scholarly journals Comparative evaluation of the antibacterial activities of the essential oils of Citrus grandis (L.) Osbeck obtained by hydrodistillation and microwave assisted extraction methods

Author(s):  
T H Tran ◽  
T P Dao ◽  
Q C T Ngo ◽  
L G Bach ◽  
X P Huynh
2013 ◽  
Vol 47 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Gabriel Abraham Cardoso-Ugarte ◽  
Gladys Paola Juárez-Becerra ◽  
María Elena SosaMorales ◽  
Aurelio López-Malo

2008 ◽  
Vol 91 (1) ◽  
pp. 174-180 ◽  
Author(s):  
Mercedes Barriada-Pereira ◽  
Iván Iglesias-García ◽  
María J Gonzlez-Castro ◽  
Soledad Muniategui-Lorenzo ◽  
Purificación López-Maha ◽  
...  

Abstract This paper describes a comparative study of 2 extraction methods, pressurized liquid extraction (PLE) and microwave-assisted extraction (MAE), for the determination of organochlorine pesticides (OCPs) in fish muscle samples. In both cases, samples were extracted with hexaneacetone (50 + 50), and the extracts were purified by solid-phase extraction using a carbon cartridge as the adsorbent. Pesticides were eluted with hexaneethyl acetate (80 + 20) and determined by gas chromatography with electron-capture detection. Both methods demonstrated good linearity over the range studied (0.0050.100 g/mL). Detection limits ranged from 0.029 to 0.295 mg/kg for PLE and from 0.003 to 0.054 mg/kg for MAE. For most of the pesticides, analytical recoveries with both methods were between 80 and 120, and the relative standard deviations were <10. The proposed methods were shown to be powerful techniques for the extraction of OCPs from fish muscle samples. Although good recovery rates were obtained with both extraction methods, MAE provided advantages with regard to sample handling, cost, analysis time, and solvent consumption. Acceptable validation parameters were obtained although MAE was shown to be more sensitive than PLE.


Foods ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 456 ◽  
Author(s):  
Ding-Tao Wu ◽  
Wen Liu ◽  
Mei-Lin Xian ◽  
Gang Du ◽  
Xin Liu ◽  
...  

Seven extraction methods, including hot water extraction (HWE), pressurized water extraction (PWE), ultrasound-assisted extraction, microwave-assisted extraction, ultrasound-assisted enzymatic extraction, high-speed shearing homogenization extraction, and ultrasound-microwave-assisted extraction, were utilized to extract polyphenolic-protein-polysaccharide complexes (PPPs) from Hovenia dulcis. Next, their physicochemical properties and in vitro antioxidant activities, antiglycation effects, and inhibition activities on α-glucosidase and α-amylase were studied and compared. The findings from this study indicate that various extraction processes exhibit notable influences on the physicochemical properties and in vitro bioactivities of PPPs. Extraction yields, contents of polyphenolics and flavonoids, apparent viscosities, molecular weights, molar ratios of monosaccharide compositions, and ratios of amino acid compositions in PPPs varied in different extraction methods. Furthermore, 13 phenolic compounds in PPPs, including rutin, myricitrin, myricetin, quercetin, kaempferol, protocatechuic acid, gallocatechin, p-hydroxybenzoic acid, ampelopsin, quercetin-7,4′-diglucoside, dihydroquercetin, 5-methylmyricetin, and naringenin, were identified. The relatively strong in vitro antioxidant activities, antiglycation effects, and inhibition activities on α-glucosidase and α-amylase were determined in both PPP-W and PPP-P obtained by HWE and PWE, respectively. The high content of total polyphenolics may be one of the main contributors to their in vitro bioactivities. The findings have shown that the PWE method can be an appropriate method to prepare PPPs with strong bioactivities for application in the functional food industry.


2020 ◽  
Vol 72 (2) ◽  
pp. 211-221
Author(s):  
Xiang Wang ◽  
Mi-Jun Peng ◽  
Zhi-Hong Wang ◽  
Qiu-Ling Yang ◽  
Sheng Peng

Ultrasound/microwave assisted extraction (UMAE) of flavonoid compounds from Eucommia ulmoides leaves was studied and the extraction conditions were optimized by the Plackett-Burman design (PBD) method combined with the Box-Behnken design (BBD). The antioxidant and antibacterial activities of the flavonoid extract were investigated. The results show that the optimal conditions were an ethanol concentration of 41%, microwave power of 178 W and an ultrasound extraction time of 26 min. Under these conditions, the yield of the flavonoid compounds was 2.454%?0.230%, which was higher than that after direct solvent extraction, ultrasound extraction and microwave extraction. The results of in vitro antioxidant assays showed that the flavonoid extract had scavenging capacity for DPPH, ABTS and hydroxyl radicals, with corresponding IC50 values of 30.76 mg/L, 21.09 mg/L, 248.4 mg/L, respectively. In addition, this extract exhibited strong antibacterial activity on Escherichia coli, Staphylococcus aureus and Salmonella typhimurium.


2020 ◽  
Vol 19 (2) ◽  
pp. 110 ◽  
Author(s):  
Robby Gus Mahardika ◽  
Occa Roanisca

Tristaniopsis merguensis Griff. is a species of the Myrtaceae family and has been widely used by people of Bangka Belitung as a traditional medicine to reduce cholesterol, gastric pains, and improve cardiac performance. Extraction methods are the crucial efficacy of herbal medicine. The conventional method, like maceration, takes a long time. In this study, the leaves of Tristaniopsis merguensis were extracted using Microwave-Assisted Extraction (MAE) to reduce extraction time. The extraction using MARS (Microwave Accelerated Reaction System) 6 by CEM Corporation with time variation times of 5, 10, 15, 30 min with temperature of 60, 80, 100oC at 1200 W. The yield using acetone extraction of Tristaniopsis merguensis leaves increases with time and temperature. The extraction dependent on solvent extraction, polar solvent like ethanol, and methanol were higher than semi-polar solvents like acetone and ethyl acetate. The polyphenol content of acetone extract using MAE (10 min, 80oC) was found to be 234.67 mg Gallic Acid Equivalent per gram (GAE/g); it was higher than acetone extract using maceration. The phytochemical results show there are no difference in the active compound using MAE and maceration, i.e. alkaloids, tannin, and flavonoids. Yield extraction, time, and phytochemical results of MAE are more favorable than a maceration.


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