THE EFFECTS OF TIME, TEMPERATURE, SOLVENT: SOLID RATIO AND SOLVENT COMPOSITION ON EXTRACTION OF TOTAL PHENOLIC COMPOUND FROM DRIED OLIVE (Olea europaea L.) LEAVES

Öz

The optimum extraction conditions for total phenolic compounds from dried olive leaves were determined by using response surface methodology. Central composite design was used to investigate the effects of four independent variables such as solvent composition (ethanol in water, 20 to 100%), extraction temperature (20 to 60 °C), extraction time (4-48 hours) and solvent/solid ratio (4 to 8). As a response total phenolic compound content of the extracts were chosen. The quadratic model is used for predicting the results and R2 was found 0.8539. The olive leaves with the initial 43.94±0.25% moisture content were dried in vacuum oven at 60 ºC to 2±0.07% moisture content before extraction. There are several solutions by choosing the target, in range, maximize or minimize the effective parameters in response surface methodology. In this study, recommended optimal conditions for the total phenolic compounds from olive leaves were found 43% ethanol in water (v/v), 50 ºC, 15 hours and 7 times solvent/solid ratio. Under the chosen optimum conditions the corresponding predicted response value for total phenolic compounds was 4586.3 mg GAE/100 g dried leaves.

Anahtar Kelimeler

• Solvent extraction
• total phenolics
• olive leave
• response surface methodology
• optimization

Kurutulmuş Zeytin Yaprağından (Olea Europaea L.) Toplam Fenoloik Madde Ekstraksiyonu Üzerine Süre, Sıcaklık, Çözücü-Katı Oranı Ve Çözücü Kompozisyonunun Etkisi (İngilizce)

Öz

Kurutulmuş zeytin yaprağından toplam fenolik maddelerin ekstraksiyonu için optimum ekstraksiyon koşulları cevap yüzey yöntemi kullanılarak belirlenmiştir. Çözücü kompozisyonu (etanol-su, %20 - %100), ekstraksiyon sıcaklığı (20 - 60 °C), ekstraksiyon süresi (4 - 48 sa) ve çözücü katı oranı (4 - 8) gibi bağımsız dört farklı değişkenin etkisinin belirlenmesinde merkezi teşekküllü dizayn kullanılmıştır. Cevap olarak ekstraktaki toplam fenolik madde içeriği seçilmiştir. Sonuçlar ikinci dereceden denklem ile açıklanmış ve R2 0.8539 olarak bulunmuştur. Ekstra çekleştirilmesi için parametrelerin minimize maksimize edilmesi veya aralığının seçilebilmesi nedeniyle çeşitli çözümler yapılabilmektedir. Bu çalışmada zeytin yaprağından toplam fenolik madde ekstraksiyonu için önerilen seçilmiş koşullar %43 etanol içeren su (h/h), 50 ºC, 15 sa ve 7 kat çözgen/katı oranı olarak belirlenmiştir. Optimum koşullar uygulanarak belirlenen kurutulmuş zeytin yaprağının toplam fenolik madde içeriği ise 4586.3 mg GAE/100 g kuru yaprak olarak bulgulanmıştır.

Anahtar Kelimeler

• Çözgen ekstraksiyonu
• toplam fenolikler
• zeytin yaprağı
• cevap yüzey yöntemi
• optimizasyon

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