SPRAY DRY-MICROENCAPSULATION OF FERULOYL ESTERASE-PRODUCING LACTOBACILLUS STRAINS

ABEIJON MUKDSI, MARIA CLAUDIA; SANTACRUZ, ARLETTE; ROSS, ROMINA; JIMENEZ-MUNGIA, MARIA TERESA; MEDINA, ROXANA BEATRIZ; PALOU, ENRIQUE; GAUFFIN CANO, MARIA PAOLA; LOPEZ-MALO, AURELIO

San Miguel de Tucumán

Simposio; V Simposio Internacional de Bacterias Lácticas; 2016

Centro de Referencia para Lactobacilos (CERELA) - CONICET

Feruloyl esterases (FE) are enzymesresponsible for the release of ferulic acid (FA), naturally present in vegetablefoods as non-digestible ester-linked forms. FA has antioxidant properties and itsconsumption has shown to exert beneficial effects in pathologies related tooxidative stress, such as metabolic syndrome and obesity. In this context,probiotic FE-producing bacteria can be used as dietary supplements orincorporated into functional foods. Spray-dry microencapsulationis an efficient method for protecting probiotic strains during food processingand storage, as well as gastrointestinal tract (GIT) transit. Hightemperatures during spray-drying are detrimental to probiotics, thus encapsulatingagents and operation conditions should be carefully selected. The aim of this study was to optimize the spray-dry encapsulation ofFE-producing Lactobacillus strains, evaluate theirviability and FE activity after drying, during refrigerated storage and theirresistance to GIT conditions. Three strains were used: L.fermentum (Lf) CRL1446, L.johnsonii (Lj) CRL1231 and L.acidophilus(La) CRL1014. Cells at late-log phase (~9 log cfu/ml) wereincorporated in a sodium alginate/maltodextrin/inulin mixture and dried in a pilotspray-dryer, adjusting operationparameters to reach outlet air temperatures below 80-85°C. Strain viability and FEactivity were determined before and after spray-drying process and duringstorage at 4°Cup to 9 months. Reconstituted powders were incubated in PBS pH7 containing methyl ferulateas substrate, and released FA was quantified by HPLC. Resistance of microencapsulated andfree cells to GIT conditions was assessed by sequential incubation insimulated gastric and intestinal juices. Physical properties ofpowders (size distribution, density, moisture, porosity) were determined. At optimized processconditions, powder recovery was ~65%. All strains survived to drying, yielding~9 log cfu/g powder, and maintained their FE activity. Lf and Lj were stableduring storage at 4°Cfor 1 month (8.2 and 8.7 log cfu/g, respectively), while viability of La decreased considerably (6.1 logcfu/g). After 9 months, cell counts were 8.3, 7.2 and 5.6 log cfu/g for Lf, Ljand La, respectively. FE activities weresimilar in La and Lj powders (39-44 U/log cfu), higherthan in Lf powder (17 U/log cfu), andincreased slightly during storage. Microencapsulated cells showed higher survivability to GIT conditionscompared to free cells. Powders presented adequate physical properties. Ourresults indicate that spray-dried microcapsules containing FE-producing Lf CRL1446 or Lj CRL1231 could be used as suitable ingredients to develop novel dietary supplements or functional foods.