Optimizing the ultrasonic-assisted extraction of antioxidants from Ulva lactuca algal biomass using factorial design

Abstract

Ultrasonic-assisted extraction (UAE) is increasingly emerging as a highly effective extraction technique. This extraction technique is affected by several experimental factors. The present work aimed to optimize the ultrasonic-assisted extraction of antioxidants from Ulva lactuca (sea lettuce), widespread macroalgae growing along the Mediterranean coast. In this respect, a full-factorial design (23) was employed to assess the effect of three different factors at two levels and their interactions on the extraction of antioxidants from sea lettuce algal biomass. The studied factors were extraction solvent, time of extraction, and temperature. The two levels chosen for extraction solvent were 100% ethanol and 50% ethanol, for the sonication time (1 h and 3 h) and temperature (25 °C and 40 °C). All experiments were done using an ultrasonic bath, and the biomass to solvent ratio was kept at 1:5. Total antioxidant capacity and quercetin concentration were set as the two responses for optimum output. The results showed that the temperature and solvent were the dominating factors that significantly affect the extraction process. The optimum extraction parameters were extraction time of 1 h, 50% ethanol, and temperature of 25 °C. Under these conditions, the maximum value for TAA was calculated as 2166.51 mg of ascorbic acid equivalent per gram (mg/g of AAE), and quercetin showed a maximum calculated value of 42.5 mg/g with combined desirability of 0.91 for the two responses. The present study results indicate that U. lactuca can be used as a source of antioxidants and phenolic compounds that can be applied in food and medicine at optimum extraction conditions. Graphical abstract

Algae: Study of Edible and Biologically Active Fractions, Their Properties and Applications

“…Extraction using ultrasound makes it possible to obtain a higher yield of phenolic substances in a short time in comparison with extraction via the maceration method. This is essential for the industrial production of natural antioxidants [ 223 , 224 ]. The study [ 225 ] used ultrasound extraction to obtain ethanol extracts from microalgae S. obliquus , C. vulgaris ( Chlorophyta ), and S. platensis ( Cyanobacteria ).…”

Optimization of Chromium and Lead Biosorption in Wastewater Using 33 Factorial Design

“…In case of A (temperature) 20 °C (low level), B (biosorbent dosage 1 g/L (low level) and C (pH) 6 pH (high level), the maximum value of removal efficiency could reach 99.8870%. As a result, the optimum conditions for Cr (III) on removal efficiency from wastewater are achieved keeping the temperature 20 °C, biosorbent dosage 1 g/L and pH 6 [10]. The results of Figure 4 show that, for the optimization of the for Pb (II) on removal efficiency as a response variable, value of the objective function is calculated as 0.98894.…”

“…(a) and Fig 2(b))[10]. In these plots, non-parallel lines indicate that the effect of one factor on the response depends on the setting of the other factor.…”

“…In case of A (temperature) 30 °C (medium level), B (biosorbent dosage) 1 g/L (low level) and C (pH) 6 (high level), the maximum value of removal efficiency could reach 98.0835%. As a result, the optimum conditions for Pb (II) on removal efficiency from wastewater are achieved keeping the temperature 30 °C, biosorbent dosage 1 g/L and pH 6 [10].…”

Ultrasonic-assisted extraction for phenolic compounds and antioxidant activity of Moroccan Retama sphaerocarpa L. leaves: Simultaneous optimization by response surface methodology and characterization by HPLC/ESI-MS analysis

“…Performing extractions at low temperatures is another advantage of UAE. Indeed, this may reduce heat losses caused by high temperatures and prevent the degradation of biologically active substances due to side undesirable reactions such as hydrolysis, ionization, and/or oxidation [ 12 ], which makes them undesirable from an economic perspective [ 13 ]. Several bioactive components, including polysaccharides, flavonoids, anthocyanins, and phenolic compounds, have been effectively extracted using the UAE [ 14 ].…”