scholarly journals Optimisation of ultrasound-assisted extraction of protein from Spirulina platensis using RSM

2018 ◽  
Vol 36 (No. 1) ◽  
pp. 98-108 ◽  
Author(s):  
Aysun Yucetepe ◽  
Oznur Saroglu ◽  
Fatih Bildik ◽  
Beraat Ozcelik ◽  
Ceren Daskaya-Dikmen

The protein extraction from the blue-green microalgae Spirulina platensis was carried out using ultrasound-assisted extraction and response surface methodology (RSM) was used to optimise extraction conditions. Extraction yield, total phenolic content, antioxidant activity and in vitro protein digestibility of protein extracts were determined. A three factors Box-Behnken design (BBD) of experiments was employed at pH values of 7, 8 and 9; temperatures of 25, 35, and 45°C; and for durations of 60, 90 and 120 minutes. Based on the RSM analysis, optimum extraction conditions (temperature 45°C, pH 7.46 and time 120 min) were obtained for extraction yield (29.05%), total phenolic content (3.52 mg caffeic acid equivalent/g dw), antioxidant activity (11.32 mg Trolox equivalent/g dw) and in vitro protein digestibility (99.36%). We report the first evaluation of the in vitro protein digestibility of Spirulina platensis and find it to be over 90%. This value is higher than the in vitro protein digestibility values of proteins obtained from other algae and plant species, and, in particular, is greater than that of commercial soybean protein isolate.

Antioxidants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 322 ◽  
Author(s):  
Mircea Oroian ◽  
Florin Ursachi ◽  
Florina Dranca

The aim of this study was to evaluate the extraction efficiency of polyphenols from crude pollen by an ultrasonic process. Prior to the polyphenols extraction, the crude pollen was defatted. The extraction from defatted pollen was carried out by varying four extraction parameters: ultrasonic amplitude (20%, 60% and 100%), solid/liquid ratio (10 g/L, 20 g/L and 30 g/L), temperature (35, 50 and 65 °C) and time (10, 20 and 30 min). The extracts were analyzed in terms of extraction yield (%), total phenolic content (TPC) and total flavones content (TFC). The extracted oil was analyzed in terms of fatty acids composition; myristic acid (159.1 µg × g−1) and cis-14-pentadecenoic acid (106.6 µg·g−1) were found in the highest amount in the pollen oil. The optimum conditions of extraction were determined and were, as follows: 100% amplitude of ultrasonic treatment, 30 g/L solid/liquid ratio, 40.85 °C and 14.30 min, which led to the extraction of 366.1 mg GAE/L of TPC and 592.2 mg QE/g of TFC, and also to an extraction yield of 1.92%.


Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 931
Author(s):  
Cristina Reche ◽  
Carmen Rosselló ◽  
Mónica M. Umaña ◽  
Valeria Eim ◽  
Susana Simal

Valorization of an artichoke by-product, rich in bioactive compounds, by ultrasound-assisted extraction, is proposed. The extraction yield curves of total phenolic content (TPC) and chlorogenic acid content (CAC) in 20% ethanol (v/v) with agitation (100 rpm) and ultrasound (200 and 335 W/L) were determined at 25, 40, and 60 °C. A mathematical model considering simultaneous diffusion and convection is proposed to simulate the extraction curves and to quantify both temperature and ultrasound power density effects in terms of the model parameters variation. The effective diffusion coefficient exhibited temperature dependence (72% increase for TPC from 25 °C to 60 °C), whereas the external mass transfer coefficient and the equilibrium extraction yield depended on both temperature (72% and 90% increases for TPC from 25 to 60 °C) and ultrasound power density (26 and 51% increases for TPC from 0 (agitation) to 335 W/L). The model allowed the accurate curves simulation, the average mean relative error being 5.3 ± 2.6%. Thus, the need of considering two resistances in series to satisfactorily simulate the extraction yield curves could be related to the diffusion of the bioactive compound from inside the vegetable cells toward the intercellular volume and from there, to the liquid phase.


1987 ◽  
Vol 37 (2) ◽  
pp. 183-192 ◽  
Author(s):  
Antonio C. Laurena ◽  
Virgilio V. Garcia ◽  
Evelyn Mae ◽  
T. Mendoza

The pomelo peel occupies 50% of the fruit mass in pomelo juice processing. It contains large amounts of phenolic compounds, which may provide benefits to human health. These components should be isolated. In this study, the effects of ethanol concentrations, material-to-solvent ratios (g/mL), temperatures and sonication time on total phenolic content (TPC), naringin content and antioxidant capacity (using DPPH assay) of extract solution was evaluated. The results showed that all experimental factors significantly influenced the extraction of total polyphenol content, naringin content, and antioxidant capacity of the extract. The extraction condition was ethanol 80%, material-to-solvent ratio of 1:25 (w/v) at 60oC, and sonication time of 7.5 min, gave the extract had total phenolic content of 9.05 ± 0.08 mg GAE/g DM, naringin content of 4.65 ± 0.08 mg NE/ g DM, and antioxidant capacity of 4.76 ± 0.03 mg AAE/g DM. The ultrasound treatment was a useful method for improving the extraction of phenolic acid compounds from pomelo peel.


Author(s):  

Ready to Eat (RTE) sorghum cookies were prepared by incorporating green gram flour at 10%, 20%, 30%, dried mango powder at 10% and evaluated for their physico-chemical and nutritional properties. Protein, fat, fiber and ash increased with increase in green gram flour substitution as carbohydrate content decreased significantly. Significant differences (p ≤ 0.05) in protein content were seen in cookies ranging from 9.52% to 13.60%. Fiber increased significantly from 9.40% to 10.90%. In vitro protein digestibility ranged from 67.75 ± 0.01% to 90.05 ± 0.10 %. Vitamins analysed increased with addition of green gram flour. Thiamine content ranged from 0.22±0.02 to 0.61±0.02 mg/100g, riboflavin from 0.09±0.00 to 1.39±0.04 mg/100g and ascorbic acid from 13.87±0.79 to 19.31±0.94 mg/100g. Value addition of under-utilized crops like sorghum and green grams can play a vital role in development of high nutritional quality RTE products.


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