Dondurularak kurutulan mikroenkapsüle ceviz yağında timol ve karvakrolün antioksidan etkisinin araştırılması
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Dosyalar
Tarih
2018
Yazarlar
Dergi Başlığı
Dergi ISSN
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Yayıncı
İnönü Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Ceviz yağı, oleik ve linoleik asitler gibi kolaylıkla okside olabilme niteliğine sahip kıymetli bileşenlerin iyi bir kaynağıdır. Gıdalara farklı amaçlarla doğal katkı maddesi olarak katılan timol ve karvakrol mükemmel bir antioksidan aktiviteye sahiptir. Bununla beraber, timol ve karvakrolün yüksek uçuculuk özellikleri sebebiyle yüksek sıcaklık derecelerindeki antioksidan etkileri sınırlıdır. Bu nedenle söz konusu bileşiklerin bitkisel yağlara antioksidan olarak ilave edilmelerinde koruyucu etkileri tam olarak belirlenememektedir. Bu problemin çözüm yollarından bir tanesi mikrokapsülasyon uygulamasıdır. Bu çalışmanın amacı, timol ve karvakrolün ceviz yağı trigliseritlerindeki (TAG) antioksidan aktivitelerini mikrokapsülasyon uygulaması ile arttırmaktır. Sodyum kazeinat, laktoz ve timol veya karvakrol içeren ceviz yağı TAG'lerinden hazırlanan kaba emülsiyon 40 mPa basınçta yüksek basınç homojenizatöründen (YBH) geçirilerek homojenize edilmiştir. Elde edilen emülsiyon dondurarak kurutulmuş ve toz haline getirilmiştir. En yüksek mikrokapsülasyon etkinliği (%82.3) YBH'inden üç kez geçirilme ile elde edilmiş olup, elde edilen emülsiyonun zeta potansiyeli ve emülsiyon parçacık büyüklüğü sırasıyla -40.4 mV ve 300 nm şeklindedir. Elde edilen örneklerin mikrokapsülasyon öncesi ve sonrası oksidatif stabiliteleri Ransimat tekniği (100°C sıcaklık ve 10 L/h hava akış hızı) ve 40°C'de 24 gün süresince gerçekleştirilen hızlandırılmış fırın testi ile ölçülmüştür. Ransimat sonuçlarına göre mikrokapsüle edilen ceviz yağı TAG'lerine ilave edilen timol test edilen tüm ilave oranlarında karvakrolden daha yüksek koruma faktörüne sahiptir. Hızlandırılmış fırın testinde de, ceviz yağı TAG'leri ve toz haldeki mikrokapsüle ceviz yağı TAG'lerinde timolün antioksidan etkisi karvakrole göre daha yüksek olduğu saptanmıştır. Ransimat test sonuçları ile uyumlu olarak hızlandırılmış oksidasyon testinde tüm oksidasyon sürelerinde en düşük peroksit sayısı %0.20 timol içeren mikrokapsüle ceviz yağı TAG'lerinde saptanmıştır. Böylelikle, mikrokapsüle ceviz yağı TAG'lerinde timol ve karvakrolün mikrokapsüle edilmeyene kıyasla daha yüksek antioksidan etki gösterdiği saptanmıştır.
Walnut oil is a good source of valuable compounds such as oleic and linoleic acids, which are tended to easily oxidize under inappropriate conditions. Thymol and carvacrol exhibit excellent antioxidant activities and are generally used as the natural additives in foods for several purposes. However, antioxidant actions of thymol and carvacrol are limited at elevated temperatures due to their high volatility. Therefore, the protective effect is underestimated when these compounds are added to the vegetable oils as antioxidant. One way to overcome this problem is to employ encapsulation application. This study was aimed to enhance the antioxidant activity of thymol and carvacrol in in walnut oil triacylglycerols (TAGs) by encapsulation application. Walnut oil TAGs was obtained by alumina column chromatography. A coarse emulsion prepared with sodium caseinate, lactose and walnut TAGs, containing thymol and carvacrol, was homogenized several times at 40 Mpa by using a high pressure homogenizer (HPH). The obtained emulsion was freeze-dried and powdered. The highest encapsulation efficiency (82.3%) was obtained by the three passes through the high pressure homogenization with a zeta potential and average emulsion droplet size of -40.4 mV and 300 nm, respectively. Oxidative stability of the samples, both before and after encapsulation, was evaluated by Rancimat technique (at 100 °C and an air flow rate of 10 L/h) and accelerated oven test at 40 °C for 24 days. The result of Rancimat test indicated that encapsulated walnut TAGs containing thymol exhibited the highest protection factor than that of carvacrol in all the tested ratios. Accelerated oven test showed that the antioxidant effect of thymol was higher than that of carvacrol in walnut TAGs and its encapsulated powder. In agreement with the result of Rancimat test, the lowest peroxide value were determined in the encapsulated walnut TAGs containing thymol (0.20%) throughout the oxidation period. Thus, it was demonstrated that the antioxidant effect of thymol and carvacrol was higher in encapsulated samples than those of unencapsulated counterpart.
Walnut oil is a good source of valuable compounds such as oleic and linoleic acids, which are tended to easily oxidize under inappropriate conditions. Thymol and carvacrol exhibit excellent antioxidant activities and are generally used as the natural additives in foods for several purposes. However, antioxidant actions of thymol and carvacrol are limited at elevated temperatures due to their high volatility. Therefore, the protective effect is underestimated when these compounds are added to the vegetable oils as antioxidant. One way to overcome this problem is to employ encapsulation application. This study was aimed to enhance the antioxidant activity of thymol and carvacrol in in walnut oil triacylglycerols (TAGs) by encapsulation application. Walnut oil TAGs was obtained by alumina column chromatography. A coarse emulsion prepared with sodium caseinate, lactose and walnut TAGs, containing thymol and carvacrol, was homogenized several times at 40 Mpa by using a high pressure homogenizer (HPH). The obtained emulsion was freeze-dried and powdered. The highest encapsulation efficiency (82.3%) was obtained by the three passes through the high pressure homogenization with a zeta potential and average emulsion droplet size of -40.4 mV and 300 nm, respectively. Oxidative stability of the samples, both before and after encapsulation, was evaluated by Rancimat technique (at 100 °C and an air flow rate of 10 L/h) and accelerated oven test at 40 °C for 24 days. The result of Rancimat test indicated that encapsulated walnut TAGs containing thymol exhibited the highest protection factor than that of carvacrol in all the tested ratios. Accelerated oven test showed that the antioxidant effect of thymol was higher than that of carvacrol in walnut TAGs and its encapsulated powder. In agreement with the result of Rancimat test, the lowest peroxide value were determined in the encapsulated walnut TAGs containing thymol (0.20%) throughout the oxidation period. Thus, it was demonstrated that the antioxidant effect of thymol and carvacrol was higher in encapsulated samples than those of unencapsulated counterpart.
Açıklama
Anahtar Kelimeler
Gıda Mühendisliği, Food Engineering
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Künye
Gürsul. Sevilay (2018). Dondurularak kurutulan mikroenkapsüle ceviz yağında timol ve karvakrolün antioksidan etkisinin araştırılması. Yayımlanmış Yüksek lisans tezi, İnönü Üniversitesi, Malatya.1-70 ss.
