Ingenieria

U.P.B. Sci. Bull., Series B, Vol. 74, Iss. 1, 2012

ISSN 1454-2331

INTENSIFICATION OF PROBIOTIC MICROORGANISMS VIABILITY BY MICROENCAPSULATION USING ULTRASONIC ATOMIZER
Emese BOTH1, László GYENGE2, Zsolt BODOR3, Éva GYÖRGY4, Szabolcs LÁNYI5, Beáta ÁBRAHÁM6
Uscarea prin pulverizare este o metodă frecvent folosită la încapsularea microorganismelor probiotice. În prezentul studiu a fostutilizat duză ultrasonică de 120 kHz pentru a obţine granule foarte fine, care pot fi folosite în produse lactate probiotice. Celule de bacterii lactice au fost încapsulate în alginat şi maltodextrină prin atomizare cu ultrasunete. Încapsularea a fost realizată pentru a întări viabilitatea celulelor bacteriene în condiţiile aparatului digestiv: în suc gastric şi intestinal. The process of spraydrying is a commonly used method to encapsulate probiotic microorganisms. In this study was used 120 kHz ultrasonic nozzle to obtain very fine drops, which can be used in probiotic dairy products. Lactic acid bacterial cells were encapsulated in alginate and maltodextrin by ultrasonic atomization. Encapsulation was executed to enhance viability of bacterial cells in digestive conditions: in gastricand intestinal juices.

Keywords: probiotics, ultrasonic, spray drying, microcapsules, viability 1. Introduction Probiotics are live microorganisms (bacteria or yeast) which when ingested or applied locally, confer demonstrated health benefits to the host. The standard for probiotic foods follows the FAO/WHO recommendation: any food sold with health claims with addition of probiotics must containat least 106 to 107 CFU viable bacteria per gram [1, 2]. Species of lactobacilli survive poorly under simulated gastrointestinal conditions [3, 4]. The physical protection of probiotics by microencapsulation is a
1

PhD student, Faculty of Applied Chemistry and Material Science, University POLITEHNICA of Bucharest, Romania, e-mail: bothemese@sapientia.siculorum.ro 2 PhD student, Faculty ofApplied Chemistry and Material Science, University POLITEHNICA of Bucharest, Romania 3 PhD student, Faculty of Applied Chemistry and Material Science, University POLITEHNICA of Bucharest, Romania 4 PhD Eng., Faculty of Sciences, Miercurea Ciuc, SAPIENTIA University, Cluj Napoca, Romania 5 Prof., Faculty of Sciences, Miercurea Ciuc, SAPIENTIA University, Cluj Napoca, Romania 6 PhD Eng., Faculty ofSciences, Miercurea Ciuc, SAPIENTIA University, Cluj Napoca, Romania

28 Emese Both, László Gyenge, Zsolt Bodor, Éva György, Szabolcs Lányi, Beáta Ábrahám

new approach to improve the probiotic survival [5]. Microencapsulation by spray drying is considered the most popular, cost effective and good long-term preservation method for lactic acid and probiotic bacteria [6]. This process isreadily available, easy to operate and energy efficient [7, 8]. Cîrîc [9] encapsulated probiotic bacteria by spray drying in sodium alginate and maltodextrin with high survival rate during the process. Alginate is the most commonly used polymer for immobilizing viable cells and it has been used in various food applications. Maltodextrin functions as an osmotically inactive bulking compound, whichcauses spacing of the bacterial cells and strengthening of the glassy matrix [7]. 2. Experimental 2.1. Microorganism and its maintenance

A pre-culture of strain Lactobacillus brevis isolated from traditional manufactured cheese in 250 mL of MRS broth (this medium is named by its inventors: de Man, Rogosa and Sharpe, developed in 1960, it was designed to favour the growth of Lactobacilli for labstudy) was incubated at 37°C for 48 h, the cultured broth was centrifuged at 5000 rpm (d=12 cm) for 20 min. The resulting pellet was resuspended in 500 mL MRS broth and cultivated for 48 h, at 37°C. Before spray-drying cultured broth was centrifuged at 5000 rpm (d=12 cm) for 20 min and pellet was resuspended in 10 mL of 8 g/L NaCl solution. Microencapsulation of the probiotic microorganisms 2.2.1....