Original article Stability of microencapsulated lactic acid bacteria under acidic and bile juice conditions Dayana Pereira de Andrade, 1 C  ıntia Lacerda Ramos, 2 Diego Alvarenga Botrel, 3 Soraia Vilela Borges, 3 Rosane Freitas Schwan 1 & Disney Ribeiro Dias 3 * 1 Department of Biology, Federal University of Lavras, Lavras, MG 37.200-000, Brazil 2 Department of Basic Science, Federal University of the Vales do Jequitinhonha and Mucuri, Diamantina, MG 39.100-000, Brazil 3 Department of Food Science, Federal University of Lavras, Lavras, MG 37.200-000, Brazil (Received 15 September 2018; Accepted in revised form 7 January 2019) Summary The probiotic strains Lactobacillus brevis CCMA1284 and Lactobacillus plantarum CCMA0359 were microencapsulated by spray drying using different matrices – whey powder (W), whey powder with inulin (WI) and whey powder with maltodextrin (WM). Viability of the microencapsulated strains in acid and bile juices and during 90 days of storage (seven and 25 °C) was evaluated. The two strains exhibited high encapsulation efficiency (> 86%) by spray drying. The different matrices maintained L. plantarum viability above six log CFU g À1 at 7 °C for 90 days, whereas similar results for L. brevis were observed only for W. The use of inulin as matrix of encapsulation did not enhance bacterial viability in the evaluated condi- tions. In general, the use of W and WM as matrices was effective for L. plantarum viability. However, only W was effective for L. brevis in the evaluated conditions. The spray drying technique was successfully adopted for the encapsulation of L. plantarum CCMA0359 and L. brevis CCMA1284 strains. Keywords Lactobacillus brevis, Lactobacillus plantarum, milk proteins, spray drying, viability. Introduction Probiotics are ‘live microorganisms that, when admin- istered in adequate amounts, confer a health benefit on the host’ (Hill et al., 2014). Most of the probiotic strains are from human or animal sources, normal inhabitants of the gastrointestinal tract (GIT). However, several probiotic microorganisms have been isolated from spontaneously fermented foods. Sponta- neous fermentations such as cocoa fermentation and indigenous fermented foods are rich sources of microorganisms that could present great potential for industrial and health application. The strains Lacto- bacillus plantarum CCMA0359 and L. brevis CCMA1284 were previously isolated and characterised while regarding their probiotic potential and will be employed in the present work (Ramos et al., 2013). To be used as probiotics, the bacterial strains must survive stressful conditions such as the acidic environ- ment, bile salts, high temperatures, moisture and oxidative stress imposed during passage through the gastrointestinal tract, processing and storage of the products used as probiotic vehicles (Barbosa & Teixeira, 2016). Microencapsulation technology is a promising proposal to increase the viability of probi- otic strains during adverse environmental conditions and provide a more favourable anaerobic environment for sensitive probiotic bacteria. This technology employs an encapsulating matrix that protects cells during food storage and allows the release of probiotic bacteria into a viable and metabolically active state in the intestine (Picot & Lacroix, 2004; Mart  ın et al., 2015). Among the microencapsulation techniques of the probiotic cells, spray drying emerges as a highly efficient and reproducible technique with relatively low costs, producing powder with low moisture content and which is suitable for industrial applications (Mart  ın et al., 2015). The microencapsulation matrices include natural or synthetic polymers that are directly in contact with the living cell and must be biocompatible, biodegradable and safe (Nazzaro et al., 2012). Milk proteins are important candidates of encapsulation matrices due to their high nutritional value in addition to their struc- tural and physicochemical properties such as gelling, ability to interact with other polymers to form com- plexes, biocompatibility and biodegradability. Milk proteins comprise of casein, whey proteins and milk *Correspondent: E-mail: diasdr@dca.ufla.br International Journal of Food Science and Technology 2019 doi:10.1111/ijfs.14114 © 2019 Institute of Food Science and Technology 1