The objective of this study was to determine the effects of different gums and their combination on quality and staling of breads baked in different ovens. In the first part of the study, the effects of gums (xanthan, guar, k-carrageenan, hydroxypropyl methylcellulose, locust bean gum and their blends) on quality of breads baked in infrared-microwave combination and conventional ovens were investigated. In addition, macro and micro-structure, dielectric and thermal properties and acrylamide content of breads were studied. Xanthan-guar blend addition improved bread quality with increasing specific volume and porosity values and decreasing hardness values of samples. More homogeneous closed-cell structure for conventionally baked control breads and channel formed cell structure for breads baked in infraredmicrowave combination oven were observed. Dielectric properties of breads were found to be a function of gum type. No acrylamide was formed in microwave baked breads. Breads baked in infrared-microwave combination oven had similar acrylamide content with conventionally baked ones. The second part of the study focused on staling. The hardness, retrogradation enthalpy, set back viscosity, FTIR outputs and crystallinity values of microwave-baked samples were found to be the highest. Infraredmicrowave combination heating made it possible to produce breads with similar staling degrees as conventionally baked ones and reduced the conventional baking time of breads by about 39%. Addition of xanthan-guar blend decreased hardness, retrogradation enthalpy and crystallinity values of breads. According to hardness data, in the presence of xanthan-guar blend staling of breads baked in all types of ovens was delayed for 1 day.

Resumo: O desenvolvimento da tecnologia de pães é um fenômeno de grande impacto na indústria de alimentos. Ao longo dos anos vários aditivos foram incorporados à tecnologia de panificação, elevando a qualidade destes produtos e fazendo crescer a sua aceitação pela população em geral. O objetivo deste trabalho foi estudar os efeitos sobre a qualidade do pão e sobre o processo de envelhecimento, da adição de enzimas na massa. As enzimas usadas foram xilanase produzida pelo fungo Thermoascus aurantiacus CBMAI 756 nas concentrações de 20, 35 e 50U/100 g de farinha de trigo e/ou da ciclodextrina glicosiltransferase (CGTase) produzida pela bactéria Bacillus clausii E16 nas concentrações de 15 e 30U/100 g de farinha de trigo, parcialmente purificadas. O mecanismo de ação dessas enzimas sobre os seus respectivos substratos arabinoxilana e amido, respectivamente, também foram avaliadas. Os pães adicionados de xilanase, CGTase e xilanase/CGTase foram produzidos em três etapas distintas. Para o estudo do envelhecimento os pães foram mantidos a temperatura de 4ºC durante 10 dias, e foram avaliados quanto à perda de água, a textura e a retrogradação da amilopectina. Os produtos obtidos pela ação da xilanase e CGTase sobre as arabinoxilanas e o amido, respectivamente, isolados da farinha de trigo, foram analisados por HPAEC-PAD e HPLC. O fungo T. aurantiacus exibiu uma variação no perfil enzimático de acordo com cada substrato usado no seu cultivo. O substrato que resultou no melhor perfil enzimático para o uso em panificação foi o sabugo de milho, porque esse extrato enzimático exibiu alta atividade xilanolítica e baixa atividade amilolítica e proteolítica. A adição de xilanase, CGTase e xilanase/CGTase aumentou o volume da massa e o volume específico dos pães. Quanto ao... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The development of bread technology is a phenomenon of great impact on food industry. For years, many additives were used on bread technology, increasing the bread quality and improving the acceptance of general population. The aim of this work was to study the effects on the bread quality and on the staling process, by adding enzymes to the dough. The enzymes used were xylanase from the fungus Thermoascus aurantiacus CBMAI 756 in the concentrations 20, 35 and 50U/100 g wheat flour and/or cyclodextryn glycosiltransferase (CGTase) from the bacteria Bacillus clausii E16 in the concentration 15 and 30U/100 g wheat flour, partially purified. The action mechanisms of these enzymes under the substrates arabinoxylan and starch, respectively, were also evaluated. The breads added of xylanase, CGTase and xylanase/CGTase were produced in three distinct stages. For bread staling study, the breads were stored at 4ºC for 10 days, and they were analyzed regarding to the moisture content, texture and amylopectin retrogadation. The products obtained by the action of xylanase and CGTase on arabinoxylans and starch, respectively, isolated from wheat flour, were analyzed by using HPAEC-PAD and HPLC. The fungus T. aurantiacus exhibited a variation on the enzymatic profile according to each substrate used on its cultivation. The substrate which resulted in a better enzymatic profile for using on breadmaking was corncob, since this enzymatic extract exhibited high xylanolytic activity and low amylolytic and proteolytic activities. The addition of xylanase, CGTase and xylanase/CGTase increased the dough volume and the specific volume of the breads. Regarding to the staling study, the enzymes added separated or together reduced amylopectin retrogradation and firmness of the crumb during storage, when compared... (Complete abstract click electronic access below) / Orientador: Célia Maria Landi Franco / Coorientador: Roberto da Silva / Banca: Myriam Salas Mellado / Banca: Caroline Joy Steel / Doutor

Quality control is essential in food industry and efficient quality assurance is becoming increasingly important. The assessment of food quality still centers on its sensory properties (appearance, aroma and texture). Bread is one of the most consumed food item all over the world. Bakery product manufacturers expect that the bread should retain all of its attributes during storage and consumers expect their bread to be ‘fresh’. Unfortunately, it remains truly ‘fresh’ for only a few hours after it leaves the oven because the ingredients of the bread undergo series of physical and chemical changes that eventually lead to deterioration, referred as “staling”, of bread quality. Bread staling is classified in two categories: crust (outer portion of bread) staling and crumb (center portion of bread) staling. Crust staling is associated to the moisture migration from crumb to crust during storage. This moisture migration leads to a phenomenon called glass transition at crust. This phenomenon changes the mechanical and dielectric properties of bread crust. Crumb staling is mainly associated to the physicochemical changes in starch. During storage, amorphous starch regains its crystallinity, which increases the firmnesss and dryness of bread crumb. Thus, the knowledge of moisture content, starch recrystallization and the glass transition helps in understanding the bread staling mechanism. There are some volatiles produced from the bread during storage, which forms the characteristic flavor or aroma of the bread. The loss of this characteristic flavor during storage also gives the information about the loss of freshness and staling. Thus, there is a need for detection and monitoring the loss of these volatiles to determine the characteristic flavor during storage. Hence, the present investigations are focused on these issues and developed a measurement facility to monitor the above physicochemical changes in bread during storage. As a part of experimental investigations, two separate test facilities have been developed. A multichannel ring electrodes with suitable instrumentation based on impedance spectroscopy technique is developed for simultaneous measurement of electrical properties of bread at crust and crumb during storage in the frequency range from 50 Hz to 100 kHz. The detailed investigations have been conducted on wheat bread. The variation in capacitance showed that the glass transition phenomenon, at room temperature, in bread crust occurs after 96 h of storage with 18% of moisture in it. The resistance changes at bread crumb showed the starch recrystallization during staling. The electrical property results are justified with the results obtained from the conventional differential scanning calorimmetery (DSC) studies. The impedance measurement at crust and crumb estimates the moisture content at the respective zones of bread. Thus the test facility is used for the simultaneous measurement of moisture content, starch recrystallization and glass transition at crumb and crust respectively without destructing the bread loaf. A few experiments are conducted on maida bread and the obtained results are compared with the wheat bread results. Another test facility has been developed for the detection of volatiles produced from the wheat bread during storage. The gas chromatography and mass spectroscopy (GC-MS) experimentations are conducted to identify the volatiles produced from the bread during storage. The major volatiles produced from wheat bread are found to be 1-Heptanol, 1-Pentanol, 1-Octanol, Furan and Hydroperoxyde. A conducting polymer based gas sensor is designed and developed to sense these volatiles and the changes in its electrical property is monitored with a suitable instrumentation based on impedance spectroscopy technique in the frequency range from 10 Hz to 2MHz. Experimental investigations are carried out in an in-house air tight closed test chamber. The bread sample and the designed sensor are kept inside the test chamber and closed tightly so that only bread volatile can interact with the sensor. The sensor response is monitored by measuring the changes in its capacitance upon exposure to organic volatiles produced from bread during storage. It is observed that the capacitance of the sensor changes with the quantitative changes of the above volatiles. Thus, the test facility is found quite suitable for the detection and monitoring the bread volatiles produced during storage, which finally affects the aroma property. Thus, the developed experimental test facilities with suitable sensors and instrumentation based on impedance spectroscopy technique are found quite suitable to monitor the changes in physicochemical properties and aroma of bread during storage. The correlation between the measured electrical properties and the changes in the textural and flavor properties of bread during storage has been established. The results obtained with the developed test facilities are in good agreement with the results obtained from the standard traditional techniques like DSC and GC-MS.

No description available.

本篇諭文約有十五萬字，共分為五章十六節，針對當前中共統戰策略（包括對內、對 外、對臺統獨）的理論和組織系統加以深入分析。 第一章 緒言 第二章 從馬克思、列寧、史達林以及中共的統戰理論和運作分析統戰的過去和現在 的功能異同。 第三章 「文革」以後中共「新時期愛國統一戰線」之策略運作及相關問題的分析。 第四章 從中共對內、對外、對臺三方面研究中共統戰組織系統和結構。 第五章 結論、根據前四章之分析結果，研判中共當前統戰之虛和實，以及統戰對中 共政治、外交之影響，並討論未來中共對臺政策的走向。

鄧小平提出「具有中國特色」的社會主義作為中國大陸現階段社會主義建設的口號， 希望能為中共奉行貳的馬列主義與現實環境之間的矛盾，提供一個可能的解決方案。 本篇論文的主旬就是從「革命理論」（由資本主義社會過渡到共產主義社會的理論） 以及「發展策略「（達成社會主義生產方式的方法、手段）兩個面向，來觀察中共如 何在一個「半殖民、半封建」的社會，建立起社會主義。中共在歷經蘇聯模式、毛澤 東的「大躍進」模式式二種發展策略後，體會出中國大陸的社會主義建設依舊無法解 決生產力和生產關係之門的矛盾，因此在鄧小平上臺後便實行「經濟體制改革（，以 發展生產力作為關鍵。但是為了解決僵硬的意識形態影響改革的問題，而對馬克思主 義採取「發展」的態度終必使得「革命理論」本身也產生修正或改變的現象，仗得發 展策略與革命理論發生辯證的關係。 「中國特色」的社會主義本身就還是一項不斷在發展的體，它未來的走向是一項耐人 尋味的問題。由於中國大陸社會主義本身繼承了史達林主義以黨和國家控制一切的特 質，因此它處處顯示出「國家主義」的色彩，雖然中共也採行某些市場機制以搞活經 濟，但是基本上具有中國特色的社會主義仍然是局限於「國家主義」模式的範疇；這 是由於在資本主義盛行的世界體系之下，社會主義建設本身還是得利用國家機器以爭 取世界分工秩序下一個較有利的地位。中國特色的社會主義一方面要求堅守社會主義 的原則，而另一方面則要求快速現代化。打破這種僵局的方法，還是在於找尋生產力 和生產關係在某一歷史階段的平衡點。

本論文共計六章十一節，約五萬五仟字，其扼要內容如下﹕ 第一章 緒論 本章在說明撰寫本論文的動機與書寫論文的方法。另外對各章節內容做一概要性解釋 與說明，使閱讀論文者能對全部內容有著基本瞭解。 第二章 共黨統戰的內涵 本章分兩節，目的在釐清對統戰紛雜的解釋與說法。 第一節 統戰的定義一從中共自己對統戰的解釋與其他各具代表性的人物中，各自對統戰的觀 點加以融合，最後再過濾出作者本人對統戰的定義解釋，以求瞭解統戰的基本定義。 第二節 統戰的思想根源。從馬克思、恩格斯、列寧、史達林與毛澤東等從上到下一路探討整 個統戰的思想，以求對其一貫性與差異性之瞭解。 第三章 「武力」與「和平」口號交錯運用時期中共對台統戰。本章分三節，其內容從一九四 九至一九七八年的三十年間將中共對台統戰做一追溯性的說明，以求瞭解到各階段統 戰方式有何異同。 第四章 現階段中共對我運用之統戰策略一兼論一國兩制。本章分三節。 第一節 一國兩制蘊釀時期中共對台之統戰策略一從一九七八年中共十一屆三中全會後到一九 八四年一國兩制口號正式提出前，將中共統戰攻勢做一解釋與分析。 第二節 後一國兩制時期中共對台之統戰策略一從一九八五到一九八六年的新情勢做一解釋與 分析。 第三節 一國兩制的析評，對中共所提出的一國兩制口號做一內容分析，以求瞭解真相。 第五章 兩航談判一本章分三節，從兩航談判的背景與經過做一說明後進而對整個談判做一檢 討，從檢討中來判斷談判本身是否為純粹統戰型式。 第六章 結論 本章除將中共對台統戰做一總檢討與整理外，也將預估未來中共對台之統戰走向及嚐 試著提出些因應之道的建議。

Made available in DSpace on 2017-07-21T18:53:04Z (GMT). No. of bitstreams: 1 ANDRESSA GABARDO GRANZA.pdf: 2807698 bytes, checksum: a0442acfb9a8bff732a7ec5ecaa9a286 (MD5) Previous issue date: 2015-02-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The development of gluten free products is becoming increasingly important as the number of celiac people have increased. Cheese breads and sour cassava starch biscuits are examples of gluten free baked products widely consumed in Brazil, however, these products have problems related to starch retrogradation, in other words, a very rapid staling in the case of baked products and the cheese breads marketed as frozen dough are susceptible to release of water (syneresis). Thus, the objective of this study was to develop a anti-staling premix able to increase freeze-thaw stability of gluten free baked products (cheese bread and sour cassava starch biscuits) without interfere negatively on the expansion property of these products. Binary and ternary mixtures were prepared using native cassava starch and oxidized cassava starch ranging the type of gum (guar, locust, xanthan and carrageenan) and the concentration used (2, 4 and 6 %). Mixtures using the acid modified cassava starch instead of oxidized cassava starch were also tested, but in this case using only guar gum at concentrations of 2, 4 and 6 %. The mixtures were evaluated for freeze-thaw stability and expansion property and the results were compared with those obtained for sour cassava starch (PA) native cassava starch (N), oxidized cassava starch (O) and acid modified cassava starch (A). The binary and ternary mixtures with better results and samples PA, N and O were evaluated for technological properties (pasting properties, swelling power and solubility and paste clarity), thermal properties (Differential Scanning Calorimetry - DSC), structural properties (Fourier Transform Infrared Spectroscopy - FTIR) and crystalline properties (X-ray diffraction); moreover, cheese breads were prepared with these samples and the staling of these products was evaluated (hardness parameter in texturometer and crumb moisture content). The mixture made with the native cassava starch, oxidized cassava starch and guar gum at a concentration of 4 % (MNO+GG 4 %) showed the best results of syneresis (loss of 4,87; 7,79 and 11 % in the 1st, 2nd and 3rd freeze-thaw cycle, respectively) compared with the other samples and the low retrogradation of this sample was confirmed by DSC analysis (enthalpy of retrogradation was non-existent) and FTIR (sample separated from others by principal component analysis - PCA). The expansion property of MNO GG+4 % sample was high (> 10 mL.g-1) and the cheese breads developed with this sample had a later staling compared with other samples, with lower hardness after 24 and 30 h of storage (23.71 and 29.59 N, respectively) and a wetter crumb (38.8 and 37.07%, respectively). These results indicate the possibility of using the premix MNO+GG 4% in gluten free baked products in place of sour cassava starch and/or native cassava starch. / O desenvolvimento de produtos livres de glúten está se tornando cada vez mais importante uma vez que o número de pessoas celíacas tem aumentado. Pães de queijo e biscoitos de polvilho são exemplos de produtos panificados livres de glúten consumidos em território brasileiro, porém, estes produtos possuem problemas relacionados com a retrogradação do amido, ou seja, um envelhecimento muito rápido no caso de produtos assados e os pães de queijo comercializados na forma de massa congelada estão susceptíveis à liberação de água (sinérese). Dessa forma, o objetivo do presente trabalho foi desenvolver uma pré-mistura capaz de retardar o envelhecimento e aumentar a estabilidade ao congelamento-descongelamento de produtos panificados livres de glúten (pães de queijo e biscoitos de polvilho), além de não interferir negativamente na propriedade de expansão dos mesmos. Misturas binárias e ternárias foram elaboradas utilizando-se o amido de mandioca nativo e o amido de mandioca oxidado variando-se o tipo de goma (guar, locusta, xantana e carragena) e a concentração utilizada (2, 4 e 6 %). Misturas utilizando o amido de mandioca ácido modificado ao invés do amido de mandioca oxidado também foram testadas, mas neste caso utilizando somente a goma guar nas concentrações de 2, 4 e 6 %. As misturas foram avaliadas quanto à estabilidade a ciclos de congelamento-descongelamento e propriedade de expansão e os resultados foram comparados com os obtidos para o polvilho azedo (PA), amido de mandioca nativo (N), amido de mandioca oxidado (O) e amido de mandioca ácido modificado (A). As misturas binárias e ternárias com melhores resultados e as amostras PA, N e O foram avaliadas quanto às propriedades tecnológicas (propriedade de pasta, poder de intumescimento e solubilidade, e claridade de pasta), térmicas (calorimetria exploratória diferencial - DSC), estruturais (Espectroscopia de infravermelho por transformada de Fourier - FTIR) e cristalinas (difração de raios X); além disso, foram elaborados pães de queijo com essas amostras e o envelhecimento dos mesmos foi avaliado (parâmetro dureza em texturômetro e teor de umidade dos miolos). A mistura feita com o amido de mandioca nativo, amido de mandioca oxidado e goma guar na concentração de 4 % (MNO+GG 4 %) apresentou os melhores resultados de sinérese (perdas de 4,87; 7,79 e 11 % no 1º, 2º e 3º ciclo de congelamento-descongelamento, respectivamente) em comparação com as demais amostras e a baixa retrogradação desta amostra foi confirmada pela análise de DSC (entalpia de retrogradação foi inexistente) e FTIR (amostra separada das demais pela análise de componentes principais – PCA). A propriedade de expansão da amostra MNO+GG 4 % foi considerada elevada (>10 mL.g-1) e os pães de queijo desenvolvidos com esta amostra tiveram um envelhecimento mais tardio em relação as demais amostras, apresentando menor dureza após 24 e 30 h de armazenamento (23,71 e 29,59 N, respectivamente) e um miolo mais úmido (38,8 e 37,07 %, respectivamente). Esses resultados indicam a possibilidade de utilização da pré-mistura MNO+GG 4 % em produtos panificados livres de glúten, em substituição do polvilho azedo e/ou amido de mandioca nativo.