Enhancement of <i>Spirulina platensis</i> bioactivity by probiotic fermentation and encapsulation by spray‐drying
Esmeray Küley, Leyla Uslu, Mustafa Durmuş, Yetkin Sakarya, Gülsün Özyurt
Abstract
Summary The enhancing impact of fermentation with Lactiplantibacillus plantarum and drying/coating on bioactivity properties of Spirulina platensis was investigated. The fermentation with Lp. plantarum took place anaerobically for 72 h at 37 C. Encapsulation of fresh and fermented samples was made by spray‐drying with a 170 °C air inlet temperature , a 20 mL/min feed flow rate and different ratios of coating material (1:0, 1:1 and 1:2 maltodextrin). Fresh Spirulina capsules exhibited different shapes, mostly rod form whilst fermented Spirulina exhibited a generally spherical shape. 1,1‐diethoxy‐ethane (34.02%) and tert‐butyldimethylsilyl 2,2,3,3,3‐pentafluoropropanoate (26.70%) were identified as the major compounds in fermented Spirulina . The total phenol content of Spirulina was in range from 14.22 mg gallic acid equivalent (GAE)/g for fermented wet spirulina to 77.27 mg GAE/g for fermented spray‐dried Spirulina coated with maltodextrin at a ratio of 1:1. The drying and fermentation processes significantly increased the total phenol content, total antioxidant activity and diphenyl picrylhydrazyl (DPPH) radical scavenging capacity of Spirulina ( P < 0.05). Bacteriostatic concentration of fermented spray‐dried Spirulina was 25 mg/mL against Salmonella Paratyphi A, Staphylococcus aureus and Enterococcus faecalis , whereas bactericidal effect was at a concentration of 25 mg/mL vs. Pseudomonas aeruginosa and E. faecalis . The combination of fermentation with Lp. plantarum and drying after coating with maltodextrin of Spirulina enhanced its antimicrobial and antioxidant properties by 0.7–20‐fold compared to fresh, wet Spirulina .