Impact of carrier material on fermentative activity of encapsulated yoghurt culture in whey based substrate

Abstract

The main objectives of this paper were to study the influence of the carrier material used for encapsulation and of bead size to fermentative activity and viability of the dairy starter culture ‘Lactoferm ABY 6’. Encapsulation of yoghurt culture in beads with diameter of 1mm provides better results than encapsulation in beads with larger diameter. Alginate beads and chitosan coated beads have proved to be a strong barrier for nutrients from substrate, so samples with those beads have lower viable cell count, lower titratable acidity and higher pH value after 5h of fermentation at 42°C, than samples with WPC-alginate beads. Also those beads have significantly (P < 0.05) lower cell leaking, than WPC-alginate beads and lower antioxidant capacity. Encapsulation of yoghurt culture in WPC-alginate carrier with diameter of approximately 1mm provided the best characteristics for fermented product. Samples with these beads have significantly (P < 0.05) higher increase of viable cell number after fermentation, despite of major cell leaking (19.7 %). Moreover, sample with these beads have the highest titratable acidity, the lowest pH value after fermentation (the best fermentative activity) and the best antioxidant characteristics. [Projekat Ministarstva nauke Republike Srbije, br. TR 31017 i br. III 46010]

Keywords

• whey
• encapsulation
• alginate
• chitosan
• WPC
• fermentation