Thèse (M.A.)--Université Laval, 2003. / Bibliogr.: f. 47-48. Publié aussi en version électronique.

The basic aim of barley malt breeders and maltsters is to produce malt with optimum fermentability levels. The purpose of this research was to understand and evaluate the effect of wort boiling and autoclaving at varying time periods (30, 45, 60, 90, and 120 min) on malt fermentability. The effect of trub content was also analyzed. Small-scale fermentations were carried out using a ‘Control malt’ and a standard SMA yeast strain. The Apparent Degree of Fermentability (ADF), Turbidity (absorbance at 600nm), and Density (oPlato) were measured at specific time intervals over three day fermentation period and non-linearly modeled. From the results obtained, we suggest that heat treating wort with or without trub, (at 100°C, 121.1°C) for a range of times results in significant decline in the ADF (p<0.05). Free amino nitrogen levels of wort declined significantly with respect to both increase in wort boiling temperature and intervals (p<0.001).

Orientador: Roberto Herminio Moretti / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-08T04:13:28Z (GMT). No. of bitstreams: 1 Teles_JulianaAndrade_M.pdf: 622280 bytes, checksum: 3493048181e488146089fb10fb6cacd0 (MD5) Previous issue date: 2007 / Resumo: O uso de extrato de malte concentrado como matéria-prima cervejeira até hoje foi pouco estudado. É sabido que produzir cervejas claras e sem resíduo adocicado, é um desafio para este ingrediente. No entanto, cervejas produzidas a partir de extrato de malte concentrado, necessitam de menores investimentos quando se comparado ao método tradicional pois, economiza em mão-de-obra, espaço e energia. Pensando nisso, o trabalho teve como objetivo, produzir diferentes mostos concentrados lupulados formulados conforme planejamento experimental aplicado (DCCR), caracterizar as cervejas produzidas com estes mostos. Estudar o uso de xarope de alta maltose com a finalidade de redução da cor e proteína no produto final e verificar durante a fervura, interações ocorridas entre malte/adjunto, lúpulo e tempo quanto à cor, amargor, polifenóis e proteínas. Verificou-se que mostos produzidos com extrato de malte concentrado possuem fermentações mais lentas. Os produtos obtidos tiveram características físico-químicas semelhantes à cerveja tipo Pilsen. Durante a fervura, o tempo foi mais influente para a produção de cervejas mais escuras. Apesar disso, o uso de xarope de alta maltose como substituição parcial dos açúcares fermentescíveis do malte, na redução da cor, foi totalmente eficaz, como também para o aumento na luminosidade e menores quantidades de proteínas. Por fim, para promover mais eficiente complexação entre proteínas-polifenóis, seriam necessárias quantidades maiores de lúpulo. Assim sendo, mostos concentrados feitos a partir de extrato de malte concentrado possuem grandes potencialidades e levam a crer que acrescentam mais vantagens do que desvantagens para a produção de cerveja / Abstract: The use of extract malt concentrated as beer raw material until today little was studied. It is known that to produce clear beers and without sweet residue, it is a challenge for this ingredient. However, beers produced from extract malt concentrated, need lesser investments when if compared with the traditional method, therefore it is saved in man power, space and energy. Thinking about this, the work had as objective, to produce differents worts hopped concentrated formulated as experimental design applied, to characterize the beers produced with these worts, to study the use of boiled must of high maltose with the purpose of reduction of the color and protein and to verify, during the boil, occurred interactions between malt/adjunct, hop and time how much to the color, bitter taste, polyphenol and proteins. It was verified that worts produced with extract of malt concentrated have slower fermentations, the gotten products had characteristics similar to the beer Pilsen type. During the boil, the time was more important for production of darker beers. Despite this, the use of high maltose syrup as partial substitution of the fermentable sugars of malt, in the reduction of the color was total efficient, as also for the increase of the luminosity and minors amounts of protein. Finally, to promote more efficient complex between proteins-polyphenols, they would be necessary more of hop. Thus being, made intent worts from extract of malt concentrated have great potentialities and lead to believe that they add more advantages of that disadvantages for beer production / Mestrado / Mestre em Tecnologia de Alimentos

This diploma thesis develops methodology of arsenic speciation analysis by selective hydride generation with cryotrapping and atomic absorption spectrometry. Using this technique it is possible to determine toxicologically important forms of arsenic, i.e arsenites, arsenates and their mono-, di-, and trimethylated forms at concentration levels below 0,1 ng.ml-1 . The first part of the thesis is focused on testing tubular membrane gas dryers with nafion membrane for drying gaseous phase containing generated hydrides. The suitability for arsenic speciation analysis was investigated and transport losses of individual arsenic species were found. The second part describes mild digestion procedures suitable for arsenic speciation analysis in tissues. Two procedures were compared, acid digestion in phosphoric acid and more recent alkalic digestion by tetramethylammonium hydroxide. Digestion procedures were tested on certified reference material DOLT - 4 (Dogfish Liver) and chicken liver matrix. Key words: Tubular nafion membrane dryers, Arsenic speciation analysis, Digestion, Phosphoric acid, Tetramethylammonium hydroxide, Chicken liver, CRM DOLT - 4, Hydride generation, Atomic absorption spectrometry

Diploma thesis "Gender and manpower in production companies in the Chomutov region" is focused on historically and sociologically oriented research of employment of men and women in production companies in the Chomutov region over last 50 and 70 years respectively. The main aspects which are included in the theoretical part of this work are gender relations in the production companies, that is the history of the employment of women, horizontal and vertical gender segregation including wages and salaries and employee education. The analyzed data are from the period of mid 20th century and the beginning of the 21st century and focus primarily on the production companies of The Tube and Iron Rolling Mill and their current successor Sandvik. By means of data analysis, the methodical part of the thesis describes differences and changes which have ocurred in the horizon of last 50 and 70 years in the manpower employment in production companies with respect to gender. KEYWORDS Gender, Feminism, Manpower, Socialism, The Tube and Iron Rolling Mill, Production, Chomutov