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.

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.

<p>Prema najnovijim istraživanjima modifikovanim skrobovima može se pripisati jo&scaron; jedna uloga &ndash; aditivi u pekarstvu, s obzirom da utiču na pobolj&scaron;anje kvaliteta hleba i<br />usporavaju proces starenja. Međutim, prema saznanjima autora ove disertacije, ne<br />postoje istraživanja na temu uticaja emulgujućih skrobova (skrob-natrijum<br />oktenilsukcinata, OSA skrobova) na kvalitet testa i hleba od p&scaron;eničnog bra&scaron;na.<br />Uzimajući u obzir činjenicu da druge vrste modifikovanih skrobova ispoljavaju dobre<br />osobine u smislu pobolj&scaron;anja kvaliteta hleba i da je OSA skrob nutritivno vredna<br />sirovina, s obzirom da se u organiznu pona&scaron;a kao prehrambeno vlakno, od velike je<br />važnosti ispitati ulogu OSA skroba kao aditiva u pekarstvu.<br />Međutim, usled kompleksne prirode testa kao sistema, bilo je te&scaron;ko odrediti relativni<br />uticaj pojedinačnih komponenti (proteina, p&scaron;eničnog skroba, OSA skroba) i njihovih<br />međusobnih interakcija na osobine testa. Stoga je, u cilju rasvetljavanja uticaja različitih OSA skrobova na viskoelastične osobine testa i retrogradaciju skrobne komponente (fenomen povezan sa starenjem hleba), p&scaron;enično bra&scaron;no frakcionisano na gluten i skrob, i vr&scaron;ena su ispitivanja strukturnih, reolo&scaron;kih i termičkih osobina hidratisanog glutena i skrobnih gelova sa dodatkom OSA skroba. Takođe su pripremani i model sistemi testa.<br />Ispitivanja na realnim sistemima (testo i hleb) izvođena su zamenom 2,5; 5 i 10%<br />p&scaron;eničnog bra&scaron;na, jednim od tri vrste OSA skroba: skrob-natrijum oktenilsukcinatom<br />(OSA-ST), preželatiniziranim skrob-natrijum oktenilsukcinatom (Pregel OSA-ST) i<br />hidrolizovanim su&scaron;enim u spreju skrob-natrijum oktenilsukcinatom (Hydrol OSA-ST).<br />Cilj je bio da se ispita uticaj dodatka OSA skrobova na strukturu testa (SEM), empirijske (miksolab, alveograf i reofermentometar) i fundamentalne (oscilatorna merenja i testovi puzanja i deformacije) reolo&scaron;ke osobine, kao i parametre kvaliteta hleba (specifična zapremina, boja kore i sredine hleba, vlaga sredine hleba, parametri raspodele veličine pora i tekstura sredine). Pored pomenutog, praćena je i promena kvaliteta hleba tokom skladi&scaron;tenja, kako bi se dobio uvid u kinetiku starenja hleba.<br />Rezultati dobijeni u ovoj disertaciji ukazali su da reolo&scaron;ko pona&scaron;anje testa sa dodatkom OSA skrobova zavisi od strukture skrobnih granula, tj. od stepena dezintegracije i depolimerizacije granule tokom procesa modifikacije. Stoga je dodatak OSA-ST doveo do ojačavanja glutenske mreže &scaron;to se odrazilo na porast modula elastičnosti i testa i glutena. Nasuprot tome, Pregel and Hydrol OSA-ST uticali su na kontinualnost glutenske mreže koja je u njihovom prisustvu bila poroznija, a time su i dobijena testa bila mek&scaron;a i rastegljivija. Istraživanja na realnim i model sistemima (p&scaron;enični skrob sa dodatkom OSA skroba) ukazala su da sva tri OSA skroba usporavaju retrogradaciju p&scaron;eničnog skroba. Takođe je dokazano da svi ispitivani emulgujući skrobovi povećavaju specifičnu zapreminu hleba u poređenju sa kontrolnim, pri čemu je Pregel OSA ispoljio najjači efekat. To se odrazilo i na strukturne osobine sredine hleba, a posledično i na mehaničke osobine sredine, čija promena je praćena u cilju određivanja kinetike starenja hleba. Prema dobijenim rezultatima, vrednosti čvrstoće sredine hleba koji je sadržao OSA-ST i Pregel OSA-ST su i nakon 24 h bile slične ili značajno niže od vrednosti čvrstoće kontrolnog uzorka određene 2 h nakon pečenja.</p> / <p>Recent studies have demonstrated that modified starches can be used as novel additives in breadmaking since they improve bread quality and retard stalling. However, up to the author&#39;s knowledge, there are no investigations concerning the influence of emulsifying starches (starch sodium octenyl succinates - OSA starches) on wheat flour dough and bread quality. Taking into account the fact that other modified starches have exhibited significant bread improving properties and that OSA starch has special nutritional value since it can act as functional fibre, it is of a great importance to investigate the feasibility of OSA starch as bread improver.<br />However, due to the complex nature of dough, it was difficult to determine the relative contributions of protein, native and modified starch components and their interactions on dough properties. Therefore, in order to resolve the influence of different OSA starches on dough viscoelastic properties and starch retrogradation (the phenomenon related to bread stalling), wheat flour was fractionated into gluten and starch; and the structural, rheological and thermal behaviour of the hydrated gluten samples and starch gels supplemented with emulsifying starches was also studied. Dough model systems were also prepared.<br />Experiments on real systems (dough and bread) were performed by incorporating<br />starch sodium octenyl succinate (OSA-ST), pregelatinized OSA starch (Pregel OSA-ST) and hydrolysed spray-dried OSA starch (Hydrol OSA-ST) at 2.5, 5 and 10 % into wheat flour. The aim was to investigate the effect of incorporating OSA starches on dough structural (SEM imaging), empirical (Mixolab, Alveograph, Rheofermentometre) and fundamental (oscillatory and creep measurements) rheological properties as well as bread quality parameters (specific loaf volume, crust and crumb colour, crumb moisture, crumb grain features, crumb texture). In addition, the bread quality attributes during storage were also monitored in order to get insight into bread stalling kinetics.<br />The results obtained in this thesis revealed that the rheological behaviour of OSA starch supplemented dough depended on the OSA starch granule rigidity, i.e. extent of OSA starch granule disintegration and polysaccharide degradation during modification. OSA-ST starch caused a reinforcement of the gluten network, as shown by the increase in storage modulus of doughs and gluten. On contrary, Pregel and Hydrol OSA-ST affected the continuity of gluten network which became porous and thus produced softer and stickier doughs in comparison to control. Investigations on real dough and model systems containing wheat and OSA starches revealed that all three types of OSA starches reduced starch retrogradation.<br />In general, all the examined emulsifying starches increased bread loaf volume in comparison to control bread with no added polymers, while Pregel OSA starch has expressed the greatest impact. It also reflected on bread crumb structural features and consequently on the crumb mechanical properties which were used for bread stalling monitoring. Firmness values of OSA-ST and Pregel OSA-ST starch supplemented bread crumbs, after 24 h of storage, were similar to or significantly lower than those of control determined 2 h after baking.</p>

<p>Sagledavajući značaj nutritivne vrednosti bezglutenskog hleba u prevenciji dodatnih zdravstvenih poremećaja kod obolelih od celijakije, kao i prisutnog trenda bezglutenske ishrane, u okviru ove disertacije analizirana je mogućnost obogaćenja bezglutenskog hleba prehrambenim vlaknima. Ispitan je uticaj različite vrste i količine (3, 5, 7%) prehrambenih vlakana (vlakna &scaron;ećerne repe i vlakna jabuke), količine hidroksipropil metil celuloze - HPMC (2, 3, 4%) i količine vode (180&ndash;230%) na reolo&scaron;ke osobine bezglutenskog testa (svojstva proticanja i viskoelastične osobine), kvalitet i nutritivnu vrednost bezglutenskog hleba. Rezultati ove disertacije ukazuju da dodatak vlakana &scaron;ećerne repe i jabuke ne umanjuje pozitivan uticaj HPMC na reolo&scaron;ke osobine bezglutenskog testa, formiranje i ojačavanje njegove strukture. Bezglutenski hleb privlačne boje, veće zapremine, manje tvrdoće sredine i odličnih senzorskih karakteristika dobijen je kod uzoraka sa 4% HPMC, 3, 5 ili 7% vlakana &scaron;ećerne repe/jabuke i 220%/190% vode. Sadržaj ukupnih prehrambenih vlakana kod uzoraka sa 3% vlakana je iznad 4,5 g/100 g, a kod uzoraka sa 7% vlakana čak oko 6 g/100 g bezglutenskog hleba. Postignut sadržaj ukupnih prehrambenih vlakana je iznad propisane vrednosti za proizvode koji mogu biti nosioci nutritivne izjave &bdquo;izvor vlakana&ldquo;, čime je ostvaren cilj ove disertacije.</p> / <p>Considering the importance of the gluten-free bread nutritional value in the prevention of additional health disorders in patients with celiac disease, as well as the arising gluten-free diet trend, the possibility of enriching gluten-free bread with dietary fibers was analyzed within this dissertation. The influence of different types and amounts (3, 5, 7%) of dietary fibers (sugar beet and apple fibers), the amount of hydroxypropylmethylcellulose - HPMC (2, 3, 4%) and the amount of water (180&ndash;230%) on rheological properties of gluten-free batter (flow and viscoelastic properties), quality and nutritional value of gluten-free bread. The results of this dissertation indicate that the addition of sugar beet and apple fibers does not diminish the positive influence of HPMC on the rheological properties of the gluten-free batter, the formation and strengthening of its structure. Gluten-free bread with appealing color, higher volume, lower hardness and excellent sensory characteristics was obtained in samples with 4% HPMC, 3, 5 or 7% sugar beet/apple fibers and 220%/190% water. The total dietary fibers content in samples with 3% fibers is above 4.5 g/100 g, and in samples with 7% fibers approximately 6 g/100 g of gluten-free bread. The accomplished total dietary fibers content is above the prescribed value for products that may bear the nutritional statement &quot;source of fiber&quot;, thus achieving the goal of this dissertation.</p>