Yazar "Bildik, Fatih" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • Küçük Resim
    Öğe
    Optimisation of ultrasound-assisted extraction of protein from Spirulina platensis using RSM
    (Czech Academy of Agricultural Sciences, 2018) Yücetepe, Aysun; Saroğlu, Öznur; Daşkaya Dikmen, Ceren; Bildik, Fatih; Özçelik, Beraat
    The protein extraction from the blue-green microalgae Spirulina platensis was carried out using ultrasound-assisted extraction and response surface methodology (RSM) was used to optimise extraction conditions. Extraction yield, total phenolic content, antioxidant activity and in vitro protein digestibility of protein extracts were determined. A three factors Box-Behnken design (BBD) of experiments was employed at pH values of 7, 8 and 9; temperatures of 25, 35, and 45 degrees C; and for durations of 60, 90 and 120 minutes. Based on the RSM analysis, optimum extraction conditions (temperature 45 degrees C, pH 7.46 and time 120 min) were obtained for extraction yield (29.05%), total phenolic content (3.52 mg caffeic acid equivalent/g dw), antioxidant activity (11.32 mg Trolox equivalent/g dw) and in vitro protein digestibility (99.36%). We report the first evaluation of the in vitro protein digestibility of Spirulina platensis and find it to be over 90%. This value is higher than the in vitro protein digestibility values of proteins obtained from other algae and plant species, and, in particular, is greater than that of commercial soybean protein isolate.
  • Küçük Resim
    Öğe
    The impact of pH and biopolymer ratio on the complex coacervation of Spirulina platensis protein concentrate with chitosan
    (Springer, 2021) Yücetepe, Aysun; Yavuz Düzgün, Merve; Şensu, Eda; Bildik, Fatih; Demircan, Evren; Özçelik, Beraat
    Spirulina platensis is one of the most significant multicellular blue-green Cyanobacterium microalgae with a high protein content. The complex coacervation as an encapsulation technique allows the formation of proteins with improved functional properties and thermal stability. In this study, the effects of pH and Spirulina platensis protein concentrate (SPPC)—chitosan ratio on complex coacervation formation were examined in terms of ?-potential, turbidity, visual observation and microscopic images. Based on the results, the strongest interaction between SPPC and chitosan occurred at pH of 5.5 and SPPC—chitosan ratio of 7.5:1 with a precipitation in the test tubes. Stable dispersions were obtained at a pH range of 2–4 for the SPPC—chitosan ratio of 7.5:1 inhibiting the precipitation which occurs at individual SPPC solutions at this pH range. Characteristic organic groups in the individual SPPC and chitosan solutions as well as the SPPC—chitosan coacervate formed at the optimal conditions were identified by using Fourier Transform Infrared (FT-IR) spectroscopy technique. Furthermore, thermal stability of the individual SPPC and chitosan solutions and the SPPC—chitosan coacervates were investigated using differential scanning calorimetry (DSC). The glass transition temperature and enthalpy were 209.5 °C and ? 3.414 W/g for the complex coacervates and 180.5 °C and ? 0.877 W/g for SPPC. It means that complex coacervation provided more thermally-stable SPPC in chitosan—SPPC coacervate than that of the individual SPPC. Our results might have important implications for the utilization of Spirulina platensis proteins especially for acidic beverage applications.