Abstract Flaxseed oil cake from a South African factory was screened for proximate composition, mineral content, fatty acid profile and storage stability. The oil cake was included at 10 and 15% levels (w/w) in brown bread and evaluated using a 96-member consumer panel. The oil cake contained between 38.0 and 47.3% protein, 12.8 and 26.1% crude fat and 3.7 and 5.1% ash. The total carbohydrates were mostly dietary fiber. Calcium, magnesium, phosphorus and potassium were in the range of 3.3 to 3.8, 4.8 to 5.9, 6.4 to 8.2 and 9.0 to 10.1 (mg/g), respectively. The oil from the flaxseed oil cake contained 58.5 to 59.7% of C18 omega-3 fatty acids. Peroxide levels of the flaxseed oil cake were below the threshold limits after 6 months storage. Thiobarbituric acid threshold values were exceeded after 5 months aerobic storage at 20C. Bread samples with inclusion levels of 10 and 15% flaxseed oil cake were acceptable to the consumer sensory panel.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Master of Science / Food Science Institute / Fadi Aramouni / Flour from the fruit of breadfruit trees (Artocarpus altilis) holds the potential to serve as an alternative to gluten-containing flour and may aid in alleviating food insecurity. This study assessed the effects breadfruit flour contributes to gluten-free bread quality. Breadfruit flour was included at a baker’s percentage (0, 20, 35, 50%) of a gluten-free flour blend, and was treated with various leavening agents (yeast, 15% baking powder, 20% baking powder) to create varying gluten-free bread formulas. Density and pH of each batter was assessed along with loaf density, yield, specific volume, pH, water activity, crust color (L*, a*, b*), crumb color (L*, a*, b*), and texture. Additionally, a consumer sensory study was performed to ascertain degree of liking of appearance, color, flavor, texture, aftertaste, likelihood to purchase, and overall acceptability. Significant differences (p < 0.05) were found in batter pH, loaf density, yield, specific volume, color (crust b*, crumb L*, a*, b*), pH, water activity, and texture among flour inclusion and leavening treatments. Consumer testing yielded significant differences (p < 0.05) between the control and a yeast leavened 20% breadfruit formula in appearance, color, flavor, aftertaste, likelihood to purchase, and overall acceptability. While most consumers rated the breadfruit treatment lower than the control, five celiac panelists rated it higher. Among all treatments, loaves produced from 20% breadfruit flour inclusion had significantly lower density, yield, hardness, adhesiveness, gumminess, chewiness, and crumb yellowness (b*), as well as higher specific volume, springiness, crust yellowness (b*) and darkness (L*), crumb darkness (L*), and magenta hue (a*) compared to other breadfruit flour inclusion levels. Similarly, loaves leavened with yeast had significantly lower batter pH, loaf pH, density, yield, hardness, chewiness, crust yellowness (a*), crumb darkness (L*), magenta hue (a*), and yellowness (b*) as well as higher loaf water activity, volume, springiness, and crust darkness (L*) compared to other breadfruit flour inclusion levels. These results indicate breadfruit flour can be used at ≤ 20% in gluten-free bread formulas to replace rice flour and has potential as a fiber supplement. Further research is needed to assess how breadfruit flour affects the quality of other gluten-free product formulas.

Breadmaking quality is an important criterion in breeding and development of hard wheat (Triticum aestivum L.) cultivars. Improvements in N management are needed to produce superior quality grain and satisfy market demands for protein content. Field experiments with three hard red and two hard white spring wheat cultivars were conducted in 1998 and 1999 at Corvallis and Pendleton, Oregon. Nitrogen rates were varied from 0 to 250 kg N ha�����, applied all at planting, or split between planting and stem elongation. Resulting grain was evaluated for protein content, protein quality, dough handling, and bread-making quality. Grain protein content of the five cultivars increased with increasing levels of applied nitrogen. There was a concurrent improvement in bread-making quality, as indicated by increasing protein quality, loaf volume, loaf crumb score. Use of split nitrogen applications contributed to increased grain protein content at both the intermediate and high N rates. At the higher N rates, a split application had no apparent influence on protein quality. However, at intermediate N rates, a split application contributed to improvements in protein quality and loaf volume. Nitrogen use efficiency and wheat end-use quality can be improved by using split applications of nitrogen during the crop cycle. / Graduation date: 2001

Please read the abstract in the section 00front of this document / Thesis (PhD (Food Science))--University of Pretoria, 2006. / Food Science / unrestricted

Bread flour quality, which is directly related bread quality, varies from time to time. It is therefore almost impossible to obtain bread with consistent quality without determining the flour's suitability for bread-making and the addition of bread improvers. Rheological tests such as the farinograph and the mixograph which are commonly used by bakeries to predict flour quality are empirical in nature which makes fundamental interpretation of the results difficult. The stress relaxation test, a more fundamental rheological test, was used in combination with the mixograph to determine if the stress relaxation test can provide additional information to the mixograph on prediction of the effect of ascorbic acid and DATEM on bread-making quality of three different flour samples. In this test, an optimally developed ball of dough was compressed between parallel plates of a TA-XT2 texture analyser. The 20 g dough was compressed to a load of 1.5 N and thereafter allowed to relax at constant deformation. The relaxation time (RT) was recorded as time taken for the compression force to decay to a force of 0.65 N. Longer RT indicated better flour quality. RT was compared with the mixograph peak time and peak height as predictors of the effect of ascorbic acid and DATEM on bread quality. Test bakes were carried out, and concentrations of ascorbic acid and DATEM were varied as in the stress relaxation test and the mixograph test. At the various stages of the baking process several dough and bread properties were assessed subjectively and scored according to a standardised scoring system. The mixograph was successful in characterising untreated flours in terms of bread-making quality and the stress relaxation test did not provide additional information in this regard. The mixograph was better able to predict the effect of improvers on the stronger Lelie while the stress relaxation test was better at predicting improver effect (especially of DATEM) on the weaker flours, Tiger and Silver Queen. The mixograph predicted the improving effect of DATEM on Tiger and Silver Queen up to a peak, followed by no further improvement. The stress relaxation test predicted improvement beyond the peak, and this continued improvement was observed in the test bake and strong correlation (p<O.05) was found between effect of DATEM on RTs and these important test bake parameters: baking height, loaf volume, drop baking height and the bread score. In addition to information on mixing properties provided by the mixograph, RT seemed to be predicting dough's stability, related to its gas-retaining properties. This stability which can be enhanced by DATEM may be related to both the extensibility of dough's gluten matrix and the stability of the liquid film surrounding the gluten matrix. / Dissertation (MSc (Agric) Food Science and Technology)--University of Pretoria, 2005. / Food Science / unrestricted

<p>U radu je ispitana interakcija tri vrste komercijalnih prehrambenih vlakana (Fibrex, inulin HPX i inulin GR) sa strukturnim komponentama hlebnog testa. Na različitim pH vrednostima (pH 7, pH 5, pH 4 i pH 3) ispitane su fizikohemijske osobine vlakana, pri čemu Fibrex ima najveći kapacitet zadržavanja vode od 421% dok inulin GR najmanji od svega 4.2%. Na osnovu reolo&scaron;ke osobina testa sa vlaknima u količini od 5 i 10% dobijen je uvid u interakciju vlakana sa proteinskim kompleksom i klajsterisanim skrobom. Reolo&scaron;ke osobine hlebnog testa zavise od količine i vrste inkorporiranih vlakana&nbsp; dok pH vrednost vode za zames ima mali uticaj na ove pokazatelje. Dodatkom 5 i 10% fibrex-a i inulina HPX dobija se hleb dobrog kvaliteta, sa značajnim padom svarljivih ugljenih hidrata i promenjenog nutritivnog sastava koji ima osobine funkcionalne hrane pri čemu fibrex tamni boju a inulin HPX i GR vizuelno ne menja boju hleba u odnosu na hleb bez vlakana. Statistička obrada podataka je potvrdila pozitivan uticaj vlakana na testa u zamrznutom stanju. Koeficijenti diskriminacije pokazuju da je najveći uticaj vlakana na zavr&scaron;nu fermentaciju testa je posle 1 dana (199.006 i 5.739), a pozitivan uticaj vlakana na zapreminu hleba izražen je posle 30 dana (9.416) a na kvalitet sredine posle 60 dana (.841). Termodinamičkim merenjima kinetike zamrzavanja/odmrzavanja testa sa vlaknima utvrđeno je da inulina GR doprinosi skraćenju postupka &scaron;to potvrđuje koeficient determinacije R2 (0.966 i 0.981) dok testo sa fibrexom ima najmanji koeficijent determinacije R2 (0.939 i 0.951) &scaron;to pokazuje da ovo vlakno najlo&scaron;ije utiče na kinetiku zamrzavanja/odmrzavanja. Kinetika zamrzavanja/odmrzavanja može se definisati matematičkim modelom koja odgovara jednačini sa kvadratnim polinom , odnosno jednačini za nestacionarni temperaturni profil sa kvadratnim članom Y= b₀+b₁^*X +b₂^*X².</p> / <p>The interaction of three different commercial<br />fibers (Fibrex, inulin HPX and inulin GR) with<br />structural elements of bread dough was tested.<br />Physico/chemical fiber characteristics at<br />different pH values point that the greatest<br />water binding capacity (421%) is attributed to<br />fibrex, contrary to the value of 4,2%<br />experienced for inulin GR. Rheology of dough<br />containing 0 to 10% of either fiber type proved<br />the insight in the interaction between fibers<br />and proteins and also fibers and starch gels.<br />Dough rheology is influenced the most by fiber<br />characteristics and incorporated quantity,<br />contrary to pH value of water at mixing stage.<br />Statistical data interpretation proved the<br />positive contribution of fibers on dough at<br />freezing<br />Discrimination coefficients are confirming that,<br />on the whole, the greatest influence fibers have<br />on final proof after1 day of freezing (199.006<br />and 5.739) and their beneficial influence is<br />experienced after 30 and 60 days of freezing on<br />bread volume (9.416) and bread crumb quality<br />(0.841), respectively. Thermodynamic<br />measuring of freezing/thawing kinetics of<br />dough containing fibers point that inulin GR is<br />beneficial in shortening the procedure,<br />confirmed by values for determination<br />coefficient R&sup2; (0.966 and 0.981), contrary to the<br />contribution of Fibrex where the smallest<br />values for those coefficients were experienced,<br />R&sup2; (0.939 and 0.951 proving that fibrex is not<br />contributing to the freezing/thawing kinetics.<br />Freezing/thawing kinetics can be adequately<br />defined by the mathematical model of square<br />polynomial, i.e. equation for the non stationary<br />temperature profile with square Y= b₀+b₁^*X +b₂^*X².</p><p>Data presented in this thesis show that,<br />understanding interactions between fibers and<br />dough structure, by the addition of 5 or 10% of<br />either Fibrex or inulin HPX, high quality bread<br />attributed with a significant decrease of<br />digestible carbohydrates and modified nutritive<br />pattern accompanied with attributes of<br />functional food can be made, while Fibrex is<br />adversly contributing to crumb colour contrary<br />to inulin HPX and GR.</p>

Thesis (Msc Food Sc (Food Science))--University of Stellenbosch, 2009. / Endoxylanases are known to improve dough stability, oven spring, loaf volume, crumb structure and shelf life. The use of endoglucanases (cellulases) usually results in increased bread loaf volume, bread score and reduced crumb firmness. Even though bakeries use ‘pure’ enzymes in their formulations, they are supplied with an enzyme mixture which can contain up to five different enzymes. These mixtures often also include an emulsifier and ascorbic acid. To compare the ability of endoxylanase and endoglucanase to improve bread quality characteristics, a commercial endoxylanase (from Aspergillus niger) and endoglucanase (from Trichoderma reseei) were evaluated together with a pure endoxylanase and endoglucanase (both from Trichoderma sp). Baking trials were conducted on small (100 g) as well as commercial (700 g) scale. Quality characteristics evaluated included dough quality, bread weight, bread height, bread volume, softness of crumb, bread slice characteristics and overall crumb texture. All the results were compared to a control. From the results of the small-scale baking trials both the pure and commercial endoxylanases significantly (P<0.05) improved bread height and softness of crumb, with the pure endoxylanase also increasing slice brightness. Both the pure and commercial endoglucanases significantly (P<0.05) increased softness of the crumb and slice brightness. When the enzymes were evaluated in combination, only an increase in bread height was observed for some of the combinations. From the results of the baking trials conducted on commercial scale, the loaf height was significantly (P<0.05) increased by the pure endoxylanase and the pure endoglucanase, while the bread volume was significantly (P<0.05) increased by all the enzymes being tested. Enzyme combinations resulted only in a significant (P<0.05) increase in bread volume. The texture of the bread crumb was significantly (P<0.05) influenced by the commercial endoxylanase, the pure endoxylanase, the pure endoglucanase as well as two of the enzyme combinations, resulting in a more open and coarse crumb texture. Slice brightness was significantly (P<0.05) decreased by the commercial endoxylanase, the pure endoxylanase, the pure endoglucanase as well as the two enzyme combinations. Both endoxylanases and endoglucanases can therefore be used to improve bread quality characteristics such as bread height and/or volume, slice brightness and softness of crumb. However, using pure enzymes specific characteristics can be targeted. This would become more feasible if pure or single component enzymes become more readily available and cost effective to use. Apart from testing the effect of the enzymes on bread quality characteristics using small-scale baking trials, it was shown in this study that testing of enzymes could also be efficiently conducted on commercial scale. In the latter the enzymes were being tested using commercial white bread flour as well as a leaner formulation. The leaner formulation allowed for the effect of the enzymes to be observed more prominently. The benefit of the evaluation on commercial scale was that the effect of the enzymes was tested in a process similar to that used in industry.

O pão é um dos alimentos mais consumidos na dieta humana, estando presente na mesa de diferentes povos e classes sociais. Além do seu aspecto apetitoso, o pão apresenta importante valor nutricional, uma vez que é fonte de carboidratos, proteínas, vitaminas e sais minerais. Na medida em que a panificação se estendeu do processo artesanal para a escala industrial, a utilização de agentes melhoradores de farinha vem se ampliando em função da necessidade de melhorar as características de processo e a vida útil dos produtos obtidos. Durante décadas, enzimas foram adicionadas à farinha na produção de pães com a finalidade de melhorar seu volume, sabor, aroma, estrutura da casca e do miolo, maciez e vida-deprateleira. O presente trabalho teve como objetivo avaliar a influência da adição de enzimas na qualidade de pães brancos e pães ricos em fibras através do uso de associações enzimáticas de transglutaminase, xilanase e amilase. Foram preparadas 17 formulações para cada tipo de pão, com diferentes concentrações das enzimas, de acordo com o planejamento experimental 23 e para análise foi utilizada a metodologia de superfície de resposta. As etapas básicas da produção dos pães foram: pesagem e amassamento; divisão, boleamento e descanso; modelagem; fermentação; forneamento e resfriamento. As farinhas com a adição da associação enzimática e padrão foram submetidas às análises de umidade, cinzas, teor de glúten, cor, absorção de água, estabilidade, elasticidade e extensibilidade. Todas as 17 formulações e a formulação padrão para pão branco e pão rico em fibra foram analisadas sensorialmente, através da Análise Descritiva Quantitativa (ADQ), e físico-quimicamente, através das análises de umidade, cinzas, textura, cor, altura das fatias e volume específico. Os resultados obtidos no presente trabalho mostraram que a adição destas enzimas não é necessária para se ter um pão com boa qualidade e com características exigidas pelos consumidores. Observou-se que o efeito da associação das três enzimas testadas não foi significativo, pois na maioria das características avaliadas o melhor resultado foi o apresentado na amostra padrão, sem adição de enzimas. / Bread is one of the most consumed foods in the human diet. It is found on the table of people from different cultures and social classes. Besides its appetizing aspect, bread also presents important nutritional value, since it is a source of carbohydrates, proteins, vitamins and mineral salts. As bread-making has gone from the handmade process to the industrial scale, the usage of bread enhancements has increased in order to attend the necessity of improving process’s characteristics and lifespan of the obtained product. Throughout many decades, enzymes were added to the flour during bread’s production with the objective of increasing its volume, taste, aroma, crust’s and crumb’s structure, softness and lifespan. The present work is proposed to evaluate how the addition of enzymes can influence on the quality of white and wholemeal bread through the use of enzymatic associations of transglutaminase, xylanase and amylase. 17 formulations have been prepared for each type of bread, each one with different enzyme concentrations, according to the experimental planning 2³. The methodology used for the analysis was the Response Surface Methodology – RSM. The basic steps of production were: weighing and kneading; dividing, ball making and resting; molding; fermenting; baking and cooling. Both the standard flours and the ones with the addition of enzymatic associations were submitted to humidity, ashes, gluten level, color, water absorption, stability, elasticity, and extensibility analysis. All 17 formulations and the standard formulation for white bread and wholemeal bread have been submitted to sensorial evaluation using Quantitative Descriptive Analysis. They have also been physically and chemically tested through the analysis of humidity, ashes, texture, color, height of the slices and specific volume. The results obtained from this research proved that the addition of those enzymes is not necessary in order to make good quality bread with characteristics demanded by its consumers. It has been observed that the effect of the association of the 3 tested enzymes was not significant. The standard sample - free of enzyme addition - presented the best results for most of the evaluated characteristics.