Over the years, brown algae bioactive polysaccharides laminarin, alginate and fucoidan have been isolated and used in functional foods, cosmeceutical and pharmaceutical industries. The extraction ...process of these polysaccharides includes several complex and time-consuming steps and the correct adjustment of extraction parameters (e.g., time, temperature, power, pressure, solvent and sample to solvent ratio) greatly influences the yield, physical, chemical and biochemical properties as well as their biological activities. This review includes the most recent conventional procedures for brown algae polysaccharides extraction along with advanced extraction techniques (microwave-assisted extraction, ultrasound assisted extraction, pressurized liquid extraction and enzymes assisted extraction) which can effectively improve extraction process. The influence of these extraction techniques and their individual parameters on yield, chemical structure and biological activities from the most current literature is discussed, along with their potential for commercial applications as bioactive compounds and drug delivery systems.
Chitosan based smart films are developed using blueberry and blackberry pomace extracts as active agents at different concentrations (1, 2 and 4% w/v). The whole concept of film production can be ...considered as eco-friendly contributing to the reduction of generally wasted material, fruit pomace. Blueberry and blackberry pomace showed excellent antioxidant potential that was not diminished after the film production. Chitosan matrix was not significantly changed to influence permeability to oxygen and mechanical properties, while water vapour permeability slightly decreased. Only the film stiffness increased with the addition of extract. Visible and significant colour changes of dry pH indicator films occurred with changing pH. The film colour was visibly transformed from pale yellow for control film, to blue-green and purple (with negative and positive a* values, respectively) with the addition of blueberry and blackberry pomace extracts, respectively. With changing pH from 2 to 10, films with blueberry changed from rose to blue green and with blackberry from red to dark violet. The most significant change was observed in the pH range from 4 to 7 that is important for determination of pH change due to the food spoilage in real foodstuff. Blackberry pomace extract had 4× more polyphenols than blueberry one. As expected, when extracts were added to chitosan films an increase in polyphenol content was also determined and antioxidant activity significantly increased. Films with blackberry pomace extract showed the highest antioxidant capacity probably due to the fact that already pure blackberry pomace extract was better antioxidant than the blueberry one. This result pointed high antioxidant activity of all produced films.
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•Chitosan smart films with blueberry and blackberry extracts at different concentrations are made by eco-friendly processes.•Blueberry and blackberry pomace showed excellent antioxidant potential that was not diminished after the film production.•Films with blackberry pomace extract showed the highest antioxidant activity.•Significant visual colour change can be used for determination of food spoilage.
Nettle is a widely known plant whose high biological activity and beneficial medicinal effects are attributed to various bioactive compounds, among which polyphenols play an important role. In order ...to isolate polyphenols and preserve their properties, advanced extraction techniques have been applied to overcome the drawbacks of conventional ones. Therefore, microwave-assisted extraction (MAE) has been optimized for the isolation of nettle leaves polyphenols and it was compared to pressurized liquid extraction (PLE) and conventional heat-reflux extraction (CE). The obtained extracts were analyzed for their individual phenolic profile by UPLC MS
and for their antioxidant capacity by ORAC assay. MAE proved to be the more specific technique for the isolation of individual phenolic compounds, while PLE produced extracts with higher amount of total phenols and higher antioxidant capacity. Both techniques were more effective compared to CE. PLE nettle extract showed antimicrobial activity against bacteria, especially against Gram-negative
ATCC 4973 and
NCTC 11168 strains. This suggests that PLE is suitable for obtaining a nettle extract with antioxidant and antimicrobial potential, which as such has great potential for use as a value-added ingredient in the food and pharmaceutical industry.
Laurus nobilis L., known as laurel or bay leaf, is a Mediterranean plant which has been long known for exhibiting various health-beneficial effects that can largely be attributed to the polyphenolic ...content of the leaves. Pressurized liquid extraction (PLE) is a green extraction technique that enables the efficient isolation of polyphenols from different plant materials. Hence, the aim of this research was to determine optimal conditions for PLE (solvent, temperature, number of extraction cycles and static extraction time) of laurel leaf polyphenols and to assess the polyphenolic profile of the optimal extract by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) as well as to evaluate the antioxidant activity determined by FRAP, DPPH and ORAC assays. The optimal PLE conditions were 50% ethanol, 150 °C, one extraction cycle and 5 min static time. The polyphenolic extract obtained at optimal PLE conditions comprised 29 identified compounds, among which flavonols (rutin and quercetin-3-glucoside) were the most abundant. The results of antioxidant activity assays demonstrated that PLE is an efficient green technique for obtaining polyphenol-rich laurel leaf extracts with relatively high antioxidant activity.
L. is a Mediterranean shrub known for its health promoting effects attributed to a large extent to polyphenols accumulated in all parts of the plant. Microwave-assisted extraction is a green ...extraction technique enabling fast and effective isolation of plant polyphenols. Therefore, the aim of this research was to optimize the microwave-assisted extraction of polyphenols from
L. leaves and fruit in terms of temperature, extraction time and microwave power and to evaluate their polyphenolic profile by UPLC/ESI-MS
and antioxidant capacity by ORAC assay. Optimal extraction conditions for leaf polyphenols were 69 °C, 512 W and 12 min, while for fruit were slightly more intensive-75 °C, 602 W and 15 min. Obtained total phenolic content in leaves and fruit was similar to that obtained after 30 min of the heat-reflux method. The polyphenolic profile of extracts included 34 compounds, with myricetin glycosides being the most abundant compounds among flavonoids in
L. leaves and fruit and gallic acid and its derivates among the phenolic acids. ORAC assay showed higher antioxidant capacity for
L. leaves extract than for fruit, which is in correlation with their respective phenolic content.
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.
Since certain constituents are not naturally present in pure fruit juices, incorporating herbal extracts can provide specific sensory properties to the beverages and improve their biopotential. In ...our previous research, it was found that sage (
L.), wild thyme (
L.), and combinations of their extracts had the highest total phenolic content and a unique composition of volatile compounds, which can contribute to the aromatic and antioxidant qualities of functional products. Therefore, this research aimed to investigate the potential of sage and wild thyme extracts, as well as their mixture (wild thyme:sage at 3:1,
/
), to enrich fruit juices (apple, pineapple, and orange). Obtained beverages were evaluated for sensory properties as well as phenolic and headspace composition (UPLC-MS/MS and HS-SPME/GC-MS analysis) and antioxidant capacity (ORAC assay). The incorporation of wild thyme extract in pineapple juice provided the most harmonious flavor and the highest content of volatile compounds (on PDMS/DVB fiber). The orange juice formulations were the most enriched with phenolic and volatile compounds (on DVB/CAR/PDMS fibers). The highest antioxidant capacity was observed in the formulation with orange juice and sage extract (22,925.39 ± 358.43 µM TE). This study demonstrated that enriching fruit juices with sage and wild thyme extracts could create functional beverages with improved sensory and health-promoting properties, providing valuable insights for the food and beverage industry to meet the growing demand of health-conscious consumers for natural and functional products.
The aim of the present study was to evaluate microwave-assisted (MAE) and pressurized liquid extraction (PLE) for the recovery of polyphenols from blackcurrant and bilberry leaves and the ...preservation of their antioxidant activity. The extractions were carried out varying the solvent/solid (SS) ratio, temperature and time. During MAE, increasing the SS ratio increased the polyphenol concentration in the extracts from blackcurrant and bilberry leaves, while increasing the temperature had a positive effect only on bilberry polyphenols. During PLE, only a temperature increase was a determining factor for the isolation of blackcurrant leave polyphenols. Based on polyphenol recovery, optimal extraction parameters were established resulting in a yield of 62.10 and 56.06 mg/g dw in the blackcurrant and bilberry MAE extracts and 78.90 and 70.55 mg/g dw in the PLE extracts. The optimized extracts were profiled by UPLC ESI MS
, and their antioxidant capacity was evaluated through FRAP, DPPH, ABTS and ORAC assays. The characterization of the extracts by UPLC ESI MS
confirmed flavonols as the predominant compounds in both blackcurrant and bilberry leaves, while flavan-3-ols and procyanidins were the main compounds responsible for high antioxidant capacity as confirmed by the ABTS and ORAC assays. Due to the extract composition and antioxidant capacity, PLE proved to be a technique of choice for the production of blackcurrant and bilberry leave extracts with high potential for use as value-added ingredients in the food and nutraceutical industry.
This study evaluated the presence of bioactives in wild nettle leaves and stalks during the phenological stage and in the context of natural habitat diversity. Thus, wild nettle samples collected ...before flowering, during flowering and after flowering from 14 habitats situated in three different regions (continental, mountain and seaside) were analyzed for low molecular weight polyphenols, carotenoids and chlorophylls using UPLC-MS/MS and HPLC analysis, while the ORAC method was performed for the antioxidant capacity measurement. Statistical analysis showed that, when compared to the stalks, nettle leaves contained significantly higher amounts of analyzed compounds which accumulated in the highest yields before flowering (polyphenols) and at the flowering stage (pigments). Moreover, nettle habitat variations greatly influenced the amounts of analyzed bioactives, where samples from the continental area contained higher levels of polyphenols, while seaside region samples were more abundant with pigments. The levels of ORAC followed the same pattern, being higher in leaves samples collected before and during flowering from the continental habitats. Hence, in order to provide the product's maximum value for consumers' benefit, a multidisciplinary approach is important for the selection of a plant part as well as its phenological stage with the highest accumulation of bioactive compounds.
In recent years, the market demand for products enhanced with ingredients derived from natural products, such as polyphenols, is rapidly increasing.
L., known as bay, sweet bay, bay laurel, Roman ...laurel or daphne is an evergreen Mediterranean shrub whose leaves have traditionally been used in cuisines and folk medicine due to their beneficial health effects, which can nowadays be scientifically explained by various biological activities of the leaf extracts. Many of these activities can be attributed to phenolic compounds present in
leaves which include flavonoids, phenolic acids, tannins (proanthocyanidins) and lignans. In order to enable efficient industrial utilization of these valuable compounds, it is crucial to establish optimal extraction procedures resulting in the highest yields and quality of the extracts. This paper offers the first systematic review of current literature on the influence of conventional and advanced extraction techniques, including microwave-assisted, ultrasound-assisted, enzyme-assisted, supercritical-CO
and mechanochemical-assisted extraction on the phenolic content of
leaf extracts, allowing more efficient planning of further research and simplifying the steps towards industrial utilization of this plant.
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