Food Engineering / Gıda Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/12
Browse
52 results
Search Results
Now showing 1 - 10 of 52
Article Citation - WoS: 10Citation - Scopus: 10An Efficient Method of Improving Essential Oil Retention and Sustained Release of Chitosan Films: Ultrasound-Assisted Preparation of Chitosan Composites With Surface Active Chickpea Proteins(Elsevier, 2024) Barış Kavur, Pelin; Yemenicioğlu, AhmetThis work aimed at preparing chitosan (CHI) composites with surface active chickpea protein (CP) showing better eugenol (EUG) retention and sustained release capacity than pristine CHI films. For this purpose, ionic complexation of CHI with CP (CHI:CP ratio = 2:1, w/w) in the presence of EUG at pH 5.0 was achieved using mechanical homogenization alone (HM) or in combination with ultrasonic homogenization (HM-HUS). The HM-HUS treatment provided better solubility of CP (4.4-fold), increased emulsified EUG in film-forming solutions, and denser films than HM treatment. The composite films obtained using HM-HUS (FLMCHI-CP-EUG/HM-HUS) retained 1.2–1.4-fold higher EUG after drying, and showed almost 2-fold slower EUG release in air at room temperature than composite films prepared by HM, and control CHI films prepared by HM (FLMCHI-EUG/HM) or HM-HUS (FLMCHI-EUG/HM-HUS). The FLMCHI-CP-EUG/HM-HUS films also showed better moisture barrier and mechanical properties than other films. The developed films were proved in a challenging coating application with onions. Escherichia coli and Listeria innocua counts of inoculated and FLMCHI-CP-EUG/HM-HUS (average coating thickness = 4.5 ± 1.3 μm) coated onions were significantly lower than those of uncoated (2.8 and 3.8 log) and FLMCHI/HM-HUS (1.4 and 1.3 log) coated onions after 5-days at room temperature. FLMCHI-CP-EUG/HM-HUS coating also reduced percentage of sprouted onions from 30 to 10% during storage. EUG odor of coated onions could not have been detected by 80% of panelists after 4 weeks. Compositing with CP boosts the performance of essential oil loaded CHI films by enabling use of film matrix as an encapsulant. © 2024 Elsevier LtdArticle Citation - WoS: 39Citation - Scopus: 41Novel Edible Films of Pectins Extracted From Low-Grade Fruits and Stalk Wastes of Sun-Dried Figs: Effects of Pectin Composition and Molecular Properties on Film Characteristics(Elsevier, 2023) Çavdaroğlu, Elif; Büyüktaş, Duygu; Farris, Stefano; Yemenicioğlu, AhmetThis study aimed to explore the characteristics of novel fig pectin films. For this purpose, films of crude fig pectin (CFP) extracted from low-grade sun-dried fruits and films of crude (CSP) and purified (PSP) stalk pectins extracted from stalk waste of processed high-quality sun-dried figs were evaluated for their physicochemical properties. The properties of pristine (CFP, CSP, and PSP films) and CaCl2 cross-linked films (CFP–Ca++, CSP-Ca++and PSP-Ca++ films) of fig pectins were also compared with films of commercial citrus (CP and CP-Ca++) and apple (AP, AP-Ca++) pectins. The cross-linking improved the mechanical strength and barrier properties of most films. CP, CP-Ca++, PSP, and PSP-Ca++ films showed greater mechanical strength and stiffness than other films. PSP-Ca++, PSP and CP-Ca++ films showed the lowest water vapor permeability (6.28, 12.85, 14.96 g.mm.m−2.day−1.kPa−1, respectively) while CSP-Ca++, CP-Ca++, CP, PSP-Ca++ films showed the lowest oxygen permeability coefficients (5403, 8265, 10776, 11124 mL.μm.m−2.24h−1.atm−1, respectively). All cross-linked fig pectin films showed 2–3 fold lower degree of swelling than CP-Ca++ film. The CFP-Ca++ film showed the highest surface hydrophobicity (contact angle = 101.8°) but the lowest water solubility (32.8%) and degree of swelling. Analysis of Pearson's correlations between pectin properties and film characteristics revealed that galacturonic acid (GA) content affects the mechanical properties, while GA content, degree of esterification (DE), and acetylation affect the moisture barrier performance; finally, GA content and DE affect the oxygen barrier performance of pectin films. Films of stalk waste pectins showed some properties beyond the limits of those obtained from commercial pectins.Article The Use of Organic Sun-Dried Fruits for Delivery of Phenolic Compounds(İzzet KARA, 2022) Dervişoğlu, Gökhan; Yemenicioğlu, AhmetThe aim of this study is to characterize and increase the total soluble (water soluble + alcohol soluble) phenolic (SPCT) and flavonoid content (SFCT) and total soluble free radical scavenging based antioxidant capacity (SACT) of major sun-dried fruits such as raisins, figs, prunes and apricots. Due to their high insoluble dietary fiber content, the bound antioxidant capacity formed 61 to 67% of the overall antioxidant capacity (water soluble + alcohol soluble + bound) of sun-dried fruits. The SPCT, SFCT and SACT of sun-dried fruits changed between 1675 and 3860 μg catechin/g (d.w.), 161 and 495 μg catechin/g (d.w.) and 13 and 28.5 μmol Trolox/kg (d.w.), respectively. The incorporation of green tea polyphenols into sun-dried raisins, figs and apricots by controlled rehydration conducted in green tea extracts increased their SPCT, SFCT and SACT 1.5 to 1.8 fold, 1.3 to 1.6 fold, and 1.5 to 2.6 fold, respectively. The method applied caused limited increases in SPCT (1.1 fold) and SFCT (1.2 fold) of prunes, but it increased SACT of these fruits 1.6 fold. This study showed the possibility of using sun-dried fruits not only as source of dietary fiber, but also for delivery of phenolic compounds. The methods used in this study for delivery of green tea phenolic compounds to selected organic sun-dried fruits could be an alternative method to increase intake of these invaluable antioxidant compounds and increase functionality of sun-dried fruits which are already accepted as good source of dietary fiber.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.Article Citation - WoS: 17Citation - Scopus: 21Utilization of Stalk Waste Separated During Processing of Sun-Dried Figs (ficus Carica) as a Source of Pectin: Extraction and Determination of Molecular and Functional Properties(Academic Press Inc., 2022) Çavdaroğlu, Elif; Yemenicioğlu, AhmetThis study aimed the utilization of fig stalk waste as an alternative pectin source. For this purpose, the characteristics of extracted stalk waste pectin (SP) were compared with those of citrus pectin (CP) and pectin extracted from defected substandard whole sun-dried figs (FP). The SP had a higher extraction yield (11.7%) than FP (9.4%). The galacturonic acid content and degree of esterification of SP (32.3 and 50.1%) were higher than those of FP (19.9 and 38.8%), but lower than those of CP (79.3 and 56.2%), respectively. The SP and CP had different sugar compositions (D-glucose, L-rhamnose, D-galactose and L-arabinose) and weight average molecular weights, but similar FTIR profiles. The SP showed almost 1.9 and 1.6-fold higher Trolox equivalent antioxidant capacity (TEAC), and 2.7 and 2.0-fold higher water absorption capacity than CP and FP, respectively. SP at 3% (w/w) showed the second highest viscosity after CP and the highest emulsion stability. Gels of SP and CP at 1.75–3% range had similar firmness, but SP formed more fracturable gels than CP. Sun-dried fig stalk waste is a better source of pectin than defected substandard whole sun-dried figs. The SP could be utilized to develop functional food with alternative textural and rheological properties.Article Citation - WoS: 17Citation - Scopus: 18Incorporation of Organic Acids Turns Classically Brittle Zein Films Into Flexible Antimicrobial Packaging Materials(Wiley, 2021) Sözbilen, Gözde Seval; Çavdaroğlu, Elif; Yemenicioğlu, AhmetThis 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 degrees C or 25 degrees 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 alpha-helix and random coils (mainly by MA) and spaced/modified intermolecular (only by LA) and intramolecular (mainly by MA) beta-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.Conference Object Potential Application of Natural Phenolic Antimicrobials and Edible Film Technology Against Bacterial Plant Pathogens(International Society for Horticultural Science, 2020) Alkan, Derya; Yemenicioğlu, AhmetIn this study, antimicrobial edible film technology used frequently for inhibition of human pathogens in processed food was employed as a postharvest bio-based preservation method to prevent bacterial spoilage of fresh fruits and vegetables. Antimicrobial edible zein films were developed by incorporation of pure phenolic acids (PAs) such as gallic acid (GA), cinnamic acid (CA), vanillic acid (VA); essential oils (EOs) such as carvacrol (CAR), thymol (THY), eugenol (EUG) and citral (CIT) and phenolic extract (PE) from clove. In order to test synergetic effect of PAs, different amounts of PAs were added into film solution to obtain films containing mixture of GA and CA, GA and VA, CA and VA at different concentrations. The antimicrobial performances of edible films were tested on selected plant pathogenic bacteria including Pseudomonas syringae, Erwinia amylovora, Xanthomonas vesicatoria and Erwinia carotovora. The overall results of antimicrobial tests showed that films containing PAs between 1 and 4 mg cm-2 inhibited all pathogens while EOs at concentrations between 2 and 4 mg cm-2 and clove extract between 4 and 8 mg cm-2 were found effective against pathogens except P. syringae. Morover, the incorporation of combination of different PA showed greater inhibitory activity on plant pathogens than incorporation of a single PA into films. The edible zein coatings have already been applied for coating of fresh fruits and vegetables at the postharvest stage to suppress their respiration rate and prolong their refrigerated storage. This work clearly showed the benefit of incorporating a single or mixture of antimicrobial phenolic compounds, EOs and PEs in edible zein films against bacterial plant pathogens. The developed films might be employed against plant pathogens by coating fresh fruits and vegetables, seeds, seedlings, tree stems, soil as well as agricultural tools and constructions without using toxic chemicals. © 2020 International Society for Horticultural Science. All rights reserved.Article Citation - WoS: 5Citation - Scopus: 5Physicochemical and Active Properties of Gelatine-Based Composite Gels Loaded With Lysozyme and Green Tea Polyphenols(University of Zagreb, 2021) Boyacı, Derya; Barış Kavur, Pelin; Güleç, Şükrü; Yemenicioğlu, AhmetResearch background. The use of gel-based systems as a novel method for the delivery of natural antimicrobial, antioxidant and bioactive compounds is a developing innovative solution for the food industry. This research aims to develop multifunctional active edible gels based on gelatine and its composites with improved mechanical properties. Experimental approach. Antilisterial and bioactive composite gels showing different physical and active properties from classical gelatine gel were developed by loading lysozyme and green tea extract into gelatine/starch and gelatine/wax composite gels. Mechanical properties, swelling profiles, colour, release profiles, and antimicrobial and bioactive properties of the gels were characterised. Results and conclusions. Gelatine/wax gels showed 1.3-to 2.1-fold higher firmness and cutting strength than gelatine and gelatine/starch composite gels that had similar firmness and cutting strengths. Work to shear of both composite gels was 1.4-to 1.9-fold higher than that of gelatine gel. The gelatine/starch gel showed the highest water absorption capacity. Green tea extract reduced soluble lysozyme in all gels, but composite gels contained higher amount of soluble lysozyme than gelatine gel. All the gels with lysozyme inhibited Listeria innocua growth in the broth media, while green tea extract showed antilisterial activity only in gelatine/wax gels. Gels with green tea extract showed antioxidant, antidiabetic (?-glucosidase and ?-amylase inhibition), antihypertensive (angiotensin-converting enzyme inhibition) and antiproliferative activities (on Caco-2 human colon carcinoma cells). However, gelatine and gelatine/wax gels showed the highest antioxidant and antidiabetic activity. The gelatine/wax gels prevented phenolic browning, while green tea extract in other gels showed moderate or extensive browning. Novelty and scientific contribution. This work clearly showed the possibility of improving mechanical properties and modifying water absorption and controlled release profiles of gelatine gels using gelatine/starch and gelatine/wax composites. The novel composite gels reduced browning of incorporated polyphenols and showed antilisterial and bioactive properties. © 2021, University of Zagreb. All rights reserved.Article Citation - WoS: 64Citation - Scopus: 77Development of Flexible Antimicrobial Zein Coatings With Essential Oils for the Inhibition of Critical Pathogens on the Surface of Whole Fruits: Test of Coatings on Inoculated Melons(Elsevier, 2019) Boyacı, Derya; Iorio, Gianmarco; Sözbilen, Gözde Seval; Alkan, Derya; Trabattoni, Silvia; Pucillo, Flavia; Yemenicioğlu, AhmetThis study aimed to develop essential oil (EO)-containing antimicrobial coatings for the inhibition of pathogenic bacteria contamination on fruit peels. Incorporation of eugenol (EUG), carvacrol (CAR), and thymol (THY) into films at > 1% (w/w) eliminated the typical brittleness of zein films. However, EUG outperformed CAR and THY in terms of mechanical properties. Films with >= 2% (w/w) CAR and THY and >= 3% EUG showed clear zones against L. innocua and E. coli in agar medium at 37 degrees C. All EO-containing films also inhibited L. innocua and E. coli inoculated at their surfaces by minimum 3.9 and 2.7 decimal (D) within 1 day at 10 degrees C. Moreover, 2% EUG-containing zein coatings caused 2-3 decimal reduction in L. innocua and E. coli counts of inoculated melon surfaces at 10 degrees C. Unlike the bare zein coatings, flexible EUG-containing films on melons did not show cracking or detachment. Zein films loaded with EUG showed a highly hydrophilic surface. The best oxygen barrier performance was observed for the EUG-richest formulation (i.e., EUG at 3%), and this was attributed to a homogenizing effect of the EO that eventually led to a denser and hole-free network. This work suggested that flexible coatings of zein containing EOs could inhibit pathogens embedded in the rough peel surface of melons.Editorial Citation - WoS: 5Citation - Scopus: 7Natural Hydrocolloids in the Food Sector - Recent Applications Beyond Conventional Uses(Wiley, 2020) Yemenicioğlu, Ahmet; Farris, Stefano; Türkyılmaz, Meltem; Güleç, ŞükrüIn food industry, natural hydrocolloids have been extensively used to increase the functionality of different food products such as beverages, bakery and confectionery, sauces and dressings, and meat and poultry. Conventional applications of hydrocolloids in the food industry are still based on their rheological and surface‐active properties (Dickinson, 2018; Nishinari et al., 2018; Yousefi & Jafari, 2019). However, recent developments in the hydrocolloids sector fuelled by sophisticated market demands and emerging new technologies expanded the applications of hydrocolloids beyond their conventional uses.