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    Effects of germination on the physicochemical and nutritional characteristics of lentil and its utilization potential in cookie-making
    (Springer, 2021) Oskaybas-Emlek, Betul; Ozbey, Ayse; Kahraman, Kevser
    Lentil is an alternative gluten-free source with high protein content. In our study, lentil seeds were germinated to enhance the functional and antioxidant properties of lentil. The raw and germinated lentil flour was obtained from lentil seed and used in cookie production. The germination affected the physicochemical, functional, chemical and morphological properties, and pasting behavior of lentil flour. The results indicated that germination caused positive effects on ash and protein content, total phenolic content (TPC), antioxidant properties, oil absorption capacity, and water solubility index. However, germination caused a decrease in the total dietary fiber and starch content due to the activation of the enzymes during germination. SEM images of the germinated lentil flour proved the degradation of starch. Lentil (raw and germinated) flour cookies and wheat flour cookies (Control) were evaluated in terms of physicochemical, TPC, antioxidant properties, textural properties, and in-vitro glycemic index (eGI) value. Germinated lentil flour cookie exhibited the lowest hardness, lightness, yellowness values, the highest TPC and antioxidant activity, and it had the same effect on eGI with control cookie. Overall results indicated that germination can be used as a natural, sustainable, and cost-effective way to improve the functional, and antioxidant properties of lentil. Germinated lentil flour cookie may be considered as a functional food due to high protein content and antioxidant properties.
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    Microbiological, antimicrobial and antioxidant characteristics of commercial Turkish kefirs
    (M H Schaper Gmbh Co Kg, 2021) Oncul, Nilgun; Ozbey, Ayse; Erinc, Hakan; Yildirim, Zeliha
    In this study, the microbiological properties, physicochemical characteristics, antimicrobial and antioxidant activities of Turkish commercial kefir products were investigated. The enumeration of Lactococci, aerobic lactobacilli, anaerobic lactobacilli, acetic acid bacteria (AAB) and yeast were performed by spread plate technique and counted as 7.35, 6.62, 6.85, 6.24 and 2.35 log CFU/g, respectively. Antimicrobial activity of kefir was evaluated using the disk diffusion method. Ten microorganisms, including seven Grampositive strains and three Gram-negative strains were tested. While Listeria monocytogenes, L. ivanovii and Escherichia coli were the sensitive bacteria for all kefir samples, L. plantarum, Staphylococcus aureus, Bacillus cereus and E. coli O157:H7 are the resistant bacteria. The means of pH, total phenolic content, Trolox Equivalent Antioxidant Capacity (TEAC) and lipid peroxidation were 4.03, 4.39 mg GAE/100mL, 0.15 mu mol Trolox/mL and 7.23%, respectively. From the beneficial health properties point of view, kefir appears to be a promising food.
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    Optimization of nanofiber-caproate/laurate esters synthesis, their characterization, and usage as emulsifier in o/w emulsion
    (Wiley, 2023) Erinc, Oezlem; Erinc, Hakan; Mert, Behic; Ozbey, Ayse
    The aim of this study is to optimize the esterification of nanofibers with caproyl/lauroyl chlorides at different substitution degrees' (DS) and to investigate the usage of nanofiber derivatives in model emulsions. First, cellulosic material was obtained and milled into nanofibers using a micro-fluidizer. Then, these nanofibers were esterified with caproyl/lauroyl chlorides in a solvent of DMAc/LiCl with DMAP as an acid scavenger. The esterification of nanofibers with caproyl/lauroyl chlorides was optimized for fatty acid chloride mole and reaction time. Esterification reactions were carried out at 80 & DEG;C with various molar ratios of acyl chlorides (3-15 moles) versus anhydroglucose unit of nanofibers and for various time durations (30-360 min). The hydrophobic derivatives with DS in the range of 0.34-2.77 were successfully obtained. Using the data obtained as a result of the optimization, nanofiber-fatty acid esters with different DS (0.50-2.75) were produced and characterized. Analyzes showed that the esterification process was successful and as the degree of esterification increased, the crystallinity index and thermal stability of the derivatives decreased. Then, the nanofiber-caproate/laurate esters with different DS were used as emulsifier (0.5 wt%) in an oil-in-water model emulsion containing 25 wt% oil and the emulsions were analyzed. The nanofiber caproate/laurate esters with a DS of 0.50-1.25 were suitable for o/w emulsions, while samples with a DS of 2.00 and above were not found suitable. Emulsions prepared by using nanofiber derivatives with 1.25 DS had higher G & PRIME; and G & DPRIME; and viscosity values and lower droplet sizes than those of other group.
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    Production of buckwheat starch-myristic acid complexes and effect of reaction conditions on the physicochemical properties, X-ray pattern and FT-IR spectra
    (Elsevier, 2022) Oskaybas-Emlek, Betul; Ozbey, Ayse; Aydemir, Levent Yurdaer; Kahraman, Kevser
    In this study, the effect of reaction parameters on complex index (CI%) value of complexes formed between buckwheat starch (BS) and myristic acid (MA) was investigated. The temperature (60-90 ?C) and MA to BS ratio (0.1-0.8 mmoL/g) were determined as the most effective parameters and their effect on CI% was evaluated using response surface methodology. The MA to BS ratio, temperature, and interaction between them had an influence on CI%. The CI% of BS-MA complexes increased with increasing MA ratio until a certain level of MA. Principal component analysis (PCA) was used for correlation analysis between parameters. Swelling power and paste clarity of BS decreased with complex formation while syneresis increased. Peak and final viscosity values of the BS-MA complexes were significantly lower than those of BS. FT-IR revealed the complex formation led to change in starch structure. The XRD confirmed the BS-MA complex formation but the BS-MA produced using 0.1 mmoL/ g at 60 ?C was not detected by XRD due to having low crystallinity, and expectedly, the lowest relative crystallinity value was achieved with this sample among complex samples. All results showed that the buckwheat be an alternative starch source for starch formation.