Phenolic Compounds Extraction of Arbutus unedo L.: Process Intensification by Microwave Pretreatment

Producción CientíficaArbutus unedo L., commonly known as the strawberry-tree fruit, is an endemic species of the Mediterranean flora. Microwave extraction technology has been considered as a fast and “green” method for the production of extracts rich in bioactive compounds, although the energy consumption is high. To overcome this bottleneck, microwave was used as a pretreatment procedure in short time periods. This technique promotes the burst of intracellular vacuoles leading to an increase in the lixiviation of phenolic compounds. Different approaches were tested, namely a solvent-free irradiation (SFI), a solvent-assisted irradiation (SAI) and a pressurized solvent-assisted irradiation (PSAI). After irradiation, a solid–liquid extraction procedure was performed using a mixture of water and ethanol. A kinetic evaluation of the total phenolic content (TPC) was performed using the Folin–Ciocalteu method. For the total anthocyanin content, a UV-spectrophotometric method was used. HPLC-UV and LC-MS were used for TPC and identification of present compounds. Microwave irradiation led to an increase in TPC of extracts after SAI (52%) and PSAI (66%) along with a reduction in time of extraction from 30 min to less than 2 min. The anthocyanin content also increased by 66% for the SAI and PSAI extractions.Fundação para Ciência e Tecnologia (fellowship SFRH/BD/52532/2014)Fundação para a Ciência e Tecnologia/Ministério da Educação e Ciência - Fondo Europeo de Desarrollo Regional (partnership PT2020)Portuguese National Mass Spectrometry Network (contracts RNEM—REDE/1518/REM/2005, ROTEIRO/0028/2013 and LISBOA-01-0145-FEDER-022125)Marie Curie Industry - Academia Partnerships and Pathways (project FP7-PEOPLE-2013-IAPP-612208

Ultrasound increases the aqueous extraction of phenolic compounds with high antioxidant activity from olive pomace

Olive pomace is a waste produced by the olive oil industry in massive quantities each year. Disposal of olive pomace is difficult due to high concentrations of phenolic compounds, which is an environmental concern. However, phenolic compounds have applications in the health industry. Therefore, extraction of phenolic compounds from olive pomace has the potential to remove an environmentally hazardous portion of pomace while creating an additional source of income for farmers and producers. Using advanced technologies including Ultrasound Assisted Extraction (UAE), combined with water as an extraction solvent, has recently gained popularity. The present study outlines the optimal UAE conditions for the extraction of phenolic compounds with high antioxidant activity from olive pomace. Optimal conditions were developed using RSM for parameters power, time and sample-to-solvent ratio. Total phenolic compounds determined by Folin Ciocalteu method and total major bioactive compounds determined by HPLC as well as antioxidant capacity (DPPH and CUPRAC) were investigated. The optimal conditions for the extraction of phenolic compounds with high antioxidant activity were 2 g of dried pomace/100 mL of water at 250 W power for 75 min. UAE improved the extraction efficiency of water and yielded extracts with high levels of phenolic compounds and strong antioxidant activity

Production of bioactive phenolic compounds by berry cell cultures

The production of phenolic compounds by berry cell cultures of strawberry (Fragaria x ananassa) was studied and the biosynthesis of phenolic compounds was stimulated by elicitation

Potential of Pyrolysis for valuable products obtaining from wheat straw lignin produced by CIMV technology

Two configurations of fast pyrolysis realized in flowing (inert gas flow) and ablative-type reactors were used for phenolic fraction obtaining. The maximum yield of phenolic compounds was achieved at 450 degrees of Celsius in the case of ablative reactor usage (7,6%). Application of catalysts (Na+ and K+) allowed to increase the yield of phenolic compounds up to 8,5%

Enhancement of the total phenolic compounds and antioxidant activity of aqueous <i>Citrus limon </i>L. pomace extract using microwave pretreatment on the dry powder

The effect of microwave pretreatment on the levels of total phenolic compounds, flavonoids, proanthocyanidins, and individual major compounds as well as the total antioxidant activity of the dried lemon pomace was investigated. The results showed that microwave pretreatment significantly affected all the examined parameters. The total phenolic content, total flavonoids, proanthocyanidins, as well as the total antioxidant activity significantly increased as the microwave radiation time and power increased (e.g., 2.5-fold for phenolics, 1.4-fold for flavonoids, and 5.5-fold for proanthocyanidins); however, irradiation of more than 480 W for 5 min resulted in the decrease of these parameters. These findings indicate that microwave irradiation time and power may enhance higher levels of the phenolic compounds as well as the antioxidant capacity of the dried lemon pomace powder. However, higher and longer irradiation may lead to a degradation of phenolic compounds and lower the antioxidant capacity of the dried lemon pomace.Practical applicationsLemon pomace could be a good source of bioactive compounds and antioxidants. Microwave irradiation could be applied for the enhancement of the total phenolic compounds and antioxidants of the lemon pomace-dried powder. The findings of this study can be applied for enhancing the bioactive compounds and the antioxidant activity of the dried lemon pomace for further extraction, isolation, and utilisation

Rapid and comprehensive evaluation of (poly)phenolic compounds in pomegranate (punica granatum L.) juice by UHPLC-MSn

The comprehensive identification of phenolic compounds in food and beverages is a crucial starting point for assessing their biological, nutritional, and technological properties. Pomegranate (Punica granatum L.) has been described as a rich source of (poly)phenolic components, with a broad array of different structures (phenolic acids, flavonoids, and hydrolyzable tannins) and a quick, high throughput, and accurate screening of its complete profile is still lacking. In the present work, a method for UHPLC separation and linear ion trap mass spectrometric (MSn) characterization of pomegranate juice phenolic fraction was optimized by comparing several different analytical conditions. The best solutions for phenolic acids, anthocyanins, flavonoids, and ellagitannins have been delineated and more than 70 compounds have been identified and fully characterized in less than one hour total analysis time. Twenty-one compounds were tentatively detected for the first time in pomegranate juice. The proposed fingerprinting approach could be easily translated to other plant derived food extracts and beverages containing a wide array of phytochemical compounds

Persistence of anticancer activity in berry extracts after simulated gastrointestinal digestion and colonic fermentation

Fruit and vegetable consumption is associated at the population level with a protective effect against colorectal cancer. Phenolic compounds, especially abundant in berries, are of interest due to their putative anticancer activity. After consumption, however, phenolic compounds are subject to digestive conditions within the gastrointestinal tract that alter their structures and potentially their function. However, the majority of phenolic compounds are not efficiently absorbed in the small intestine and a substantial portion pass into the colon. We characterized berry extracts (raspberries, strawberries, blackcurrants) produced by in vitro-simulated upper intestinal tract digestion and subsequent fecal fermentation. These extracts and selected individual colonic metabolites were then evaluated for their putative anticancer activities using in vitro models of colorectal cancer, representing the key stages of initiation, promotion and invasion. Over a physiologically-relevant dose range (0–50 µg/ml gallic acid equivalents), the digested and fermented extracts demonstrated significant anti-genotoxic, anti-mutagenic and anti-invasive activity on colonocytes. This work indicates that phenolic compounds from berries undergo considerable structural modifications during their passage through the gastrointestinal tract but their breakdown products and metabolites retain biological activity and can modulate cellular processes associated with colon cancer

Antioxidant Capacity Of Frangipani (Plumeria Alba) Powder Extract

This research aimed to identify the antioxidant capacity, vitamin C (ascorbic acid), and total phenolic compounds of frangipani flower powder. The powder was extracted using ethanol, methanol, acetic acid, and water (aquadest). Antioxidant capacity of each extract were determined using 2,2-diphenyl-1-picrylhydrazyl radical scavenging method, vitamin C were determined using 2,4 Dinitrophenylhydrazine, and total phenolic compounds were determined using Folin Ciocalteu reagent. All of parameters were measured by spectrofotometer. The result shows that the highest value of antioxidant capacity was ethanolic extract (18.19%) and the lowest value was acetic acid extract (12.74%). The highest value of vitamin C was aqueous extract (3.49 mg/100g) and the lowest value was acetic acid extract (3.02 mg/100g). The highest value of total phenolic content was aqueous extract (25.49 mg GAE/g) and the lowest value was acetic acid extract (22.74 mg GAE/g). In conclusion, the higher antioxidant capacity was not always followed by the higher of vitamin C and total phenolic compounds

Extraction of Anthocyanins and Total Phenolic Compounds from Açai (Euterpe oleracea Mart.) Using an Experimental Design Methodology. Part 3: Microwave-Assisted Extraction

In this work, two methods based on microwave-assisted extraction techniques for the extraction of both anthocyanins and total phenolic compounds from acai have been developed. For that, a full factorial design (Box-Behnken design) has been used to optimize the following four variables: solvent composition (25-75% methanol in water), temperature (50-100 degrees C), pH (2-7), and sample/solvent ratio (0.5 g: 10 mL-0.5 g: 20 mL). The anthocyanins and total phenolic compounds content have been determined by ultra high-pressure liquid chromatography and Folin-Ciocalteu method, respectively. The optimum conditions for the extraction of anthocyanins were 38% MeOH in water, 99.63 degrees C, pH 3.00, at 0.5 g: 10 mL of ratio, while for the extraction of total phenolic compounds they were 74.16% MeOH in water, 99.14 degrees C, pH 5.46, at 0.5 g: 20 mL of ratio. Both methods have shown a high repeatability and intermediate precision with a relative standard deviation lower than 5%. Furthermore, an extraction kinetics study was carried out using extraction periods ranging from 2 min until 25 min. The optimized methods have been applied to acai-containing real samples. The results with such real samples have confirmed that both methods are suitable for a rapid and reliable extraction of anthocyanins and total phenolic compounds