Piyasada satışa sunulan çörekotu (Nigella sativa L.) yağlarının bazı fiziksel ve kimyasal özellikleri açısından değerlendirilmesi
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Dosyalar
Tarih
2022
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Necmettin Erbakan Üniversitesi Fen Bilimleri Enstitüsü
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Bu çalışmada piyasada satışa sunulan soğuk sıkım çörekotu yağlarının fizikokimyasal özellikleri
(peroksit, serbest yağ asitleri, yağ asidi bileşimi, timokinon konsantrasyonu) belirlenmiştir. Analiz
sonuçlarına göre en yüksek peroksit değeri C örneğinde (88.57 meq O2/kg) bulunmuştur. En yüksek % FFA değeri ise %37.06 mg KOH/g yağ olarak belirlenmiştir. Ayrıca, depolama ve stabilitelerinin belirlenmesi amaçlanmıştır. Oksidasyona karşı dayanıklığın belirlenmesi amacı ile Ransimat metodu ve 65ᵒC’de fırın testi uygulanmış olup, depolama sürecinde çörekotu yağlarının peroksit değeri izlenmiştir. Fırın testi sürecinde peroksit değişiminin en düşük 9.837 meqO2/kg ve en yüksek ise 124.539 meqO2/kg olduğu gözlemlenmiştir. Depolama süresi sonunda bazı çörekotu yağlarının peroksit değerlerinde azalma
bazılarında ise artış olduğu gözlemlenmiştir. Örneklerde timokinon konsantrasyonu en yüksek 19.79 (mg/gr yağ), en düşük ise 0.11 (mg/gr yağ) bulunmuştur. Bu kapsamda değerlendirmeye alınan yağların timokinon analiz sonuçları oldukça farklılık göstermiştir. Bu farklılık da yaklaşık 180 katdır. Oksidasyon kararlılığı açısından değerlendirildiğinde örneklerin indüksiyon süresi en yüksek 15.82 saat en düşük 1.76 saat olduğu görülmüştür. Bu da değerlendirmeye alınan yağların dayanıklılıklarının yaklaşık 8 kat farklı olduğunu göstermiştir. Örneklerin yağ asidi bileşimi değerlendirildiğinde doymamış yağ asitlerinden olan linoleik asit %48.30-57.85 aralığında ve oleik asit ise %25.69-42.10 aralığında tespit edilmiştir. Ana doymamış yağ asidi ise palmitik asit olup, örneklerdeki oranı %5.32-10.91aralığında gözlemlenmiştir. Sonuçlardaki bu farklılıkların; bitkilerin türü, bitkilerin toplanma zamanı, toplanma yöntemi, kurutma, yağ üretimi aşamasında yapılan hatalardan, yağların uygun olmayan nem ve sıcaklıkta beklemiş ve kalitelerin değişmiş olabileceğinden, ticari yağlara karıştırma yapılmış olabileceğinden kaynaklandığı düşünülmektedir.
In this study, the physicochemical properties (peroxide, free fatty acids, fatty acid composition, thymoquinone concentration) of cold pressed black cumin oils offered for sale in the market were determined. According to the analysis results, the highest peroxide value was found in sample C (88.57 meq O2/kg). The highest % FFA value was determined as 37.06% mg KOH/g oil. In addition, it is aimed to determine their storage and stability. In order to determine the resistance against oxidation, the Ransimat method and the oven test at 65ᵒC were applied, and the peroxide value of black cumin oils was monitored during the storage period. During the oven test process, it was observed that the lowest peroxide change was 9.837 meqO2/kg and the highest was 124.539 meqO2/kg. At the end of the storage period, it was observed that the peroxide values of some black cumin oils decreased and some increased. The highest thymoquinone concentration in the samples was 19.79 (mg/gr fat) and the lowest 0.11 (mg/gr fat). The results of the thymoquinone analysis of the oils evaluated differed considerably. This difference is about 180 times. When evaluated in terms of oxidation stability, it was seen that the induction time of the samples was 15.82 hours at the highest and 1.76 hours at the lowest. This showed that the stability against oxidation of the evaluated oils was approximately 8 times different. When the fatty acid composition of the samples was evaluated, linoleic acid, which is one of the unsaturated fatty acids, was found to be in the range of 48.30-57.85% and oleic acid in the range of 25.69-42.10%. The main unsaturated fatty acid is palmitic acid, and its ratio in the samples was observed in the range of 5.32-10.91%. These differences in results; It is thought that it may be due to the type of the plants, the harvesting time of the plants, the harvesting method, the drying, the mistakes made during the oil production phase, the oils may have been kept in unsuitable humidity and temperature and the quality may have changed, and the commercial oils may have been mixed with other oils.
In this study, the physicochemical properties (peroxide, free fatty acids, fatty acid composition, thymoquinone concentration) of cold pressed black cumin oils offered for sale in the market were determined. According to the analysis results, the highest peroxide value was found in sample C (88.57 meq O2/kg). The highest % FFA value was determined as 37.06% mg KOH/g oil. In addition, it is aimed to determine their storage and stability. In order to determine the resistance against oxidation, the Ransimat method and the oven test at 65ᵒC were applied, and the peroxide value of black cumin oils was monitored during the storage period. During the oven test process, it was observed that the lowest peroxide change was 9.837 meqO2/kg and the highest was 124.539 meqO2/kg. At the end of the storage period, it was observed that the peroxide values of some black cumin oils decreased and some increased. The highest thymoquinone concentration in the samples was 19.79 (mg/gr fat) and the lowest 0.11 (mg/gr fat). The results of the thymoquinone analysis of the oils evaluated differed considerably. This difference is about 180 times. When evaluated in terms of oxidation stability, it was seen that the induction time of the samples was 15.82 hours at the highest and 1.76 hours at the lowest. This showed that the stability against oxidation of the evaluated oils was approximately 8 times different. When the fatty acid composition of the samples was evaluated, linoleic acid, which is one of the unsaturated fatty acids, was found to be in the range of 48.30-57.85% and oleic acid in the range of 25.69-42.10%. The main unsaturated fatty acid is palmitic acid, and its ratio in the samples was observed in the range of 5.32-10.91%. These differences in results; It is thought that it may be due to the type of the plants, the harvesting time of the plants, the harvesting method, the drying, the mistakes made during the oil production phase, the oils may have been kept in unsuitable humidity and temperature and the quality may have changed, and the commercial oils may have been mixed with other oils.
Açıklama
Yüksek Lisans Tezi
Anahtar Kelimeler
Çörekotu yağı, Nigella sativa L. yağı, Oksidasyon, Peroksit değeri, Soğuk pres yağ, Stabilite, Timokinon, Black cumin oil, Cold press oil, Nigella sativa L. oil, Oxidation, Peroxide value, Stability thymoquinone
Kaynak
WoS Q Değeri
Scopus Q Değeri
Cilt
Sayı
Künye
Aksoy, M. (2022). Piyasada satışa sunulan çörekotu (Nigella sativa L.) yağlarının bazı fiziksel ve kimyasal özellikleri açısından değerlendirilmesi. (Yayımlanmamış yüksek lisans tezi). Necmettin Erbakan Üniversitesi, Fen Bilimleri Enstitüsü, Gıda Mühendisliği Anabilim Dalı, Konya.
