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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Extra??o e caracteriza??o de amido nativo e modificado da palma forrageira (Opuntia ficus indica)

Leopoldino, Kleison Jos? Medeiros 08 March 2017 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-08-10T11:27:23Z No. of bitstreams: 1 KleisonJoseMedeirosLeopoldino_TESE.pdf: 3670503 bytes, checksum: fac71654a7e7a4975a849e81e26459a7 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-08-10T14:23:36Z (GMT) No. of bitstreams: 1 KleisonJoseMedeirosLeopoldino_TESE.pdf: 3670503 bytes, checksum: fac71654a7e7a4975a849e81e26459a7 (MD5) / Made available in DSpace on 2017-08-10T14:23:36Z (GMT). No. of bitstreams: 1 KleisonJoseMedeirosLeopoldino_TESE.pdf: 3670503 bytes, checksum: fac71654a7e7a4975a849e81e26459a7 (MD5) Previous issue date: 2017-03-08 / Na modifica??o do amido pelo processo oxidativo foi utilizada uma solu??o de periodato de s?dio (APOX), enquanto na fosforila??o foi utilizada tripolifosfato de s?dio variando-se a sua concentra??o em rela??o ao tempo com o intuito de estabelecer limites de f?sforo adequados para uso em alimentos. A obten??o e modifica??o qu?mica do amido da Palma Forrageira (Opuntia ficus indica) ? o objeto de estudo deste trabalho. Os resultados demonstraram um aumento do teor de f?sforo obtendo-se o m?ximo de acordo com a Portaria N? 42/98 de 2005 no tempo de 40 minutos com 7% de tripolifosfato de s?dio. Os resultados indicaram ainda que ambos os fatores estudados (tempo e concentra??o) influenciam na fosfata??o do amido (APF) devido a intera??o destas vari?veis independentes. Das propriedades avaliadas do amido nativo (APNM), amido liofilizado (APL) e os modificados foram determinados a composi??o centesimal, teor de f?sforo, teor de amido, amilose e a forma e tamanho dos gr?nulos de amido. As propriedades f?sico-quimicas foram analisadas nas amostras do amido nativo, liofilizado e modificado sendo determinada a densidade, poder de intumescimento, ?ndice de solubilidade, caracteriza??o do gel, turbidez, sin?rese, viscosidade de pasta, an?lise calorim?trica. O amido nativo da palma forrageira apresentou densidade 1,67 g.mL-1 e a modifica??o diminuI a densidade do amido nativo. O poder de inchamento e o ?ndice de solubilidade do amido nativo, liofilizado e modificados apresentaram diferen?as significativas. A modifica??o, tamb?m, diminuiu a absorb?ncia porque facilita a passagem da luz, enquanto a sin?rese foi influenciada pela modifica??o, ocorrendo um aumento com o n?mero do ciclo de armazenamento, e uma diminui??o com a modifica??o qu?mica. O amido fosfatado apresentou maior viscosidade de pasta do que o amido nativo devido os mesmos possu?rem maior poder de intumescimento e ?ndice de solubilidade em ?gua. O amido nativo extra?do da palma forrageira apresentou pureza 99,30%. / Obtaining and chemical modification of starch from forage Palma (Opuntia ficus indica) is the object of study of this work. The starch was extracted from cactus pear presented purity 99.30% and modified routes this starch were oxidation and phosphorylation with the assessment of the effects of this change. The starch was modified by sodium periodate to the oxidation process, while for the phosphorylation process was varied the concentration of sodium tripolyphosphate compared to reaction times in order to establish phosphorus limits suitable for use in foods based on Codex Alimentarius . The results showed an increase in phosphorus content to give maximum accordance with the rules in time 40 minutes with 7% sodium tripolyphosphate. The results further indicated that both factors studied (time, concentration) influence the starch phosphate treatment due to the interaction of these independent variables. Of the properties evaluated the native and modified starch were determined chemical composition, phosphorus, starch, amylose and the shape and size of the starch granules. Chemical modification of starch caused higher phosphorus and ash and decreased levels of starch and amylose, achieving experimentally most phosphating according to the legislation in time from 40 minutes to 7% of sodium tripolyphosphate after going through a process dialysis. The functional properties of the samples were analyzed on native starch and modified and determined density, swelling power, solubility index characterizing the gel turbidity, syneresis, paste viscosity, calorimetric analysis. The native starch from cactus pear density showed 1.67 g.mL-1 and the modification decreased the density of native starch. The swelling power and solubility index of the native and modified starch showed significant differences. The modification also decreased the absorbance because it facilitates the passage of light, while syneresis was influenced by modifying, with an increase in the storage cycle number, and a decrease in chemical modification. The phosphate starch showed higher viscosity slurry than native starch because they possess greater power of swelling and solubility rate in water.

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