Browsing by Title

Non-communicable diseases such as cardiovascular diseases (CVDs) and erosive, unsustainable industrial fat-production methods pose two of the biggest threats to human health in great part of our planet. CVDs and obesity have been linked to diets high in fat and low in dietary fibre, pushing food manufacturers to adapt to more sustainable ingredients. For this reason, this research developed and researched about a new and sustainable plant-based oleogel intended to act as a substitute for saturated and hydrogenated fats. Its characterization was conducted through several techniques, including optical and field emission electron scanning microscopy, differential scanning calorimetry, Fourier transmission infrared spectroscopy, and synchrotron X-ray powder diffraction. The results showed that the build-up of the formation of the new oleogel was possible, while ensuring that both processing requirements and ingredients are readily available at food manufacturing plants, globally. These findings pose a great opportunity for plant-based fat-replacement formulations, through a sustainable approach. Considering previous studies, this novel system could potentially help in reducing the burden of obesity and CVDs, turning it into a functional food component. Further research on food applications and digestibility models could give more insight on the future applications of this fat-replacement system.

The literature review focused on the chemical properties of Fusarium mycotoxins and their masked forms, analytical methods for their determination and the toxicological and legislative aspects. In the experimental study, a multi-method was developed and validated for the simultaneous quantification of several Fusarium toxins and their masked forms in barley, oats and wheat using liquid chromatography-tandem mass spectrometry (LC-MS/MS) technique. The simple “dilute-and-shoot” sample preparation procedure was applied, where the extraction was performed with a mixture of acetonitrile, water and acetic acid (79:20:1, v/v/v). Moreover, the aim was to obtain new data on the occurrence of the masked mycotoxins in barley, oats and wheat by analysing 95 cereal grain samples. The type A trichothecenes T-2 and HT-2 toxins (T-2 and HT-2) and the type B trichothecenes deoxynivalenol (DON) and nivalenol (NIV) as well as zearalenone (ZEN), together with 11 masked forms of them, were included based on their importance for the food safety in northern Europe. The analytes were separated on a reversed-phase column and detected in selected reaction monitoring (SRM) mode. Better peak shapes for the early eluting compounds and shorter analysis time were obtained with acetonitrile than methanol as the organic phase, thus it was chosen for the method. The method was validated according to the criteria set in the legislation. The limits of quantification varied from 0.3 to 15.9 ?g/kg. The recoveries were 92?115%, thus being within the tolerable ranges established in the legislation. The inter-day precisions (4?27%) were under the maximum permissible values. Therefore, the method proved to fit for the purpose. In this study, occurrence data on the masked mycotoxins in Finland were obtained for the first time. The presence of ZEN-16-glucoside (ZEN-16-G) and NIV-3-glucoside (NIV-3-G) were reported for the first time worldwide in some of the cereals. The most frequently found toxins were DON, NIV and HT-2. All of the masked mycotoxins included in the method were determined, the most common being DON-3-glucoside (DON-3-G), HT-2-glucoside (HT-2-G) and NIV-3-G.

The purpose of this thesis was to design, build and test a system, which is capable of measuring in real time simple quantities influencing on tire-soil contact of agricultural tractors mobility. The measuring equipment is based on acceleration and distance sensors connected to the Arduino Uno microcontroller. The tractor’s CAN bus was logged and the data was saved using a CAN bus card connected to a Raspberry Pi minicomputer. The sensors were calibrated, and their sensitivity checked before performing the experiments while driving in the field. Accelerometers were placed on top of the rear axle of the tractor at both ends in housings printed for them and distance sensors were mounted behind the rear axle. All sensors were logged by using Raspberry's Raspbian operating system with a python program. The Raspberry was chosen as a computer because of its demanding low space, low cost, and versatility of interfaces. The properties of the field were monitored by monthly penetrometer measurements as well as SoilScout sensors embedded in the ground, which indicated the moisture and temperature of the ground at that depth in real time. The purpose of this was to find out the changes in the field during the growing season, which would also affect the tractor's mobility. The measurement were carried out successfully and the result were considered to be reliable and provide many other opportunities for the future. The results clearly indicated the factors influencing the tractor’s mobility and the different stages of the tillage could be recognized. Future challenges remain the filtering of large amounts of data and the application of measuring equipment in further research. The measurement equipment developed in the work is well suited for its purpose in terms of measurement accuracy and economical affordability. In the future, better accuracy could be achieved with more accurate measuring devices as well as data obtained from this work.

Finland is the northernmost cultivation area in the world and the selection of forage grass species is mostly limited by long winters and short growing seasons. Forage grasses are usually grown as mixtures of species and produced intensively for silage. The grass species most commonly used in mixtures are timothy (Phleum pratense L.) and meadow fescue (Festuca pratensis L.) which are both winter hardy species. As the climate changes in the future, more southern and more productive species like perennial ryegrass (Lolium perenne L.) and festulolium (Festuca sp. x Lolium sp.) may become more usable. The duration of snow cover has been predicted to shorten to 46 days in southern Finland by year 2050 (compared with 98 days at present). The autumns, when plants develop their tolerance against winter stresses, are also predicted to become warmer in the future. Changes in winter weather may also increase the frequency of problems such as plant exposure to freezing temperatures, associated with decreased snow cover and ice encasement due to fluctuating winter temperatures. This study presents the results of experiments carried out in Helsinki (Finland) between years 2009–2013. The experiments were done to assess the freezing tolerances and vernalisation of forage grasses and cereals hardened under field conditions. The vernalisation of plants was detected in all species as a decrease in days to heading during the vernalisation period. Perennial ryegrass and meadow fescue started flowering after the vernalisation was fulfilled during December-January. Winter cereals had already vernalised already in November. Hardening periods started at their earliest in the beginning of October. However, a deeper freezing tolerance developed during December in 2009–2010 and 2011–2012. During the winters of 2009–2010 and 2011–2012 hardening periods were long and hardening-induced temperature sums were the highest. During these winters the freezing tolerances were better in all species than during the other two winters.

Chemical composition of oats and its suitability for baking were reviewed in the literature part. The special features of baking without gluten and possibilities to increase the quality of gluten-free bread were also discussed. The aim of the experimental research was to develop high protein gluten-free oat-based bread. The effect of different protein concentration on structural, textural and sensory properties of gluten-free oat bread was studied. Also the effect of processing method on bread quality was studied by using sourdough technology and straight dough technology. Gluten-free oat bread recipe and baking protocol as well as sourdough fermentation conditions were optimized on the basis of preliminary trials. Oat-based breads with varying protein content were baked by using straight dough and sourdough technologies. Reference sample was oat-based bread without added protein. Specific volume, moisture content, texture profile analysis (crumb hardness, chewiness and resilience) and starch retrogradation of gluten-free breads were analysed. For shelf life measurements, breads were stored in plastic bags at room temperature from 1 to 3 days. Sensory profile of bread samples were evaluated on the day of baking by a trained panel. Descriptive analysis method was used. Palatable high protein gluten-free oat-based bread was obtained in this study. Increasing amount of protein improved the crumb structure and shelf life of gluten-free breads. All of the protein supplemented breads had agreeable sensory profile. Sourdough did not further improve the quality of high protein gluten-free bread except for increased aroma intensity. Oats and its fractions can be successfully applied as an ingredient for gluten-free baking to enhance the nutritional quality.

Lactobacilli especially Limosilactobacillus reuteri’s strains inhabit the GI tract of humans with glycerol/diol dehydratase activity metabolizing glycerol and producing a broad-spectrum antimicrobial system called reuterin. It consists of 3-hydroxypropanal (3-HPA), acrolein, and its derivatives. Due to the toxic activity of ubiquitous acrolein, an analytical toolbox to determine acrolein formation by food cultures is needed. We developed assays to estimate microbial formation of acrolein using a colorimetric method based on tryptophan and a fluorescence-based approach with 2-amino-1-methyl benzimidazole (AMBI) as a probe. We compared tryptophan and AMBI-based quantification of reuterin produced by resting cells or during the growth of Lb. reuteri DSM 20016. With 600 mM glycerol, resting cells produced 329 ± 35 mM 3-HPA as quantified by HPLC-RI, and 390 ± 13 mM of 3-HPA/acrolein based on the colorimetric method with 3-HPA as standard. Acrolein (40 ± 11 mM) was detected using an AMBI probe. We also detected 3-HPA and acrolein formation during the exponential growth phase in the presence of 50 mM glycerol in different media. Also, as acrolein induces redox stress, redox potential and sensitivity to reuterin/acrolein of the engineered green fluorescence protein (roGFP2) were determined. Ultimately, the roGFP2 gene was tried to clone in E. coli (JM109) using the pTH1mp constitutive expression vector to establish as a biosensor for acrolein detection. Our results suggest that quantification of acrolein by fluorescence-based approaches and biosensors constitute novel methods to estimate any risk of acrolein formation in presence of glycerol/diol dehydratase-positive microbes and glycerol during food fermentation.

Selective degeneration and dysregulation of specific neuronal populations is a common hallmark shared by neurodegenerative diseases affecting the aging population. Parkinson’s disease (PD) is one of the most prevalent neurodegenerative diseases with debilitating clinical manifestations that follow a chronic and progressive course. Pathological hallmarks of PD involve gradual and specific loss of DA (DA) neurons and widespread presence of Lewy body (LB) inclusions that consist of aggregated presynaptic protein, α-Synuclein (αSyn). Treatment of PD remains to be at symptomatic management as the underlying mechanisms that trigger neurodegeneration are still not fully elucidated. Over the past two decades, microRNAs (miRNAs) have become a major area of interest within biomedical fields and gained increasing momentum in the context of neurodegenerative diseases. In recent developments, changes in mature miRNA profiles have been reported in aging tissue and many age-related diseases, including PD. More recently, a number of studies have found that the most essential enzyme in the miRNA biogenesis pathway, Dicer, exhibits reduced expression with aging. To these ends, a genetic mouse model based on heterozygous knockout of Dicer (DicerHET) was introduced to simulate Dicer downregulation. Initial investigations identified the DicerHET model as a promising tool for studying the relationship between disrupted miRNA biogenesis and neurodegeneration associated with PD. To facilitate future investigations and speed up screening of potential therapeutic compounds using this genetic model, in the current work, we aimed to produce a DicerHET in vitro model with a practical and convenient genetic engineering approach. The main focus of this work was to validate the model and establish a standardized reproducible approach suitable for research that addresses the role of miRNA biogenesis in PD. The desired DicerHET genotype was generated in vitro by employing traditional Cre/loxP system in conjunction with a virally mediated Cre expression. More specifically, primary cortical cultures, derived from Dicer flox/+ mice embryos, were transduced with Cre expressing lentiviral vectors (lenti-hSYN-T2A-Cre) to delete the “floxed” Dicer allele. To establish optimal parameters for the procedure, we analysed recombination efficiency under different transduction conditions. The most efficient recombination was achieved after 5 days of induction in cultures. However, we observed that DicerHET genotype did not attenuate survival of the cells, as assessed by immunohistochemistry. Further, as a proof of concept, we exposed the DicerHET cultures to pre-formed fibrils (PFFs) - a PD related stressor that causes αSyn aggregation. pSer129-αSyn-positive LB-like aggregates were detected in all the PFF-treated cultures, however, with a greater accumulation in the DicerHET cultures. Interestingly, increased aggregation was not accompanied by increased cell death, suggesting that DicerHET genotype does not increase vulnerability of cortical neurons to pSer129-αSyn aggregation. Based on our earlier studies we presume that DA neurons may bear a specific vulnerability towards the age-related Dicer depletion. More conclusive evidence on this intriguing relationship could be provided in future research using the DicerHET model that can be readily applied to primary DA cultures.

Dietamoeba fragilis is a very common human intestinal parasite in the world and also in Finland. D. fragilis causes dientamoebiasis in humans, and symptoms of infection may vary from mild bowel symptoms to prolonged diarrhoea and weight loss. Some of the infected patients are completely asymptomatic. Despite its prevalence, insufficient data exist on the life cycle and host organisms of D. fragilis. Interestingly, D. fragilis has been found in dogs in a few studies. Thus, more research is needed on the role of household pets as part of the parasite’s life cycle and choice of host organism. Comprehensive study on the role of dogs in the life cycle of D. fragilis is warranted. The purpose of this thesis was to design a study on the role of dogs in the D. fragilis parasite life cycle “The presence of Dientamoeba fragilis parasites and multiresistant ESBL-bacteria in dog owners and their pets”, to present research methods and to apply research permit from the ethics committee. The aim of the study is to analyze the prevalence of D. fragilis in dogs in Finland and the role of the dog in the spread of D. fragilis parasite within humans. In addition to D. fragilis, the study combines collection of samples for ESBL bacteria analyses, but this thesis focuses only on the part of study D. fragilis. Two different real-time PCR methods are tested in this project: an in-house method and an Amplidiag® Stool Parasites method, out of which Amplidiag® Stool Parasites method is selected to be used in the study. In the thesis documents for the ethics committee's referral are written and ethical permit to conduct the study from the HUS ethics committee is applied. A favourable opinion will allow a comprehensive study of dogs and humans to be carried out. Ethics permit is need to recruit participants for research on the basis of a laboratory-confirmed D. fragilis -discovery. The committee confirms that the study is ethically acceptable. During the thesis project, the committee gave the study a conditional favourable decision. The implementation of the study will start in the spring of 2023, when the final assent is received.

Background: Cancer is the leading cause of death worldwide, claiming 7.6 million lives a year. Five behavioural factors have been recognised to be responsible for 30 % of the disease burden. Among them is low fruit and vegetable consumption. Fruit and vegetable consumption has been inversely associated with cancer risk but the mechanisms behind this effect are still largely debated. Dietary antioxidants present in large quantities in plant foods have been hypothesised to contribute to this protection. Objective: The aim of this study was to investigate the relationship between dietary total antioxidant capacity (TAC) and overall cancer incidence. This was done applying a new antioxidant measurement that reflects the whole set of direct antioxidant reducers (vitamin C, alpha-tocopherol, carotenoids and flavonoids) present in diet. The average TAC intake levels of the participants were assessed and the main dietary contributors to the TAC scores were examined. Subjects: Study subjects included 67 634 middle aged French women participating in an on-going prospective cohort study called E3N. Their dietary assessment was made between June 1993 and July 1995 using a semi-quantitative food frequency questionnaire able to quantitatively and qualitatively assess the average daily intake of 208 different foods, recipes and beverages. Cancer cases were self-reported and validated against medical records. The follow up of the participants ended in May 2008. Methods: Four different total antioxidant capacity scores were created using two different TAC methods, the ferric reducing ability parameter (FRAP) and the total radical-trapping antioxidant parameter (TRAP), and including or excluding coffee from the dietary TAC calculation. Coffee exclusion was justified with the fact that it is the largest contributor to the dietary TAC intake, and because of its association with some negative lifestyle behaviours, it can act as a confounder even if adjustments are made. Statistical analyses for cancer risk according to dietary TAC intake were made using Cox proportional hazards model adjusting for energy intake without alcohol, tobacco smoking, alcohol intake, BMI, physical activity level, educational background, region of residence and family history of cancer. Results: When coffee was included in the dietary TAC scores a significant but modest increase in cancer risk was observed towards higher TAC intakes (p for trend < 0.05 for both FRAP and TRAP). On the contrary, when coffee was excluded from the TAC scores a significant although modest decrease in overall cancer risk was observed (p for trend = 0.016 for both FRAP and TRAP without coffee). In the indexes where coffee was included in the score it contributed up to 43 % and 76 % of total FRAP and TRAP scores respectively. After coffee the main contributors to dietary TAC intake were tea, wine, fruits, vegetables, fruit juice and chocolate. The mean daily intake of TAC was 20.5 mmol of FRAP and 20.2 TE of TRAP in the scores including coffee. When coffee was excluded from the scores, the mean intake levels dropped to 9.4 mmol and 4.9 TE. Conclusion: Dietary total antioxidant capacity was associated with a statistically significant but modest decrease in cancer incidence when intake of coffee, the main TAC source, was not taken into account. Coffee seems to be acting as a confounding factor since when it was included in the TAC scores, there was a small but statistically significant positive association with cancer risk. For future studies it would be crucial to standardise the TAC methods so that comparisons between studies could be made. On the other hand in vitro nature of the TAC methods should be kept in mind; a fact that challenges the interpretation of the results from the biological perspective.

Onion (Allium cepa L.) is an important vegetable, which provides major nutritional benefits. In Finland, basal rot caused by Fusarium fungal species (FBR) has become the most destructive disease of onion in recent years. It causes damping off and stunted growth on onion seedlings and root death and abscission and bulb rot on mature onions. The average onion crop loss caused by basal rot has been up to 10% in conventional farming and as high as 30% in organic farming. In this study, a seedling assay was conducted to test the virulence of different Fusarium isolates on a commercial onion cultivar. The study goals were, primarily, to find out which of the Fusarium isolates, originating from onion and crop rotation plants grown in Finland, are pathogenic, and secondly, to compare the virulence of different isolates. Altogether 115 Fusarium isolates were tested for virulence on onion seedlings in a greenhouse. Fifty-five of the tested isolates of F. oxysporum, F. proliferatum and F. redolens were more or less virulent. 19.4% of F. oxysporum isolates, 35.3% of F. proliferatum isolates and 18.2% of F. redolens isolates showed high virulence. Among the aggressive pathogens isolated from onion samples, F. oxysporum f.sp. cepae is still the dominant onion pathogen, F. proliferatum is a new pathogen on onion in Finland, and relatively more aggressive than F. oxysporum. The F. solani and F. tricinctum isolates tested did not have any detrimental effects on the onion seedling health or growth. In order to control FBR in Finland, avoiding planting onion in the infested soils, growing onions from local seedlings to avoid new contamination and storing onions at cold temperatures are recommended.