Masters Degree Dissertations

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12504/107

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Browsing Masters Degree Dissertations by Subject "Bread"

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    Contribution of selected ingredients to the quality of wheat/unpeeled orange fleshed sweet potato puree composite bread
    (Kyambogo University (Unpublished work), 2024-02) Skaka, Vitalis
    The development of bread from composite formulations is increasing and has attracted much attention from researchers driven by the desire to find non-wheat-bread-making alternatives in order to reduce dependence on imported wheat. However, formulation and production of acceptable composite bread requires understanding the effects of ingredients on bread quality. this study aimed at assessing the contribution of selected ingredients to the quality of composite dough made from wheat flour and unpeeled orange-fleshed sweet potato (OFSP) puree as well as physical qualities, nutritional composition, and consumer acceptability of the resultant bread. A 2-level fractional factorial design (28-3) at resolution IV was used to design a screening experiment and Response Surface Methodology (RSM) was used to analyze data. Prmax and water Absorption of the composite dough were studied using the alveoconsistograph. Physical properties and nutritional composition of composite bread were analyzed using AACC, AOAC and ICC standard methods. Consumer acceptability was assessed by an untrained panel of evaluators using a 9-point Hedonic scale. Significant models were developed at p<0.05 and coefficient of determination, R2 was used to test fitness of the model terms. Prmax and Water absorption decreased as proportions of unpeeled OFSP puree increased from 20% to 50%. Proportion of unpeeled OFSP puree negatively affected crumb colour, specific volume, springiness, flavour, aroma and general acceptability but had a positive effect on weight, moisture content, Total carotenoid content, β-carotene content, vitamin A content, reducing sugar content, protein content, Amylose and amylopectin ratio and starch content. Yeast positively affected volume and crust colour with negative effect on baking loss, staling rate, firmness and chewiness. Treatment of unpeeled OFSP (pasteurized and unpasteurized/fresh) negatively affected texture. Variety had a significant effect on crude fiber with NASPOT13O having a negative effect and NKB135 exhibiting a positive effect. Fat negatively affected cohesiveness. Ascorbic acid (improver) had the least effect on the study responses. Principal component Analysis indicated a negative correlation between nutritional and sensory properties. a positive correlation between textural properties and sensory properties and a high correlation between physical and sensory properties of the bread were observed. The study concluded that the most significant among the selected ingredients that affected quality of wheat/unpeeled OFSP puree bread were proportion of puree, yeast and fat. The study also concluded that treatment and variety had significant effects on the quality of the composite bread.
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    Dough rheology and baking properties of bread from wheat/ hybrid banana composite flour
    (Kyambogo University (Unpublished work), 2024-02) Kimera, Baker
    In spite of high productivity and good agronomic adoptability of hybrid cooking bananas, they have undesirable sensory characteristics hence low consumer acceptability. This study aimed at evaluating the effect of partial substitution of wheat with hybrid cooking banana flour on the dough rheology and baking properties of composite bread. Five hybrid banana varieties; M30, M9, N15, N21 and N23 were used in this study. Bananas at green maturity were processed into flour and blended with wheat to make various composite flours (10/90, 20/80, 30/70 and 40/60%). Unblended wheat flour (100%) was used as a control. The different blends were then used to make the wheat composite bread using the straight-dough method. Rheological properties of the composite dough were analyzed using a consistograph (water absorption capacity and maximum pressure), alveograph (peak height, extensibility and baking strength) and farinograph (mixing tolerance index and development time). Textural properties (hardness, springiness, cohesiveness) were determined using the texture analyzer while sensory attributes were investigated using the 9-point hedonic scale. The dough rheology values reported in this study ranged from; water absorption capacity (47.25% to 54.45%), maximum pressure (1315.50 mbar to 2911.50 mbar), peak height (82.50 mm to 151.50 mm), extensibility (19.50 mm to 113.50 mm), baking strength (67.50 J to 244.50 J), development time (1.10 min to 5.40 min) and mixing tolerance index (86.00 BU to 175.50 BU). Hardness increased with increasing banana flour percentage inclusions, ranging from 2.09 N to 4.39 N. Springiness had no specific trend across the hybrids, but ranged from 0.35 to 0.80. Cohesiveness decreased with an increase in banana flour inclusion levels, ranging from 0.05 to 0.56. Sensory evaluation results showed a decrease in panel acceptability of the composite bread as the percentage inclusion of hybrid banana flour increased. The best scores for the sensory parameters evaluated were recorded at 10% inclusions of M30. Inclusion of hybrid banana flour up to 10% for all varieties studied as well as 20% inclusions for M30, N21 and N15 was comparable to 100% wheat flour. It is therefore recommended to use up to 20% inclusion levels of hybrid cooking banana flour from M30, N21 and N15 in preparation of hybrid banana / wheat composite bread.
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    Optimisation of the quality of bread from wheat, banana and cassava composite flour
    (Kyambogo University(Unpublished work), 2018-10) Nakisozi, Henriettah
    Bananas and cassava are important staple foods in terms of caloric intake in Uganda. These traditional crops are highly perishable with little value addition. This study examined the prospects of application of banana, cassava and wheat composite flour in the development of bread. Sixteen composite flour blends were prepared using D-optimal constrained mixture design within a range of 40 to 80% for wheat, 10 to 30% for cassava and 10 to 30% for banana. Nutrient quality and sensory acceptability of the breads were optimized using design expert software. Baseline assessment on bread consumption was conducted from Kampala city. Information on bread consumption and purchasing behaviour was collected using a questionnaire. Banana (EAHB) cultivar cassava (NASE 19) and wheat were used for bread development. Moisture was analyzed using hot air oven (BTI-29, India), dry ashing for ash using a muffle furnace (FSL 340-0 I 00, Gallenkamp, UK), Kjeldahl method for crude protein, Soxhlet method for crude fat and Gravimetric method for crude fiber. Total carbohydrate content of bread was determined by difference method. Loaf weight and loaf volume were evaluated using a digital laboratory scale (CE-4101, China) and rapeseed displacement method, respectively. Bread firmness was determined using a TA XTplus texture analyzer (Stable Micro Systems, Gudaiming, Surrey, UK). Sensory attributes (taste. odor, color, texture and overall acceptability) were evaluated on a five-point hedonic scale. Bread consumption was high (66.4%) amongst young people. A large (37. l %) proportion of the population consumed bread daily and sweet bread was mostly (88.2%) liked. Over 70% of respondents preferred white bread to whole meal bread. Large companies (56. l %) were the main purchasing points because bread was considered to be fresh. Freshness (36.4%) was the most important criteria for preference of bread. Blending had a significant effect on carbohydrate, protein, ash, loaf volume, taste and odor (p<0.05). Banana addition increased mineral amounts in bread whereas cassava increased total carbohydrate. The optimum blending ratio for both nutritional and sensory acceptability was in the range of 71.2% wheat, 10.6% cassava and 18.2% banana flours. Loaf volume ranged between 803.3 and 13 l0cm3. Loaf volume of bread processed from less than 70% wheat flour was inferior. Crumb firmness values ranged from 6.4 to 29.8 N. Bread developed from 50% wheat, 40% banana and 10% cassava had the highest (29.8 N) firmness whereas that made from 80% wheat, 10% banana and l 0% cassava had the lowest (6.4 ) firmness. It was concluded that controlled processing of banana and cassava flours, maintaining wheat flour around 70% and high proportion of banana flour (about 17%) in the blend, would lead to production of high quality bread with high content of minerals and bioactive compounds such as polyphenols, flavonoids etc. Bread from banana, cassava and wheat was of good quality to consumers.