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    Technological Properties of Xanthan Gums Obtained from Waste Bread Using as a Carbon Source and Performance in Pudding as Model Food
    (2019) Apaydın, Demet; Demirci, Ahmet Şükrü; Palabıyık, İbrahim; Mirik, Mustafa; Gümüş, Tuncay
    Technological properties of aqueous solutions of xanthan gums produced by various Xanthomonas species using waste bread (WB) hydrolyzate as a carbon source to reduce the overall product cost and to utilize waste bread were investigated and compared with commercial xanthan gum. While the highest water holding capacity was detected in the commercial xanthan gum, oil holding capacity was higher in xanthan gums from X. campestris DSM 19000 and X. axonopodis pv. begoniae than commercial gum. Pudding samples were prepared by the gums obtained and Ostwald de Waele model was successfully described the flow behavior. The highest consistency coefficient (K) value were obtained by the sample without gum addition as 161.2 Pa.sn, this was followed by the sample with the gum from X. axonopodis pv.begoniae with 139.3 Pa.sn and X. hortorum pv.pelargonii with 133.2 Pa.sn . Flow behavior index (n) values varied between 0.12 and 0.49 and increased with the addition of the gum. Therefore, this study showed that the pudding samples prepared with the gums from X. axonopodis pv. begoniae and X. hortorum pv. pelargonii isolates using waste bread as substrate were found to be more resistant to shear rate and had a more robust gel structure.
  • [ X ]
    Öğe
    Xanthan gum biosynthesis using Xanthomonas isolates from waste bread: Process optimization and fermentation kinetics
    (Academic Press, 2019) Demirci, Ahmet Şükrü; Palabıyık, İbrahim; Apaydın, Demet; Mirik, Mustafa; Gümüş, Tuncay
    Waste bread hydrolysate was used as a biosource for xanthan production by various isolates and standard bacteria (Xanthomonas campestris DSM 19000). Influence of operational conditions used in the process of xanthan production were evaluated through yield of xanthan, rheological properties of aqueous solution and fermentation kinetics. For the highest yield and viscosity, optimum conditions including carbon source concentration, inoculum volume and agitation rate were determined for 4 different strains by using response surface methodology. The highest gum yield as 14.3 g/L was obtained by Xanthomonas axonopodis vesicatoria and the highest conversion rate of waste bread to xanthan gum was found as %14.1 for Xanthomonas hortorum pv. pelargonii. Whereas, the highest aqueous solution viscosity of gum produced from standard bacteria was 11.2 Pa.sn at glucose ratio of 4%, inoculum volume of 5% and mixing rate of 225 rpm. For fermentation kinetics; the values of growth associated parameters revealed that they are mostly affected by the rate of xanthan gum production and substrate consumption. In general, optimum conditions to obtain the highest xanthan gum yield were different from that to achieve the highest viscosity. This study shows the potential of waste bread hydrolyzates as the promising economic carbon source for xanthan gum production. © 2018 Elsevier Ltd