Soy extract and maltodextrin as microencapsulating agents for Lactobacillus acidophilus: a model approach

Abstract

The present study aimed to optimise the microencapsulation of Lactobacillus acidophilus La-05 by spray drying, using soy extract and maltodextrin as encapsulants. Air inlet temperature, maltodextrin/soy extract ratio and feed flow rate were investigated through Central Composite Rotational Design (CCRD). Probiotic viability increased with increasing the proportion of soy extract. Temperature and feed flow rate had a negative effect. Particle diameter ranged from 4.97 to 8.82 μm, water activity from 0.25 to 0.52 and moisture from 2.30 to 7.01 g.100g⁻¹ Particles produced following the optimised conditions (air temperature of 87 °C, maltodextrin/soy extract ratio of 2:3 w.w⁻¹, feed flow rate of 0.54 L.h⁻¹) reached Encapsulation yield (EY) of 83%. Thermogravimetry and FTIR analysis suggested that microcapsules could protect L. acidophilus cells against dehydration and heating. During storage, microencapsulated probiotic had high cell viability (reductions ranged between 0.12 and 1.72 log cycles). Soy extract/maltodextrin presented well-encapsulating properties of Lactobacillus acidophilus La-05.

KEYWORDS:

• Spray drying
• microcapsules
• probiotic
• encapsulation yield
• optimisation

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the article.

Additional information

Funding

This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001.