Browsing by Subject "dietary fibre"
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(2022)The current definition for dietary fibre was adopted by the Codex Alimentarius Commission (CAC) in 2009, but implementation still requires updating food composition databases with values based on appropriate analysis methods. The Finnish National Food Composition Database Fineli is among the first to be updated with CODEX-compliant values of total dietary fibre (TDF), insoluble dietary fibre (IDF), dietary fibre soluble in water but precipitated in 78 % aqueous ethanol (SDFP) and dietary fibre soluble in water and not precipitated in 78 % aqueous ethanol (SDFS). Previous data on population intakes of dietary fibre fractions is sparse. The aim of this study was to assess intakes and sources of dietary fibre and dietary fibre fractions in Finnish children based on updated values of the national food composition database Fineli. In addition, associations of sociodemographic factors with energy adjusted total dietary fibre intake were assessed. Our sample included 5206 children at increased genetic risk of type 1 diabetes from the Type 1 Diabetes Prediction and Prevention birth-cohort, born between 1996 and 2004. We assessed the intakes and sources based on 3-day food records collected at the ages of 6 months, 1, 3, and 6 years. Associations of child’s age, sex, breastfeeding status and sociodemographic factors were assessed with independent samples t-test, Mann-Whitney U-test, and univariate analysis of variance. Food sources of dietary fibre were assessed with source analysis. Older children and boys had higher intakes of absolute dietary fibre. The highest energy-adjusted intake of TDF was however observed in 1-year-olds (2.85 g/MJ in boys; 2.77 g/MJ in girls). At the age of 6 months, non-breastfed girls and boys had higher energy-adjusted intake of TDF than their breastfed counterparts, while at the age of one the setting reversed. Children of older parents, parents with a higher level of education, non-smoking mothers, and children with no older siblings had higher energy-adjusted intakes of total dietary fibre. Cereal products, fruits and berries, potatoes, and vegetables were the major food sources of total dietary fibre as well as the dietary fibre fractions. IDF was the major dietary fibre fraction followed by SDFP and SDFS. Proportions of IDF and SDFP decreased with age, while the proportion of SDFS increased. Our study based on updated CODEX-compliant food database values found that on average the TDF intake of Finnish children met the recommendations. The proportions of dietary fibre fractions as well as the roles of different foods as dietary fibre sources shifted with the child’s age, reflecting age related changes in the child’s diet.
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(2013)Most barley is used for animal feed or malting. However, barley contains technologically and nutritionally valuable components. The compositions of different barley cultivars as well as the factors affecting the concentrations of different nutrients (beta-glucan, protein, starch and ash) were surveyed in the literature part of this Master’s thesis. Special attention was paid to beta-glucan as it has attained significant interest in the food industry due to its positive health effects. In addition, the effect of grain composition on the pearling, milling and air classification properties of barley were surveyed. The nutrient composition and milling properties of ten different barley varieties were examined in the experimental part of the thesis. The varieties were divided into four subgroups based on their potential end usage: 1) speciality barley, 2) feed barley, and 3) starch barley, and 4) malting barley. The milling properties were analysed by sieve analysis and volumetric particle size distribution from the whole grain barley flours. In addition, coarse fractions were separated from the whole grain flour by air classification. These fractions were also analysed by the abovementioned particle analyses. Beta-glucan, protein and ash concentrations were usually higher in the speciality barley varieties and their coarse fractions. Starch concentrations were lower in these varieties and fractions. Feed and starch barleys had somewhat higher beta-glucan concentration compared to malting barleys, which respectively had the highest starch concentrations. Zero to 25 % of the grain’s outer layers was removed by pearling. Compositional analyses revealed that pearling decreased the amount of ash and increased the concentration of starch and betaglucan until about 15 % of the grain was pearled off. Starch and beta-glucan concentrations did not change significantly after this pearling level. Pearled barley flour was manufactured by pearling off 15–20 % of the grain’s outer layers, and milling the remaining pearled grains with a fine impact mill. Flour was then air classified to give fine and coarse fractions. The coarse fractions contained enriched concentrations of beta-glucan, protein and ash. However, their concentrations and yields were dependent on the speed of the classifier wheel. By contrast, starch was enriched in the fine fractions. The highest beta-glucan concentration was obtained with the beta-glucan-rich speciality variety D, which initially had 9.4 % beta-glucan. The beta-glucan concentration was enriched up to 11.4 % by pearling. Air classification of whole grain flour resulted maximally in 13.5 % and air classification of pearled grain flour in 15.5 % beta-glucan concentration. Based on the results, the beta-glucan concentration of the raw material seems to play the most important role in the enrichment. However, proper milling technology and air classifier settings are of utmost importance.
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(2022)Background Short-chain fatty acids (SCFAs), such as butyrate, acetate and propionate, mainly originate from dietary fibre fermentation in the colon. In recent years, additional gastrointestinal (local) and systemic effects of SCFAs have been observed in vitro and in both animals and humans in vivo. Faecal SCFAs have been associated with several conditions and diseases, including irritable bowel syndrome, type 2 diabetes, colorectal cancer, and cardiovascular diseases. Aim(s) The BEAN MAN study was carried out to assess the effects of the partial replacement of red and processed meat with legumes on nutrient intake, nutritional status, and the risk factors of type 2 diabetes, colorectal cancer and cardiovascular diseases. This thesis was part of the BEAN MAN study and investigated the effects of partially replacing red and processed meat with legumes on the concentration and composition of faecal SCFAs in healthy, working-age Finnish men. As a secondary outcome, the intake of dietary fibre and soluble polysaccharides were assessed and correlations between the total and individual SCFAs were analysed. Methods The BEAN MAN study was a 6-week randomized dietary intervention, with two diet groups in a parallel design. The Conventional Finnish diet group (Conventional FIN) was given 760 g/week of red and processed meat, corresponding the average meat consumption of Finnish men. The Flexitarian/Legume group (Flex/Leg) received 200 g/week of red and processed meat, and legume products to provide an equal amount of protein as 560 g of red meat. The faecal samples obtained from the participants before and at the end of the intervention period were freeze-dried, and SCFA were extracted and analysed using gas chromatography. Dietary fibre intake was analysed based on 4-day food records. Results At the endpoint, no significant differences in total (p = 0.560) nor individual SCFAs concentration and composition between the two diet groups were observed (ANCOVA, baseline as a covariate). The dietary fibre intake of the Flex/Leg group was higher (p < 0,001) when compared to the Conventional FIN. This was not the case for soluble polysaccharides. No correlation between the dietary fibre intake and the concentration of total or individual SCFA was found. Conclusion The concentration and composition of faecal SCFAs were not significantly affected by the partial replacement of red and processed meat with legumes during the 6-week intervention. This may highlight a more complex relationship between diet, microbiota and the production of SCFA.
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(University of HelsinkiHelsingin yliopistoHelsingfors universitet, 2007)The benefits of dietary fiber for gastrointestinal health and in the treatment and management of gastrointestinal disease in humans is well recognised. Studies have shown that different types of fiber have different effects on the function and health of the animal and humans. The aim of this study was to determine whether feeding inulin as dietary fibre would have an effect on serum free fatty acids. We were particularly interested in those fatty acids that could act as precursors of prostaglandins and leukotriens as regulators of inflammatory processes. Six male purpose bred beagle dogs were used in this study. The study was constructed in three phases of 21 days duration each. In phase 1, inulin was fed as tablets weight adjusted at a dose of 6g/day to five dogs and 4g/day to one dog. In phase 2, dogs 1-5 received 12g/day inulin and dog 6 at 8g/day. In phase 3 none of the dogs got inulin as food additive. For assessment of serum fatty acids, the serum samples were collected at the end of each phase. The serum analysis was performed using high performance liquid chromatography (HPLC). Following FFA profile was determined: linoleic acid, linolenic acid, myristic acid, oleic acid, palmitic acid, palmitoleic acid, and stearic acid. Feeding inulin caused a significant increase in median total serum FFA (p <0.05). The median increase was from 184.28 mAU (range: 109.70 – 537.47) before inulin feeding to 232.92 mAU (range, 216.26- 304.36) after inulin feeding. No significant change was seen concerning the individual FFAs. However, for linolenic acid and palmitic acid a non-significant tendency for a relative decrease was noticed (p = 0.093 ; p= 0.076) The study showed, that inulin supplementation to food has also systemic effects in dogs probably on lipid metabolism, most likely on the hepatic re-esterification of FFA causing a non-specific increase in serum total FFA. Further studies need to assess, whether this effect is connected with a decrease in serum triglycerides and cholesterol as it is reported in rats and people. Furthermore, it needs to be studied whether this non-specific increase influences the relation between pro- and anti-inflammatory mediators.
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(2021)The increasing awareness of consumers on sustainability issues associated to meat consumption has led to the increased demand for plant-based meat alternatives. There has been little information on the effects of dietary fibres (DF) in the formulation of meat analogues, but they could be potential raw materials due to their high nutritional value and diverse functional properties. Therefore, the aims of the study were to understand the role of processing parameters on protein-DF interaction and structure formation during high moisture extrusion (HME). Depending on the type of DF, protein, and extrusion conditions, influences on the structure can be either advantageous or cause limitations. HME was used to produce meat analogues from pea protein isolate (PI) and concentrate (PC), and 18 different protein-bran formulations were prepared with inclusion of oat bran (OB), wheat bran (WB) or a combination of both in concentrations of 5, 10, and 15%. The proximate composition of raw materials and extrudates was determined. In order to understand the effect of DFs on the meat analogues, the produced extrudates were evaluated in terms of colour, textural properties, microstructure, and protein-protein interactions. OB and WB had an influence on the formulations by decreasing the protein content while increasing the DF and starch content which could be related to changes occurring during processing. Increased tensile strength and cutting strength were observed in one direction resembling meat fibres. However, meat analogues with brans exhibited weaker structures by increasing softness. The findings on protein solubility indicated both non-covalent and disulphide bonds having a role in the structural stabilisation and fibrillation of meat analogues. However, the inclusion of brans did not have a significant effect on protein-protein interactions. In conclusion, brans have potential as raw materials in meat analogues for texture improvement. Further studies on consumer acceptance and improving process optimisation are suggested.
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(2020)Oats (Avena sativa L.) are increasing their popularity as a food ingredient since they have excellent nutritional value and great applicability in various food categories. Oats have been mainly used as feed and their food processing properties have not been studied as extensively as of the other cereal grains. Previous studies indicate that oat milling process can cause changes in the carbohydrate quality and properties of raw material. The aim of this Master’s thesis was to understand the impact of oat milling process and dry fractionation on oat ingredient characteristics in 10 samples representing Finnish oat varieties. The selected oat ingredients were non-heated oat groats, oat flour produced by industrial scale milling process and starch-rich fraction obtained from the oat flour by air classification aiming at bran-endosperm separation. The hypothesis was that the oat milling process as well as fractionation affect the physicochemical properties of oat ingredients and that the different oat raw materials may differ regarding their carbohydrate properties and processing behaviour. Dietary fibre, damaged starch and amylose contents of the oat ingredients were analysed. To understand the physicochemical properties of different oat ingredients, the pasting properties were measured with Rapid Visco Analyser (RVA). As expected, oat milling affected both quality and physicochemical properties of the oat raw materials. Milling caused a significant increase in the damaged starch content and caused changes in almost all pasting parameters. Furthermore, sample-dependent behaviour was observed in pasting properties. The oat samples showed differing behaviour during dry fractionation. The pasting properties of the air classified starch-rich fractions were different from the raw material oat flour. These results confirm that different oat raw materials exhibit different behaviour during oat milling process and that the milling process has a significant impact on physicochemical characteristics of oats.
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