Effect of Microencapsulation on the Development of Antioxidant Activity and Viability of Lactobacillus acidophilus LA5 in Whey Drink During Fermentation

Abstract

Encapsulation could be used for increasing of probiotic’s viability and maintaining of product’s quality during storage. The encapsulation process was performed using alginate-resistant starch and Eudragit S100 nanoparticles and by the extrusion technique. In whey drink, the viability of encapsulated L. acidophilus was upper in comparison to the free probiotic bacteria (P=0.001). The viability of bacteria reduced significantly during the study (P<0.001 in both groups), and encapsulated bacteria were more stable during the storage time than free forms (P=0.046). In gastrointestinal conditions, the viability of bacteria was reduced significantly during the 120 min study period in both groups (P<0.001 for free form and P=0.001 for microencapsulated bacteria). Encapsulated bacteria were more stable than free form (P<0.001). Free bacteria containing whey products exhibited an increasing antioxidant activity from beginning day to the fifth week (0.1-2.6 mmol Trolox equivalents/mL sample). Whey drinks with encapsulated bacteria showed similar antiradical properties for the first time, but their increasing activity rate within 35 days was lower than free form samples (0.1-0.9 mmol Trolox equivalents/mL sample). This technique of encapsulation can prevent bacteria from reducing their survivability. Whey products prepared using L. acidophilus (especially in free form) could be considered as a potent antioxidant functional drink.