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Sürdürülebilir Kalkınma Amaçları

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• MakaleAçık Erişim2025/r/gumushane/11659
  Valorisation of bread wastes via the bacterial cellulose production

  Güzel, Melih

  The short shelf life of bread can be attributed to changes in its textural and sensory properties, a process termed staling, and large amounts of bread residue and waste are generated daily. Because the main component of bread is starch, the use of bread wastes as a substrate for bacterial cellulose (BC) production can significantly contribute to valorisation and reuse of wastes. This study aimed to investigate the BC production potential of various stale breads, convert these wastes into usable forms for food and other industries, and increase their economic value. Stale breads were hydrolyzed with dilute acid, and BC-producing bacteria from Kombucha tea were isolated and identified as Gluconobacter oxydans MG2021 (GO). BCs were produced from bread hydrolysates with GO and Komagataeibacter hansenii GA2016 (KH), and their properties were examined. The results indicated that stale breads represented a good source for BC production, as high BC yields were obtained using GO (8.81%–25.02%) and all BCs had superior properties such as high crystallinity (75.96%–91.39%), thermal stability, liquid holding capacity, and fine fibers (40.16–85.39 nm). This study demonstrated that bread wastes could be used as a low-cost substrate for large-scale BC production, and the abundance of bread wastes demonstrated their potential as a resource for commercial BC producers.

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• MakaleAçık Erişim2024/r/gumushane/20034
  Determination of total phenolic, flavonoid and monomeric anthocyanin contents and antioxidant properties of 15 different fruit vinegars produced by traditional method

  Güzel, Melıh

  In this study, vinegars were produced using traditional method from 15 different fruits (rosehip, pear, fig, wild pear, apple, plum, hawthorn (yellow and red), pomegranate, grape (cimin, cardinal), peach, cranberry, quince and medlar). It was aimed to determine the total phenolic, total flavonoid and total monomeric anthocyanin contents and antioxidant capacities of vinegars. As a result, it was concluded that the phenolic, flavonoid contents and the antioxidant capacity in all 3 methods (TEAC, FRAP and DPPH) of rosehip vinegar was significantly higher than other vinegars. In addition, wild pear and hawthorn vinegars were very rich in phenolic and flavonoid compounds and these vinegars had very high antioxidant capacity. The results of the study suggest that an alternative consumption method can be provided by producing vinegar, which is a healthy, aromatic and alternative product with high added value, from fruits such as rosehip, wild pear, hawthorn, cranberry, quince and medlar, whose usage and consumption are limited due to their natural structure.

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• MakaleAçık Erişim2024/r/gumushane/13995
  Characterization of cellulose produced by bacteria isolated from different vinegars

  Güzel, Melih

  Traditional vinegars are naturally produced from sugar- or starch-containing raw materials, through alcoholic fermentation followed by acetic fermentation. Fermentation is a spontaneous and complex process involving interactions between various microorganisms. In this study, we produced vinegar using traditional methods from six fruits: rosehip, pear, fig, wild pear, apple, and plum. Bacteria that produce bacterial cellulose (BC) were isolated from these vinegars and identified. In addition, we investigated the properties of BC produced from these bacteria. The strains isolated from vinegars were identified as Gluconobacter oxydans strain MG2022, Acetobacter tropicalis strain MG2022, Acetobacter fabarum strain MG2022, Komagataeibacter saccharivorans strain MG2022, K. saccharivorans strain EG2022, and Acetobacter lovaniensis strain OD2022. In total, 0.83–2.04 g/L BC was produced and the bacterial strain isolated from pear vinegar yielded the most BC. BC produced by the bacterial strain isolated from wild pear vinegar had the highest thermal stability and crystallinity (87.44 %). Overall, this study shows that different fruits contain different BC-producing bacteria in their natural flora and vinegars obtained from fruits can be used in BC production. Also, different BC-producing bacteria can be isolated from different vinegars, and BC produced by these bacteria might have different properties.

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• MakaleYalnız künye2020/r/gumushane/14807
  Preparation and characterization of bacterial cellulose produced from fruit and vegetable peels by Komagataeibacter hansenii GA2016

  Güzel, Melih; Akpınar, Özlem

  This study focused on the investigation of bacterial cellulose production potency of some fruit and vegetable peels (cucumber, melon, kiwifruit, tomato, apple, quince and pomegranate) with Komagataeibacter hansenii GA2016. Fruit and vegetable peels were hydrolyzed, used for bacterial cellulose (BC) production and their chemical, physical, thermal and structural features were compared to BC from Hestrin–Schramm medium (HSBC) and plant cellulose (CP). Except for pomegranate peel hydrolysate, all the fruit and vegetable peel hydrolysates supplied to K. hansenii GA2016 supported the BC production. Among the fruit and vegetable peel hydrolysates, the highest BC production was observed in kiwifruit peel hydrolysate (11.53%), while the lowest production was observed in apple peel hydrolysate (1.54%). Water-holding capacities of the BCs were ranged from 627.50% to 928.79% and higher than HSBC (609.30%), average fiber diameters were ranged from 47.64 nm to 61.11 nm and thinner than HSBC (74.29) and CP (10,420 nm), crystallinities were ranged from 80.27% to 92.96%, thermal capacities BCs were higher than HSBC and CP. For the BC productions, utilization of the fruit and vegetable peels as the sole nutrient source could reduce the production costs and among the polysaccharides, increase the use of BC in industry.

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• MakaleAçık Erişim2019/r/gumushane/18031
  Investigation of Phytochemical and Antioxidant Properties of Fruit and Vegetable Peels

  Akpinar, Ozlem; Güzel, Melıh

  Plants are rich in phytochemicals which have positive effects on health. In this study, the phytochemical components of the some fruit and vegatable peels, produced in the significant amounts in Turkey, including kiwi (Actinidia deliciosa), melon (Cucumis melo), tomato (Solanum lycopersicum), apple (Malus domestica), quince (Cydonia oblonga) and pomegranate (Punica granatum) were determined. The moisture, ash, fat, ascorbic acid and β carotene contents of the peels were determined. Peels were extracted in 0%, 25%, 50% and 75% ethanol solutions and total phenolic, total flavonoids and total monomeric anthocyanin contents and antioxidant capacities of the extracts were investigated. It was concluded that the concentrations of 25% and 50% ethanol were more successful than other concentrations to extract the phenolic compounds. Total monomeric anthocyanin, flavonoid, phenolic contents and antioxidant capacity of the pomegranate peel were found to be significantly higher than the other peels. It was determined that the melon rind contained more β-carotene and quince peel contained more ascorbic acid content than the other peels.

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• MakaleYalnız künye2019/r/gumushane/15220
  Production and Characterization of Bacterial Cellulose from Citrus Peels

  Güzel, Melih; Akpınar, Özlem

  Cellulose is the most common polymer in the world, formed by β-1,4 linked glucopyranose units. In this study, citrus peels (lemon, mandarin, orange and grapefruit) were used for the production of bacterial cellulose (BC). The peels were hydrolyzed with dilute acid and hydrolysates were used for BC production. The production of BC was carried out at 28–32 °C for 21 days under static conditions with Komagataeibacter hansenii GA2016. BC yields were found to be between 2.06 and 3.92%. It was found that the FTIR spectra of the BCs produced in citrus peel hydrolysates were similar to BC produced in the commercially available nutrients. The result of this study showed that all the BCs produced from citrus peels were characterized to have high water holding capacity, thin fiber diameter, high the thermal stability and high crystallinity.

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• MakaleYalnız künye2019/r/gumushane/13382
  Valorisation of fruit by-products: Production characterization of pectins from fruit peels

  Güzel, Melih; Akpınar, Özlem

  The aim of the study is to determine the physical, chemical, structural and thermal properties of the pectins obtained from melon rinds, kiwifruit and pomeganate peels and compared with the pectins obtained from apple and orange peel used in the commercial pectin production process. Pectins extractions from these wastes were performed with citric acid, at 80 °C and 60 min. All pectins, extracted, were found to be high methoxyl pectines. The water holding capacity of the melon rind, kiwifruit and pomegranate peels pectins were lower than the orange and apple peel pectins while the thermal stability of the kiwifruit peel pectin was close to the apple and orange peel pectins. The morphological structures of the extracted pectins showed that they had micro-fractures and hollow openings. The crystallinity of the melon rinds, kiwifruit and pomegranate peel pectins were smilar to orange peel pectin. The result of this study showed that the kiwifruit peel had advantages in terms of commercial pectin production due to its high pectin yield, water holding capacity, esterification degree and thermal stability.

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• MakaleAçık Erişim2019/r/gumushane/12954
  Effect of pH on protein extraction from sour cherry kernels and functional properties of resulting protein concentrate

  Çelik, Mehtap; Güzel, Melih; Yildirim, Metin

  The aims of this research were to examine the effect of pH on extraction of proteins from sour cherry (Prunus cerasus L.) kernels, and to investigate the functional properties of the resulting protein concentrate. The optimum pH values for the protein extraction and isoelectric precipitation were determined as 10.0 and 4.5, respectively. The protein concentrate contained 4.03 ± 0.16% moisture, 3.31 ± 0.17% ash, 2.94 ± 0.36% carbohydrate, 1.93 ± 0.16% lipid, and 80.48 ± 2.38% protein. Water holding capacity, oil holding capacity and the least gelling concentration of the protein concentrate were 2.42 ± 0.09 g water/g, 1.73 ± 0.17 g oil/g and 8%, respectively. Results showed that emulsifying activity and stability indices, foaming capacity and stability of protein concentrate were 38.91 ± 2.50 m2/g, 37.49 ± 2.41 min, 35.00 ± 3.54% and 71.80 ± 7.25% (after 30 min), respectively. The functional and chemical properties of the protein concentrate indicate that it may find application as functional ingredient for various food products.

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• MakaleAçık Erişim2019/r/gumushane/11389
  Effect of pH on Protein Extraction from Mahaleb Kernels and Functional Properties of Resulting Protein Concentrate

  Güzel, Melih; Çelik, Mehtap; Yildirim, Metin

  The aims of this research were to examine the effect of pH on extraction of proteins from mahaleb (Prunus mahaleb L.) kernels, and to investigate the functional properties of resulting protein concentrate. The optimum pH values for the protein extraction and precipitation were determined as 10.0 and 4.5, respectively. The protein concentrate containing 92.73% dry matter, 6.29% ash, 6.02% carbohydrate, 1.42% fat and 73.11% protein was produced by using these extraction and precipitation pH values. Water-holding capacity, oil-holding capacity and the least gelling concentration of the protein concentrate were 2.81 g water/g, 1.66 g oil/g and 12%, respectively. Moreover, emulsifying activity and stability indices, foaming capacity and stability of protein concentrate were 27.21 m2/g, 81.05 min, 43.75% and 71.33% (after 30 min), respectively. The functional and chemical properties of the protein concentrate indicate that it may find application as functional ingredient for various food products.

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• Derleme MakaleAçık Erişim2018/r/gumushane/18296
  Production and Properties Bacterial Celluloses and Their Use in Food and Non-Food Applications

  Akpinar, Ozlem; Güzel, Melıh

  Cellulose is the most common polymer in the world, formed by β-1,4 linked glucopyranose units. Besides plants, celluloses can be produced by some bacteria. The uses of these bacterial celluloses have been increasing in food, pharmaceutical, biotechnology, biomedical, cosmetics, paper and electronics areas. It has many superior properties compared to plant celluloses, such as purity, elasticity, network structure, high crystallize, surface area, water holding capacity and tensile strength, thinner and porous structure. This review includes the production methods for bacterial celluloses, the properties of these polymers and their use in food and non-food applications

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