Full text
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| Author(s): |
Joelise de Alencar Figueira Angelotti
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia de Alimentos |
| Defense date: | 2009-02-18 |
| Examining board members: |
Helia Harumi Sato;
Gabriela Alves Macedo;
Luciana Francisco Fleuri
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| Advisor: | Helia Harumi Sato |
| Abstract | |
The aim of this work was to quantitatively determine sugarcane starch in five varieties of sugarcane (RB86-7515, SP83-2847, RB72-454, SP80-3280 and RB85-5536) during one harvest (May to November 2007), and study some of the characteristics of sugarcane starch. The variety RB86-7515 showed a higher starch content than the other varieties analyzed throughout the entire harvest. No correlation between the temperature, pluviometric index and starch level was found in any of the samples of sugarcane juice. The sugarcane starch granules examined under the scanning electron miscroscope showed a spherical shape with a diameter between 1-3 mm, smaller than the starch granules of maize and cassava. The sugarcane, corn, potato and soluble starches formed complexes with iodine, which showed greater absorption in the range from 540 to 620 nm. The crude sugarcane starch showed greater susceptibility to the enzyme glucoamylase than the waxy corn, cassava and potato starches. The sugarcane starch showed a susceptibility to debranching by the amylolytic enzyme pululanase, which hydrolyzed the a-1,6 glucosidic linkages in a way similar to waxy corn starch, which contains a high amount of amylopectin. The sugarcane starch showed susceptibility to the a-amylases from Bacillus subtilis, Bacillus licheniformis and Aspergillus oryzae, similar to the other starches tested, producing glucose, maltose, maltotriose, maltotetraose, maltopentaose and a-limit dextrins. This work aimed to adequate the methodologies used to determine residual a-amylase in raw sugar. The Bernfeld method is based on the determination of the reducing sugars by an iodometric method based on discoloration of the starch-iodine complex. The Phadebas method is based on the hydrolysis of the starch polymer dyed with Cibachron Blue F3GA, and the method using BPNPG7 r ¿ nitrophenyl maltoheptaoside (benzylidene blocked maltoheptaoside, Megazyme, Ireland) is based on the hydrolysis of the substrate, releasing p-nitrophenol. These three methods were tested for the determination of residual a-amylase in raw sugar, and the Bernfeld method was shown to be more adequate (AU) | |
| FAPESP's process: | 06/59514-0 - Determination and characterization of starch from sugarcane and adjustment of methodology for the determination of residual alpha-amilase in raw sugar |
| Grantee: | Joelise de Alencar Figueira Angelotti |
| Support Opportunities: | Scholarships in Brazil - Master |