Multi-frequency power ultrasound green extraction of polyphenols from Pingyin rose: Optimization using the response surface methodology and exploration of the underlying mechanism

Abstract Thermal pre-flocculation to enable dispersed air flotation is an economical and ecofriendly technology for harvesting microalgae from water. However, the underlying mechanism and optimal conditions for this method remain unclear. In this study, Chlorella vulgaris (C. vulgaris) and Scenedesmus obliquus (S. obliquus) were harvested using a thermal flotation process. The surface structure and characteristics (morphology, electricity, and hydrophobicity) of the microalgae were analyzed using FT-IR (Fourier transform infrared spectroscopy), SEM (scanning electron microscopy), zeta potential, and a hydrophobic test. Further, response surface methodology (RSM) was used to optimize the flotation process. The hydrophobicity of S. obliquus exceeded that of C. vulgaris; as such, under the thermal pre-flocculation, S. obliquus (88.16%) was harvested more efficiently than C. vulgaris (47.16%). Thermal pre-flocculation denatured the lipids, carbohydrate, and proteins of microalgal cell surfaces. This resulted in a decrease in the electrostatic repulsion between the cells and air bubbles. The highest harvesting efficiency was 91.96% at 70 °C, 1,412 rpm, and 13.36 min. The results of this study demonstrate the potential for economic and ecofriendly harvesting of microalgae for biofuels and other bioproducts industries.

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Green extraction of Cu (II) in PEG-zinc sulfate aqueous two phase system using response surface methodology

Journal of Dispersion Science and Technology ◽

10.1080/01932691.2021.1878036 ◽

2021 ◽

pp. 1-9

Author(s):

Behnia Shahrokhi ◽

Mohsen Pirdashti ◽

Seyyed Mohammad Arzideh

Keyword(s):

Response Surface Methodology ◽

Response Surface ◽

Zinc Sulfate ◽

Phase System ◽

Two Phase ◽

Green Extraction ◽

Aqueous Two Phase System

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Optimization of green extraction methods for cinnamic acid and cinnamaldehyde from Cinnamon (Cinnamomum cassia) by response surface methodology

Food Science and Biotechnology ◽

10.1007/s10068-018-0441-y ◽

2018 ◽

Vol 27 (6) ◽

pp. 1607-1617 ◽

Cited By ~ 6

Author(s):

Hyun-Gyu Lee ◽

Yunhee Jo ◽

Kashif Ameer ◽

Joong-Ho Kwon

Keyword(s):

Response Surface Methodology ◽

Response Surface ◽

Cinnamic Acid ◽

Extraction Methods ◽

Green Extraction ◽

Cinnamomum Cassia

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Green extraction optimization of triterpenoid glycoside-enriched extract from Centella asiatica (L.) Urban using response surface methodology (RSM)

Scientific Reports ◽

10.1038/s41598-021-01602-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Wachiraporn Thong-on ◽

Thanika Pathomwichaiwat ◽

Suthida Boonsith ◽

Wanida Koo-amornpattana ◽

Sompop Prathanturarug

Keyword(s):

Response Surface Methodology ◽

Response Surface ◽

Centella Asiatica ◽

Raw Material ◽

Secondary Outcome ◽

Asiatic Acid ◽

Optimal Conditions ◽

Green Extraction ◽

Triterpenoid Glycoside ◽

Assisted Extraction

AbstractCentella asiatica (L.) Urban extracts are widely used as food, drugs and cosmetics, and the main active compounds are glycosides (madecassoside and asiaticoside) and aglycones (madecassic acid and asiatic acid). Green extraction is an interesting concept that can produce safe and high-quality extracts that use less solvent, time and energy with the environmental friendly. This study investigated the optimum conditions for extracting a triterpenoid glycoside-enriched C. asiatica extract using microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE). Central composite design and response surface methodology (RSM) were used for the experimental design and data analysis. Four-month-old C. asiatica tetraploid plants were selected as the elite raw material containing high amount of triterpenoid glycosides for the extraction experiments, and the triterpenoid content was determined by a validated HPLC method. The results demonstrated that the RSM models and equations were reliable and could predict the optimal conditions to enhance C. asiatica extract yield, glycoside and aglycone amounts. The percent of ethanol was the major factor that had a significant effect on C. asiatica yield and glycoside and aglycone content during MAE and UAE. The maximum triterpenoids content in extract; 7.332 ± 0.386% w/w madecassoside and 4.560 ± 0.153% w/w asiaticoside 0.357 ± 0.013% w/w madecassic acid and 0.209 ± 0.025% w/w asiatic acid were obtained by MAE with 80% ethanol at 100 watts for 7.5 min, whereas the optimal conditions for highest total triterpenoids extraction from dry plant was UAE with 80% ethanol, temperature 48 °C, 50 min enhanced 2.262 ± 0.046% w/w madecassoside, 1.325 ± 0.062% w/w asiaticoside, 0.082 ± 0.009% w/w madecassic acid and 0.052 ± 0.007% w/w asiatic acid as secondary outcome. Moreover, it was found that MAE and UAE consumed energy 59 and 54%, respectively, lower than that of the conventional method, maceration, in term of kilowatt-hour per gram of total triterpenoids. These optimized green conditions could be recommended for C. asiatica extraction for triterpenoid glycoside-enriched extracts production for the pharmaceutical or cosmeceutical industries and triterpenoids quantitative analysis in raw materials.

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