Extrato aquoso de yacon (Smallanthus sonchifolius) desidratado por atomização
Carregando...
Data
2012-02-16
Autores
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Federal de Goiás
Resumo
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.
Descrição
Citação
NISHI, Adriana Candida Faustino. Aqueous extract of spray-dried Yacon (Smallanthus
sonchifolius). 2012. 84 f. Dissertação (Mestrado em Ciencias da Saude) - Universidade Federal de Goiás, Goiânia, 2012.