Food Engineering / Gıda Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/12
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Article Citation - WoS: 15Citation - Scopus: 17Effect of Different Microencapsulating Materials on the Viability of S. Thermophilus Ccm4757 Incorporated Into Dark and Milk Chocolates(Elsevier Ltd., 2021) Öztürk, Burcu; Elvan, Menşure; Özer, Merve; Tellioğlu Harsa, ŞebnemThis study aimed to evaluate the viability and bioaccessibility of Streptococcus thermophilus CCM4757 strain supplemented in dark and milk chocolates during storage period and pass through simulated in vitro gastro-intestinal tract. Microencapsulated and non-microencapsulated S. thermophilus CCM4757 strain added into the chocolates. Emulsion technique was used to microencapsulate cells with various biopolymers; carboxymethylcellulose, pectin, gum arabic, and cellobiose. The microencapsulated S. thermophilus with these coating materials was found to be viable higher than 9 log CFU/g up to 180 days of storage at 4 °C. Microbiological, physicochemical, and sensorial attributes of the chocolates containing microencapsulated and non-microencapsulated S. thermophilus CCM4757 were analyzed. The microencapsulated S. thermophilus showed a good survivability in milk (7.12 log CFU/g) and dark (6.90 log CFU/g) chocolate samples during 180-day storage at 4 °C. Supplementation of S. thermophilus did not affect significantly (P > 0.05) the sensory attributes of the chocolates. The results showed that S. thermophilus CCM4757 exhibited good cell survivability higher than 85% in chocolates under simulated gastro-intestinal fluids. S. thermophilus supplementation into the chocolate protected the viability of cells and did not affect the sensorial characteristics and moisture content of chocolates. The present study demonstrated that the dark and milk chocolates could be used as an important matrix to carry probiotics. © 2021 Elsevier LtdArticle Citation - WoS: 42Citation - Scopus: 53Effects of Ultraviolet-Light Emitting Diodes (uv-Leds) on Microbial Inactivation and Quality Attributes of Mixed Beverage Made From Blend of Carrot, Carob, Ginger, Grape and Lemon Juice(Elsevier Ltd., 2021) Baykuş, Gökçen; Pelvan Akgün, Merve; Ünlütürk, SevcanEfficacy of ultraviolet light-emitting diodes (UV-LEDs) with peak and coupled emissions at 280, 365 and 280/365 nm on inactivation of E. coli K12 in mixed beverage (MB) was investigated. MB comprised of 31.6% carrot, 44.3% carob, 8.7% grape, 10.2% ginger, and 5.2% lemon juice. The impact of UV-LEDs on some physicochemical and phytochemical properties of MB was compared to that of heat treatment (70 °C, 120 s). While, UV-LED irradiation using coupled 280/365 nm for 40 min resulted in the highest inactivation of E. coli K12 (>4 log) out of tested wavelengths, the number of mesophilic bacteria (TAC), and yeast and molds (YM) in mixed beverage were reduced by 2.59 log CFU/mL (from 5.69 log CFU/mL of initial load), and 0.17 log CFU/mL (from 3.28 log CFU/mL of the initial load), respectively. Although, the color parameters slightly changed after irradiation, the color of MB did not show visual difference (?E = 0.94) compared to untreated samples. UV-LED treatment caused a significant increase in total phenolic compound (1.75-fold) and antioxidant capacity (4.60 fold) compared to heat-treated samples (p < 0.05). UV-LED treatment caused a decrease in carotenoid content (71.3%) lower than that of heat-treated samples (88.9%), indicating that UV-LED irradiation preserved the total carotenoid content better than the heat treatment. Industrial relevance: Light-emitting diodes (LEDs) are new sources of ultraviolet light utilized for non-thermal processing of foods. In this study, a static bench top unit was designed to investigate the efficacy of UV-LEDs with different treatment times and peak emissions by considering the inactivation of E. coli K12 in newly formulated mixed drink (MB). UV-LED irradiation of MB using coupled 280/365 nm for 40 min provided the highest microbial inactivation and preserved bioactive compounds better than the heat treatment. It can be proposed as an effective method for the processing of fruit juices which is rich in bioactive constituents. © 2020 Elsevier LtdArticle Citation - WoS: 25Citation - Scopus: 30Prediction of Chemical Parameters and Authentication of Various Cold Pressed Oils With Fluorescence and Mid-Infrared Spectroscopic Methods(Elsevier Ltd., 2021) Doğruer, Ilgın; Uyar, H. Hilal; Uncu, Oğuz; Özen, BanuIt was aimed to compare the performances of two spectroscopic methods, fluorescence and mid-infrared spectroscopy, in terms of their adulteration detection and estimation of several chemical properties for various cold pressed seed oils. Spectroscopic profiles, fatty acid, free fatty acid and total phenol contents of pumpkin seed, grape seed, black cumin oil, and sesame seed oils were determined and these oils were mixed with sunflower oil at 1–50% (v/v). Both spectroscopic techniques provided comparable results for determination of adulteration of each oil type and the most successful prediction was obtained for pumpkin seed oil at levels >%1. Combined data set of oils resulted in successful quantification of their free fatty acid value, total phenol and major fatty acids contents with both spectroscopic methods regardless of oil type. Both techniques could be used as reliable, fast and environmentally friendly alternatives in the analyses of different types of seed oils. © 2020 Elsevier LtdArticle Citation - WoS: 71Citation - Scopus: 76Characterization of Bacterial Cellulose Nanocrystals: Effect of Acid Treatments and Neutralization(Elsevier Ltd., 2021) Arserim-Uçar, Dilhun Keriman; Korel, Figen; Liu, LinShu; Yam, Kit LIn this study, bacterial cellulose nanocrystals (BCNCs) were obtained from bacterial cellulose nanofibers (BCNFs) by controlled hydrolysis of sulfuric and hydrochloric acids. The influence of hydrolysis temperature and acid type with the addition of the post-treatment step was studied. The obtained BCNCs were analyzed based on the structural characterization and the properties of the nanocrystals. The BCNCs crystallinity increased, and the size of nanocrystals decreased with increasing 10 °C hydrolysis temperature for both acid hydrolysis conditions. Hydrolysis conditions with neutralization post-treatment did not alter the thermal stability of nanocrystals, and BCNCs had high thermal stability like raw BCNFs. Elemental analysis results indicated that sulfur content (S %) was very low for sulfuric acid hydrolyzed samples, and X-ray results did not show any sulfate salt peaks. Thermal stable BCNCs with high crystallinity were successfully produced to meet the process requirements in various applications, especially in the food industry.Article Citation - WoS: 34Citation - Scopus: 42Importance of Some Minor Compounds in Olive Oil Authenticity and Quality(Elsevier Ltd., 2020) Uncu, Oğuz; Özen, BanuBackground: Consumption and production of olive oils have been increasing steadily worldwide mainly due to proven health benefits and sensorial characteristics of olive oil. M the same time, rising demand makes it harder to protect olive oil genuineness; therefore, inauthentic products have been always a serious problem in olive oil industry. Scope and approach: Some minor compounds such as pigments (chlorophylls and carotenoids) including their derivatives pyropheophytins (PPPs), diacylglycerols (DAGs) and fatty acid ethyl esters (FAEEs) are all prominent compounds with their discriminatory and descriptive properties. Among several different approaches, use of these components to differentiate genuine and adulterated olive oils could be a promising choice since it is harder to mimic these compounds in fake mixtures. Recent studies focus on these compounds as authentication and quality tools for olive oil and potential of these compounds are aimed to be reviewed. Key findings and conclusions: Results from literature indicated that these parameters could be used in both authenticity and quality determination of olive oils with some limitations. Pigments were found to be more promising in geographical and/or varietal classification. All of the discussed components have successful applications in determination of olive oil quality with respect to storage history and oil grades. However, in detection of certain types of adulteration techniques such as soft deodorization, reviewed parameters did not work effectively alone. Regulations could be updated with these findings and use of combined parameters including discussed compounds could be further investigated for unsolved authentication problems.Article Citation - WoS: 151Citation - Scopus: 179Active Packaging Films as a Carrier of Black Cumin Essential Oil: Development and Effect on Quality and Shelf-Life of Chicken Breast Meat(Elsevier Ltd., 2019) Konuk Takma, Dilara; Korel, FigenFabrication of active PET films assembled with antimicrobial chitosan and alginate coatings incorporating black cumin oil(BCO) was performed by layer-by-layer(LbL) technique and effect of active packaging film on quality and shelf-life of chicken breast meats stored at 4 degrees C for 5 days was investigated. Multilayer films were characterized in terms of surface morphology, color, thickness, and antimicrobial activity. Incorporation of BCO into film demonstrated antimicrobial activity against Staphylococcus aureus and Escherichia coll., and spherical particles on surface profile. Changes in weight loss, color, pH, total aerobic mesophilic(TAMC), and psychrotrophic bacteria counts(PBC) of chicken meat, packaged in trays containing antimicrobial films, were observed. Increase in pH values was higher in control samples than samples packaged with antimicrobial film during storage. Samples stored in active packaging had slightly lower TAMC and PBC compared to control samples. Results indicated that active film containing BCO has the potential to maintain safety and quality of chicken meat.Article Citation - WoS: 11Citation - Scopus: 12Characterization of the Self-Assembly and Size Dependent Structural Properties of Dietary Mixed Micelles by Molecular Dynamics Simulations(Elsevier Ltd., 2019) Tuncer, Esra; Bayramoğlu, BesteThe bile salts and phospholipids are secreted by the gallbladder to form dietary mixed micelles in which the solvation of poorly absorbed lipophilic drugs and nutraceuticals take place. A comprehensive understanding of the micellization and structure of the mixed micelles are crucial to design effective delivery systems for such substances. In this study, the evolution of the dietary mixed micelle formation under physiologically relevant concentrations and the dependence of structural properties on micelle size were investigated through coarse grained molecular dynamics simulations. The MARTINI force field was used to model cholate and POPC as the representative bile salt and phospholipid, respectively. The micellization behavior was similar under both fasted and fed state concentrations. Total lipids concentration and the micelle size did not affect the internal structure of the micelles. All the micelles were slightly ellipsoidal in shape independent of their size. The extent of deviation from spherical geometry was found to depend on the micellar POPC/cholate ratio. We also found that the surface and core packing density of the micelles increased with micelle size. The former resulted in more perpendicular alignments of cholates with respect to the surface, while the latter resulted in an improved alignment of POPC tails with the radial direction and more uniform core density.Article Citation - WoS: 82Citation - Scopus: 103A Comparative Study of Mid-Infrared, Uv-Visible and Fluorescence Spectroscopy in Combination With Chemometrics for the Detection of Adulteration of Fresh Olive Oils With Old Olive Oils(Elsevier Ltd., 2019) Uncu, Oğuz; Uncu, Oğuz; Özen, Banu; Özen, Fatma BanuThe work aimed to detect and quantify adulteration of fresh olive oils with old olive oils from the previous harvest year by using different spectroscopic approaches in combination with chemometrics. Adulterated samples prepared in varying concentrations (10.50%(v/v)) were analyzed with fluorescence, Fourier transform-infrared (FT-IR), and ultraviolet-visible (UV-vis) spectroscopic methods. Orthogonal partial least square-discriminant analysis (OPLS-DA) and partial least squares (PLS) regression techniques were used for the differentiation of adulterated oils from the pure oils and prediction of adulteration levels, respectively. After the application of various pre-treatment methods, all of the OPLS-DA classification models generated for every spectroscopic technique successfully differentiated adulterated and non-adulterated oils with over 90% correct classification rate. FT-IR + UV-vis and fluorescence spectral data were also successfully used to predict adulteration levels with high coefficient of determinations for both calibration (0.94 and 0.98) and prediction (0.91 and 0.97) models and low error values for calibration (4.22% and 2.68%), and prediction (5.20% and 2.82%), compared to individual FT-IR and UV-vis spectroscopy were obtained. Therefore, FT-IR + UV-vis and fluorescence spectroscopy as being fast and environmentally friendly tools have great potential for both classification and quantification of adulteration practices involving old olive oil.Article Citation - WoS: 14Citation - Scopus: 18Evaluation of Three Spectroscopic Techniques in Determination of Adulteration of Cold Pressed Pomegranate Seed Oils(Elsevier Ltd., 2020) Uncu, Oğuz; Napiórkowska, Alicja; Szajna, Tomasz K.; Özen, BanuIt was aimed to compare three spectroscopic methods in determination of adulteration of cold pressed pomegranate seed oils (PSOs) with sunflower oil in this research. UV–visible, mid-infrared and fluorescence spectra of pure and adulterated pomegranate oils (1–50%, v/v) were collected and data were analyzed with multivariate statistical analysis techniques. According to orthogonal partial least square discriminant analysis, best differentiation between pure and mixed samples was obtained with mid-infrared spectroscopy having 100% success rate. Fluorescence and UV–visible spectroscopy also provided good discrimination between samples with 96 and 88% successful classification rates, respectively. As a result of partial least square regression analysis, detection limits for mid-infrared, UV–visible and fluorescence spectroscopies are determined as >1, 5 and 10% in order. Since all spectroscopic methods provided detection of mixtures of cold pressed PSOs with sunflower oil at low concentrations they could serve as easy to use and rapid techniques in control laboratories. © 2020 Elsevier B.V.Article Citation - WoS: 14Citation - Scopus: 23Expanding Horizons of Active Packaging: Design of Consumer-Controlled Release Systems Helps Risk Management of Susceptible Individuals(Elsevier Ltd., 2018) Boyacı, Derya; Yemenicioğlu, AhmetThe objective of this study was the development of zein based antilisterial films that contain a consumer-controlled and pH-triggered release mechanism for lysozyme (LYS). For this purpose, composite films were formed by mixing hydrophobic zein with hydrophilic soy protein isolate (SPI) or lentil protein isolate (LPI). Active property of films was formed by maintaining 30 to 50% of total LYS in free form (LYSfree). On the other hand, the pH-triggered release mechanism was formed by exploiting attractive charge-charge interactions between LYS (pI: 11.4) and SPI or LPI (pI values ≈ 4.5), and binding remaining LYS (LYSbound) in film matrix. The pH-triggered release mechanism of composite films worked in buffers that had pHs varying between 4.3 and 7.3. The composite films bound majority of LYS between pH 5.3 and 7.3, but they released LYS at pH ≤ 4.5. The pH-triggered release of LYS was achieved with zein-LPI films activated by acidification in packed cold-stored beef, lamb and smoked salmon. The zein-SPI films performed pH-triggered LYS release in packed food with the exception of packed smoked salmon. The LYSfree and LYSbound released from pH-triggered films showed antimicrobial activity on Listeria innocua. Consumer-controlled release mechanisms enable increasing antimicrobial stress over pathogens during transfer from market to home and cold storage at home. Thus, such films could initiate personalized packaged food to help risk management of susceptible individuals.