Extrato aquoso de yacon (Smallanthus sonchifolius) desidratado por atomização

• Autor(a) principal: NISHI, Adriana Candida Faustino
• Data de Publicação: 2012
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tde/1475
• topic: Smallanthus sonchifolius; frutooligossacarídeos, Yacon, Alimentos funcionais, spray dryer; Smallanthus sonchifolius; fructooligosaccharides; Yacon; functional food; spray dryer; CNPQ::CIENCIAS DA SAUDE::NUTRICAO

Yacon (Smallanthus sonchifolius) is a tuberous root native to the Andean region, considered a functional food due to the presence of bioactive components that contribute to the balance of the intestinal microbiota. To incorporate these compounds into the diet of the population, the development of dry extract standardized as fructooligosaccharides (FOS) and phenolic compounds (CF) was proposed, using the spray drying technique. To obtain yacon dry extracts, roots were characterized, and subsequently, an aqueous extract was prepared through the grinding and filtering technique. Then, a study on the drying process was conducted in order to assess the effects of the addition of different adjuvants (aerosil, maltodextrin and pregelatinized starch) on the final concentration of fructooligosaccharides (FOS) and phenolic compounds (PC) in the dry matter. The study was based on twolevel factorial design with three focal points, using adjuvant concentration (20, 50% w / w) and feeding flow rate (2, 6 mL / min) as factors. The best combination of the drying parameters was determined by considering the effects of independent variables (adjuvant concentration and feeding flow rate) on the FOS and PC contents in the dry extracts. In the root characterization, the following contents on a dry basis were found: moisture 9.29 ± 0.085; ash 3.33 ± 0.07, protein 4.29 ± 0.173, lipids 0.80 ± 0.0359, total carbohydrates 81.49 ± 4.18, total fructose 56.47 ± 0.97, reducing sugars 24.05 ± 0.13 and FOS 32.43 ± 0.971. The fresh aqueous extract showed FOS 33.47 (% w / w) and PC 0.44 (% w / w) with better antioxidant activity compared to BHT (2,6-Di-tert-butyl-4-methylphenol). The aqueous extract concentrated in a rotary evaporator showed density 1.04 ± 0.002, viscosity 4.34 ± 0.056, and total solids 10.67 ± 0.051. In general, the dried extracts obtained with aerosil, maltodextrin and pregelatinized starch showed FOS contents from 27.20 to 32.4, 24.25 to 31.3 and 23.54 to 35.64 (% w / w ), respectively, and PC from 0.267 to 0.320, 0.319 to 0.399 and 0.407 to 0.425 (% w / w), respectively. The statistical analysis for the three types of adjuvants and the effects of independent variables on the response variables (FOS and PC) showed that the dried extracts were influenced in different ways. Aerosil: Analysis of variance for the linear model showed that this model was not significant, F equal to 2.44 in the response FOS content. PC was influenced by X2, F 29.10 and r2 0.8534. Maltodextrin: The FOS content was influenced by X1, F 13, and r2 0.7222. PC was influenced by X2, F 9.70 and r2 0.6599. Pregelatinized starch: The linear model did not describe the experimental data for the FOS content. The surface response of the PC content in function of X1 and X2 showed a trend to increase the PC content by reducing the adjuvant concentration and increasing the feeding flow rate. Moisture content of less than 5% in all the extracts indicates that the configuration of the equipment variables was correctly set. The yield was affected by constraints of the technique to extracts rich in sugars and with low molecular weight, ranging from 10 to 55%, which lowest results were found for extracts dried with starch. The images of the microstructure of extracts dried with aerosil resulted in spherical particles with diameter between 0.5 and 1.0 μm, while maintaining the appearance of fine and loose powder. Extracts dried with maltodextrin and pregelatinized starch tended to form clusters.