Food Engineering / Gıda Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/12
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Article Effect of Partial Replacement of Sucrose With Stevia and Sucralose on the Physicochemical and Structural-Mechanical Properties of Apple Marmalade(2024) Berk, Berkay; Şirin, Pınar; Ünlütürk, SevcanIn this study, low-sugar apple marmalade formulations were developed by partial replacement of sucrose with stevia and sucralose. Their rheological, textural, physicochemical properties and microstructures were evaluated. The concentration of sweeteners was found to have a significant effect on the physicochemical and rheological properties of the formulations. The hardness of marmalades decreased with addition of sweeteners. Herschel–Bulkley model was found to be the best model describing rheological behavior. The consistency index decreased with increasing sweeteners substitution, whereas the flow behavior index showed an increasing trend with the increase of the sweeteners content. Additionally, the microstructure of marmalades with sweetener substitution exhibited a porous structure in the gel network. The increase in sucralose concentration resulted in more surface deformation resulting in weaker gel formation than stevia. Marmalade prepared with 50% stevia substitution was found the best combination and resulted in good sensory properties like marmalade samples containing 500 g sugar.Article Citation - WoS: 17Citation - Scopus: 18Incorporation of Organic Acids Turns Classically Brittle Zein Films into Flexible Antimicrobial Packaging Materials(Wiley, 2022) Sozbilen, G.S.; Çavdaroğlu, E.; Yemenicioglu, A.This study aimed to turn classically brittle zein films into flexible antimicrobial ones by the use of lactic (LA), malic (MA) and tartaric acids (TA). The most effective plasticizer was LA (400% elongation at break [EB] at 4%), while MA (189% EB at 4.5%) and TA (68% EB at 5%) showed moderate and limited plasticizing effects, respectively. The LA- and MA-loaded films maintained their flexibility during 30-day storage at 4°C or 25°C. Fourier transform infrared (FTIR) analysis suggested that the plasticization of LA and MA could be related to secondary structural changes in zein such as increased α-helix and random coils (mainly by MA) and spaced/modified intermolecular (only by LA) and intramolecular (mainly by MA) β-sheets. Atomic force and scanning electron microscopy showed that LA and MA gave more homogenous and smoother films than TA. Films with LA showed the highest water vapour permeability followed by those of control, MA- and TA-loaded films. Films with 3%–4% LA or MA formed clear zones on Listeria innocua and Klebsiella pneumonia, but only films with LA formed clear zones on Escherichia coli. All OA-loaded films gave unclear zones on Staphylococcus aureus in disc-diffusion tests, but this bacterium was inactivated rapidly in antimicrobial tests based on surface inoculation tests. LA is the best OA to develop flexible antimicrobial films from zein, an industrial by-product that films could not have been utilized as a widespread packaging material due to their brittleness. © 2021 John Wiley & Sons, Ltd.Article Citation - WoS: 34Citation - Scopus: 32Lymphedema After Sentinel Lymph Node Biopsy: Who Is at Risk(Mary Ann Liebert, Inc., 2022) Isik, A.; Soran, A.; Grasi, A.; Barry, N.; Sezgin, E.Background: Sentinel lymph node biopsy (SLNB) is the accepted approach to stage the clinically negative axilla. The incidence of lymphedema (LE) after SLNB is about 5%. We hypothesize that patients undergoing axillary excision of >5 lymph nodes (LNs) are at increased risk of developing LE. Methods and Results: A single institution prospective breast cancer database was retrospectively reviewed from January 2013 to December 2017, to identify patients who underwent SLNB and were diagnosed with LE. Inclusion criteria was (1) de novo breast cancer, (2) SLNB in clinically node negative patients, and (3) no preoperative diagnosis LE of an extremity. Exclusion criteria was history of axillary lymph node dissection. Age, body mass index, tumor-node-metastasis status, surgery type, neoadjuvant or adjuvant chemotherapy, radiotherapy, and hormone therapy were analyzed. Of the 3325 patients identified, 2940 patients met the inclusion criteria and were included in the final analysis. Median follow-up time was 24 months. Forty-seven (2%) patients were diagnosed with LE, and nine patients (19%) had >5 LNs excised. LE was diagnosed in 3.7% of patients who had >5 LNs excised versus 1.4% of patients with ≤5 LNs excised. Incidence of LE was higher in patients with >5 LNs excision (p = 0.006). Conclusion: Our study showed that patients have a higher likelihood of developing LE when >5 LNs are excised. © Copyright 2022, Mary Ann Liebert, Inc., publishers 2022.Article Structural Changes in Fasted State Dietary Mixed Micelles Upon Solubilization of Beta-Carotene(2022) Bayramoğlu, BesteIt was aimed to investigate the structural changes taking place in duodenal mixed micelles (MM) at fasted state with the incorporation of fatty acids (FA) and the morphological transformations in these MMs upon solubilization of β-carotene (BCR) through coarse-grained (CG) molecular dynamics (MD) simulations. All simulations were performed with GROMACS 2019 simulation package using the Martini force field. Lauric acid (LA), stearic acid (SA) and linoleic acid (LNA) were used to explore the effects of FA chain length and unsaturation. Micelle swelling was observed with the incorporation of all FAs. The increase in size was in line with increasing FA chain length and unsaturation. MMs incorporating LA and SA were ellipsoidal in shape, while polyunsaturated LNA resulted in a worm-like MM. Upon solubilization of BCRs, swelling was observed only in the MMs with long-chain SA and LNA. No micelle growth was observed in the plain and LA MMs despite their smaller sizes. This was attributed to their low-density hydrophobic cores, which allowed a condensation effect induced by the interactions between BCRs and POPC tails. It is inferred that when the micelle is large enough to solubilize BCRs, whether or not swelling will take place depends on the core density. The increase in micelle size was very small in the MM incorporating LNA compared to that in the MM with SA, which was accompanied by an elliptical-to-cylindrical shape transformation. This was due to the fluid nature of the worm-like LNA micelle, which readily allowed the solubilization of 3 BCRs within its core. By resolving the internal structures of BCR incorporated MMs, this study gives valuable insight into the effects of FA chain length and unsaturation on the solubilization behavior of dietary MMs. The results are expected to give direction to the development of rational design strategies for effective BCR delivery systems.Book Part Citation - Scopus: 1Enzyme Production From Sourdough(CRC Press, 2023) Elvan, Menşure; Harsa, ŞebnemSourdough is a traditional fermented food well known around the world. It contains a wide variety of components, such as cereals and pseudocereals, and is rich in microflora that can potentially be used for enzyme production. Sourdough is a good source of lactic acid bacteria that have high enzyme production capability. Enzymes have different roles during sourdough fermentation: mainly, amylase and xylanase enzymes have important effects in improving texture; protease and phytase enzymes increase the nutritional value of sourdough; lipoxygenase improves the shelf life of products; and esterase plays a leading role in aroma and flavor formation. Additionally, it is possible to isolate sourdough enzymes for their potential to improve the health attributes of other foods, i.e., enzymes to break down gluten, hydrolyze phytic acid, and degrade fructans. Moreover, these enzymes may also be used to improve the technological properties of grain-based foods and beverages. Currently, there are no studies on the large-scale production of enzymes based on sourdough, although microorganisms isolated from sourdough have the potential for industrial-scale food applications as the sourdough microflora and derived enzymes have Generally Recognized as Safe (GRAS) and green label status. This chapter reviews sourdough enzymes and their importance for improving the quality and shelf life of foods in different food industries and products. © 2024 selection and editorial matter, Marco Garcia-Vaquero and João Miguel F. Rocha.Book Part Discovery, Characterization, and Databases of Enzymes From Sourdough(CRC Press, 2023) Ağırbaşlı, Zeynep; Harsa, ŞebnemSourdough enzymes have not been investigated in wide scale yet. Therefore, this chapter summarizes the main strategies and techniques used for the identification of sourdough enzymes together with the compilation of this information in databases for a wide variety of applications. The chapter describes a panel of methods based on different approaches, such as biochemical and molecular techniques for the identification of several key microbial enzymes emerged from sourdough or a combination thereof. Review includes information on the enzymes in carbohydrate metabolism, protein metabolism, phenolic metabolism, and stress metabolism together with enzymatic formation of bioactive compounds in sourdough. © 2024 selection and editorial matter, Marco Garcia-Vaquero and João Miguel F. Rocha.Research Project Spektroskopik Tekniklerin Sirke Üretiminin İzlenmesi ve Sirkenin Tağşişinin Tespitinde Kullanımı(2021) Özen, Fatma BanuDeğişik ham madde ve teknikler ile üretilen sirke, tağşişe maruz kalan gıda ürünleri arasında yer almaktadır. Ürün içeriği, ham madde ve üretim tipine göre farklılıklar gösterdiğinden tağşiş belirlemede zorluklar yaşanabilmektedir. Bu çalışma ile üzüm sirkesine etanol sirkesi ve asetik asit ekleme ile yapılan tağşişin, orta bölge kızılötesi (mid-IR) ve UV-görünür bölge (UV Vis) spektroskopik yöntemlerden elde edilen verilerin kemometrik teknikler ile değerlendirilmesi yoluyla tespit edilmesi amaçlanmıştır. Ayrıca geleneksel ve derin kültür yöntemleri ile üretim sırasında elde edilen kimyasal parametrelerin (pH, brix, toplam asitlik, toplam fenol ve flavonoid içerikleri, organik asit, şeker ve fenolik madde profilleri), mid-IR ve UV-Vis spektroskopik verilerden tahmini de bu çalışmanın diğer bir hedefidir. UV-Vis ve mid-IR verilerinin beraber kullanılmasıyla elde edilen ortogonal kısmi en küçük kareler-ayrım analizi (OPLS-DA) modeli tağşiş belirlemede en iyi sonucu vermiştir. Bu modele göre iki tağşiş tipini de kapsayan ve model oluşturmakta kullanılmayan doğrulama seti ile %96,49 oranında doğru sınıflama elde edilmiştir. Mid-IR spektroskopi verileri ile üzüm sirkesinin brix, pH, toplam asitlik, toplam fenol içeriği, toplam flavonoid içeriği, asetik asit, sitrik asit, glikoz ve fruktoz tahminlenmesinde güvenilir (doğrulama seti R2 değerleri 0,85'den büyük) istatistiksel performansa sahip kemometrik modeller oluşturulmuştur. Toplam fenol içeriğinin belirlenmesinde UV-Vis spektroskopi de iyi bir sonuç vermiştir. Ayrıca iki spektroskopik verinin beraber kullanılması toplam flavonoid içeriği, tartarik asit, kafeik asit ve p-kumarik asit için oluşturulan kemometrik tahmin modellerinde iyileşmeye neden olmuştur. Kullanılan spektroskopik ve kemometrik yöntemler üzüm sirkesi için hem tağşişin hem de birçok kalite ve kimyasal parametresinin belirlenmesinde iyi sonuçlar vermiştir.Book Part Citation - Scopus: 1Enzyme Technology in Value Addition of Wine and Beer Processing(Elsevier, 2022) Uzuner, SibelSome endogeneous and exogeneous enzymes participate in the brewery and winery technologies. Industrial enzymes provide quantitative advantages (increased juice yields) and qualitative advantages (enhanced extraction and flavor) for processing (shorter maceration, settling, and filtration time). This review aims to explain the flow process of brewing and wine-making, discuss different enzymes used in brewery and wine-making industry. Also, this chapter summarizes the key enzymes used at different stages of wine-making and brewing, and the challenges of the exogeneous, commercial and immobilized enzymes. Finally, the use of immobilized enzymes is presented as a significant strategy to improve catalyst during brewing and wine-making.Book Citation - Scopus: 15Edible Food Packaging With Natural Hydrocolloids and Active Agents(CRC Press, 2022) Yemenicioğlu, AhmetThe aim of this book is to show the potential of natural hydrocolloids and active agents to develop sustainable edible packaging materials for food preservation. For this, the current and future sources of natural hydrocolloids have been reviewed along with their extraction methods, impact on health and ability to form different packaging such as film, casing, coating, mat, pad, etc. Similarly, natural active compounds were evaluated carefully considering their sources, extraction methods, regulatory status, and compatibility with edible packaging. The book emphasizes the recent developments in methods, strategies and technologies employed to enhance the performance of antimicrobial, antioxidant and bioactive packaging. The basic testing methods used to evaluate antimicrobial and antioxidant activity of edible packaging in model media and food were discussed, and carefully selected example active edible packaging applications for different food categories were provided with critical details such as the thin balance between effectiveness of packaging and sensory properties of food. As such, it helps in understanding necessary parameters in designing an effective active edible packaging that is applicable to the target food category. Moreover, readers are primed for the first time on how to develop a fully natural antimicrobial, antioxidant or bioactive edible food packaging. This book is different from most of the similar books' avail as it provides neither methodologies about classical active packaging based on chemicals and fossil polymeric films nor is it a thorough collection of different food packaging applications. It is also not a book that concentrates on physicochemical characterization methods and engineering aspects of packaging. Instead, this is a book that provides systematic knowledge about key methods of evaluating natural resources, agro-industrial wastes and by-products for development of edible packaging, and concentrates on concepts, strategies, technologies, and applications of active edible packaging based solely on natural components. It is designed to share both positive and negative experiences in an emerging field that is expected to play a central role in improving food safety and quality, human health and environmentally friendly practices.Book Part Citation - Scopus: 8Uv Processing and Storage of Liquid and Solid Foods: Quality, Microbial, Enzymatic, Nutritional, Organoleptic, Composition and Properties Effects(Elsevier, 2021) Hakgüder Taze, Bengi; Pelvan Akgün, Merve; Yıldız, Semanur; Kaya, Zehra; Ünlütürk, SevcanNon-thermal food processing technologies have been explored extensively in recent years in order to develop food products with extended shelf life as well as preserved nutritional and organoleptic characteristics in accordance with the changing consumer demands (Falguera et al., 2011a; Sanchez-Moreno et al., 2009). Ultraviolet (UV) irradiation is one of the non-thermal processes that can be applied to reduce the microbial load in liquid foods and surfaces, and to sterilize food packages and packaging materials, and environments involved in food processes (Jimenez-Sanchez et al., 2017a; Bintsis et al., 2000). UV light is subdivided into three regions as short-wave UV (UV-C, 200 and 280 nm), medium-wave UV (UV-B, 280 to 315 nm), and long wave UV (UV-A, 315 to 400 nm). The different types of effects on microorganisms can be caused by UV light of different wavelengths. The effectiveness of UV light on microorganisms results primarily from the fact that DNA molecules absorb UV photons between 200 and 300 nm, with peak absorption around 260–265 nm. This causes DNA damage by altering the nucleotide base pairing, thereby creating new linkages between adjacent nucleotides, particularly between pyrimidine bases, on the same DNA strand and ultimately results in cell death (Zimmer and Slawson, 2002). Peak et al. (1984) proposed that the dimer formation is not the only requirement to damage the DNA. Absorption of different wavelength photons by different molecular groups in the long DNA molecule can damage or destroy these bond groups. Thus, different bonds in the DNA can be affected with photons of different energy (Neister, 2014).