Masters Degrees (Food Science)

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Browsing Masters Degrees (Food Science) by Subject "Alternative baking water"

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    Effect of substituting baking water with brewer's spent grain supernatant on the micro-structure and crumb structure of white wheat flour bread
    (Stellenbosch : Stellenbosch University, 2019-04) Van Zyl, Nicola Jean; Manley, Marena; Van Rensburg, Eugene; Gorgens, Johann F.; Stellenbosch University. Faculty of Agrisciences. Dept. of Food Science.
    ENGLISH ABSTRACT: The ubiquitous opinion regarding brewer’s spent grain (BSG), is that it is currently underutilised, based on its residual nutritional contents and potential for re-use. This is a process by-product that is available throughout the year, in most countries, at a very low cost from micro- to industrial-sized breweries. For this research assignment, freshly produced BSG was processed using a screw-press which enabled the extraction of BSG-supernatant, a liquid consisting of 98% water. Using the supernatant would require less energy-intensive processing, compared to preparing a composite-flour from the spent grain through drying and milling of BSG. Very little research has been undertaken with the objective of determining the effect on bread quality parameters when using an alternative baking water. The functional role of baking water in producing a quality bread product was reviewed. The knowledge gained therefrom enabled the evaluation of the potential of BSG-supernatant as an alternative baking water in white bread formulations. The experimental design and research objectives of this investigation were employed in order to review the proposed removal of the excess moisture within fresh BSG. The liquid fraction is separated from its solid, fibrous origin and clarified through the gravimetric sedimentation of suspended fibrous-particulates. The BSG-supernatant’s effect on the dough’s rheological behaviour and quality scores were evaluated according to bread industry standards and regulations. Macro- and micro-structural properties of the bread samples were evaluated using Texture Analysis (TA), C-Cell Visual Analysis (2D) and X-ray micro-Computed Tomography (3D) across a shelf-life period (Days 2, 3 and 4). The micro-structural properties of bread loaves were evaluated in terms of their cell properties within the crumb-structure, as well as its porosity and water holding capacity (WHC). BSGsupernatant was determined to have no significant effect on the micro-structural properties of the bread loaf, although the crumb-structure of the BSG-supernatant breads had a greater WHC than did that of the control formulations. The control- and treatment formulations were compared on a 5% significance level and it was concluded that BSG-supernatant can be used as an alternative baking water, for white bread formulations, without being detrimental to loaf quality.