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Deacetylation is a chemical modification process (DD, 0-50-100%) that was applied to purified salep glucomannan at different glycerol concentrations (G, 0-5-10%) to decrease its high hydrophilic film behavior and improve its barrier, mechanical and structural characteristics. The solubility and water vapor permeability of films were significantly reduced by deacetylation. The film mechanical parameters were decreased by 50% DD, but 100% DD increased these parameters compared with the unmodified film. The improved interactions between glucomannan chains induced by deacetylation were revealed by FTIR. SEM results indicated that acetyl-free films had a smooth and compact microstructure when treated with glycerol, but 50% DD films showed aggregation at the surface. XRD analysis showed the conformational rearrangement and improvement in the crystallinity of the films due to deacetylation. Deacetylated films possessed higher thermal stability. Overall, deacetylation provides a promising and potential approach to improve salep film performance, which can benefit its applications in the food industry.

Kurt, Abdullah/0000-0003-1452-3278 WOS: 000402343000047 PubMed: 28504162 The aim of this study was to. investigate the effects of different extraction temperatures (25, 55 and 85 degrees C) on the structural characteristics of glucomannan (GM) purified from salep. All extraction conditions reduced protein content and molecular weight of salep. The effectiveness of removing the impurities and the highest purity of GM25 were observed with size exclusion profile. FTIR experiments demonstrated the presence of acetyl group, reduction of protein content and increment of polymer interaction of GM25. XRD patterns of GM25 with narrower and higher intensity than GM55, GM85 and native salep indicated strengthened interaction of GM25. Higher particle size was determined for GM25. The degradation peak observed with DSC increased from 293 to 314 degrees C and GM25 had the higher thermal stability which was also supported with TGA results. These results could provide widening the applications in food industry and other fields and also progressing development of salep with a better structural characteristic. (C) 2017 Elsevier Ltd. All rights reserved.

Kurt, Abdullah/0000-0003-1452-3278 WOS: 000361920900078 PubMed: 26344324 Glucomannan is the main and important constituent of salep. The other contents are called as impurities. In this study, the removal of them was achieved by ethanol treatment to increase salep quality (40%, 50%, 60%, and 70%). The highest glucomannan and the lowest impurities contents were succeeded with the 40% ethanol treatment (SF40). Apparent viscosity of SF40 increased about 5 folds as compared with native salep. SF40 also had higher intrinsic viscosity [eta] and lower critical concentration (C*) than other samples. The improved molecular entanglement between glucomannan chains were demonstrated with increased Berry number C chi[eta]. The storage (G') and loss (G '') moduli spectra of SF40 were found higher within the whole range of frequency and temperature. This simple ethanol process could be used as a promising modification method for improving the properties of salep. (C)15 Elsevier Ltd. All rights reserved.

Kurt, Abdullah/0000-0003-1452-3278 WOS: 000373828300015 PubMed: 27083350 The influence of concentration (0-0.5%, w/w) of gum tragacanth (GT) on thixotropy, dynamic, and creep-recovery rheological properties of ice cream mixes prepared with milk or water based were investigated. These properties were used to evaluate the viscoelastic behavior and internal structure of ice cream network. The textural properties of ice cream were also evaluated. Thixotropy values of samples were reduced by increasing GT concentration. The dynamic and creep-recovery analyses exhibited that GT addition increased both ice cream elastic and viscous behaviors. The increasing of Burger's model parameters with GT concentration indicated higher resistance network to the stress and more elastic behavior of samples. The applying of Cox-Merz rule is possible by using shift factor (alpha). GT also led to an increase in Young's modulus and the stickiness of ice creams. The obtained results highlighted the possible application of GT as a valuable member to promote structural properties of ice cream. (C) 2016 Elsevier Ltd. All rights reserved.

Kurt, Abdullah/0000-0003-1452-3278 WOS: 000333787700008 PubMed: 24607159 The aims of this study were to report the film-forming properties of salep glucomannan (SG) and characterize its physical, barrier, mechanical, sorption and thermal properties for the first time. Galactomannan films (LBG, locust bean gum; GG, guar gum) were also prepared to compare with SG films. The steady and oscillatory theological behaviors of the film solution were evaluated. The viscosity of the SG was less dependent than that of LBG and GG on temperature. The physical properties of SG films showed good potential for food applications. The oxygen and water vapor barrier properties of SG were better than LBG and GG films. SG film was less mechanically resistant than LBG but more flexible than galactomannan films. The highest transition temperature (T-g) was determined to be -11.46 +/- 0.65 degrees C for SG film. The results showed that SG has good potential for use in producing an edible film for various food applications. (C) 2014 Elsevier Ltd. All rights reserved.