Browsing by department "Elintarvike- ja ympäristötieteiden laitos"

The present literature was reviewed to understand the recent indications of lipid degradation affecting β glucan molecular weight in aqueous solutions, the main topics being oat lipid reactions, oat β glucan, and oat bran/β glucan fortified yogurts, as well as the possible interplay of these three. A non-heat treated, a heat treated, and a heat treated and defatted oat bran concentrate (OBC) were produced, all with ~20% β glucan. OBCs were subjected to a storage trial in dark for 0–12 weeks at 4, 22 and 40 °C. Lipid degradation was followed during storage by assessing volatile compounds (HS-SPME-GC-MS), neutral lipid classes (NP-HPLC-ELSD) and tocopherol and tocotrienol levels (NP-HPLC-FLD) as well as β glucan molecular weights (HP-SEC). Acid milk gels were prepared as a model system for yogurts with added OBCs, and analysed for spontaneous and forced syneresis and textural changes. Lipid oxidation was observed in all OBCs, and hydrolysis in the non-heat treated OBC, but no changes in β glucan molecular weight were observed in the dry stored OBCs. OBC addition caused structural changes in an acid milk gels, the water retaining properties were improved, and the gels were softer and smoother than without added OBCs. Time and temperature affected OBC lipid oxidation and hydrolysis behaviours. Adding OBCs to gels changed gel textures compared to both without vs. with OBCs and adding fresh vs. stored OBCs.

The literature part of the study reviewed the recommended gluten quantification method, immunological ELISA R5. R5 is a monoclonal antibody that recognizes mainly the epitope that is abundant in especially gluten protein subgroup, ω-gliadin. The current PWG-gliadin reference material used in ELISA leads to inaccuracy of the gluten content, because it cannot represent sample materials that differ in their gliadin composition. The aim of the experimental study was to compare the prolamin compositions of different wheat cultivars and their reactivity against R5 antibody in sandwich ELISA. The aim was to find the most suitable ratio of barley prolamin, C-hordein, to be used as a reference material for wheat gluten quantification. The ω-gliadin proportions of different cultivars were calculated from RP-HPLC-chromatograms. In order to compare the total wheat gluten reactivity of the cultivars in ELISA R5 with gliadin standard and C-hordein in different ratios (10, 20 and 30% in BSA), Km-values that measure the rate of sensitivity in the assay, were calculated. The method to separate gliadin- and glutenin subgroups in RP-HPLC was optimized (solvent to extract gliadin and glutenin, temperature, injection volume, gradient). For cv. Crusoe the ω-, α/β- and γ-gliadins and HMW- and LMW-glutenins were identified. The selected wheat cultivars were categorized into four groups. The proportion of ω-gliadin in total gliadin ranged from 0.8 to 14.1% between the cultivars, whereas for PWG-gliadin this has been reported to be 7.7%. In terms of similar reactivity (Km-value) in ELISA, 20% C-hordein was found to be the most suitable reference material (Km 90) for the selected wheat cultivars (Km average 92), instead of the current gliadin standard (Km 68). The advantage of C-hordein standard is that the concentration and thus reactivity can be adjusted to match the sample materials with different prolamin profiles. Unlike with current gliadin reference material, it can be used without any conversion factors, which improves the method accuracy.

The current multidisciplinary interests on human intestinal microbiomes have stimulated large scale research initiatives, involving collection and processing of up to thousands of fecal samples within a single study. Hence, there is a need for high throughput protocols that are cost-efficient and validated for their performance to ensure that the relative abundance of different bacteria, the main outcome of microbiota studies, is not biased due to technical artefacts originating from sample processing. Infant’s microbiota colonization is one of the central research areas in human microbiome research because of the long-lasting and profound health implications of the pioneering microbes. This experimental study aimed to develop and validate a high throughput fecal sample collection and processing system for microbial DNA extraction operating in 96 well format. This newly developed method was used to extract DNA from 647 fecal samples collected from mother-infant pairs within a clinical study that will study the effect of antenatal antibiotic prophylaxis on infant’s gut microbiota development. A subset of 28 mother-infant pair samples (14 from each antibiotic and non-antibiotic groups) were selected to study the prevalence of a probiotic bacterium, Lactobacillus rhamnosus GG (LGG), among infants and their mothers longitudinally from birth to 3 months by using species-specific PCR amplification method targeting sortase C gene. In addition, the prevalence of L. rhamnosus GG in 3-month-old infants was compared between the above samples and those (n=30) collected in another clinical trial conducted ~10 years earlier. From extensive testing and validation, an efficient high throughput system for fecal sample collection and processing for extraction of microbial DNA in 96 well format was established. Tests were performed to validate the performance of a) fecal sample collection system b) commercial, readymade bead beating tubes for bacterial cell lysis and c) selfmade wash buffers as part of the automatic DNA purification system. Performance was evaluated based on the quality and quantity of the resultant DNA. We show that this new fecal processing system can yield high quality microbial DNA from 96 fecal samples within ~6 hrs. Based on the ratios of dominant gram-positive and gram-negative bacteria evaluated using PCRs and next generation sequencing, the new DNA extraction method resulted into similar microbiota composition than the previously validated manual DNA extraction method. However, the DNA yield per sample was markedly lower due to the lower input volume of the sample. Based on the sortase C gene PCR tests, the prevalence of LGG was similar (~60%) among 3-month-old children in both clinical studies conducted ~10 years apart, although false negatives among the recent samples due to the low amount of DNA cannot be excluded. Following the temporal pattern of colonization, we observed no evidence for the transfer of LGG at the time of birth from the mother to her child, instead the infants became positive for LGG typically between 1-3 weeks after birth. The carriage of LGG seemed to be dependent on their diet. During this project, we found out that the PCR method employed for detection of LGG was not fully specific for this strain, and hence a more specific qPCR assay was developed.

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.

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.

Introduction: The importance of good nutrition is not always recognized among athletes and their coaches. Young athletes need professional guidance, so they can learn how to execute dietary practices that support their athletic performance and overall well-being. The growing body of scientific evidence on performance enhancing nutrition and its practical applications challenges the Finnish field of competitive sports to invest in professional nutrition coaching among athletes. Aims of the study: The aim of this study was to examine, if eating habits of young endurance athletes can be influenced by a nutrition intervention carried out using a mobile application (MealLoggerTM) with an inbuilt nutrition program. We also examined, whether the motivation towards sports and nutrition and the perceived competence for following a certain diet are related to athletes’ adherence to the nutrition program and to the measured changes in food intake. Materials and methods: 17 young individual endurance athletes followed through a four-week nutrition intervention by keeping a photo food journal and logging their food servings with the smart phone application MealLoggerTM. A common application inbuilt nutrition program with servings goals for different food groups was designed in advance and implemented after a group education session on optimal sports nutrition. During the intervention period, the participants received real-time feedback from the mobile application on their adherence to the nutrition program. In addition, individualized meal photo comments were provided by a nutritionist three times a week. The athletes also received common weekly motivational messages through the application. Food intake was measured at baseline, after the intervention and 8-weeks after the intervention using food frequency questionnaire (FFQ). The motivation and perceived competence were assessed with Self-Determination theory (SDT) questionnaires. The adherence to the nutrition program was assessed by comparing the logged food servings to the defined nutrition goals. Results: Twelve participants (71%) completed the post-intervention questionnaires. No statistically significant changes in consumption of food groups included in the nutrition program were detected. The consumption of berries increased 2,36 times per week (SD 4,07 p=0,049). The consumption of skimmed milk decreased 3,00 times per week (SD 4,28, p=0,042) and the consumption of milk/alternatives in total decreased 3,67 times per week (SD 5,82, p=0,034). MealLoggerTM data was retrieved from 15 participants. Most of the participants (n=8) with high adherence (H) achieved at least 3 out of 4 goals on every week. Most participants (n=7) with low adherence (L) failed to achieve any of the nutrition goals on any of the four weeks. No statistically significant differences in motivation or perceived competence were found between the H and L. The overall engagement to the mobile application was lower in L compared to H. The participants in L were mostly female, significantly younger and more likely to be living with a guardian, responsible for the acquisition and preparation of food. Discussion: Despite detecting only small dietary improvements, the application showed good feasibility and acceptability among the high adherence participants. In the future, to provide more effective nutrition coaching an appropriate baseline assessment should be included. The goals of the nutrition program should be adjusted according to the athletes’ individual needs. More democratic coaching styles, with parental involvement should be explored in order to increase engagement and adherence of young athletes.

Johdanto: Ikääntyessä iholla tapahtuva D-vitamiininmuodostus heikkenee ja lihakset ja luusto haurastuvat. Heikko lihaskunto on yhteydessä kaatumisriskiin, ja kaatuminen on yleisin syy vanhusten murtumiin. Monissa tutkimuksissa on osoitettu, että luustovaikutustensa lisäksi D-vitamiinilla on vaikutuksia luurankolihakseen. D-vitamiinihoidon on osoitettu vähentävän kaatumisia, mikä saattaa osin selittyä parantuneen tasapainon kautta. Joissakin tutkimuksissa on havaittu heikko tilastollinen yhteys Dvitamiinin ja kroonisen kivun välillä. D-vitamiinin puutokseen liitettyjä kipuja on esitetty luustoperäisiksi, mutta D-vitamiinin lihasvaikutukset huomioiden ne saattavat olla ainakin osin lihasperäisiä. Tavoitteet: Tämän poikkileikkaustutkimuksen tavoitteena oli tutkia, onko seerumin 25-hydroksi-Dvitamiinipitoisuus (25OHD) yhteydessä lihastoimintoihin itsenäisesti kotona asuvilla reumatauteja sairastavilla yli 50-vuotiailla. Hypoteesina oli, että D-vitamiinin puutos on yhteydessä heikentyneisiin neuromuskulaarisiin lihastoimintoihin, joita tässä tutkimuksessa mitattiin tasapainon perusteella. Aineisto ja menetelmät: Tutkimukseen rekrytoitiin yli 50-vuotiaita, koska tässä kohderyhmässä lihastoimintojen heikentymisen ja D-vitamiinin puutoksen odotettiin olevan yleisiä. Tutkittavien tuli kuitenkin olla kohtalaisen hyväkuntoisia, jotta he jaksaisivat fyysiset testit ja tutkimuksen mahdollisesti aiheuttaman henkisen rasituksen. Siksi lihastoimintojen ongelmia kuvaamaan valittiin polymyalgia rheumaticaa sairastavia, itsenäisesti kotona asuvia ihmisiä. Tutkimukseen osallistui myös joitakin yli 50- vuotiaita fibromyalgiaa ja nivelreumaa sairastavia henkilöitä. Seerumin 25OHD-pitoisuus määritettiin EIA-menetelmällä (IDS, UK). D-vitamiinin yhteyttä tutkittiin tasapainoon (Rombergin vakio tasapainolevyllä) ja lihasvoimaan (puristusvoima molempien käsien parhaan tuloksen keskiarvona, jalkojen nopeusvoima hyppylevyllä), kipuun ja toimintakykyyn. Tilastomenetelminä käytettiin ristiintaulukointia, t-testiä, lineaarista regressiota, logistista regressiota ja Pearsonin korrelaatiota. Tulokset: Tutkimukseen osallistui 47 henkilöä, joista viisi oli miehiä. Potilaat olivat 53-81 -vuotiaita (keski-ikä 70 v) ja hieman ylipainoisia (BMI 28). 25OHD oli keskimäärin 64 nmol/l. Ravitsemustila oli keskimäärin hyvä (MNA-pisteet 24). 25OHD oli alle 50 nmol/l 32 %:lla ja vastaavasti alle 75 nmol/l 74 %:lla tutkittavista. Potilaista 83 % käytti D-vitamiinivalmistetta. 25OHD korreloi positiivisesti ravitsemustilan (MNA) ja käänteisesti tasapainon ja kiputiheyden kanssa. 25OHD, ikä, sukupuoli ja MNA-pisteet selittivät 13,9 % (adjusted r2) huojunnan vaihtelusta ja 14,5 % (r2 Cox & Snell) kiputiheyden vaihtelusta. Ainoastaan 25OHD-pitoisuudella oli tilastollisesti merkitsevä itsenäinen selitysosuus huojuntaan (p = 0,024) ja kiputiheyteen (p = 0,045). Niillä, joilla 25OHD oli vähintään 75 nmol/l, oli 83 % pienempi riski kärsiä päivittäisestä kivusta kuin niillä, joilla 25OHD-pitoisuus oli alle 75 nmol/l. Lihasvoimalla, lihasmassalla ja kivun voimakkuudella ei havaittu yhteyttä D-vitamiinistatukseen. Johtopäätökset: Tässä tutkimuksessa reumatauteja sairastavien yli 50-vuotiaiden potilaiden matalat 25OHD-pitoisuudet olivat yhteydessä tasapainovaikeuksiin ja päivittäisiin kipuihin. Lihasmassa ja lihasvoima eivät olleet yhteydessä D-vitamiinistatukseen. Löydösten pohjalta olisi tulevaisuudessa tarpeen tutkia tarkemmin D-vitamiinikorvaushoidon vaikutuksia tasapainomittareihin ja kiputiheyteen.

Amaranth, quinoa, kañiwa and lupine are good sources of protein, fat, dietary fibre and bioactive compounds. The literature review deals with the nutritional properties and the stability of bioactive compounds and the effect of extrusion cooking on amaranth, quinoa, kañiwa and lupine. The main aim of this study was to (1) chemically characterize amaranth, quinoa, kañiwa and lupine, and (2) to determine the effect of extrusion cooking on the nutritional properties and the stability of bioactive compounds. Extrudates were processed using twin screw extruder at two different extrusion temperatures (140 and 160 °C) containing two different contents of tested flour mixtures (20 and 50%). The raw materials and the extrudates were stored at -18 °C and chemically characterized to determine fatty acid composition, tocopherol composition and total phenolic acid content. Fatty acid composition was determined using GC while tocopherol composition was detected using HPLC. The total phenolic acid content was analyzed using Folin-Ciocalteu method. The protein and dietary fibre content in lupine accounted for 29 and 50 g/100 g d.m., respectively. The extrudates containing 50% lupine and processed at 140 °C possessed higher content of oleic, linoleic and linolenic fatty acids. At higher content of tested flours, extrusion cooking at 160 °C resulted in better retention of unsaturated fatty acids in the extrudates of amaranth, kañiwa and quinoa. Higher extrusion temperatures resulted in lower retention of tocopherols in all the extrudates. The total phenolic acid resulted in higher contents in the extrudates of kañiwa when compared to other extrudates. At higher seed contents of tested flours (%), higher retention of total phenolic acid was achieved during extrusion cooking at 140 °C in the extrudates of amaranth, quinoa and kañiwa. This study showed that extrusion conditions could be optimized in order to obtain lesser effects on the nutritional properties and better retention of bioactive compounds. The research study provides supportive information for obtaining gluten-free cereal snack products with lower glycemic index.

The aim of this project was to study the physical and chemical changes in the myofibrillar protein fraction during low-temperature long-time (LTLT) heat treatment of pork, in relation to cathepsin activity and evolution of tenderness. Porcine Longissimus dorsi muscles were cut, vacuum packaged and cooked in water baths at 53, 58, 63, 68 and 73°C. The process was monitored at: 1, 8 and 24h. Allo-Kramer shear force (AKSF), residual activity of cathepsin B+L, surface hydrophobicity (SH) and particle size of myofibrils were measured. Results showed that toughness decreased markedly between 53°C and 63°C and later increased to 73°C. Toughness also decreased with time. Myofibrillar SH, increased with temperature, but not with time, indicating aggregation and/or gelation. Treatments with low AKSF had smaller particles, suggesting that meat was easier to break, both macroscopically and microscopically. The high associated catheptic activity could be the reason for the weakening of myofibrils. They also might be able to prevent their aggregation and transition into a hard compact gel. As temperature increases, denaturation-aggregation-gelation overcomes proteolysis and bigger particles were detected. In conclusion, LTLT sous-vide cooking (53 and 63°C) allows the control of short term changes in myofibrils (so they do not toughen) and permits the slow ones (proteolysis) to decrease toughness of prime cuts.

Oats are a good source of protein and dietary fibre, especially ?-glucan. Due to the health benefits of ?-glucan, oats have gained popularity in snack food formulations. The literature review deals with oats and its components, removal of lipids and fractionation of oat products. The particular emphasis of the literature review was given to studies on the effects of different oat fractions and extrusion process variables on the properties of oat-containing extrudates. The aim of this study was to find out how different oat fractions and extrusion process variables (screw speed, water content and feed rate) affect the physical and chemical properties of the extrudates. The measured physical properties were expansion, hardness and water content. Extrusion trials were carried out by using defatted oat endosperm flour (EF) as the main ingredient. Whole grain oat flour (WF) was used as a reference. To improve the nutritional quality, defatted oat protein concentrate (PC) and defatted oat bran concentrate (OBC) were added to EF. The oat fractions were defatted by supercritical carbon dioxide (SC-CO2). Pregelatinised corn starch (CS) and waxy corn starch (WS) were added in some trials to increase the expansion of the extrudates. A co-rotating twin-screw extruder was used for the extrusion. Different process variables were: water content of the mass (16, 18 and 20%), screw speed (240, 370 and 500 rpm) and feed rate (68, 76 and 84 g/min). The temperature profile of the extruder barrel was held constant in all of the trials: 40, 70, 70, 100, 110, 130 and 130 °C (sections 1 6 and die). Screw speed had significant effect on the expansion and hardness. Expansion increased and hardness decreased with increasing screw speed. Water content of the mass affected all the response variables in WF extrudates and all but not hardness and torque in EF extrudates. Increased water content of mass decreased the expansion and hardness in WF extrudates. Feed rate did not have significant effect on the physical properties. When using EF, more expanded and less hard extrudates compared to the WF were obtained. Addition of PC or OBC (10%) decreased the expansion and increased the hardness. Mixing of EF with corn starch (CS or WS; 30%) gave less hard and more expanded extrudates compared to pure EF. The highest expansion was achieved by the addition of WS. Even addition of OBC (20%) in a presence of WS (30%) gave highly expanded and less hard extrudates with high ?-glucan content 7.4% (dry weight). Decreasing the particle size of OBC (by ultra-fine milling) or the molecular weight of ?-glucan (by enzymatic hydrolysis) did not affect the physical properties of the extrudates even though small decrease in hardness was observed in the trial with enzyme-hydrolysed OBC. The results showed that defatted oat fractions can successfully be used in extrusion when mixed with corn starch. Screw speed had the most profound effect on the physical properties of the oat-containing extrudates followed by the water content of mass.