Browsing by Subject "fiber"

Background: The infant gut microbiome undergoes major temporal changes in the first year of life, crucial for supporting normal development and long-term health. The immense diversity of fiber structures in breast milk and later in solid foods pose unique selection pressures on the gut microbiome maturation by providing novel substrates for the microbiota. However, the longitudinal impact of complementary food-derived fibers on the taxonomic and functional maturation of the gut microbiome during the gradual transition from breast milk to solid foods is not well understood. Objectives: My objective was to examine how breast milk, its fiber and complementary food fibers in the broader context of overall infant diet may affect the gut microbiome bacterial species composition and support age-appropriate gut bacterial maturation trajectories during first year of life. Methods: Longitudinal and cross-sectional development of 68 infant gut microbiomes and 33 metabolomes were examined with linear mixed models to determine the impact of infant nutrition on gut microbiome taxa and functional development. Nutrition assessments were based on detailed quantitative weighted 3-day food records (months 3,6,9,12) and the intakes of total dietary fiber with its food sources and fiber fractions relied on current internationally approved CODEX-compliant values. Questionnaires were utilized to monitor when various complementary foods were introduced, enabling more comprehensive nutritional analyses. Bacterial species identification was based on MetaPhlAn2 quantification of bacterial species from metagenomic data and metabolomic profiles were generated using four liquid chromatography-mass spectrometry (LC-MS) methods. Results: My examinations place the previously described sequential trajectories in infant gut microbiome maturation into detailed fiber-dependent nutritional context relying on metagenomic species identification. I discovered 176 complementary food derived fiber-bacterial species associations. The majority of the associations (147, 84%) were positive whereas breastfeeding and related variables tended to be inversely associated with the same species, showing strongest inverse correlations to later trajectory species indicative of slower maturation. Both bacterial species and metabolomic profiles displayed pronounced longitudinal shifts in response to solid food fibers. Each introduction of novel dietary source of fiber associated to diversification of the microbiome revealing fiber-species specific temporal patterns. Conclusions: The longitudinal analyses highlight that sufficient fiber intake from appropriate sources during the weaning period likely function to build capacity for the species permanence in the more diverse and stable mature gut microbiome composition and function reached in later childhood.

The literature review dealed with fat replacers in frankfurters. Manufacturing, properties and usages of microcrystalline cellulose were described. Also other fat replacers that are at the moment in use are described, such as hydrocolloids and proteins from vegetable. The literature review also described different methods that have been used to measure properties of frankfurters. The aim of the experimental work was to find out the influence of two different types of microcrystalline cellulose, Vivapur® 105(i) and Arbocel® M80(ii), on the properties of frankfurters, and can they been used as a fat replacer. Three different concentrations of microcrystalline cellulose (MCC) (1 %, 3 % and 5 %) Were studied and compared to the control sample. Measured properties of frankfurters were pH, water holding, cooking loss, firmness and bite force. Also amount of free water was measured with NMR. Although adding MCC decreased pH of frankfurter closer to the isoelectric point, it did not affect as lowering water holding. Both MCC(i) and MCC(ii) increased significantly (p<0,05) firmness of the frankfurters when measuring was made with warm samples, excluding MCC(i) 3 % concentration. Effect was not as visible in the measurements of bite force.