Çiğit ve ayçiçek yağlarının doğal antioksidan içerikleri ile bu yağların stabilitelerinin arttırılmaları üzerinde araştırmalar
Küçük Resim Yok
Tarih
1985
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Ege Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
- 106 - 5. ÖZET Bu araştırmada, ayçiçeği ve çiğit yağlarında, serbest tokoferollerden farklı olarak, doğal antioksidanlar olup ol madığının saptanması amaçlanmıştır. Bu düşüncenin gerçekleştirilebilmesi için,yağların sabunlaşmayan madde leri,pr epe rat if
SUMMARY The aim of this research is to estimate the presence of natural antioxidants apart from free tocopherols in sun flower and cottonseed oils. For this purpose »unsaponifiable substances of oils were fractionated by means of preperative column chromatog raphy with step gradient elution solvent systems. The presence of an antioxidant substance in each fraction Was traced by using Warburg manometer with a model system. This system may be accepted as a liquid chromatography that has a dedector which in sensitive to antioxidants and prooxidants. Since there is no similar work in the literature, we believe that the qualitative determination of antioxidant substances in uhsaponifiable fractions by manoraetric methods would be useful for similar studies. It was estimated that in the unsaponifiable fractions of sunflower oil there are two antioxidant substances which are more apolar and different from the free tocopherols. The structures of these antioxidants were illustrated by using gas chromatography, micro preperative high pressure liquid. chromatography, pyrolysis gaz chromatography, thin layer chromatography and analytical high pressure liquid chromatography. As a result it was fount out that these antioxidant subtances were trimers of tocopherols (A-l) and dimers of 5-tocopherols (A-2). The fact that the tocopherol trimers and dimers in sunflower oils were naturaly present in the seed apart from the chemical procedures applied and the chemical reactions which occured during processing and the analysis of ois was shown by using preperative column chromatography, micro preperative high pressure liquid chromatography and gas chromatography.After the qualitative determinations of dimer and trimers tocopherols their quantitative determinations were made by using preperative column chromatography and gas chromatography. As a result of this determination it was found that the refined sunflower oil contains more trimers then the refined cotton seed oil. Although the natural tocopherol trimers were estimated as a single substance by preperative column chromatography and high pressure liquid chromatography, it was intended to find out that these trimers were consisted of more than one tocopherol trimers having nearly similar.- polarities by using micro preperative high pressure liquid chromatography and gas chromatography techniques. It was estimated that the deodorizer condensates (scum) of sunflower and cottonseed oils can be economic sources for obtaining monomer and tocopherol trimers which are used for the inhibition of autoxidative rancidity of oils and oil containing foods. It was found that the amount of. total tocopherols was 6.559 % in the unsaponifiable substan ces of deodorizer condensates of sunflower oil; and 20.072 % in the unsaponifiable substances of deodorizer condensates cottonseed oil. The effect of natural and synthetic antioxidant on the autoxidation of refined sunflower oil was examined by manometric methods and it was found that the trimers show antioxidant properties at a concentration of 1405 mg/100 g. The tocopherol trimers show antioxidant properties even at high concentrations while the free tocopherols show prooxi- dant properties at a concentration higher than 50-70 mg/100g. This is an important property and it is intended to find an explanation about the causes of this situation.
SUMMARY The aim of this research is to estimate the presence of natural antioxidants apart from free tocopherols in sun flower and cottonseed oils. For this purpose »unsaponifiable substances of oils were fractionated by means of preperative column chromatog raphy with step gradient elution solvent systems. The presence of an antioxidant substance in each fraction Was traced by using Warburg manometer with a model system. This system may be accepted as a liquid chromatography that has a dedector which in sensitive to antioxidants and prooxidants. Since there is no similar work in the literature, we believe that the qualitative determination of antioxidant substances in uhsaponifiable fractions by manoraetric methods would be useful for similar studies. It was estimated that in the unsaponifiable fractions of sunflower oil there are two antioxidant substances which are more apolar and different from the free tocopherols. The structures of these antioxidants were illustrated by using gas chromatography, micro preperative high pressure liquid. chromatography, pyrolysis gaz chromatography, thin layer chromatography and analytical high pressure liquid chromatography. As a result it was fount out that these antioxidant subtances were trimers of tocopherols (A-l) and dimers of 5-tocopherols (A-2). The fact that the tocopherol trimers and dimers in sunflower oils were naturaly present in the seed apart from the chemical procedures applied and the chemical reactions which occured during processing and the analysis of ois was shown by using preperative column chromatography, micro preperative high pressure liquid chromatography and gas chromatography.After the qualitative determinations of dimer and trimers tocopherols their quantitative determinations were made by using preperative column chromatography and gas chromatography. As a result of this determination it was found that the refined sunflower oil contains more trimers then the refined cotton seed oil. Although the natural tocopherol trimers were estimated as a single substance by preperative column chromatography and high pressure liquid chromatography, it was intended to find out that these trimers were consisted of more than one tocopherol trimers having nearly similar.- polarities by using micro preperative high pressure liquid chromatography and gas chromatography techniques. It was estimated that the deodorizer condensates (scum) of sunflower and cottonseed oils can be economic sources for obtaining monomer and tocopherol trimers which are used for the inhibition of autoxidative rancidity of oils and oil containing foods. It was found that the amount of. total tocopherols was 6.559 % in the unsaponifiable substan ces of deodorizer condensates of sunflower oil; and 20.072 % in the unsaponifiable substances of deodorizer condensates cottonseed oil. The effect of natural and synthetic antioxidant on the autoxidation of refined sunflower oil was examined by manometric methods and it was found that the trimers show antioxidant properties at a concentration of 1405 mg/100 g. The tocopherol trimers show antioxidant properties even at high concentrations while the free tocopherols show prooxi- dant properties at a concentration higher than 50-70 mg/100g. This is an important property and it is intended to find an explanation about the causes of this situation.
Açıklama
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Anahtar Kelimeler
Gıda Mühendisliği, Food Engineering, Antioksidanlar, Antioxidants, Bitkisel yağlar, Plant oils, Kalite, Quality, Üretim yöntemleri, Production methods
