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Master's Dissertation
DOI
https://doi.org/10.11606/D.11.2012.tde-20052013-163950
Document
Author
Full name
Fernanda Viginotti Alves
E-mail
Institute/School/College
Knowledge Area
Date of Defense
Published
Piracicaba, 2012
Supervisor
Committee
Sarmento, Silene Bruder Silveira (President)
Aguiar, Claudio Lima de
Lopes, Jorge Jose Correa
Title in Portuguese
Interferência do amido e da dextrana nas análises tecnológicas do caldo de cana-de-açúcar
Keywords in Portuguese
Amido
Análise ótica
Cana-de-açúcar
Dextrana
Abstract in Portuguese
A indústria Sucroenergética tem como uma de suas preocupações atuais a presença de polissacarídeos, como o amido e a dextrana, no caldo de cana-deaçúcar. Além de afetar a qualidade do açúcar, estes polissacarídeos podem alterar resultados de análises tecnológicas do caldo e, possivelmente, causar erros no pagamento da cana. Foram objetivos deste estudo: a) isolar e caracterizar o amido isolado de cana da variedade RB 86-7515 e b) avaliar a interferência de adições crescentes deste amido isolado e de dextranas comerciais com pesos moleculares 40.000 e 5.348.000 Dalton nas análises de polarimetria e refratometria do caldo e de uma solução de sacarose (sistema modelo) a 19% (m/m). As adições de amido e dextrana interferiram nas leituras de Pol e Brix, tanto em solução de sacarose como no caldo. Foi constatada forte correlação positiva entre as variáveis (Pol% x doses de amido ou dextrana e Brix% x doses de amido ou dextrana), tanto para o ensaio em solução de sacarose como para caldo. A dextrana teve maior interferência sobre as análises, embora a interferência do amido também tenha sido evidente. Por tratar-se de um sistema complexo (composição mista de várias substâncias, inclusive amido e dextrana originalmente presentes) o caldo de cana apresentou na maioria dos ensaios, incrementos menores de leituras no polarímetro e refratômetro que o sistema modelo. A adição de amido em solução de sacarose causou incrementos de Pol% a partir de dose compreendida entre 500 e 1000 ppm, enquanto no caldo esses acréscimos foram significativos a partir de doses entre 100 e 500 ppm. A adição de dextrana em solução de sacarose causou variação significativa da Pol% a partir de dose entre 100 e 500 ppm, independente do peso molecular, e no caldo entre 1000 e 5000 ppm para as de peso molecular menor e entre 500 e 1000 ppm para a de maior peso. Na análise de Brix% a adição de amido em solução de sacarose causou variação significativa a partir de dose compreendida entre 0 e 100 ppm, e no caldo a partir de dose entre 500 e 1000 ppm. No caso da dextrana, o ensaio com solução de sacarose apresentou variação significativa do Brix% a partir de dose compreendida entre 0 e 100 para a de menor peso e entre 100 e 500 ppm para a de maior peso. No caldo esses acréscimos foram significativos a partir de doses entre 100 e 500 ppm para ambas as dextranas. O amido isolado de cana foi caracterizado revelando a predominância de grânulos esféricos, com diâmetro médio variando de 2,8 a 3,1 ?m e coloração muito próximo à branca. Seu teor de amilose foi de 17,5%, com padrão de cristalinidade do tipo A e cristalinidade relativa de 44,21% (elevada). A endoterma de gelatinização variou entre 66 e 81°C, com entalpia de 10,57 J.g-1.
Title in English
Interference of starch and dextran in technological analysis of sugarcane juice
Keywords in English
Dextran
Starch
Sugarcane
Technological analysis
Abstract in English
The Sucroenergetic industry has as one of their current concerns the presence of polysaccharides, such as starch and dextran, in sugar cane juice. In addition to affecting the quality of sugar, these polysaccharides can alter the results of technological analysis of the juice and possibly cause errors in the payment of sugarcane. The aims of this study were: a) isolate and characterize the isolated starch of sugarcane variety RB 86-7515 b) evaluate the influence of increasing additions of isolated starch and commercial dextrans with molecular weights 40,000 and 5,348,000 Daltons in the analysis of polarimetry and refraction of the juice and a sucrose solution (system model) to 19% (w/w). The additions of starch and dextran affected the Brix and Pol readings, both sucrose solution as in the juice. There was a strong positive correlation between the variables (% Pol x doses of starch or dextran and Brix% x doses of starch or dextran) for the test in sucrose solution and juice. Dextran has been more interference in the analysis, although interference of starch has also been evident. Because it is a complex system the juice showed in most trials, smaller increments on polarimetry and refractometry that the model system, by the presence of other substances. The addition of starch in sucrose solution caused increments of Pol% from the dose between 500 and 1000 ppm, while in the juice these additions were significant at doses of 100 to 500 ppm. The addition of dextran in solution of sucrose caused significant variation of Pol% from the dose between 100 and 500 ppm, regardless of molecular weight, and in juice between 1000 and 5000 ppm for the lower molecular weight and between 500 and 1000 ppm for the highest weight. In the analysis of Brix% the starch addition in sucrose solution caused a significant variation from the dose between 0 and 100 ppm, and in juice from the dose between 500 and 1000 ppm. In the case of dextran, the test with sucrose solution presented a significant variation of Brix% from the dose between 0 and 100 to the lower weight and between 100 and 500 ppm for higher weight. In juice these additions were significant from the doses between 100 to 500 ppm for both dextrans. The starch was isolated from sugar cane and was characterized revealing the predominantly spherical granules with an average diameter ranging from 2.8 to 3.1 ?m and coloration close to white. Its amylose content was 17.5%; with crystallinity pattern of type A and relative crystallinity of 44.21% (high). The gelatinisation endotherm varied between 66 and 81 °C with enthalpy of 10.57 J.g-1.
 
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Publishing Date
2013-06-12
 
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