Browsing by Author "Yilmaz, M.T."

Now showing 1 - 3 of 3

Characterisation and Functional Roles of a Highly Branched Dextran Produced by a Bee Pollen Isolate Leuconostoc Mesenteroides Bi-20
(Elsevier Ltd, 2022) Yilmaz, M.T.; İspirli, H.; Taylan, O.; Taşdemir, V.; Sagdic, O.; Dertli, E.
Lactic Acid Bacteria (LAB) from different niches can be responsible for the production of distinct exopolysaccharides (EPS) that might possess important structural and technological features. In this respect, the aim of this study was to isolate an EPS producer LAB strain from bee pollen environment. Leuconostoc mesenteroides BI-20 with a slimy-mucoid colony morphology was identified from bee pollen and the structural, technological and functional characteristics of EPS produced by this strain were determined. EPS BI-20 was a highly branched dextran containing 20% (1 → 3)-linked α-D-glucose branches determined by 1H and 13C NMR analysis. The presence of (1 → 6)/(1 → 3)-linked α-D-glucose linkages in dextran BI-20 was also confirmed by FTIR analysis. Dextran BI-20, with a molecular weight of 1 × 108 Da, possessed strong thermal properties, amorphous nature and highly branched and fibrous microstructural characteristics determined by DSC, TGA, XRD and SEM analysis, respectively. In terms of functional roles, dextran BI-20 demonstrated strong antioxidant capacity detected by ABTS and CUPRAC tests. Finally, no digestion was observed in dextran BI-20 under simulated gastric conditions. Results of this study unveiled techno-functional characteristics of dextran BI-20 produced by a bee pollen isolate LAB strain. © 2021 Elsevier Ltd
Effect of Electrospun Nisin and Curcumin Loaded Nanomats on the Microbial Quality, Hardness and Sensory Characteristics of Rainbow Trout Fillet
(Academic Press, 2019) Meral, R.; Alav, A.; Karakas, C.; Dertli, E.; Yilmaz, M.T.; Ceylan, Z.
Nisin and curcumin loaded (NCL) nanomats having 172 nm mean diameter were successfully fabricated. The effect of NCL nanomats in terms of limitation of Total Mesophilic Aerobic (TMAB) and Lactic acid bacteria (LAB) in fish fillets was tested during the analysis period. On the 4th day, while TMAB load of C was 6.61 log CFU g−1, that of the sample coated with NCL nanomats was found to be 3.28 log CFU g−1. TMAB load of control samples reached above 6 log CFU g−1 on the 4th day of cold storage, TMAB load of fish samples coated with nanomats reached the same level up to the 12th day. The shelf life of coated fillets was extended to 12 day. 3–4 logarithmic decrease was obtained in LAB count by NCL nanomats during the analysis period. On the 4th storage day, the hardness value of C sample decreased 21% compared to NCL samples. All sensory attributes of C samples were acceptable by the 4th day of the storage; while sensory attributes of NCL samples were acceptable by the 10th day of storage. The study revealed that nisin and curcumin loaded nanomats could be effectively used to improve the quality of fish fillets. © 2019 Elsevier Ltd
Importance of Electrospun Chitosan-Based Nanoscale Materials for Seafood Products Safety
(Elsevier, 2020) Ceylan, Z.; Meral, R.; Özogul, F.; Yilmaz, M.T.
Fish fillets can be coated/treated with nanoscale chitosan using the electrospinning technique. To obtain successfully nanoscale chitosan, the determination of molecular weight, concentration, solvent system of chitosan, and electrospinning parameters should be optimized. Therefore especially, applied voltage, distance, flow rate, environmental conditions, and collector type in the electrospinning unit should also be well defined. The electrospun chitosan-based nanoscale materials have functional and structural advantages since they provide high encapsulation efficiency, a large surface-to-volume ratio, and good stability of encapsulated bioactive compounds such as thymol. Morphological properties, encapsulation efficiency, thermal stability properties, zeta potential, and size of the electrospun chitosan-based nanoscale materials could also affect the shelf life of aquatic food products. Furthermore, chitosan-based nanofibers and nanoparticles, as well as bioactive material(s)-loaded chitosan-based nanofibers delay the microbiological spoilage, physical and chemical deterioration, as well as sensory changes. Therefore this chapter highlights that chitosan-based nanoscale materials could prolong the shelf life of seafood products. Consequently, the use of characterized chitosan-based nanoscale material(s) can be a promising and cost-effective technique to maintain seafood products safety. © 2020 Elsevier Inc.