Investigation of the effect of ultrasound-assisted extraction on the yield and tannin content of white oregano extracts

Ulmus pumila L. bark underwent distilled water extraction under three temperature condition (4°C, room temperature, or 80°C) and two extraction times (1, or 5 min) in order to develop a functional beverage products. Changes in yield, pH, color, total phenolic (TP) content, tannin content and antioxidant activity of the aqueous extracts were evaluated for each extraction temperature and duration. Extraction conditions did not affect yield or pH value of the extracts; however CIE b* values were high in extracts prepared under high extraction temperature (80°C) and long extraction duration (5 min) conditions. Both extraction temperature and duration affected the TP and tannin contents of the extracts; however, all extraction conditions resulted in ≥450 mg GAE/g TP content and ≥80 mg CE/g tannin content. All extracts exhibited ABTS and DPPH radical scavenging ability similar to that of vitamin C. Nitric oxide inhibition activity was lower in the 5 min duration sample than in the 1 min sample. The 4°C extraction temperature produced an extract with the highest reducing power and hydrogen peroxide values. Extraction temperature also affected sensory evaluation results with the 80°C extraction temperature producing significantly higher flavor, bitterness, and color score, than those obtained under 4°C and room temperature extraction conditions.

The influence of technological parameters - temperature, hydromodule (proportion between row material/solvent (g/cm3)) and duration of extraction, on the yield and composition of ethanol extracts from Bulgarian white oregano (Origanum heracleoticum L.) whit 70 % ethanol was studied. The yield of extracts and tannins content were defined. The highest yield and content of tannins in ethanol oregano extracts was determined in the following parameters: hydromodule 1:10, 60 OC and the duration of the process 6 hours.

Optimization of extraction method for Kleeb Bua Daeng formula and comparison between ultrasound-assisted and microwave-assisted extraction

Astringency is one of the most important sensory attributes in red wine and is attributed to the presence of phenolic compounds. The objective of this study was to determine the relationship between tannin, anthocyanin, and small (SPP) and large (LPP) polymeric pigment concentrations in numerous Washington State red wines and to relate these values to perceived astringency. Three groups of wines were formed from a larger collection of wines based on tannin concentration: low (&lt;400 mg/L CE), medium (400–800 mg/L CE), and high (&gt;800 mg/L CE). Cabernet Sauvignon wines representing low, medium, and high tannin concentrations were selected and evaluated by 18 untrained panelists. Sensory results indicated that panelists gave significantly higher astringency ratings to wines high in tannin concentration compared with wines low in tannin concentration (<i>p</i> ≤ 0.05). In a second study, a trained panel evaluated Cabernet Sauvignon and Merlot wines representing combinations of low, medium, and high tannin, anthocyanin, SPP, and LPP concentrations. Results indicated that perceived astringency was significantly correlated with tannin, SPP, and LPP levels, while bitterness was significantly correlated with SPP, LPP, and tannin levels (<i>p</i> ≤ 0.05). These results indicated a relationship between polyphenolic compounds (tannins, SPP, and LPP) and the sensory attributes of astringency and bitterness.

Ultrasound-assisted extraction (UAE) was optimized for fast and effective isolation of blackthorn flower polyphenols. The effects of ethanol concentration (50% and 70%) in extraction solvent, ultrasound amplitude (50%, 75%, and 100%) and extraction time (3, 6, and 9 min) were evaluated. UPLC-MS2 was used to determine phenolic profile of blackthorn flowers extracts. A total of 28 different phenolic compounds were identified, belonging to the classes of hydroxycinnamic acids, flavonol glycosides and flavanols. Kaempferol and quercetin derivatives were the most abundant compounds represented by kaempferol-pentoside and rhamnoside in concentrations up to 494.94 and 436.62 mg/100 g and quercetin-pentoside in concentration up to 226.75 mg/100 g. Observed parameters of UAE did not affect the qualitative phenolic composition of blackthorn flower extracts. On the contrary, the concentration of polyphenols increased with higher ethanol concentration in solvent, higher ultrasound amplitude and prolongation of extraction time. The established conditions for optimal extraction of blackthorn flower polyphenols using ultrasound were: 70% ethanol as extraction solvent, 75% of ultrasound amplitude and 9 min extraction time, resulting in extract rich in polyphenols with a great potential for use in pharmaceutical and food industry. PRACTICAL APPLICATION: In this study, ultrasound-assisted extraction (UAE) was optimized in order to establish fast and effective method for production of crude blackthorn flower extract rich in polyphenols. UPLC-MS2 analysis showed 28 different phenolic compounds belonging to the classes of hydroxycinnamic acids, flavonol glycosides, and flavanols with quercetin and kaempferol glycosides in the highest concentrations, implicating high potential of blackthorn flowers' extract for use in food and pharmaceutical industries.

Iraqi Cordia myxa known as Bumber, belongs to the family Boraginaceae. It contains diverse phytochemicals depending on the plant part used. Different parts of Cordia myxa show different phytochemicals with various pharmacological effects. The study aims to evaluate and compare the extract yields, total polyphenolic content (TPC) and total flavonoid content (TFC) of extracts obtained by optimized ultrasound-assisted extraction and conventional extraction and assess their activity against L. tropica promastigotes, responsible for cutaneous leishmaniasis in Iraq. Preliminary phytochemical investigation revealed that Iraqi Bumber leaf extract contains saponin, alkaloids, tannins, flavonoids, coumarins and phenolics. The optimum conditions for the highest extract yield were 15 min, 70 % and 40 kHz. The extract yield percentage obtained by ultrasound-assisted extraction was higher than that of conventional extraction methods at 14.8 % and 6.93 % of dry extract respectively. The TFC and TPC of the optimized extract were 4 and 3.5 times higher than the extract obtained by a conventional method, respectively. Moreover, the current study revealed that promastigote inhibition by Iraqi Bumber leaf extract acquired by optimized ultrasound-assisted extraction was 89 % with IC50 38.98 μg/mL. In comparison, inhibition by the extract obtained by the conventional extraction method was 75 % with an IC50 of 46.81 μg/mL. For the first time, the TFC and TPC of the Iraqi plants were determined, along with their anti-leishmanial activities. The Iraqi plant may be a potential antileishmanial drug or be used as an adjuvant with conventional antileishmanial treatments to increase their effectiveness, decrease side effects and shorten the treatment period.

Ultrasound-assisted extraction of polyphenols from rosehip (Rosa canina L.) was investigated. The aim of the study was to examine the extraction parameters such as extraction time (30-90 min), temperature (30-50 °C) and solvent concentration (40-100% ethanol, v/v), and to obtain the best possible combinations of these parameters by using response surface methodology. The experiments were performed according to the face-centred central design. Total phenolic content was expressed in gallic acid equivalent (GAE) per gram of dried matter (DM). The second-order polynomial model gave a satisfactory description of the experimental data. 47.23 mg GAE g(-1) DM was predicted at the optimum operating conditions (40% EtOH composition, 50 °C of temperature, and 81.23 min of extraction time). All of the parameters (ethanol concentration, extraction time and extraction temperature) used in this research have the significant effect on the extraction efficiency of total phenolic content in rosehip extracts (P < 0.05). The solvent concentration was proved to be the most significant effective on the yields obtained by ultrasound-assisted extraction.

Ultrasound assisted extraction of wedelolactone, a major coumestan present in Eclipta alba, is investigated in the present work.Various process parameters such as type of solvent, power, solvent to solid ratio and extraction temperature, which affect the extraction yield, are optimized. In the ultrasound-assisted extraction with final optimized conditions, i.e., methanol as solvent, 170 W power, 60:1 solvent to solid ratio, 50 °C temperature and 60% duty cycle, amaximum extraction yieldof 0.62 mg/g is obtained in 45 minutes. The kinetic model (Peleg's model) has been used for the prediction of the yield of wedelolactone in the extract at a given time for all experimental conditions. The values of predicted yields show good agreement with the experimental data for all parameters, i.e., power, solvent to solid ratio and temperature. The extraction of wedelolactone from Eclipta alba is also carried out by conventional extraction methods, i.e., Soxhlet and batch extraction. Ultrasound-assisted extraction gives higher extraction yield in less time as compared to batch extraction (0.41 mg/g in 90 min) and Soxhlet extraction(0.7 mg/g in 360 min). The ultrasound-assisted extraction of wedelolactone from Eclipta alba is an effective way of extraction with the advantages of lower time and higher extraction.

Bryophyllum pinnatum is a potential medicinal plant widely used in different tribes in Bangladesh. The leaves of B. pinnatum were used in the present study for the compatibility assessment of a proposed ultrasound-assisted green extraction method with the conventional extraction method. An aqueous Ultrasound-Assisted Extraction (UAE) by using both fresh and dried leaves of B. pinnatum was proposed in the present study and successively compared with the traditional methanolic and aqueous (decoction) extraction method. The promising extraction yield was found through the proposed extraction method which was much better than decoction and almost similar to the methanolic extraction method. Phytochemical contents were also observed similar to the methanolic extract. Both methanolic and UAE extracts obtained from B. pinnatum leaves showed favorable antimicrobial sensitivity against both grams positive (Staphylococcus aureus and Streptococcus pyogenes) and gram-negative (Escherichia coli and Salmonella typhi) bacteria. Extracts obtained from the decoction method showed slightly poor antimicrobial activities. The difference in efficiency and efficacy of aqueous UAE extract obtained from fresh and dried leaves was observed insignificant. This indicates there is no necessity to impart the drying stage before extraction normally practiced in the conventional extraction method. Drying of plant material is a common stage of the conventional extraction cycle which ultimately lengthy the process and impose cost due to energy consumption and labor. Ultrasound-assisted extraction may successfully decrease the overall extraction cycle and ultimately reduce the overall cost of extraction. This method also creates opportunities to replace the water instead of with hazardous organic solvent for phytochemical extraction.

Artichoke leaves, an important waste product of the food industry, have an important antioxidant and antimicrobial capacity. Although there are several studies in the literature to determine their antioxidant and antimicrobial activity, a comparison of green extraction technologies including microwave, ultrasound probe and ultrasound bath methods in relation to the maceration technique has not been performed. Also, several parameters such as the extraction temperature, power, extraction mode and extraction time are important parameters for obtaining targeted compounds in the highest amount. For this reason, we aimed to compare various extraction methods including microwave-assisted extraction, ultrasound-assisted extraction with probe, ultrasound-assisted extraction in a water bath and maceration in terms of extraction parameters for obtaining bioactive compounds from artichoke leaves. Microwave-assisted extraction at two different power values, ultrasound-assisted extraction with probe in continuous or pulsed mode with two different extraction times each, ultrasound-assisted extraction in a water bath at two different power values with two different extraction times each and maceration with two different times were used for the extraction. The extraction temperature is an important parameter affecting the thermal degradation of bioactive compounds. We used a constant extraction temperature of 50 °C. Total phenolic and total flavonoid content, antioxidant capacity, phenolic compound profile analysis by LC-QTOF-MS and antimicrobial activity by agar diffusion and broth microdilution methods were determined. The bioactive compounds were found to be significantly affected by the parameters used in each extraction method. The microwave-assisted extraction method was more efficient than the other extraction methods at both power values. This method also required the shortest extraction time. The ultrasound-assisted probe extraction method was the second most efficient method. The type of process, continuous or pulsed, did not affect the results, but shortening the extraction time led to lower results. A longer extraction time of the ultrasound-assisted extraction in a water bath method led to better results, similar to the ultrasound-assisted probe extraction, regardless of the used power. The extracts were highly effective against many opportunistic and pathogenic microorganisms. This study provides valuable insights into the extraction parameters of different extraction methods to obtain bioactive compounds from artichoke leaves, which could have potential applications in the food and pharmaceutical industries.

The use of synthetic dyes as color enhancers or generators has caused various environmental and health problems. Plant tannin biomordants offer an alternative solution to address these issues. The sample used in this study were Cengkodok (M. malabathricum) plants that grow wild in places that get enough sunlight such as shrubs. Phytochemical screening on various parts of the cengkodok plant revealed that the highest tannin content is found in the leaf. However, until now there has been no scientific evidence that presents differences in tannin levels in cengkodok leaf with various types of solvents. This study aims to determine the yield and total tannin content of cengkodok leaf extract obtained through maceration process using methanol, ethanol, and ethyl acetate solvents. The extract yield was determined by comparing the weight of the dry extract with the powdered cengkodok leaf material. The total tannin content was analyzed using UV-Vis spectroscopy at a wavelength of 755.8 nm with Folin-Ciocalteu reagent and sodium carbonate. Tannic acid was used as a reference. The research results showed that the yield values for Cengkodok leaf extracted with methanol, ethanol, and ethyl acetate were 5.05%, 4.72%, and 1.59%, respectively. The total tannin content of cengkodok leaf extracts with methanol, ethanol, and ethyl acetate solvents was 0.47%±0.04, 0.37%±0.01, and 0.19%±0.04, respectively. Based on this research, it can be concluded that methanol is the most effective solvent in extraction and determination of total tannin content of Cengkodok leaf extracts.

Pharmaceutical companies worldwide have celebrated success producing synthetic derivatives of therapeutic plant extracts. These extracts have remained a primary treatment option globally. In this study, the impact of temporal extraction, extracting solvent and extract concentration on antibacterial potency of garlic was evaluated. Garlic extract was prepared according to these parameters; extraction period (1-2;3 days), solvent concentration (50%, 80%, 100%), reconstituted extract concentration (50mg/ml, 100mg/ml) and antibacterial activity established using the well diffusion method. Ethanol is a good extracting solvent but this is concentration dependent. Garlic extract showed varying antibacterial potency based on extraction parameters against Staphylococcus aureus. Empirically, a linear relationship existed between solvent concentration, extraction period (1-2 days) and antibacterial activity of garlic for as concentration of extraction solvent increased (80%-100%), with extraction period (1-2 days) the antibacterial activity also increased. It was also observed that with equal mass of plant material for extraction and equal volume of extracting solvent, 24-hours extraction period empirically produced more bioactive compounds that caused inhibition than 48-hours extraction time. Also with equal mass of material for extraction and volume of extracting solvent over a period of extraction (1-3 days), 80% ethanol produced more bioactive compounds that cause inhibition. From the findings, it appeared that longer extraction time (for fixed quantity of material to be extracted and fixed volume of extracting solvent) allowed other factors to influence bioactive compounds that caused inhibition. In addition, for a fixed volume of extracting solvent, weight of plant material for extraction (eg 20g-30g) within solubility limits is proportional to the availability of bioactive compounds particularly for 1-day extraction. The work also found that there’s extracting solvent concentration dependent reconstituted extract concentration inhibition effect and that if effective solvent concentration is considered a constant, then reconstituted extract concentration would be directly proportional to inhibition zone. Further research on temporal extraction and solvent concentration effect backed by correlation studies and statistical analysis is necessary.

Ultrasound assisted extraction of total phenolics from Cassia auriculata leaves and evaluation of its antioxidant activities

This study was carried out with the aim of optimizing the ultrasound-assisted extraction (UAE) of phenolic compounds from male chestnut flowers (C. sativa Mill) to develop a bioactive extract with potential to be used as a natural antioxidant preservative ingredient in the food industry. Time (t, 1–39 min), solvent concentration (S, 0–100%), and ultrasonic power (P, 5–500 W) were used as the independent variables for a 5-level experimental circumscribed central composite design (CCCD) coupled with response surface methodology (RSM) to optimize the extraction of phenolic compounds by UAE. Regarding the variables, the three showed a significant effect on the extraction of phenolic compounds. The content of phenolic compounds (including flavonoids and tannins) and the extraction yield (extract weight gravimetrically assessed) were the response criteria for the optimization. Based on the statistically validated predictive polynomial models, it was possible to reach a maximum content of phenolic compounds at the global optimal conditions of 24 ± 3 min, 259 ± 16 W, and 51 ± 7% ethanol. Additionally, pentagalloyl-glucoside and trigalloyl-hexahydroxydiphenoyl-glucoside were the major phenolic compounds identified. The optimized extract was then analyzed for their biological properties. The bioactive potential of the chestnut flower extract obtained under these optimized conditions was evaluated using in vitro assays for antioxidant, anti-inflammatory, and antimicrobial activity, as well as cytotoxicity and hepatotoxicity tests. The results revealed that the enriched extract has antioxidant, antitumoral, and anti-inflammatory activities without toxicity issues. Overall, this study allowed to define the optimal conditions for the extraction of phenolic compounds from chestnuts male flowers by UAE, to obtain an enriched extract with biological properties that could be further used as a natural antioxidant ingredient with applications on functional foods.

In this study, phenolic compounds of Kahramanmaraş red pepper (Capsicum annuum L.) seeds which are waste products from red pepper processing line were extracted by ultrasound-assisted (UAE) and conventional solvent extraction (SE) methods. Two different extraction methods were evaluated in terms of total phenolic contents (TPC) and antioxidant capacity. Response surface methodology (RSM) was used to optimize UAE conditions of phenolic extracts including extraction temperature (40, 50 and 60 °C), extraction time (20, 40 and 60 min) and solvent volume (50, 75 and 100 mL) for obtaining maximum total phenolics with higher antioxidant capacity. Effects of temperature, time and volume of solvent on extraction of phenolics were evaluated. As a result of RSM analysis, the optimum conditions determined as an extraction temperature of 51 °C, an extraction time of 60 min, and solvent volume of 50 mL. The results showed that ultrasonic treatment was more effective than conventional extraction method on phenolic extraction yield.