Ultrafiltrasyon yöntemiyle Nar Kabuğundan fenolik bileşiklerin geri kazanılması ve sürecin optimizasyonu
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Dosyalar
Tarih
2019
Yazarlar
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Yayıncı
Trakya Üniversitesi Fen Bilimleri Enstitüsü
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Bu çalışmada nar kabuklarından özütlenen fenolik bileşikler ultrafiltrasyon yöntemiyle deriştirilerek zenginleştirilmiştir. Özütleme ve ultrafiltrasyon (UF) süreçleri yanıt yüzey yöntemi kullanılarak optimize edilmiştir. Özütleme sürecinde sıcaklık, süre ve çözücü derişiminin toplam fenolik madde miktarı ve antioksidan aktivite değerine olan etkileri incelenmiştir. Nar kabuklarından maksimum miktarda fenolik bileşiğin elde edildiği optimum özütleme koşulları 1014 mg GA/L özüt toplam fenolik madde miktarının elde edildiği 48 o C sıcaklık, 85 dakika ve %22 etanol derişimi olarak belirlenmiştir. Nar kabuğu özütünün deriştirilmesinde 2 kDa molekül ağırlığı ayırma sınırına (MWCO) sahip rejenere selüloz yapıda membran kullanılmıştır. Optimizasyon işleminde maksimum toplam fenolik madde miktarı artışı ve minimum permeat akısı azalışı amaçlanmıştır. 524 mg GA/L fenolik madde içeren besleme özütünün 37 o C sıcaklık ve 1,5 bar transmembran basıncı (TMP)’nda işlendiği UF sürecinde özütün toplam fenolik madde miktarında 8,5 kat artış sağlanmış ve bu süreçte permeat akısında %20 azalma tespit edilmiştir. UF sürecinde meydana gelen membran kirlenmesinin toplam fenolik madde artışına ve permeat akısı azalışına etkisi seri direnç analizi modeli kullanılarak incelenmiştir. Kirlenme analizlerinde beslemenin toplam fenolik madde miktarı ve sıcaklık sabit tutularak TMP 0,5-1,5 bar aralığında değiştirilmiştir. UF sürecinde yüksek TMP kullanılması kek tabakası direncinde artışa; geri dönüşümlü kirlenme direncinde ise azalmaya neden olmuştur. Toplam direnç ve geri dönüşümsüz kirlenme direnci ise değişmemiştir. Kek tabakası direncinde meydana gelen artış fenolik bileşiklerin geri kazanım verimi üzerine olumlu etki göstermiştir.
The objective of this study was to concentrate the phenolic compounds extracted from pomegranate husks by ultrafiltration (UF). Both the extraction and UF processes were optimized by using the response surface method according to Box-Behnken model. The effects of temperature, time and solvent concentration on the total phenolic content and antioxidant activity of the extracts were investigated during extraction. Optimum conditions, which the maximum total phenolics of 1014 mg GA/L extract were extracted from the pomegranate husks, were determined as 48 o C temperature, 85 minutes and 22% ethanol concentration. Then, the pomegranate extracts were ultrafiltered through a regenerated cellulose membrane with a moleculer weight cut off 2 kDa. A maximum increase in the total phenolic content of feed and a minimum decrease in the permeate flux were aimed in the optimization process. After UF processed at 37 o C temperature and 1,5 bar transmembrane pressure (TMP) and 524 mg GA/L total phenolic content of feed, 8,5-fold increase in the total phenolic content of feed was achieved. It was found that 20% decrease in the initial permeate flux during this process. The effect of TMP (0,5-1,5 bar) on membrane fouling and UF performance was also investigated at constant the total phenolic content of feed and temperature using a resistance-in-series model. An increase in the cake layer resistance was observed with an increase in TMP. However, it caused a decrease in the reversible fouling resistance. There was no effect of TMP on the total and irreversible fouling resistances. Optimization results showed that the increase in the cake layer resistance had a positive effect on the recovery of the phenolic compounds.
The objective of this study was to concentrate the phenolic compounds extracted from pomegranate husks by ultrafiltration (UF). Both the extraction and UF processes were optimized by using the response surface method according to Box-Behnken model. The effects of temperature, time and solvent concentration on the total phenolic content and antioxidant activity of the extracts were investigated during extraction. Optimum conditions, which the maximum total phenolics of 1014 mg GA/L extract were extracted from the pomegranate husks, were determined as 48 o C temperature, 85 minutes and 22% ethanol concentration. Then, the pomegranate extracts were ultrafiltered through a regenerated cellulose membrane with a moleculer weight cut off 2 kDa. A maximum increase in the total phenolic content of feed and a minimum decrease in the permeate flux were aimed in the optimization process. After UF processed at 37 o C temperature and 1,5 bar transmembrane pressure (TMP) and 524 mg GA/L total phenolic content of feed, 8,5-fold increase in the total phenolic content of feed was achieved. It was found that 20% decrease in the initial permeate flux during this process. The effect of TMP (0,5-1,5 bar) on membrane fouling and UF performance was also investigated at constant the total phenolic content of feed and temperature using a resistance-in-series model. An increase in the cake layer resistance was observed with an increase in TMP. However, it caused a decrease in the reversible fouling resistance. There was no effect of TMP on the total and irreversible fouling resistances. Optimization results showed that the increase in the cake layer resistance had a positive effect on the recovery of the phenolic compounds.
Açıklama
Anahtar Kelimeler
Geri Kazanım, Membran Filtrasyon, Ultrafiltrasyon, Fenolik Bileşikler, Özütleme, Membran Kirlenmesi, Recovery, Membrane Filtration, Ultrafiltration, Phenolic Compounds, Extraction, Membrane Fouling
