Optimization of Microwave and Ultrasound Extraction Methods of Açai Berries in Terms of Highest Content of Phenolic Compounds and Antioxidant Activity

Optimizing physicochemical properties, antioxidant potential, and antibacterial activity of dry ginger extract using sonication treatment

This research paper focused on enhancing the physico-chemical attributes, antioxidant capacity, and antibacterial effectiveness of dry ginger extract through sonication as an assistant extraction treatment. Ginger, resulting from the rhizome of Zingiber officinale Roscoe, is known for its culinary and medicinal uses outstanding to its antioxidant and antimicrobial possessions from phenolic acids and flavonoids. The study explored the use of sonication as an assistant extraction method and found that it significantly augmented the total phenolic content of the ginger extract by 28 % compared to traditional extraction methods, reaching 10.55 ± 1.50 mg GAE/g, DW. The research assessed the physicochemical belongings, antioxidant action, and antibacterial possibility of the sonicated ginger extract. The sonicated extract exhibited scavenging activity against the DPPH radical of 56.0 %. Pearson correlation investigation revealed a strong confident correlation between the phenolic content and antioxidant activity (r = 0.92, p < 0.01), as well as volatile compounds exhibited a moderate confident correlation with antibacterial action (r = 0.67, p < 0.05). The sonicated ginger extract also demonstrated potent antibacterial action, preventing the growth of both Gram-positive and Gram-negative bacteria. These findings contribute to the development of more efficient methods for extracting phenolic from ginger and provide insights into the relationships between phenolic and bioactive properties.

Phytochemical, Antimicrobial, and Antioxidant Activity of Different Extracts from Frozen, Freeze-Dried, and Oven-Dried Jostaberries Grown in Moldova

In this paper, the qualitative and quantitative profile is evaluated of the bioactive compounds, antioxidant activity (AA), microbiostatic properties, as well as the color parameters of jostaberry extracts, obtained from frozen (FJ), freeze-dried (FDJ), and oven-dried berries (DJ). The optimal extraction conditions by ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) were selected after determination of the total polyphenol content (TPC), total flavonoid content (TFC), total antocyanin content (TA), AA by 2,2-diphenyl-1-picrylhydrazyl-hydrate (DPPH), and the free radical cation 2,2-azinobis-3-ethylbenzothiazoline-6-sulfonates (ABTS). Non-conventional extraction methods are less destructive to anthocyanins, while drying the berries reduced TA, regardless of the extraction method. The oven-drying process reduced the concentration of TA in DJ extracts by 99.4% and of ascorbic acid by 92.42% compared to FJ. AA was influenced by the jostaberry pretreatment methods. The DPPH and ABTS tests recorded values (mg Trolox equivalent/g dry weight) between 17.60 and 35.26 and 35.64 and 109.17 for FJ extracts, between 7.50 and 7.96 and 45.73 and 82.22 for FDJ, as well as between 6.31 and 7.40 and 34.04 and 52.20 for DJ, respectively. The jostaberry pretreatment produced significant changes in all color parameters. Mutual information analysis, applied to determine the influence of ultrasound and microwave durations on TPC, TFC, TA, AA, pH, and color parameters in jostaberry extracts, showed the greatest influence on TA (0.367 bits) and TFC (0.329 bits). The DPPH and ABTS inhibition capacity of all FJ' extracts had higher values and varied more strongly, depending on pH, heat treatment, and storage time, compared to the AA values of FDJ' and DJ' extracts. A significant antimicrobial effect was observed on all bacterial strains studied for FJP. FDJP was more active on Bacillus cereus, Staphylococcus aureus, and Escherichia coli. DJP was more active on Salmonella Abony and Pseudomonas aeruginosa. The antifungal effect of DJP was stronger compared to FDJP. Jostaberry extracts obtained under different conditions can be used in food production, offering a wide spectrum of red hues.

Effects of the spray-drying process using maltodextrin on bioactive compounds and antioxidant activity of the pulp of the tropical fruit açai (Euterpe oleracea Mart.)

Aҫai fruit is characterized by the properties of its bioactive compounds; however, this fruit is highly perishable and its compounds are sensitive when exposed to non-optimal environmental factors. Therefore, the objective of this study was to encapsulate the fruit pulp by spray drying to improve the nutritional value and extend the shelf life of the products derived from acai fruit. Maltodextrin was used as a wall material and the process was optimized to obtain the desirable values of the response variables. For this, a central compound design (CCD) was developed to determine the influence of temperature (110-170 °C) and the wall material proportion (5-15 %) on dependent variables: the retention of ascorbic acid, moisture percentage, hygroscopicity, solubility, water activity, and yield. Furthermore, the effects of spray drying on bioactive compounds (AA, TPC, TFC, TA, TCC, GA, CT, and QC) and antioxidant activity (ABTS, DPPH, and ORAC) were evaluated. The maximum design temperature (170 °C) and wall material proportion (15 %) significantly influenced the response variables where encapsulation was applied, with high ascorbic acid retention (96.886 %), low moisture (0.303 %), low hygroscopicity (7.279 g/100 g), low level of water activity (0.255), a water solubility index of 23.206 %, and a high yield of 70.285 %. The bioactive compounds analyzed and the antioxidant capacity presented significant retention values for AA (96.86 %), TPC (65.13 %), TFC (82.09 %), TA (62.46 %), TCC (7.28 %), GA (35.02 %), CT (49.03 %), QC (37.57 %), ABTS (81.24 %), DPPH (75.11 %), and ORAC (15.68 %). Therefore, it is concluded that the powder obtained under these conditions has desirable physical properties, and the drying process preserved a notable retention of bioactive compounds and their antioxidant activities.

Characterization of Lipid Extracts from Different Colors of Peach Palm Fruits-Red, Yellow, Green, and White-Obtained through Ultrasound-Assisted Green Extraction

This study represents a pioneering investigation and comparative analysis of lipid extracts from four different colors of peach palm (Bactris gasipaes Kunt) fruits-red, yellow, green, and white-by employing a green method based on ethanolic ultrasound-assisted extraction. This study examined the extraction yield, physico-chemical-quality attributes, chromatographic profiles (GC), color measurements, total carotenoid content, differential thermogravimetry (TG/DTA), and infrared spectroscopy (FTIR). The obtained lipid extracts displayed a high quality, considering the physico-chemical parameters of the Codex Alimentarius, and a fatty acids profile characterized by unsaturated fatty acids, notably omegas (ω-3, ω-6, and ω-9). The indices of atherogenicity (A.I.), thrombogenicity (I.T.), and hypocholesterolemic and hypercholesterolemic ratios revealed superior outcomes for the red peach palm lipid extract (approximately 0.35, 0.52, and 2.75, respectively), along with higher levels of β-carotene (748.36 µg of β-carotene per 100 g-1 of lipid extract) compared to the yellow, green, and white counterparts. Consequently, this research successfully demonstrates the efficacy of using a green extraction method in preserving the lipid's quality, which can display cardiovascular functionality and thermal stability. These findings underscore the considerable potential of peach palm lipid extract as a valuable raw material for diverse industrial applications across various sectors. The results support its utilization in the production of functional food products and nutraceuticals due to its favorable fatty acid composition, potent antioxidant properties exhibited by its high β-carotene content, and notable cardiovascular functionality indices.

Seaweed-derived phenolic compounds as diverse bioactive molecules: A review on identification, application, extraction and purification strategies

Seaweed, a diverse group of marine macroalgae, has emerged as a rich source of bioactive compounds with numerous health-promoting properties. Among these, phenolic compounds have garnered significant attention for their diverse therapeutic applications. This review examines the methodologies employed in the extraction and purification of phenolic compounds from seaweed, emphasizing their importance in unlocking the full potential of these oceanic treasures. The article provides a comprehensive overview of the structural diversity and biological activities of seaweed-derived phenolics, elucidating their antioxidant, anti-inflammatory, and anticancer properties. Furthermore, it explores the impact of extraction techniques, including conventional methods and modern green technologies, on the yield and quality of phenolic extracts. The purification strategies for isolating specific phenolic compounds are also discussed, shedding light on the challenges and advancements in this field. Additionally, the review highlights the potential applications of seaweed-derived phenolics in various industries, such as pharmaceuticals, cosmetics, and functional foods, underscoring the economic value of these compounds. Finally, future perspectives and research directions are proposed to encourage continued exploration of seaweed phenolics, fostering a deeper understanding of their therapeutic potential and promoting sustainable practices in the extraction and purification processes. This comprehensive review serves as a valuable resource for researchers, industry professionals, and policymakers interested in harnessing the untapped potential of phenolic compounds from seaweed for the betterment of human health and environmental sustainability.

Non-thermal technologies for the conservation of açai pulp and derived products: A comprehensive review

Açai (Euterpe oleracea) is one of the main sustainable extractive crops in the Amazon region, widely consumed by the local population and a significant export product. This review presents the current knowledge regarding nonthermal technologies employed in açai processing. This review aims to discuss and compare the main results attained by the application of HPP, ultrasound, ozone, UV light, cold plasma, and pulsed electric field on microbial inactivation, enzymatic inhibition, and the content of anthocyanin and other bioactive compounds after açai pulp processing. The discussion compares these technologies with pasteurization, the current main technology applied to açai sanitization. This review shows that there are still many gaps to be filled concerning açai processing in thermal and non-thermal technologies. Data analysis allowed the conclusion that pasteurization and HPP are, up to now, the only technologies that enable a 5-log CFU reduction of yeasts, molds, and some bacteria in açai. However, no study has reported the inactivation of Trypanosoma cruzi, which is the major gap found in current knowledge. Other technologies, such as pulsed electric field, cold plasma, and ultrasound, require further development and process intensification studies to be as successful as HPP and pasteurization.

Evaluation of maceration, microwave, ultrasound-assisted extraction methods on free, esterified and bound phenolic profile and antioxidant activity of black rice

Black rice (Oryza sativa L.) is a rich source of phenolics and anthocyanins. It was aimed to investigate the effect of different extraction methods such as conventional solvent extraction, ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE) on antioxidant activity and phenolic profiling of black rice free, esterified, and bound phenolics fractions. Spectrophotometric methods were used to evaluate antioxidant activity and HPTLC was used for phenolics profiling. The highest content of % yield, total anthocyanin (TAC), total phenolic (TPC), and total flavonoid (TFC) contents were detected in MAE. It was also observed that antioxidant activity based on DPPH, ABTS, superoxide radical-scavenging and ferric reducing antioxidant power (FRAP) assays showed highest activity in MAE. Eight phenolic compounds were identified and quantified by a validated HPTLC method. MAE showed most abundant phenolic compounds. A significant positive correlation was established between % yield, total phenolic content, and total flavonoid content (p < 0.05) where a significant negative correlation was established between % yield, TPC, and TFC with IC50 of antioxidant activity (p < 0.05). Diverse phenolic contents and antioxidant activity were studied with different forms of phenolics with the different extraction methods. It designates that the extraction techniques had effects on the bioactive compounds as well biological properties.

Cold Plasma-Assisted Extraction of Phytochemicals: A Review

In recent years, there has been growing interest in bioactive plant compounds for their beneficial effects on health and for their potential in reducing the risk of developing certain diseases such as cancer, cardiovascular diseases, and neurodegenerative disorders. The extraction techniques conventionally used to obtain these phytocompounds, however, due to the use of toxic solvents and high temperatures, tend to be supplanted by innovative and unconventional techniques, in line with the demand for environmental and economic sustainability of new chemical processes. Among non-thermal technologies, cold plasma (CP), which has been successfully used for some years in the food industry as a treatment to improve food shelf life, seems to be one of the most promising solutions in green extraction processes. CP is characterized by its low environmental impact, low cost, and better extraction yield of phytochemicals, saving time, energy, and solvents compared with other classical extraction processes. In light of these considerations, this review aims to provide an overview of the potential and critical issues related to the use of CP in the extraction of phytochemicals, particularly polyphenols and essential oils. To review the current knowledge status and future insights of CP in this sector, a bibliometric study, providing quantitative information on the research activity based on the available published scientific literature, was carried out by the VOSviewer software (v. 1.6.18). Scientometric analysis has seen an increase in scientific studies over the past two years, underlining the growing interest of the scientific community in this natural substance extraction technique. The literature studies analyzed have shown that, in general, the use of CP was able to increase the yield of essential oil and polyphenols. Furthermore, the composition of the phytoextract obtained with CP would appear to be influenced by process parameters such as intensity (power and voltage), treatment time, and the working gas used. In general, the studies analyzed showed that the best yields in terms of total polyphenols and the antioxidant and antimicrobial properties of the phytoextracts were obtained using mild process conditions and nitrogen as the working gas. The use of CP as a non-conventional extraction technique is very recent, and further studies are needed to better understand the optimal process conditions to be adopted, and above all, in-depth studies are needed to better understand the mechanisms of plasma-plant matrix interaction to verify the possibility of any side reactions that could generate, in a highly oxidative environment, potentially hazardous substances, which would limit the exploitation of this technique at the industrial level.

Sonoprocessing improves phenolics profile, antioxidant capacity, structure, and product qualities of purple corn pericarp extract

For the first time, purple corn pericarp (PCP) was converted to polyphenol-rich extract using two-pot ultrasound extraction technique. According to Plackett-Burman design (PBD), the significant extraction factors were ethanol concentration, extraction time, temperature, and ultrasonic amplitude that affected total anthocyanins (TAC), total phenolic content (TPC), and condensed tannins (CT). These parameters were further optimized using the Box-Behnken design (BBD) method for response surface methodology (RSM). The RSM showed a linear curvature for TAC and a quadratic curvature for TPC and CT with a lack of fit > 0.05. Under the optimum conditions (ethanol (50%, v/v), time (21 min), temperature (28 °C), and ultrasonic amplitude (50%)), a maximum TAC, TPC, and CT of 34.99 g cyanidin/kg, 121.26 g GAE/kg, and 260.59 of EE/kg, respectively were obtained with a desirability value 0.952. Comparing UAE to microwave extraction (MAE), it was found that although UAE had a lower extraction yield, TAC, TPC, and CT, the UAE gave a higher individual anthocyanin, flavonoid, phenolic acid profile, and antioxidant activity. The UAE took 21 min, whereas MAE took 30 min for maximum extraction. Regarding product qualities, UAE extract was superior, with a lower total color change (ΔE) and a higher chromaticity. Structural characterization using SEM showed that MAE extract had severe creases and ruptures, whereas UAE extract had less noticeable alterations and was attested by an optical profilometer. This shows that ultrasound, might be used to extract phenolics from PCP as it requires lesser time and improves phenolics, structure, and product qualities.

Effect of hot water, ultrasound, microwave, and pectinase-assisted extraction of anthocyanins from black goji berry for food application

Lycium ruthenicum, commonly known as black goji berry, is a rich anthocyanin source containing a high amount of monoacylated anthocyanins. This study investigates the effect of different extraction methods to extract anthocyanins from black goji berry for food application. Different hot water extraction conditions were applied to investigate the effect of specific substrate: solvent ratio (1:15 and 1:20 (w/v)), extraction time (30 and 60 min) and extraction temperature (40, 50 and 60 °C) on the extraction yield, total anthocyanin content (TAC) and the total phenolic content (TPC) of the anthocyanin extracts. Best hot water extraction conditions for obtaining an anthocyanin extract with high TAC (13.8 ± 1.14 mg CGE/g), TPC (69.7 ± 2.50 mg of GAE/g), and extraction yield (48.3 ± 3.25%) consuming less solvent, time and heat were substrate: solvent ratio of 1: 15 (w/v), extraction temperature of 50 °C, and extraction time of 30 min. The effect of pectinase, ultrasound, and microwave on hot water extraction of anthocyanins from black goji berry was investigated using the best conditions for hot water extraction. Pectinase-assisted extraction [1.5% (w/v) pectinase, substrate: solvent ratio of 1:15 (w/v) at 50 °C for 30 min] was the best extraction method to extract black goji berry anthocyanins demonstrating higher extraction yield, TAC, TPC, and the highest percentage of petunidin-3-O-(trans-p-coumaroyl)-rutinoside-5-O-glucoside.

Quality of Beef Burgers Formulated with Fat Substitute in a Form of Freeze-Dried Hydrogel Enriched with Açai Oil

The growing number of people at high risk of cardiovascular disease development contributed to both changes in diets by consumers and the reformulation of food products by food producers. Cardiovascular diseases are caused by the i.a. consumption of meat that contains animal fat rich in saturated fatty acids (SFA). The use of fat substitutes in meat seems to be a promising tool for the reduction of cardiovascular disease occurrence. In the presented study, beef fat was replaced at 0 (CO), 25 (S-25%), 50 (S-50%), 75 (S-75%), and 100% (S-100%) by a fat substitute in a form of a lyophilized hydrogel emulsion enriched with encapsulated açai oil. The chemical (TBARS, volatile compound profile, fatty acid profile, pH), and physical (TPA, consumer rating, L*a*b* color, cooking loss) analyses were performed on raw and grilled burgers subjected to storage at cold conditions (4 °C) in days 0 and 7. Burgers formulated with hydrogels had a higher content of polyunsaturated fatty acids (PUFAs) of about 32% (p < 0.05) and reduced SFAs by 22%. Reformulation of the burger resulted in lower nutritional indices of the atherogenicity index (AI) (0.8 for CO, 0.3 for S-100%, p < 0.05) and thrombogenicity index (TI) (1.8 for CO, 0.6 for S-100%, p < 0.05), as well as led to an increased h/H ratio (1.3 for CO, 3.9 for S-100%, p < 0.05). Furthermore the application of freeze-dried hydrogels reduced cooking loss. Moreover, consumers did not observe significant differences (p < 0.05) between the control and S-25% and S-50% burgers. Thus, the use of lyophilized hydrogels formulated with konjac flour and sodium alginate and enriched with encapsulated acai oil can be successfully applied as a fat substitute in beef burgers.

Hydrogel Emulsion with Encapsulated Safflower Oil Enriched with Açai Extract as a Novel Fat Substitute in Beef Burgers Subjected to Storage in Cold Conditions

This study evaluates the effects of using a fat substitute in beef burgers composed of a hydrogel emulsion enriched with encapsulated safflower oil and açai extract. The influences of the fat substitute on the chemical (TBARS, fatty acids, and volatile compounds profile) and physical (weight loss, cooking loss, water-holding capacity, color, and texture analyses) characteristics of the burgers were analyzed after 0, 4 and 8 days of storage at 4 ± 1 °C. The obtained results were compared with control groups (20 g of tallow or 8 g of safflower oil). The fat substitute used improved burger parameters such as chewiness, hardness and the a* color parameter remained unchanged over storage time. The addition of açai extract slowed the oxidation rate of polyunsaturated fatty acids and reduced the changes in the volatile compounds profile during the storage of burgers. The utilization of a fat substitute enriched the burgers with polyunsaturated fatty acids and lowered the atherogenic index (0.49 raw, 0.58 grilled burger) and the thrombogenicity index (0.8 raw, 1.09 grilled burger), while it increased the hypocholesterolemic/hypercholesterolemic ratio (2.59 raw, 2.09 grilled burger) of consumed meat. Thus, the application of the presented fat substitute in the form of a hydrogel enriched with açai berry extract extended the shelf life of the final product and contributed to the creation of a healthier meat product that met the nutritional recommendations.

The Effect of Cold Plasma Pretreatment on Water-Suspended Herbs Measured in the Content of Bioactive Compounds, Antioxidant Activity, Volatile Compounds and Microbial Count of Final Extracts

Cold plasma is a new technology of promising potential to use as a part of technological extraction lines constructed to implement green chemistry solutions or simply to reduce resources in solvent-based extraction lines. The present study was undertaken to verify the effect of nitrogen cold plasma pre-treatment conducted for 8 min (20 kHz) on the content of antioxidants, antioxidant activity, the profile of volatile compounds, microbial count, pH and color measured in herb extracts (12 herbs: Echinacea purpurea; Salvia officinalis; Urtica dioica; Polygonum aviculare; Vaccinium myrtillus; Taraxacum officinale; Hypericum perforatum; Achillea millefolium; Sanguisorba officinalis; Leonurus cardiaca; Ballota nigra; Andrographis paniculata) obtained with its usage. The surface morphology of extracted herbs was examined as well. Herbs used for extraction were ground and suspended in water before cold plasma treatment, which is a novel approach not studied before. Most plasma-treated extracts were characterized by a higher content of polyphenols (11 out of 12). Content of flavonoids and anthocyanins increased in four extracts and in the case of anthocyanins was significantly higher in comparison to control (up to 77%). The antioxidant activity measured at least by one method (ABTS, DPPH, FRAP) was also higher in nine plasma-treated solutions. Moreover, plasma decreased total aerobic bacteria, affected the color and increased pH of the extracts. The surface structure of the plant material after the extraction process was significantly damaged, which probably led to a higher extraction yield of bioactive compounds and in consequence to the higher antioxidant activity of extracts obtained with the cold plasma treatment.