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Kurt, Abdullah/0000-0003-1452-3278; Atalar, Ilyas/0000-0001-8560-0010 WOS: 000432774000021 This study investigated the potential use of quince seed to improve the rheological, melting, textural and sensory characteristics of ice cream. The high dietary fiber, polysaccharide and protein contents of these seeds made them a candidate to achieve these aims due to their water-holding properties, gelation behavior, and emulsifying characteristics. Four different formulations were developed that contained quince seed powder (QSP) at levels of 0, 0.25, 0.50 and 0.75%. In general, inclusion of 0.25% QSP decreased the flow behavior parameters, but 0.50% QSP had no effect on the rheological parameters of the mixes compared with the control mix. The viscosity, yield stress and thixotropic behaviors of mixes were enhanced by the addition of 0.75% QSP due to the occurrence of interactions and stabilizations. This modification also provided weak gel characteristics and a higher material stiffness property to the mixes, which indicated the presence of a large number of intermolecular interactions. Complex modulus/viscosity and loss tangent variations also supported the flow behavior improvement of the QSP added mixes. Better melting properties and textural characteristics were observed for the 0.5 and 0.75% QSP added samples. Reduction in the melting rate and retardation of complete melting times were achieved by QSP addition. The effect of QSP on reducing the ice crystallization caused to decrease the hardness of the ice cream and resulted in a smooth product with a higher overall acceptability. The enrichment of ice cream with QSP could be an effective way to enhance the nutritional and structural characteristics of dairy products. (c) 2018 Elsevier Ltd. All rights reserved.

Kurt, Abdullah/0000-0003-1452-3278 WOS: 000401105000016 PubMed: 28457433 The aim of this study was to investigate the effects of different extraction temperatures (25, 55 and 85 degrees C) on the rheological characteristics of glucomannan (GM) purified from salep. GM was isolated using the following method: extraction of GM with water, removal of impurities by centrifugation and precipitation of GM with ethanol. The extraction yield of GM was approximately 45% for all products. Higher GM (95%) and lower starch (3%) contents were obtained for GM25. GM25 showed higher apparent and intrinsic viscosity, storage and loss modulus and lower activation energy than GM55 and GM85. The addition of different salts and sugars did not affect viscosity due to the non-polyelectrolyte behavior of GM. Gel behavior of purified samples appeared at pH 9. The usage of salep in milk was reduced by purification. These results are potentially useful for widening the applications for salep and for furthering research and development of GM. (C) 2017 Elsevier Ltd. All rights reserved.

Kurt, Abdullah/0000-0003-1452-3278 WOS: 000399484800028 Controlled deacetylation of salep glucomannan (SGM) was performed in this study for the first time. SGM, with different degrees of deacetylation (DD), were prepared with the control sample. The rheological properties of SGM were affected by the deacetylation process. Deacetylated samples showed lower apparent viscosities and pseudoplastic characteristics. The gelation of SGM occurred at 90 and 100% DD for 0.75% and 1% SGM concentrations, and increasing the concentration from 0.5% to 1% increased the gelation kinetics of the samples. The whiteness index and strength of salep gel increased as the DD and concentration increased. The remarkable decrease in absorption bands at approximately 1736 cm(-1) with deacetylation was detected with an FTIR experiment. The SEM images showed that deacetylation resulted in a smooth surface. Removing acetyl groups with the aid of alkali weakened the solubility but improved the thermal stability of SGM, which was determined with DSC and TGA experiments. (C) 2017 Elsevier Ltd. All rights reserved.