thesis is based on a two-part study in which research was carried out via postal questionnaires and interviews with farmers in Raasepori Municipality, on the southern coast of Finland. In the first part of the study, I sent postal questionnaires to all farms in Raasepori to identify farms with managed traditional rural biotopes. I asked farmers about activities on their farms to determine whether farmers managing traditional rural biotopes differed from other farmers according to nature-based activities or entrepreneurship and to determine whether non-agricultural activities take place on traditional rural biotopes. I considered the results in the context of existing extension services and agri-environmental schemes and explored how holistic conservation tools and approaches, including adaptive management, and social-ecological systems could be used to improve services for farmers engaged in TRB management. In the second part of the study, I conducted in-depth semi-structured interviews with TRB managers to determine whether sites were managed as part of the farming system or apart from it, motivations for managing traditional rural biotopes, interest and knowledge of conservation of traditional rural biotopes and experiences with extension and inspection services. I tested whether managers who used traditional rural biotopes in their farming system differed from those who did not and examined farmer engagement in traditional rural biotope management according to two sociological theories used in studying farmer behavior: theory of planned behavior and farming styles. I also compare summary findings of management activities to an inventory carried out by Pykälä and Bonn (2000) and present evidence of non-agricultural direct-use benefits (direct use ecosystem services) provided by traditional rural biotopes. Results indicate that farmers mainly manage traditional rural biotopes for intrinsic values, especially of open landscape, and are less motivated by extrinsic values such as fodder production or collecting special agri-environmental subsidies. Farmers with managed traditional rural biotopes are more likely to engage in entrepreneurship activities that bring the public to their farms or result in branding of their products. Findings support the theory of planned behavior insofar as agency and personal values are important to decision-making. Managers of traditional rural biotopes do not form a distinct farming style, but a group of farmers was identified whose farming system is based on managing traditional rural biotopes and direct sale of the traditional rural biotope products, was identified as a distinct farming style. We called it TRB entrepreneurship . Implications of the findings for extension services and policy development are that farmers and landowners engaged in management should be viewed as partners in conservation and that adaptive management and understanding of manager heterogeneity should be used to develop and target extension services and conservation strategies.
  • Napola, Jaakko (Helsingin yliopisto, 2014)
    Tutkimuksessa selvitettiin kuusen itä- ja keskieurooppalaisten alkuperien menestymistä ja käyttömahdollisuuksia metsänviljelyssä Etelä-Suomessa. Tutkimuksen pääaineiston muodostivat 32 kuusen alkuperäkoetta, jotka Metsäntutkimuslaitos on perustanut vuosina 1959 87, sekä viisi muuta koeviljelystä, joissa on mukana ulkomaisia alkuperiä. Pääaineiston koeviljelykset sisältävät 149 ulkomaista alkuperää 16 maantieteelliseltä lähtöisyysalueelta. Alkuperät ryhmiteltiin alankoaineistoon (Baltia, Länsi-Venäjä, Valko-Venäjä ja Koillis-Puola) sekä vuoristoaineistoon (muiden muassa Böhmerwald, Sudeetit-Beskidit, Tatra ja Karpaatit). Kokeiden ikä oli mitattaessa 15 40 kasvukautta (keskimäärin 25 kasvukautta) istutuksesta. Eri koeviljelyksistä saadut tulokset muutettiin yhteismitallisiksi suhteuttamalla ne suomalaisten vertailuerien keskiarvoon. Tarkasteltuja kasvu- ja laatutunnuksia olivat pituus, rinnankorkeusläpimitta, rungon keskitilavuus ja puuston tilavuus sekä elävyys, poikaoksat ja korot. Korolla tarkoitetaan rungon kuoren halkeamaa tai muuta vaurioita, jossa on mustaa sienikasvustoa. Siemenen siirtomatkan eli leveys- ja pituusastesiirron sekä koepaikan lämpösumman vaikutusta elävyyteen, kasvuun ja rungon laatuun tutkittiin alankoaineistossa lineaarisen sekamallin avulla. Selitysasteet jäivät alhaisiksi. Korkein selitysaste oli poikaoksapuiden osuutta selittävällä mallilla, 38,7 prosenttia. Alankoaineistossa suhteellinen elävyys oli keskimäärin 97 prosenttia suomalaisten vertailuerien keskiarvosta (= 100) ja suhteellinen runkotilavuus 113 prosenttia. Koropuiden suhteellinen osuus oli alankoaineistossa 103 prosenttia ja poikaoksapuiden suhteellinen osuus 90 prosenttia. Käyttökelpoisin lähtöisyysalue metsänviljelyn kannalta on Viro. Virolaisia kuusialkuperiä voidaan viljellä Etelä-Suomessa alueilla, joiden lämpösumma on yli 1250 d.d. Länsi-Venäjän alkuperiä (Pihkova ja Novgorod) voidaan toistaiseksi suositella käytettäväksi vain etelärannikolla, koska sisämaassa ei ole näillä alkuperillä perustettuja koeviljelyksiä. Latvialaiset alkuperät menestyvät hyvin etelärannikolla ja paikoin sisämaassa, mutta niiden kasvatukseen liittyy kohonnut korovaurioiden riski. Valko-Venäjän ja Koillis-Puolan alkuperät ovat nopeakasvuisia, mutta korojen yleisyyden vuoksi niitä ei voida suositella käytettäväksi Suomessa. Keski-Euroopan vuoristoalkuperistä parhaiten menestyvät Böhmerwaldin, Tatran ja Karpaattien alkuperät. Näitäkään alkuperiä ei kuitenkaan voida suositella käytettäväksi Suomessa niiden kasvatukseen liittyvien riskien takia. Tutkimus vahvistaa oikeaksi nykyisen suosituksen, jonka mukaan Viron alkuperiä voidaan viljellä Suomessa Salpausselän eteläpuolella.
  • Uimonen, Sirpa (Helsingin yliopisto, 2011)
    The purpose of this study was to find out whether food-related lifestyle guides and explains product evaluations, specifically, consumer perceptions and choice evaluations of five different food product categories: lettuce, mincemeat, savoury sauce, goat cheese, and pudding. The opinions of consumers who shop in neighbourhood stores were considered most valuable. This study applies means-end chain (MEC) theory, according to which products are seen as means by which consumers attain meaningful goals. The food-related lifestyle (FRL) instrument was created to study lifestyles that reflect these goals. Further, this research has adopted the view that the FRL functions as a script which guides consumer behaviour. Two research methods were used in this study. The first was the laddering interview, the primary aim of which was to gather information for formulating the questionnaire of the main study. The survey consisted of two separate questionnaires. The first was the FRL questionnaire modified for this study. The aim of the other questionnaire was to determine the choice criteria for buying five different categories of food products. Before these analyses could be made, several data modifications were made following MEC analysis procedures. Beside forming FRL dimensions by counting sum-scores from the FRL statements, factor analysis was run in order to elicit latent factors underlying the dimensions. The lifestyle factors found were adventurous, conscientious, enthusiastic, snacking, moderate, and uninvolved lifestyles. The association analyses were done separately for each choice of product as well as for each attribute-consequence linkage with a non-parametric Mann-Whitney U test. The testing variables were FRL dimensions and the FRL lifestyle factors. In addition, the relation between the attribute-consequence linkages and the demographic variables were analysed. Results from this study showed that the choice of product is sequential, so that consumers first categorize products into groups based on specific criteria like health or convenience. It was attested that the food-related lifestyles function as a script in food choice and that the FRL instrument can be used to predict consumer buying behaviour. Certain lifestyles were associated with the choice of each product category. The actual product choice within a product category then appeared to be a different matter. In addition, this study proposes a modification to the FRL instrument. The positive towards advertising FRL dimension was modified to examine many kinds of information search including the internet, TV, magazines, and other people. This new dimension, which was designated as being open to additional information, proved to be very robust and reliable in finding differences in consumer choice behaviour. Active additional information search was linked to adventurous and snacking food-related lifestyles. The results of this study support the previous knowledge that consumers expect to get many benefits simultaneously when they buy food products. This study brought detailed information about the benefits sought, the combination of benefits differing between products and between respondents. Household economy, pleasure and quality were emphasized with the choice of lettuce. Quality was the most significant benefit in choosing mincemeat, but health related benefits were often evaluated as well. The dominant benefits linked to savoury sauce were household economic benefits, expected pleasurable experiences, and a lift in self-respect. The choice of goat cheese appeared not to be an economic decision, self-respect, pleasure, and quality being included in the choice criteria. In choosing pudding, the respondents considered the well-being of family members, and indulged their family members or themselves.
  • Heikkilä, Mari (Helsingin yliopisto, 2007)
    The chemical composition of breast milk has been studied in detail in the past decades. Hundreds of new antibacterial and antiviral components have been found. Several molecules have been found to promote the proper function of neonatal intestine. However, microbiological studies of breast milk have been, until recently, focused mainly on detecting harmful and pathogenic bacteria and viruses. Natural microbial diversity of human milk has not been widely studied before the work reported in this thesis. This is mainly because breast milk has traditionally been thought to be sterile - even if a certain amount of commensal bacteria have usually been detected in milk samples. The first part of this licentiate thesis contains a short literature review about the anatomy and physiology of breast feeding, human milk chemical and microbiological composition, mastitis, intestinal flora and bacteriocins. The second part reports on the experiments of the licentiate work, concentrating on the microbial diversity in the milk of healthy breast-feeding mothers, and the ability of these bacteria to produce antibacterial substances against pathogenic bacteria. The results indicate that human milk is a source of commensal bacteria for infant intestine. 509 random isolates from 40 breast milk samples were isolated and identified by 16S rRNA sequencing. Median bacterial count was about 600 colony forming units per milliliter. Over half of the isolates were staphylococci, and almost one third streptococci. The most common species were skin bacteria Staphylococcus epidermidis and oral bacteria Streptococcus salivarius and Streptococcus mitis. Lactic acid bacteria, identified as members of Lactobacillus-, Lactococcus- and Leuconostoc -genera, were found in five milk samples. Enterococci were found in three samples. A novel finding in this study is the capability of these commensal bacteria to inhibit the growth of pathogens. In 90 precent of the milk samples commensal bacteria inhibiting the growth of Staphylococcus aureus were found. In 40 precent of samples the colonies could block the growth completely. One fifth of the isolated Staph. epidermidis strains, half of Str. salivarius strains, and all lactic acid bacteria and enterococci could inhibit or block the growth of Staph. aureus. In further study also Listeria innocua- and Micrococcus luteus active isolates were found in 33 and 11 precent of milk samples (out of 140). Furthermore, two Lactococcus lactis isolates from the breast milk were shown to produce bacteriocin nisin, which is an antimicrobial molecule used as a food preservative. The importance of these human milk commensal bacteria in the development of newborn intestinal flora and immune system, as well as in preventing maternal breast infections, should be further explored.
  • Tall, Anna (University of Helsinki, 2007)
    Julkaisuja / Helsingin yliopisto, soveltavan biologian laitos ; 34
  • Harmanen, Heikki (University of Helsinki, 2007)
    Julkaisuja / Helsingin yliopisto, soveltavan biologian laitos ; 33