A survey about application of native Zedo gum as a stabilizer in probiotic yogurt supplemented with microalgae Spirulina platensis

Spirulina has been used for decades as human food because of its high protein content and nutritional value. In this study, possibility of simultaneous application of Spirulina platensis and Zedo gum in probiotic yogurt was investigated. For the first time, Zedo gum, a non-starch water-soluble hydrocolloid, was applied for stabilizing the microalgae powder whereas it does not suspend in milk easily. The effect of Spirulina platensis and Zedo gum (0-0.5%) during storage days on different yogurt types (plain/probiotic) were studied using central composite design. Qualitative indices like probiotic viability (in MRS agar-vancomycin) and antioxidative capacity (by DPPH method) were evaluated. Hunter Lab total color difference (ΔΕ) in yogurt layers was used as an indicator of Zedo gum stabilization. Apparent and damping factor were measured via oscillatory rheometer and syneresis assay was done by centrifuging. Results indicated that Lactobacillus paracasei viability was dependent on microalgae amount and storage time. Analysis revealed that incorporated Spirulina amount had antioxidant effect in yogurt. The lowest ΔΕ was obtained at maximum Zedo gum. All the studied sensory texture attributes were improved by using Zedo gum indicating a positive role of Zedo gum in stabilizing of microalgae in yogurt.

Keywords:

set yogurt , Spirulina platensis , Zedo gum