Ultrasound-Assisted Extraction of Okra Mucilage: Rheological Properties of its Aqueous Solutions

Year 2024, Volume: 22 Issue: 1, 1 - 13, 29.03.2024

Tolga Akcan , Şelale Öncü Glaue

https://doi.org/10.24323/akademik-gida.1460950

Abstract

Using chemical and physicochemical techniques, we extracted the mucilaginous component of okra (Abelmoschus esculentus L.) by the ultrasound-assisted extraction method, then evaluated the resulting polysaccharide extract's rheological properties. Our investigation encompassed examining the flow behavior of polysaccharides extracted under different okra to distilled water ratios (1:10 and 1:30) and various polysaccharide concentrations (1, 2, 3 and 4%, w/v) over a temperature range of 10°C to 80°C. Employing the power law model, we derived parameters and found that okra polysaccharides displayed non-Newtonian pseudoplastic flow characteristics. The flow behavior index ranged from 0.234 to 0.947, with the consistency coefficient ranging from 4.37 to 244.50 mPa.s. Increasing temperature resulted in a decrease in both the consistency coefficient (K) and flow behavior index (n), while concentration elevation led to higher consistency coefficient values. However, the flow behavior index did not exhibit consistent trends with concentration variations. Three statistical parameters; correlation coefficient (R2), root mean square error (RMSE) and chi-square (χ2) were used to evaluate the fit of the power law model to the experimental data. Our study further explored temperature’s impact on the apparent viscosities of okra polysaccharide samples and modeled the influence of temperature on the consistency index using the Arrhenius equation. Samples with solid-to-solvent ratios of 1:10 and 1:30 showed increasing activation energy with concentration rise, with the highest value recorded at 275.84 kJ/mol for the 1:10 ratio sample with a 4% concentration. In SEM images, okra polymers exhibit irregular, wavy, rough textured surface, and amorphous appearance. These findings hold promise for optimizing ultrasound extraction protocols and enhancing the industrial utilization of mucilages through their rheological properties.

Keywords

Okra mucilage, Rheological properties, Ultrasound, Extraction method

Bamya Müsilajının Ultrason Destekli Ekstraksiyonu: Sulu Çözeltilerinin Reolojik Özellikleri

Abstract

Kimyasal ve fizikokimyasal teknikler kullanılarak, bamyanın müsilajinöz bileşeni ultrason desteği ile ekstrakte edilmiş, ardından elde edilen polisakkarit ekstraktının reolojik özellikleri değerlendirilmiştir. Araştırmamız, 10°C ile 80°C sıcaklık aralığında farklı bamya-damıtık su oranları (1:10 ve 1:30) ve çeşitli polisakkarit konsantrasyonları (%1, 2, 3 ve 4, w/v) altında ekstrakte edilen polisakkaritlerin akış davranışlarının incelenmesini kapsamaktadır. Güç yasası modelini kullanarak parametreler türetilmiş ve bamya polisakkaritlerinin Newtonyen olmayan psödoplastik akış özellikleri gösterdiğini bulunmuştur. Akış davranış indeksi 0,234 ile 0,947 arasında değişirken, kıvam katsayısı 4,37 ile 244,50 mPa.s arasında değişmiştir. Artan sıcaklık hem kıvam katsayısında (K) hem de akış davranış indeksinde (n) düşüşe neden olurken, konsantrasyon artışı daha yüksek kıvam katsayısı değerlerine yol açmıştır. Ancak, akış davranış indeksi konsantrasyon değişimleri ile tutarlı eğilimler sergilememiştir. Güç yasası modelinin deneysel verilere uyumunu değerlendirmek için üç istatistiksel parametre; korelasyon katsayısı (R2), kök ortalama kare hatası (RMSE) ve ki-kare (χ2) kullanılmıştır. Çalışmamızda ayrıca sıcaklığın bamya polisakkarit örneklerinin görünür viskoziteleri üzerindeki etkisi araştırılmış ve Arrhenius denklemi kullanılarak sıcaklığın kıvam indeksi üzerindeki etkisi modellenmiştir. Bamya-damıtık su oranı 1:10 ve 1:30 olan numuneler konsantrasyon artışıyla birlikte artan aktivasyon enerjisi göstermiş, en yüksek değer %4 konsantrasyona sahip 1:10 oranlı numune için 275,84 kJ/mol olarak kaydedilmiştir. SEM görüntülerinde, bamya polimerleri düzensiz, dalgalı, pürüzlü dokulu yüzey ve amorf görünüm sergilemektedir. Bu bulgular, ultrason ekstraksiyon protokollerinin optimize edilmesi ve reolojik özellikleri aracılığıyla müsilajların endüstriyel kullanımının artırılması için umut vaat etmektedir.

Keywords

Bamya müsilajı, Reolojik özellikler, Ultrason, Ekstraksiyon yöntemleri

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