Effect of sample pre-treatment on isoflavones quantification in soybean

2016 ◽  
Vol 70 (8) ◽  
Author(s):  
Magdalena Wójciak-Kosior ◽  
Ireneusz Sowa ◽  
Grażyna Szymczak ◽  
Karolina Zapała ◽  
Ryszard Kocjan ◽  
...  

AbstractHigh performance liquid chromatography is the most common technique for analysing isoflavones in soy; however, the appropriate sample pre-treatment is required, including extraction and, often, hydrolysis. In the present work, the kinetics of extraction was investigated with regard to the number of extraction steps and their duration for the exhaustive extraction of bonded forms of isoflavones and aglycones. In addition, a systematic experimental study of hydrolysis depending on the temperature and acidity of the medium was conducted. The results showed that the assisted methods were more effective for the isolation of isoflavones. Moreover, the differences between the results obtained using ultrasound-assisted extraction (UAE), microwave-assisted extraction and pressurised liquid extraction were not statistically significant; however, the appropriate number of extraction steps and their duration for UAE were required. The investigation also revealed that, due to the varying susceptibility of glycosides on conversion to free forms and the stability of the aglycones obtained, two parallel hydrolysis procedures should be conducted to obtain the highest hydrolysis efficiency. The optimised conditions, taking into account the shortest time combined with the highest efficiency, were as follows: 4 M HCl and 60 min for genistein; 8 M HCl and 30 min for glycitein and daidzein.

2020 ◽  
Vol 16 (7) ◽  
pp. 998-1004
Author(s):  
Aziz H. Rad ◽  
Raana B. Fathipour ◽  
Fariba K. Bidgoli ◽  
Aslan Azizi

Background and Objectives: Tea is considered one of the most consumed drinks around the world and the health benefits of it have recently attracted the attention of different researchers. It has also been proven beneficial in preventing the danger of some diseases like cancer and cardiovascular problems. Further, lipid oxidation is one of the major problems in food products. Considering the above-mentioned issues, the present review focused on various techniques used to extract polyphenols from different kinds of tea, as well as their use in the food industry. Results and Conclusion: Based on our findings in this review, the main components of tea are polyphenols that have health benefits and include catechins, epicatechin, epigallocatechin, epicatechin gallate, epigallocatechin gallate, gallic acid, flavonoids, flavonols, and theophlavins. From these components, catechin is regarded as the most beneficial component. Many techniques have been discovered and reformed to extract tea compounds such as solvent-based extraction, microwave-assisted water extraction, and ultrasound-assisted extraction techniques. Overall, the microwave-assisted water extraction method is a useful method for extracting tea polyphenols, which may be used in the meat, oil, and dairy industries.


Author(s):  
Ling Wu ◽  
Qiurong He ◽  
Jing Zhang ◽  
Yongxin Li ◽  
Weiqing Yang ◽  
...  

Abstract Background Polycyclic aromatic hydrocarbons (PAHs) have attracted worldwide attention due to their carcinogenic, teratogenic and mutagenic effects, environmental persistence and bioaccumulation characteristics. Therefore, the sensitive, reliable and rapid detection of PAHs in sediment is of great importance. Objective To develop a high-performance liquid chromatography (HPLC) with fluorescence and ultraviolet detection after QuEChERS treatment for simultaneous determination of 16 U.S. Environmental Protection Agency priority PAHs in sediment samples. Methods The samples were ultrasonically extracted with acetone and then the supernatant was purified with a modified QuEChERS method. After centrifugation, the supernatant was injected into the HPLC system for analysis. The separation was accomplished on a ZORBAX Eclipse PAH column (150 × 4.6 mm, 3.5 μm) and the column temperature was set at 30 °C. The flow rate of the mobile phase consisting of water and acetonitrile in gradient elution mode was fixed at 0.9 mL/min. Detection was conducted on an ultraviolet detector and a fluorescence detector simultaneously. The qualitative analysis was based on retention time and the quantification was based on standard curves. Results Under the optimal conditions, this method showed good linearities in the range of 10–200 μg/L with correlation coefficients greater than 0.9993. The method had the limits of detection (LODs) ranging from 0.00108 to 0.314 ng/g. The mean recoveries ranged from 78.4 to 117% with the intra-day and inter-day relative standard deviations (RSDs) of 0.592–10.7 and 1.01–13.0%, respectively. The proposed method was successfully applied to the detection of 16 PAHs in sediment samples collected from the Funan River in Chengdu, China with the total contents of 431 to 2143 ng/g·dw. Conclusions The established method is simple, rapid, environment-friendly and cost- effective. It can be applied to the analysis of 16 PAHs in sediment samples. Highlights A method of QuEChERS with ultrasound-assisted extraction combined with HPLC has been established for the analysis of 16 PAHs in sediment samples and the proposed method has been successfully applied to the analysis PAHs in real sediment samples.


2020 ◽  
Vol 16 (1-2) ◽  
Author(s):  
Cassiano Brown da Rocha ◽  
Caciano Pelayo Zapata Noreña

AbstractThe grape pomace is a by-product from the industrial processing of grape juice, which can be used as a source of bioactive compounds. The aim of this study was to separate the phenolic compounds from grape pomace using an acidic aqueous solution with 2 % citric acid as a solvent, using both ultrasound-assisted extraction, with powers of 250, 350 and 450 W and times of 5, 10 and 15 min, and microwave-assisted extraction using powers of 600, 800 and 1,000 W and times of 5, 7 and 10 min. The results showed that for both methods of extraction, the contents of total phenolic compounds and antioxidant activity by ABTS and DPPH increased with time, and microwave at 1,000 W for 10 min corresponded to the best extraction condition. However, the contents of phenolic compounds and antioxidant activity were lower than exhaustive extraction using acidified methanol solution.


Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1120
Author(s):  
María del Carmen Razola-Diaz ◽  
Eduardo Jesús Guerra-Hernández ◽  
Celia Rodríguez-Pérez ◽  
Ana María Gómez-Caravaca ◽  
Belén García-Villanova ◽  
...  

Orange peel is the main by-product from orange juice industry. It is a known source of bioactive compounds, mostly phenolic compounds, and it has been widely studied for its healthy activities. Thus, this research focuses on the establishment of ultrasound-assisted extraction of phenolic compounds in orange peel using a sonotrode. For this purpose, a Box–Behnken design of 27 experiments was carried out with four independent factors—ratio ethanol/water (v/v), time (min), amplitude (%), and pulse (%). Quantitative analyses of phenolic compounds were performed and the antioxidant activity was measured by ABTS and DPPH methods. The validity of the experimental design was confirmed by ANOVA and the optimal sonotrode extraction conditions were obtained by response surface methodology (RSM). The extracts obtained in the established conditions were analyzed by High Performance Liquid Chromatography (HPLC) coupled to mass spectrometer detector and 74 polar compounds were identified. The highest phenolic content and antioxidant activity were obtained using 45/55 ethanol/water (v/v), 35 min, amplitude 90% (110 W), and pulse 100%. The established method allows an increment of phenolics recovery up to 60% higher than a conventional extraction. Moreover, the effect of drying on phenolic content was also evaluated.


Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2879
Author(s):  
Aleksandar Radivojac ◽  
Oskar Bera ◽  
Zoran Zeković ◽  
Nemanja Teslić ◽  
Živan Mrkonjić ◽  
...  

Consumers are becoming more mindful of their well-being. Increasing awareness of the many beneficial properties of peppermint essential oil (EO) has significantly increased product sales in recent years. Hydrodistillation (HD), a proven conventional method, and a possible alternative in the form of microwave-assisted hydrodistillation (MWHD) have been used to isolate peppermint EO. Standard Soxhlet and alternatively supercritical fluid (SFE), microwave-assisted, and ultrasound-assisted extraction separated the lipid extracts. The distillations employed various power settings, and the EO yield varied from 0.15 to 0.80%. The estimated environmental impact in terms of electricity consumption and CO2 emissions suggested that MWHD is an energy efficient way to reduce CO2 emissions. Different extraction methods and solvent properties affected the lipid extract yield, which ranged from 2.55 to 5.36%. According to the corresponding values of statistical parameters, empiric mathematical models were successfully applied to model the kinetics of MWHD and SFE processes.


2012 ◽  
Vol 441 ◽  
pp. 640-644
Author(s):  
Ke Jie Fu ◽  
Li Sheng Yang ◽  
Chang Sheng Feng ◽  
Liang Chen

A detecting method for toxic flame retardant finishing agent tris-(2,3-dibromopropyl) -phosphate (TRIS for short) in textiles was studied. In the method, an acetonitrile ultrasound-assisted extraction process was included in sample pre-treatment, and HPLC/DAD was used in the separation and identification of extractives. After that, the conditions of pre-treatment and chromatograph were optimized. The results showed that the limit of detection (LOD) by this method (S/N10) is 1.0 mg/kg, its recovery ranged from 78.1% to 98.4%, and RSD of the precision test is 3.2%, of which all met the requirements for routine testing.


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