Microencapsulamento de Lactobacillus acidophilus a partir de extrato solúvel de Yacon (Smallanthus sonchifolius): um estudo de parâmetros de processo

Abstract

The yacon potato is a native South America tuber that has funcional food characteristics, the yacon botato had a high concentration of fructooligosaccharides (FOS) that can help in the formation of fecal bolus and phenolic compounds which act as antioxidants in the body. Given these attributes, this project was developed to benefit the yacon potato in a powdered product with probiotic properties by spraydrying atomization and the addition of Lactobacillus acidophilus. The yacon potato was purchased at Pernambuco Supply Center - CEASA, located in Recife - PE. The physicalchemical characterization was performed in the sample and an aqueous extract was prepared. For spray-drying, a 30% total solids solution was prepared with the addition of Lactobacillus acidophilus LAFTI L10. The process was optimized using a factorial design 2³ with 8 factorial points and 3 central points, totaling 11 trials, in wich the independent variables are drying air temperature (° C), feed rate (l/h) and encapsulating agents used (maltodextrin and/or gum arabic) and the answers are Encapsulation efficiency, Moisture (%), Water Activity (aw), Colorimetric nalysis, Hygroscopicity (g.100g-1), Phenolic compounds, Potencial Antioxidant and Viable Cell Count (log CFU / g) and the microparticles morphology was determined by electronic microscopy. All analysis was made in triplicate samples and the results expressed as mean ± standard deviation. The optimized conditions obtained from the analysis of the response surface graphs for the spray-drying powders were different drying temperatures (110º, 130º and 150 ° C), Mass flow rate (0.48 L / h; 0.60 L / h 0.72 L / h) and wall material (WM) [maltodextrin (MD) and gum arabic (GA)], reaching a final concentration of 30%. Even of the process condition and the WM used, microencapsulation showed protection from L. acidophilus LAFTI L10 in which the efficiency of microencapsulation was (78.37 to 99.59%), in addition to low moisture content (3.97 to 8.3%), from aw (0.14 to 0.38). The project demonstrated that encapsulation of GA as a wall material provided the obtainment of a powder with good cell viability, better profile in the antioxidant activity of DPPH and FRAP, thus, it can be considered a promising technique to be used in the production of new food products with functional properties.