Biyoaktif madde yüklenmiş siklodekstrin-metal organik kafes sentezi ve karakterizasyonu
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Dosyalar
Tarih
2023
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Bursa Teknik Üniversitesi, Lisansüstü Eğitim Enstitüsü
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Günümüzde doğal ürünlere gösterilen yönelim, gıdalarda sentetik antimikrobiyal ve antioksidan özellikli maddelerin yerine doğal koruyucuların kullanılmasını gündeme getirmiştir. Bu amaçla, doğal koruyucuların kullanımında karşılaşılan zorlukların üstesinden gelmek için pek çok çalışma yürütülmektedir. Karvakrol (Car) antioksidan özelliği ile dikkat çeken doğal fenolik bir bileşiktir. Ancak Car'ün düşük stabilitesi, suda düşük çözünürlüğü ve yüksek uçuculuğu kullanımını kısıtlamaktadır. Literatür incelendiğinde Car moleküllerinin kullanım kısıtlamalarını ortadan kaldırabilmek adına başka bir yapı tarafından enkapsüle edilmesi çalışılan konular arasındadır. Metal organik kafesler (MOF'ler), yapıları ve yüksek yüzey alanları nedeniyle son yıllarda enkapsülasyon çalışmalarında ön plana çıkmaktadır. Ancak bu yapıların eldesinde gıda ile uyumlu olmayan malzemelerin kullanımı oldukça yaygındır. Diğer taraftan, gıda alanında kullanımı açısından sorun olmayan siklodekstrin (CD) molekülü ile de MOF'ler oluşturulabilmektedir. Bu da gıda uygulamalarında CD tabanlı MOF'lerin kullanımını gündeme getirmektedir. CD'ler uygun misafir molekülleri ile ev sahibi-misafir tipi inklüzyon kompleksler (IC'ler) oluşturarak misafir moleküllerinin özelliklerinde iyileştirmeye neden olurlar. Bu çalışma kapsamında Car molekülünün CD tabanlı MOF ile enkapsülasyon metanol difüzyon yöntemi kullanılarak gerçekleştirilmiştir. Car ile kavite genişliğinin uyumundan dolayı CD olarak β CD tercih edilmiştir. β CD-MOF yapısına 1 mmol, 5 mmol ve 10 mmol konsantrasyonda Car yüklemesi yapılmıştır. Car yüklenmiş β CD-MOF'un üretim verimi ve sistemin enkapsülasyon etkinliği (EE) hesaplanmıştır. Elde edilen yapıların morfolojik olarak incelenmesi için taramalı elektron mikroskobu (SEM) ile görüntüleme yapılmış ve yapılardaki farklılıklar ortaya konulmuştur. SEM ile beraberinde enerji dağılımı spektroskopisi (EDS) ile örneklerdeki karbon, oksijen ve potasyum elementlerinin dağılım ve yoğunlukları incelenmiş ve homojen bir dağılım gösterdiği görülmüştür. Örneklerin kristal yapıları X-ışını difraktometresi (XRD) ile incelenmiştir ve IC oluşumuna bağlı olarak değişimler gözlemlenmiştir. Car yüklenmesine bağlı olarak β CD-MOF yapısındaki kimyasal değişimler ise fourier dönüşümlü infrared (FTIR) analizi sonuçları ile gösterilmiştir. Ayrıca örneklerin termal yapısındaki değişimler termal gravimetrik analiz (TGA) ve diferansiyel tarama kalorimetresi (DSC) ile değerlendirilmiştir. Bununla beraber, DPPH ve CUPRAC metotlarından yararlanılarak elde edilen antioksidan aktivitesi sonuçları Trolox eşdeğeri olarak hesaplanmıştır. Analiz sonuçları, elde edilen gıda ile uyumlu Car β CD-MOF yapısının antioksidan özellik gösterdiğini desteklemiştir. Aynı zamanda Car'ün β CD-MOF ile enkapsülasyonu sonucunda çözünürlüğünün arttığı görülmüştür.
Today, the trend towards the use of natural products has led to the use of natural preservatives instead of synthetic antimicrobial and antioxidant substances in foods. For this purpose, many studies have been carried out to overcome the difficulties encountered in the use of natural preservatives. Carvacrol (Car) is a natural phenolic compound that attracts attention with its antioxidant properties. However, Car's low stability, low water solubility and high volatility limit its use. When the literature is examined, encapsulation of Car molecules by another structure in order to eliminate the usage restrictions is among the frequently studied topics. Metal organic frameworks (MOFs) have come to the forefront in encapsulation studies in recent years due to their structure and high surface area. However, the use of materials that are incompatible with food is quite common in the production of these structures. On the other hand, MOFs can also be formed with cyclodextrin (CD) molecule, which is not a problem in terms of food use. This brings up the use of CD-based MOFs in food applications. CDs form host-guest type inclusion complexes (ICs) with suitable guest molecules, leading to improvement in the properties of the guest molecules. In this study, the encapsulation of Car molecule with CD-based MOF was realized using a methanol diffusion method. β CD was preferred as CD due to the compatibility of Car and cavity width. The β CD-MOF structure was loaded with Car at concentrations of 1 mmol, 5 mmol and 10 mmol. The production yield of Car-loaded β CD-MOF and the encapsulation efficiency (EE) of the system were calculated. Scanning electron microscopy (SEM) imaging was used to morphologically examine the obtained structures and the differences in the structures were revealed. In addition to SEM, the distribution and concentrations of carbon, oxygen and potassium elements in the samples were analyzed by energy dispersive spectroscopy (EDS) and a homogeneous distribution was observed. The crystal structures of the samples were analyzed by X-ray diffractometer (XRD) and changes were observed due to IC formation. The chemical changes in the β CD-MOF structure due to Car loading were shown by Fourier transform infrared (FTIR) analysis. In addition, changes in the thermal structure of the samples were evaluated by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). In addition, the antioxidant activity results obtained by DPPH and CUPRAC methods were calculated as Trolox equivalent. The analysis results supported that the obtained food compatible Car β CD-MOF structure showed antioxidant properties. At the same time, it was observed that the solubility of Car increased as a result of its encapsulation with β CD-MOF.
Today, the trend towards the use of natural products has led to the use of natural preservatives instead of synthetic antimicrobial and antioxidant substances in foods. For this purpose, many studies have been carried out to overcome the difficulties encountered in the use of natural preservatives. Carvacrol (Car) is a natural phenolic compound that attracts attention with its antioxidant properties. However, Car's low stability, low water solubility and high volatility limit its use. When the literature is examined, encapsulation of Car molecules by another structure in order to eliminate the usage restrictions is among the frequently studied topics. Metal organic frameworks (MOFs) have come to the forefront in encapsulation studies in recent years due to their structure and high surface area. However, the use of materials that are incompatible with food is quite common in the production of these structures. On the other hand, MOFs can also be formed with cyclodextrin (CD) molecule, which is not a problem in terms of food use. This brings up the use of CD-based MOFs in food applications. CDs form host-guest type inclusion complexes (ICs) with suitable guest molecules, leading to improvement in the properties of the guest molecules. In this study, the encapsulation of Car molecule with CD-based MOF was realized using a methanol diffusion method. β CD was preferred as CD due to the compatibility of Car and cavity width. The β CD-MOF structure was loaded with Car at concentrations of 1 mmol, 5 mmol and 10 mmol. The production yield of Car-loaded β CD-MOF and the encapsulation efficiency (EE) of the system were calculated. Scanning electron microscopy (SEM) imaging was used to morphologically examine the obtained structures and the differences in the structures were revealed. In addition to SEM, the distribution and concentrations of carbon, oxygen and potassium elements in the samples were analyzed by energy dispersive spectroscopy (EDS) and a homogeneous distribution was observed. The crystal structures of the samples were analyzed by X-ray diffractometer (XRD) and changes were observed due to IC formation. The chemical changes in the β CD-MOF structure due to Car loading were shown by Fourier transform infrared (FTIR) analysis. In addition, changes in the thermal structure of the samples were evaluated by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). In addition, the antioxidant activity results obtained by DPPH and CUPRAC methods were calculated as Trolox equivalent. The analysis results supported that the obtained food compatible Car β CD-MOF structure showed antioxidant properties. At the same time, it was observed that the solubility of Car increased as a result of its encapsulation with β CD-MOF.
Açıklama
Anahtar Kelimeler
FTIR, Mikroenkapsülasyon, Microencapsulation, Uçucu yağlar, Essential oils
