Avaliação de bactérias do ácido lático, endógenas da mandioca, nas características do polvilho azedo

• Ano de defesa: 2010
• Autor(a) principal: Corrêa, Maria Ivaneide Coutinho
• Orientador(a): Mancilha, Ismael Maciel de
• Banca de defesa: Passos, Flávia Maria Lopes , Cruz, Renato Souza
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Ciência e Tecnologia de Alimentos
• Departamento: Ciência de Alimentos; Tecnologia de Alimentos; Engenharia de Alimentos
• País: BR
• Palavras-chave em Português: Polvilho azedo; Fermentação; Bactérias lácticas; Amido de mandioca
• Palavras-chave em Inglês: Cassava starch; Fermentation; Lactic bacteria
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS::CIENCIA DE ALIMENTOS
• Link de acesso: http://locus.ufv.br/handle/123456789/479

The fermentation process order to obtain sour cassava starch occurs through a natural and spontaneous process, where a grate number of factors which interfere in the characteristics of this product are observed. Therefore, the purpose of the present work is to contribute for the standardization of the fermentation conditions through the evaluation of the fermentative process developed for 24 days. It was evaluated the performance of inoculums constituted of 14 lactic acid bacteria strains isolated from the natural process. These experiments were carried out in fermentation tanks at industrial scale and in the laboratory, employing five isolates called back slooping . For that, the physical, chemical and rheological properties from the sour cassava starch were evaluated as well as the expansion index and the sensorial acceptance of cookies made from the respective starches. The fermentative performance of fourteen isolates individually evaluated and in the format of pool (ISO) consisting of five of those isolates, as well as the BS pool formed by the back slooping in batch reactor and in industrial level, having as the control (CR) the xii process developed in a natural way without the addition of inoculums was determined. The results showed that the fourteen isolates were identified as lactic acid bacteria. From those, the five isolates obtained in different stages of the fermentation process (which promoted the highest expansion indexes in starch cookies), were selected and identified as belonging to the genus Lactobacillus. The inoculums fermentative performance in the form of pool (ISO and BS) and the CR, in laboratory scale, followed by artificial drying, revealed that there was no difference among the three treatments regarding the pH, the titratable acidity and the expansion index. When that was compared to the control (CR) performance in 150 L reactors with the control (ICR) in the level of the developed industry in 9000 L reactors, followed by drying in the sun, no difference in the expansion index or the sensorial acceptance of cookies was observed, allowing to infer that it is possible to obtain quality sour starch by both large and small producers. Besides that, in 150 L reactors, it was observed the inoculums in the form of pool (ISO and BS) and the CR did not present differences regarding the pH, the titratable acidity or the expansion index. The paste properties obtained in rapid visco analyser (RVA) revealed that the sour cassava starch obtained in industrial scale, treatments with inoculums in the form of pool (ISO and BS) and the CR, presented less viscosity, stability to agitation and retrogradation tendency in relation to the cassava starch. However, the sensorial acceptance of cookies produced with the starches originated from the fermentation with the inoculums in the form of pool (ISO and BS) was superior in relation to the control (CR). The sour cassava starch, obtained after sixteen days of fermentation, using the inoculums in the form of pool, presented superior quality in relation to the sensorial acceptance. Such results allow to conclude that when the sensorial acceptance criterion is used it is possible to infer that sixteen days of fermentation, using inoculums in the form of pool (ISO or BS), is enough to obtain sour cassava starch of good quality.