Extraction of phenolic compounds from lime peel waste using ultrasonic-assisted and microwave-assisted extractions

Different extraction methods shape the phenolic signature and biological activity of Morinda lucida extracts: A novel source of bioactive compounds preparing functional applications

The extraction of bioactive compounds is based on the application of various extraction techniques. Therefore, the stem and root bark of the plant species Morinda lucida L. were used in this research, while the extraction procedure was performed using three extraction techniques: HAE (homogenizer extraction), UAE (ultrasound extraction) as modern, and MAC (maceration) as conventional extraction technique. The presence of different classes of secondary metabolites was determined using the UHPLC method, while the content of total phenols and flavonoids was determined spectrophotometrically. The biological potential was investigated by in vitro antioxidant and enzyme assays. Different extraction technologies showed significant differences in only two classes of phenols, namely lignans and phenolic acids, which were significantly higher in HAE than in UAE and MAC. These findings highlight the significant effect of stem and bark extracts of M. lucida, opening the way for innovative industrial exploitation of these matrices.

Maximizing polyphenol yield: ultrasound-assisted extraction and antimicrobial potential of mango peel

This study investigated the ultrasound-assisted extraction (UAE) techniques used to enhance the polyphenols and antioxidants of mango peel extract (MPE). Additionally, it explored the bacteriostatic activity of MPE against various microorganisms. The UAE method was optimized using response surface methodology (RSM) at different times, temperatures, and ratios, with optimal conditions found to be 35 minutes, 45 °C, and a 1:35 ratio. The optimized yield results for total polyphenol content (TPC) were 17.33 ± 1.57 mg GAE/g, total flavonoid content (TFC) was 12.14 ± 0.29 mg QE/g, and radical scavenging activity (RSA) was 72.11 ± 2.19%. These response models were extremely significant with p-values less than 0.05. MPE showed selective effectiveness against Bacillus cereus, Geobacillus stearothermophilus, and Escherichia coli (E. coli). The results highlight the potential of mango peel as a sustainable source of bioactive compounds, contributing to waste reduction in the food industry and the development of natural antimicrobial agents. This study contributes to further research on the application of MPE in processed foods.

Ultrasound-assisted extraction and concentration of phenolic compounds from jabuticaba sabará (Plinia peruviana (Poir.) Govaerts) peel by nanofiltration membrane

Jabuticaba peel, rich in antioxidants, offering health benefits. In this study, the extraction of phenolic compounds from jabuticaba peel using ultrasound-assisted (UA) and their subsequent concentration by nanofiltration (NF) employing a polyamide 200 Da membrane was evaluated. The UA extractions were conducted using the Central Composite Rotatable Design (CCRD) 22 methodology, with independent variables extraction time (11.55 to 138 min) and temperature (16.87 to 53.3 °C), and fixed variables mass to ethanol solution concentration at pH 1.0 (1:25 g/mL), granulometry (1 mm), and ultrasonic power (52.8 W). The maximum concentrations obtained were 700.94 mg CE/100 g for anthocyanins, 945.21 mg QE/100 g for flavonoids, 133.19 mg GAE/g for phenols, and an antioxidant activity IC50 of 24.36 μg/mL. Key phenolic compounds identified included cyanidin-3-glucoside, delphinidin-3-glucoside, and various acids like syringic and gallic. NF successfully concentrated these compounds, enhancing their yield by up to 45%. UA and NF integrate for sustainable extraction.

Alginate beads loaded with rambutan extract: characterization and stability during in vitro gastrointestinal digestion

BACKGROUND

Fallen young rambutan fruit is an underrated agricultural waste which may contain several bioactive compounds. In this study, fallen young rambutan fruit was assessed regarding its phenolic contents and antioxidant activities. In order to expand its utilization, rambutan extract-loaded hydrogel beads were developed by a basic spherification technique using sodium alginate. The effect of ratios of polymer and extract and different calcium sources were evaluated. The recovery of bioactive compounds from the hydrogel beads was determined using in vitro gastrointestinal digestion models.

RESULTS

Use of 50% (v/v) ethanol yielded rambutan extract with good chemical properties. The production of hydrogel beads using a ratio of 1:3 with calcium lactate provided the highest production yield of 122.94%. The hydrogel beads developed using the ratio of 1:3 with a combination of calcium lactate and calcium chloride showed high recovery of phenolic compounds and antioxidant activity after simulated intestinal digestion, which were greater compared to unencapsulated extract.

CONCLUSION

The findings demonstrate that the ratio of wall material to rambutan extract and the calcium source influence the physical properties, chemical properties and in vitro gastrointestinal digestion stability of alginate beads. The obtained hydrogel beads may have potential for application in the food or pharmaceutical industries. © 2024 Society of Chemical Industry.

Implementation of RSM and ANN Optimization Approach for Natural Deep Eutectic Solvents-Based Extraction of Bioactive Compounds from Orange Peel

The present investigation has focused on developing an eco-friendly method to extract bioactive compounds from orange peel using natural deep eutectic solvents (NADES). NADES-II composed of choline chloride (ChCl) and ethylene glycol (1:2) and 50% water shows the maximal extraction yield with higher antioxidant activity in terms of DPPH and ABTS scavenging activity with a high total phenolic content (TPC) and total flavonoid content (TFC). The microwave-assisted extraction (MAE) process was optimized using response surface methodology (RSM) and an artificial neural network (ANN). ANN showed a higher value of R 2 and lower values of other statistical parameters when compared to RSM. The ideal extraction conditions were optimized as a 13 min rising time, 52 °C temperature, a 21 min holding time, and a 20 mL/g liquid-to-solid ratio. MAE was compared with the conventional heating-stirring extraction (HSE) method using the NADES-II solvent under optimum conditions. The results show that higher extraction yield and antioxidant capacities (DPPH and ABTS), TPC, and TFC can be obtained from orange peel using the MAE process compared to the HSE process. Overall, this study shows an optimiztic approach for the extraction of bioactive compounds from an orange peel using eco-friendly solvents and microwave technology. It also highlights the potential of this approach for valorizing orange peel waste.

Nitrophenols in the environment: An update on pretreatment and analysis techniques since 2017

Nitrophenols, a versatile intermediate, have been widely used in leather, medicine, chemical synthesis, and other fields. Because these components are widely applied, they can enter the environment through various routes, leading to many hazards and toxicities. There has been a recent surge in the development of simple, rapid, environmentally friendly, and effective techniques for determining these environmental pollutants. This review provides a comprehensive overview of the latest research progress on the pretreatment and analysis methods of nitrophenols since 2017, with a focus on environmental samples. Pretreatment methods include liquid-liquid extraction, solid-phase extraction, dispersive extraction, and microextraction methods. Analysis methods mainly include liquid chromatography-based methods, gas chromatography-based methods, supercritical fluid chromatography. In addition, this review also discusses and compares the advantages/disadvantages and development prospects of different pretreatment and analysis methods to provide a reference for further research.

Green Methods to Recover Bioactive Compounds from Food Industry Waste: A Sustainable Practice from the Perspective of the Circular Economy

The worrying and constant increase in the quantities of food and beverage industry by-products and wastes is one of the main factors contributing to global environmental pollution. Since this is a direct consequence of continuous population growth, it is imperative to reduce waste production and keep it under control. Re-purposing agro-industrial wastes, giving them new life and new directions of use, is a good first step in this direction, and, in global food production, vegetables and fruits account for a significant percentage. In this paper, brewery waste, cocoa bean shells, banana and citrus peels and pineapple wastes are examined. These are sources of bioactive molecules such as polyphenols, whose regular intake in the human diet is related to the prevention of various diseases linked to oxidative stress. In order to recover such bioactive compounds using more sustainable methods than conventional extraction, innovative solutions have been evaluated in the past decades. Of particular interest is the use of deep eutectic solvents (DESs) and compressed solvents, associated with green techniques such as microwave-assisted extraction (MAE), ultrasonic-assisted extraction (UAE), pressurized liquid extraction (PLE) and pulsed-electric-field-assisted extraction (PEF). These novel techniques are gaining importance because, in most cases, they allow for optimizing the extraction yield, quality, costs and time.

Valorisation of Agri-Food Waste for Bioactive Compounds: Recent Trends and Future Sustainable Challenges

Worldwide, a massive amount of agriculture and food waste is a major threat to the environment, the economy and public health. However, these wastes are important sources of phytochemicals (bioactive), such as polyphenols, carotenoids, carnitine, coenzymes, essential oils and tocopherols, which have antioxidant, antimicrobial and anticarcinogenic properties. Hence, it represents a promising opportunity for the food, agriculture, cosmetics, textiles, energy and pharmaceutical industries to develop cost effective strategies. The value of agri-food wastes has been extracted from various valuable bioactive compounds such as polyphenols, dietary fibre, proteins, lipids, vitamins, carotenoids, organic acids, essential oils and minerals, some of which are found in greater quantities in the discarded parts than in the parts accepted by the market used for different industrial sectors. The value of agri-food wastes and by-products could assure food security, maintain sustainability, efficiently reduce environmental pollution and provide an opportunity to earn additional income for industries. Furthermore, sustainable extraction methodologies like ultrasound-assisted extraction, pressurized liquid extraction, supercritical fluid extraction, microwave-assisted extraction, pulse electric field-assisted extraction, ultrasound microwave-assisted extraction and high hydrostatic pressure extraction are extensively used for the isolation, purification and recovery of various bioactive compounds from agri-food waste, according to a circular economy and sustainable approach. This review also includes some of the critical and sustainable challenges in the valorisation of agri-food wastes and explores innovative eco-friendly methods for extracting bioactive compounds from agri-food wastes, particularly for food applications. The highlights of this review are providing information on the valorisation techniques used for the extraction and recovery of different bioactive compounds from agricultural food wastes, innovative and promising approaches. Additionally, the potential use of these products presents an affordable alternative towards a circular economy and, consequently, sustainability. In this context, the encapsulation process considers the integral and sustainable use of agricultural food waste for bioactive compounds that enhance the properties and quality of functional food.

Trends in extracting Agro-byproducts' phenolics using non-thermal technologies and their combinative effect: Mechanisms, potentials, drawbacks, and safety evaluation

The agro-food industries generate significant waste with adverse effects. However, these byproducts are rich in polyphenols with diverse bioactivities. Innovative non-thermal extraction (NTE) technologies (Naviglio extractor®, cold plasma (CP), high hydrostatic pressure (HHP), pulse-electric field (PEF), ultrasound-assisted extraction (UAE), etc.) and their combinative effect (integrated UAE + HPPE, integrated PEF + enzyme-assisted extraction, etc.) could improve polyphenolic extraction. Hence, this article comprehensively reviewed the mechanisms, applications, drawbacks, and safety assessment of emerging NTE technologies and their combinative effects in the last 5 years, emphasizing their efficacy in improving agro-byproduct polyphenols' extraction. According to the review, incorporating cutting-edge NTE might promote the extraction ofmore phenolic extractfrom agro-byproducts due to numerous benefits,such as increased extractability,preserved thermo-sensitive phenolics, and low energy consumption. The next five years should investigate combined novel NTE technologies as they increase extractability. Besides, more research must be done on extracting free and bound phenolics, phenolic acids, flavonoids, and lignans from agro by-products. Finally, the safety of the extraction technology on the polyphenolic extract needs a lot of studies (in vivo and in vitro), and their mechanisms need to be explored.

Extracting bioactive compounds and proteins from Bacopa monnieri using natural deep eutectic solvents

This study employed novel extraction methods with natural deep eutectic solvents (NADES) to extract bioactive compounds and proteins from Bacopa monnieri leaves. The conditional influence of ultrasonic-assisted extraction (UAE), microwave-assisted extraction (MAE), and enzymatic-assisted extraction (EAE) on the recovery efficiency of phenolics, proteins, flavonoids, and terpenoids was evaluated. The conditions of UAE were 50 mL/g LSR, 600W of ultrasonic power, and 30% water content with 40°C for 1 min to obtain the highest bioactive compounds and protein contents. The conditions of MAE were 40 mL/g LSR, 400W of microwave power with 30% water content for 3 min to reach the highest contents of biological compounds. The conditions of EAE were 30 mL/g of LSR, 20 U/g of enzyme concentration with L-Gly-Na molar ratio at 2:4:1, and 40% water content for 60 min to acquire the highest bioactive compound contents. Scanning electron microscopy (SEM) is employed to analyze the surface of Bacopa monnieri leaves before and after extraction. Comparing seven extraction methods was conducted to find the most favorable ones. The result showed that the UMEAE method was the most effective way to exploit the compounds. The study suggested that UMEAE effectively extracts phenolics, flavonoids, terpenoids, and protein from DBMP.

Optimizing the ultrasonic extraction of polyphenols from mango peel and investigating the characteristics, antioxidant activity and storage stability of extract nanocapsules in maltodextrin/whey protein isolate

In this study, the extraction and nanoencapsulation of mango peel extract (MPE) were investigated to enhance its stability and preserve its antioxidant properties. Initially, using the central composite design (CCD)-response surface methodology (RSM), optimal conditions for the extraction of MPE via an ultrasonic system were determined to be a temperature of 10.53 °C, a time of 34.35 min, and an ethanol concentration of 26.62 %. Subsequently, the extracted extract was spray-dried and nanoencapsulated using three types of coatings: maltodextrin, whey protein isolate (WPI), and their combination. The results showed that nanoencapsulation led to a significant improvement in the stability of phenolic compounds in the extract during storage compared to free extract. Furthermore, capsules prepared with the combined coating exhibited the highest levels of phenolic compounds and antioxidant activity. Therefore, it can be concluded that nanoencapsulation can serve as an effective method for preserving the bioactive properties of MPE.

Ultrasound assisted phytochemical extraction of persimmon fruit peel: Integrating ANN modeling and genetic algorithm optimization

In the present study, ultrasound assisted extraction (UAE) of phytochemicals from persimmon fruit peel (PFP) was modeled using an artificial neural network (ANN) and optimized by integrating with genetic algorithm (GA). The range of process parameters selected for conducting the experiments was ultrasonication power (XU) 150---350 W, extraction temperatures (XT) 30---70 °C, solid to solvent ratio (XS) 1:15---1:35 g/ml, and ethanol concentration (XC) 40---80 %. The range of responses total phenolic content (YP), antioxidant activity (YA), total beta carotenoid (YB) and total flavonoid content (YF) at various independent variables combinations were found to be 7.72---24.62 mg GAE/g d.w., 51.44---85.58 %DPPH inhibition, 24.78---56.56 µg/g d.w. and 0.29---1.97 mg QE/g d.w. respectively. The modelling utilised an ANN architecture with a configuration of 4-12-4. The training process employed the Levenberg-Marquardt method, whereas the activation function chosen for the layers was the log sigmoid. The optimum condition predicted by the hybrid ANN-GA model for the independent variables, XU, XT, XS and XC was found to be 230.18 W, 50.66 °C, 28.27 g/ml, and 62.75 % respectively. The extraction process was carried out for 25 min, with 5-minute intervals, at various temperatures between 30 and 60 °C, to investigate the kinetic and thermodynamic characteristics of the process, under the optimal conditions of XU, XS and XC. The UAE of phytochemicals from persimmon peel followed pseudo second order kinetic model and the extraction process was endothermic in nature.

A comprehensive review of ultrasonic assisted extraction (UAE) for bioactive components: Principles, advantages, equipment, and combined technologies

The increasing focus on health and well-being has sparked a rising interest in bioactive components in the food, pharmaceutical, and nutraceutical industries. These components are gaining popularity due to their potential benefits for overall health. The growing interest has resulted in a continuous rise in demand for bioactive components, leading to the exploration of both edible and non-edible sources to obtain these valuable substances. Traditional extraction methods like solvent extraction, distillation, and pressing have certain drawbacks, including lower extraction efficiency, reduced yield, and the use of significant amounts of solvents or resources. Furthermore, certain extraction methods necessitate high temperatures, which can adversely affect certain bioactive components. Consequently, researchers are exploring non-thermal technologies to develop environmentally friendly and efficient extraction methods. Ultrasonic-assisted extraction (UAE) is recognized as an environmentally friendly and highly efficient extraction technology. The UAE has the potential to minimize or eliminate the need for organic solvents, thereby reducing its impact on the environment. Additionally, UAE has been found to significantly enhance the production of target bioactive components, making it an attractive method in the industry. The emergence of ultrasonic assisted extraction equipment (UAEE) has presented novel opportunities for research in chemistry, biology, pharmaceuticals, food, and other related fields. However, there is still a need for further investigation into the main components and working modes of UAEE, as current understanding in this area remains limited. Therefore, additional research and exploration are necessary to enhance our knowledge and optimize the application of UAEE. The core aim of this review is to gain a comprehensive understanding of the principles, benefits and impact on bioactive components of UAE, explore the different types of equipment used in this technique, examine the various working modes and control parameters employed in UAE, and provide a detailed overview of the blending of UAE with other emerging extraction technologies. In conclusion, the future development of UAEE is envisioned to focus on achieving increased efficiency, reduced costs, enhanced safety, and improved reliability. These key areas of advancement aim to optimize the performance and practicality of UAEE, making it a more efficient, cost-effective, and reliable extraction technology.

Advances in the Preparation, Stability, Metabolism, and Physiological Roles of Anthocyanins: A Review

Anthocyanins are natural flavonoid polyphenolic compounds widely found in fruits and vegetables. They exhibit antioxidant properties and prophylactic effects in the immune and cardiovascular systems, confer protection against cancer, and contribute to the prevention of cardiovascular diseases. Thus, their incorporation into functional foods, pharmaceuticals, supplements, and cosmetic formulations aims at promoting human well-being. This review comprehensively outlined the structural attributes of anthocyanins, expanding upon diverse methodologies employed for their extraction and production. Additionally, the stability, metabolic pathways, and manifold physiological functions of anthocyanins were discussed. However, their constrained fat solubility, susceptibility to instability, and restricted bioavailability collectively curtail their applicability and therapeutic efficacy. Consequently, a multidimensional approach was imperative, necessitating the exploration of innovative pathways to surmount these limitations, thereby amplifying the utilitarian significance of anthocyanins and furnishing pivotal support for their continual advancement and broader application.

Optimizing Ultrasonic-Assisted and Microwave-Assisted Extraction Processes to Recover Phenolics and Flavonoids from Passion Fruit Peels

This study optimized the ultrasonic-assisted extraction (UAE) and microwave-assisted extraction (MAE) processes to acquire phenolics and flavonoids from passion fruit peels using a mixture of ethanol, acetone, and water. An augmented simplex-centroid design was employed to find the suitable volume ratio among solvent ingredients to attain the highest extraction yield of phenolics and flavonoids. One-factor experiments were conducted to investigate the influence of UAE and MAE parameters on the recovery yield of phenolics and flavonoids before the two processes were optimized using Box-Behnken Design (BBD) models. The optimal UAE conditions for recovering phenolics and flavonoids from passion fruit peel powder (PFP) were 28 mL/g of liquid-to-solid ratio (LSR), 608 W of ultrasonic power, and 63 °C for 20 min to acquire total phenolic content (TPC) and total flavonoid content (TFC) at 39.38 mg of gallic acid equivalents per gram of dried basis (mg GAE/g db) and 25.79 mg of rutin equivalents per gram of dried basis (mg RE/g db), respectively. MAE conditions for attaining phenolics and flavonoids from PFP were 26 mL/g of LSR and 606 W of microwave power for 2 min to recover TPC and TFC at 17.74 mg GAE/g db and 8.11 mg RE/g db, respectively. The second-order kinetic model was employed to determine the UAE and MAE mechanism of TPC and TFC and the thermodynamic parameters of the extraction processes. The antioxidant activities of passion fruit peel extracts at optimal conditions were examined to compare the efficiency of UAE and MAE. This study establishes an effective approach for obtaining phenolics and flavonoids from passion fruit peels.

The Most Potent Natural Pharmaceuticals, Cosmetics, and Food Ingredients Isolated from Plants with Deep Eutectic Solvents

There is growing interest in reducing the number of synthetic products or additives and replacing them with natural ones. The pharmaceutical, cosmetic, and food industries are especially focused on natural and bioactive chemicals isolated from plants or microorganisms. The main challenge here is to develop efficient and ecological methods for their isolation. According to the strategies and rules of sustainable development and green chemistry, green solvents and environmentally friendly technologies must be used. The application of deep eutectic solvents as efficient and biodegradable solvents seems to be a promising alternative to traditional methods. They are classified as being green and ecological but, most importantly, very efficient extraction media compared to organic solvents. The aim of this review is to present the recent findings on green extraction, as well as the biological activities and the possible applications of natural plant ingredients, namely, phenolics, flavonoids, terpenes, saponins, and some others. This paper thoroughly reviews modern, ecological, and efficient extraction methods with the use of deep eutectic solvents (DESs). The newest findings, as well as the factors influencing the efficiency of extraction, such as water content, and hydrogen bond donor and acceptor types, as well as the extraction systems, are also discussed. New solutions to the major problem of separating DESs from the extract and for solvent recycling are also presented.

Effect of Microwave and Ultrasound-Assisted Extraction on the Phytochemical and In Vitro Biological Properties of Willow (Salix alba) Bark Aqueous and Ethanolic Extracts

White willow (Salix alba) is a medicinal plant used in folk medicine. In this study, aqueous and ethanolic willow bark extracts were obtained via ultrasonic-assisted extraction (UAE) and microwave-assisted extraction (MAE), and analyzed regarding their phytochemical (total phenolics, phenolic acids, flavonoids, and tannins) content and in vitro biological properties (antibacterial and antifungal activity, acetylcholinesterase AChE inhibitory activity and anti-inflammatory effects). The highest phenolic, tannin, and flavonoid contents were found for willow bark extracts obtained via microwave-assisted extraction using ethanol as a solvent (SA-ME). The polyphenol load of all MAE and UAE extracts was higher when conventional solid-liquid extraction was applied (ρ < 0.05). The antioxidant capacities were stronger for microwave-assisted ethanolic extracts, with the lowest IC₅₀ values of 12 μg/mL for DPPH^• and a value of 16 μg/mL for ABTS•+, whereas the conventional extraction had the highest IC₅₀ values (22 μg/mL and 28 μg/mL, respectively). Willow bark extract showed antibacterial activity against Gram-positive bacteria S. aureus and P. aeruginosa. AChE inhibitory activity was dependent on the extraction method and solvent used, and the highest inhibition among samples was observed for SA-ME. Taken altogether, our findings suggest that willow (Salix alba) bark extract obtained via ethanolic microwave-assisted extraction is a phytochemical-rich resource with in vitro, anti-inflammatory, and AchE inhibitory properties and, therefore, potential multiple medicinal end-uses.

Fenugreek bioactive compounds: A review of applications and extraction based on emerging technologies

Fenugreek (Trigonella foenum-graecum L.) is a pharmaceutically significant aromatic crop with health benefits linked to its phytochemicals. This article aims to overview progress in using emerging technologies to extract its bioactive compounds and extraction mechanisms. Also, the trends in the applications of this herb in the food industry and its therapeutical effects were explained. Fenugreek's flavor is the primary reason for its applications in the food industry. At the same time, it has antimicrobial, antibacterial, hepatoprotection, anticancer, lactation, and antidiabetic effects. Phytochemicals responsible for these effects include galactomannans, saponins, alkaloids, and polyphenols. Besides, data showed that emerging technologies boost fenugreek extracts' yield and biological activity. Among these, ultrasound (55.6%) is the most studied technology, followed by microwave (37.0%), cold plasma (3.7%), and combined approaches (3.7%). Processing conditions (e.g., treatment time and intensity) and solvent (type, ratio, and concentration) are significant parameters that affect the performance of these novel extraction technologies. Extracts obtained by sustainable energy-saving emerging technologies can be used to develop value-added health-promoting products.

Ultrasonic-assisted extraction for phenolic compounds and antioxidant activity of Moroccan Retama sphaerocarpa L. leaves: Simultaneous optimization by response surface methodology and characterization by HPLC/ESI-MS analysis

This study was designed to optimize the ultrasound-assisted extraction of phenolic compounds and the antioxidant activity of Moroccan Retama sphaerocarpa extracts using response surface methodology (RSM). A central composite design has been conducted to investigate the effects of three factors: extraction period (X₁), solvent concentration (X₂), and solvent-to-material ratio (X₃) on extraction yield, total phenolic content (TPC), flavonoids content (TFC), and antioxidant activity. The obtained results showed that the experimental values agreed with the predicted ones, confirming the capacity of the used model for optimizing the extraction conditions. The best extraction conditions for the simultaneous optimization were an extraction time of 38 min, a solvent concentration of 58%, and a solvent-to-material ratio of 30 mL/g. Under these conditions, the optimized values of yield, TPC, TFC, and DPPH-radical scavenging activity (DPPH_IC50) were 18.91%, 154.09 mg GAE/g, 23.76 mg QE/g, and 122.47 μg/mL, respectively. The further HPLC/ESI-MS analysis of the obtained optimized extract revealed the presence of 14 phenolic compounds with piscidic acid, vitexin, and quinic acid as major compounds. These research findings indicate promising applications for efficiently extracting polyphenolic antioxidants, especially in the food industry.

Waste Orange Peels as a Source of Cellulose Nanocrystals and Their Use for the Development of Nanocomposite Films

To date, approximately 30-50% of food is wasted from post-harvesting to consumer usage. Typical examples of food by-products are fruit peels and pomace, seeds, and others. A large part of these matrices is still discarded in landfills, while a small portion is valorized for bioprocessing. In this context, a feasible strategy to valorize food by-products consists of their use for the production of bioactive compounds and nanofillers, which can be further used to functionalize biobased packaging materials. The focus of this research was to create an efficient methodology for the extraction of cellulose from leftover orange peel after juice processing and for its conversion into cellulose nanocrystals (CNCs) for use in bionanocomposite films for packaging materials. Orange CNCs were characterized by TEM and XRD analyses and added as reinforcing agents into chitosan/hydroxypropyl methylcellulose (CS/HPMC) films enriched with lauroyl arginate ethyl (LAE). It was evaluated how CNCs and LAE affected the technical and functional characteristics of CS/HPMC films. CNCs revealed needle-like shapes with an aspect ratio of 12.5, and average length and width of 500 nm and 40 nm, respectively. Scanning electron microscopy and infrared spectroscopy confirmed the high compatibility of the CS/HPMC blend with CNCs and LAE. The inclusion of CNCs increased the films' tensile strength, light barrier, and water vapor barrier properties while reducing their water solubility. The addition of LAE improved the films' flexibility and gave them biocidal efficacy against the main bacterial pathogens that cause foodborne illness, such as Escherichia coli, Pseudomonas fluorescens, Listeria monocytogenes, and Salmonella enterica.

Optimization of Ultrasound- and Microwave-Assisted Extraction for the Determination of Phenolic Compounds in Peach Byproducts Using Experimental Design and Liquid Chromatography-Tandem Mass Spectrometry

The conversion of plant byproducts, which are phenolic-rich substrates, to valuable co-products by implementing non-conventional extraction techniques is the need of the hour. In the current study, ultrasound- (UAE) and microwave-assisted extraction (MAE) were applied for the recovery of polyphenols from peach byproducts. Two-level screening and Box-Behnken design were adopted to optimize extraction efficiency in terms of total phenolic content (TPC). Methanol:water 4:1% v/v was the extraction solvent. The optimal conditions of UAE were 15 min, 8 s ON-5 s OFF, and 35 mL g^-1, while MAE was maximized at 20 min, 58 °C, and 16 mL g^-1. Regarding the extracts' TPC and antioxidant activity, MAE emerged as the method of choice, whilst their antiradical activity was similar in both techniques. Furthermore, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated to determine chlorogenic acid and naringenin in byproducts' extracts. 4-Chloro-4'-hydroxybenzophenone is proposed as a new internal standard in LC-MS/MS analysis in foods and byproducts. Chlorogenic acid was extracted in higher yields when UAE was used, while MAE favored the extraction of the flavonoid compound, naringenin. To conclude, non-conventional extraction could be considered as an efficient and fast alternative for the recovery of bioactive compounds from plant matrices.

Polymethoxyflavones from citrus peel: advances in extraction methods, biological properties, and potential applications

Citrus peel, as an effective component of citrus by-products, contains a large number of natural active components, including pectin, vitamins, dietary fiber, essential oil, phenolic compounds, flavonoids, and so on. With the development of the circular economy, citrus peel has attracted extensive concern in the food industry. The exploitation of citrus peel would assist in excavating potential properties and alleviating the environmental burden. Polymethoxyflavones (PMFs) exist almost in citrus peel, which have remarkable biological activities including antioxidant, anti-inflammatory, anti-cancer, and anti-obesity. Therefore, PMFs from citrus peel have the potential to develop as dietary supplements in the near future. Collectively, it is essential to take action to optimize the extraction conditions of PMFs and make the most of the extracts. This review mainly compiles several extraction methods and bioactivities of PMFs from citrus peel and introduces different applications including food processing, pharmaceutical industry, and plant rhizosphere to develop better utilization of citrus PMFs.

Extraction of phenolics and anthocyanins from purple eggplant peels by multi-frequency ultrasound: Effects of different extraction factors and optimization using uniform design

In this work, multi-frequency ultrasound (working modes for the single-, dual- and tri-frequency in simultaneous ways) was applied to extract bioactive compounds from purple eggplant peels. The single-factor experiments were performed by varying six independent variables. A six-level-five-factor uniform design (UD) was further employed to evaluate the interaction effects between different factors. It was found that extraction temperature and extraction time significantly affected the total phenolic content (TPC), whereas the total monomeric anthocyanins (TMA) was mainly influenced by ethanol concentration, extraction temperature and solid-liquid ratio. Based on partial least-squares (PLS) regression analysis, the optimal conditions for TPC extraction were: 53.6 % ethanol concentration, 0.336 mm particle size, 44.5 °C extraction temperature, 35.2 min extraction time, 1:43 g/mL solid-liquid ratio, and similar optimal conditions were also obtained for TMA. Furthermore, the TPC and TMA extraction were investigated by ultrasound in different frequencies and power levels. Compared with single-frequency (40 kHz) and dual-frequency ultrasound (25 + 40 kHz), the extraction yield of TPC and TMA with tri-frequency ultrasound (25 + 40 + 70 kHz) increased by 23.65 % and 18.76 % respectively, which suggested the use of multi-frequency ultrasound, especially tri-frequency ultrasound, is an efficient strategy to improve the TPC and TMA extracts in purple eggplant peels.

Optimization of ultrasound-assisted extraction of phenolic content & antioxidant activity of hog plum (Spondias pinnata L. f. kurz) pulp by response surface methodology

Background

The pulp of hog plum (Spondias pinnata L. f. kurz) has been documented as a potential source of nutritional, physiological, and pharmacological purposes due to its phenolic content (TPC) and antioxidant activity. However, an optimal extraction condition for hog plum pulp remains elusive. Optimization of extraction process conditions using Ultrasound-assisted extraction (UAE) technique has recently attracted research interest.

Objectives

The present study focused on optimizing the UAE extraction conditions of TPC and antioxidant activities (DPPH and FRAP) from hog plum pulp by using response surface methodology (RSM).

Methods

The RSM with a three-factor-three-level Box-Behnken design (BBD) was used to optimize the extraction conditions. The BBD was used to investigate the effects of three independent variables, X₁: ultrasonic temperature (40–60 °C), X₂: ultrasonic time (30–60 min), and X₃: ethanol concentration (40–80%) on TPC, DPPH and FRAP assays. Fifteen experimental trials have been carried out to optimize the UAE extraction conditions. A second-order polynomial model was used for predicting the responses. Statistically, the model was validated using an analysis of variance (ANOVA).

Results

The ANOVA results revealed that UAE extraction temperature, time, and ethanol concentration had a significant (p < 0.01) influence on the TPC, DPPH, and FRAP, suggesting that all extraction parameters included in this investigation were crucial to the optimization process. For TPC, DPPH, and FRAP, the R² values were 0.9976, 0.9943, and 0.9989, respectively, indicating that the models developed based on second-order polynomials were satisfactorily accurate for analyzing interactions between parameters (response and independent variables). RSM analysis showed that the optimal extraction parameters which maximized TPC, DPPH, and FRAP were 52.03 °C temperature, 30 min, time, and 79.99% ethanol. Under optimal conditions, experimental values for TPC, DPPH, and FRAP were 370 ± 26 mg GAE/100g DM, 57 ± 7%, and 7650 ± 460 mg AAE/100 g DM, respectively. The experimental values showed a good agreement with the predicted values with residual standard error values below 0.2% under optimum conditions. Pearson's correlation coefficients (r) demonstrate that the TPC showed a weak positive correlation with DPPH (r = 0.3508) and moderate correlation with FRAP (r = 0.3963).

Conclusion

The experimental results agreed with the predicted values, confirming the model's appropriateness and RSM's efficacy in optimizing the UAE extraction conditions. This optimized UAE extraction method may be effective in the industrial extraction process; moreover, further research should be conducted to determine the efficacy of these extracts when applied to food.

Understanding the effects of ultrasound processng on texture and rheological properties of food

The demand for the production of high quality and safe food products has been ever increasing. Consequently, the industry is looking for novel technologies in food processing operations that are cost-effective, rapid and have a better efficiency over traditional methods. Ultrasound is well-known technology to enhance the rate of heat and mass transfer providing a high end-product quality, at just a fraction of time and energy normally required for conventional methods. The irradiation of foods with ultrasound creates acoustic cavitation that has been used to cause desirable changes in the treated products. The technology is being successfully used in various unit operations such as sterilization, pasteurization, extraction, drying, emulsification, degassing, enhancing oxidation, thawing, freezing and crystallization, brining, pickling, foaming and rehydration, and so forth. However, the high pressure and temperature associated with the cavitation process is expected to induce some changes in the textural and rheological properties of foods which form an important aspect of product quality in terms of consumer acceptability. The present review is aimed to focus on the effects of ultrasound processing on the textural and rheological properties of food products and how these properties are influenced by the process variables.

Optimized Cellulase-Hydrolyzed Deoiled Coconut Cake Powder as Wheat Flour Substitute in Cookies

Deoiled coconut cake powder (DCCP) was hydrolyzed to reduce the ratio of insoluble/soluble dietary fiber (RIS) by partially converting insoluble dietary fiber to soluble using Celluclast 1.5 L, a commercial cellulase preparation in citrate buffer medium. Firstly, the influence of citrate buffer amount, enzyme concentration, pH, and retention time on the enzymatic hydrolysis efficiency was investigated. Then, response surface methodology (RSM) was employed to optimize the process in which the insoluble and soluble dietary fiber contents were the responses. The results revealed that 10.3 g buffer/g of materials, 3.7 U/g of the materials, and 60 min of retention time were the optimal conditions for the enzymatic hydrolysis to obtain the insoluble and soluble contents of 68.21%db and 8.18%db, respectively. Finally, DCCP or hydrolyzed DCCP (HDCCP) was partially substituted for wheat flour at different replacement ratios in a cookie recipe at 0, 10, 20, 30, and 40%. The cookies with a 10% replacement ratio of hydrolyzed deoiled coconut cake powders had a lower RIS by more than two folds those of DCCP and had the same sensorial score as the control sample. This study proposed that Celluclast 1.5 L effectively reduced RIS by partially converting insoluble to soluble dietary fiber, improving the soluble dietary fiber content in fiber-enriched cookies.

Extract of Murraya koenigii selectively causes genomic instability by altering redox-status via targeting PI3K/AKT/Nrf2/caspase-3 signaling pathway in human non-small cell lung cancer

BACKGROUND

Lung cancer is the leading cause of cancer-related death worldwide. Dietary bioactives have been used as alternative therapeutics to overcome various adverse effects caused by chemotherapeutics. Curry leaves are a widely used culinary spice and different parts of this plant have been used in traditional medicines. Curry leaves are a rich source of multiple bioactives, especially polyphenols and alkaloids. Therefore, extraction processes play a key role in obtaining the optimum yield of bioactives and their efficacy.

PURPOSE

We aim to select an extraction process that achieves the optimum yield of bioactives in curry leaves crude extract (CLCE) with minimum solvent usage and in a shorter time. Further, to investigate the anticancer properties of CLCE and its mechanism against lung cancer.

METHODS

Different extraction processes were performed and analyzed polyphenol content. The bioactives and essential oils present in curry leaves were identified through LC-MS/MS and GC-MS analysis. The cytotoxicity of microwave-assisted CLCE (MA-CLCE) was investigated through MTT and colony-forming assays. The DNA damage was observed by comet assay. The apoptotic mechanisms of MA-CLCE were investigated by estimating ROS production, depolarization of mitochondrial membrane potential (MMP), and apoptotic proteins. The glutathione assay estimated the antioxidant potential of MA-CLCE in normal cells.

RESULTS

Generally, conventional extraction methods require high temperatures, extra energy input, and time. Recently, green extraction processes are getting wider attention as alternative extraction methods. This study compared different extraction processes and found that the microwave-assisted extraction (MAE) method yields the highest polyphenols from curry leaves among other extraction processes with minimum processing. The MA-CLCE functions as an antioxidant under normal physiological conditions but pro-oxidant to cancer cells. MA-CLCE scavenges free radicals and enhances the intracellular GSH level in alveolar macrophages in situ. We found that MA-CLCE selectively inhibits cell proliferation and induces apoptosis in cancer cells by altering cellular redox status. MA-CLCE induces chromatin condensation and genotoxicity through ROS-induced depolarization of MMP. The depolarization of MMP causes the release of cytochrome c into the cytosol and activates the apoptotic pathway in lung cancer cells. However, pretreatment with ascorbic acid, an antioxidant, inhibits the MA-CLCE-induced apoptosis by reducing ROS production, which impedes mitochondrial membrane disruption, preventing BAX/BCL-2 expression alteration. Simultaneously, MA-CLCE downregulates the expression of survival signaling regulator PI3K/AKT, which modulates Nrf-2. MA-CLCE also diminishes intracellular antioxidant proficiency by suppressing Nrf-2 expression, followed by HO-1 expressions.

CONCLUSION

Among several extraction methods, MA-CLCE is rich in several bioactives, especially polyphenols, alkaloids, and essential oils. Here, we reported for the first time that MA-CLCE functions as a pro-oxidant to lung cancer cells and acts as an antioxidant to normal cells by regulating different cellular programs and signaling pathways. Therefore, it can be further developed as a promising phytomedicine against lung cancer.

Optimization of the ultrasonic-assisted extraction process to obtain total phenolic and flavonoid compounds from watermelon (Citrullus lanatus) rind

This context presents the study of ultrasonic-assisted extraction (UAE) to obtain phenolic and flavonoid compounds from watermelon rind powder (WRP). The antioxidant activity of the extracts was investigated using DPPH and ABTS⁺ assays. One-factor experiments were conducted to examine the effect of each factor (solid-to-liquid ratio (SLR), acetone concentration (AC), temperature, and time) on the UAE of WRP. Box-Behnken Design (BDD) model was employed to optimize the UAE conditions based on total phenolic contents (TPC), total flavonoid content (TFC), and their antioxidant activities. The optimal conditions were 1:30.50 SLR, 70.71% AC, 29.78 °C, and 10.65 min extraction time. There were no significant differences between predicted and experimental results (less than 6.0%), recommending a feasible and innovative process of deploying UAE to extract phenolics and flavonoids effectively from watermelon rind.

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Sonication increases the extraction of total phenolic and flavonoid contents.

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Sonication increases the antioxidant activity of watermelon rind extracts.

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Box-Behnken Design model is used to optimize ultrasonic-assisted extraction conditions.

Valorization of Food Processing Waste to Produce Valuable Polyphenolics

Traditional incineration and landfill of food processing waste (FPW) have polluted the environment and underutilized valuable bioactive compounds, including polyphenols in food waste. As one of the most widely occurring compounds in the FPW, polyphenols possess high utilization value in many fields such as human health, energy, and environmental protection. Extracting polyphenols directly from FPW can maximize the value of polyphenols and avoid waste of resources. However, traditional polyphenol extraction methods mostly use the Soxhlet extraction, infiltration, and impregnation method, consuming a large amount of organic solvent and suffering from long extraction time and low extraction efficiency. Emerging green extraction methods such as supercritical fluid extraction, ultrasonic-assisted extraction, microwave-assisted extraction, and other methods can shorten the extraction time and improve the solvent extraction efficacy, resulting in the green and safe recovery of polyphenols from FPW. In this paper, the traditional treatment methods of FPW waste and the application of polyphenols in FPW are briefly reviewed, and the traditional extraction methods and emerging green extraction methods of polyphenols in FPW are compared to obtain insight into the start-of-the-art extraction approaches.

Antioxidant Effect of Nanoparticles Composed of Zein and Orange (Citrus sinensis) Extract Obtained by Ultrasound-Assisted Extraction

In the present research, an orange extract (OE) was obtained and encapsulated in a zein matrix for its subsequent physicochemical characterization and evaluation of its antioxidant capacity. The OE consists of phenolic compounds and flavonoids extracted from orange peel (Citrus sinensis) by ultrasound-assisted extraction (UAE). The results obtained by dynamic light scattering (DLS) and scanning electron microscopy (SEM) indicated that zein nanoparticles with orange extract (NpZOE) presented a nanometric size and spherical shape, presenting a hydrodynamic diameter of 159.26 ± 5.96 nm. Furthermore, ζ-potential evolution and Fourier transform infrared spectroscopy (FTIR) techniques were used to evaluate the interaction between zein and OE. Regarding antioxidant activity, ABTS and DPPH assays indicated no significant differences at high concentrations of orange peel extract and NpZOE; however, NpZOE was more effective at low concentrations. Although this indicates that ultrasonication as an extraction method effectively obtains the phenolic compounds present in orange peels, the nanoprecipitation method under the conditions used allowed us to obtain particles in the nanometric range with positive ζ-potential. On the other hand, the antioxidant capacity analysis indicated a high antioxidant capacity of both OE and the NpZOE. This study presents the possibility of obtaining orange extracts by ultrasound and coupling them to zein-based nanoparticulate systems to be applied as biomedical materials functionalized with antioxidant substances of pharmaceutical utility.

Current extraction methods and potential use of essential oils for quality and safety assurance of foods

Essential oils (EOs) or vegetable oils have become the focus of several studies because of their interesting bioactive properties. Their application has been successfully explored in active packaging, edible coatings, and as natural flavoring to extend the shelf life of various types of food products. In addition, alternative methods of extraction of EOs (ultrasound-assisted extraction, microwave-assisted extraction, pressurized liquid extraction and supercritical fluid extraction) have been shown to be more attractive than traditional methods since they present better efficiency, shorter extraction times and do not use toxic solvents. This review paper provides a concise and critical view of extraction methods of EOs and their application in food products. The researchers involved in the studies approached in this review were motivated mainly by concern about food quality. Here, we recognize and discuss the major advances and technologies recently used to enable shelf life extension of food products.

Antimicrobial Properties of Bacterial Cellulose Films Enriched with Bioactive Herbal Extracts Obtained by Microwave-Assisted Extraction

The use of bacterial cellulose (BC) as scaffold for active biofilms is one of the most interesting applications, especially for the biomedical and food industries. However, there are currently few studies evaluating the potential of incorporating herbal extracts into various biomaterials, including BC. Thus, the aim of this study is to report a screening of the total phenolic content and antioxidant and antimicrobial activity of ethanolic extracts of oregano, rosemary, parsley, and lovage. At the same time, the bioactive potential of BC enriched with the four ethanolic extracts is described. Microwave-assisted extraction was used to extract bioactive compounds from the four selected herbs. The physical, mechanical, structural, and chemical properties of BC were also assessed. Next, BC was enriched with the extracts, and their effect against Escherichia coli, Staphylococcus aureus, and Candida albicans was evaluated. The results showed that the bioactivity of the herbs varied significantly, with rosemary extract being the most bioactive. The BC films possessed good mechanical properties, and a three-dimensional network fibrillar structure appropriate for ethanolic-extract incorporation. The BC samples enriched with rosemary extracts had the highest antibacterial activity against S. aureus, while E. coli. and C. albicans seemed to be resistant to all extracts, regardless of herbs.

Polysaccharides as wall materials in spray-dried microencapsulation of bioactive compounds: Physicochemical properties and characterization

Natural bioactive compounds (BCs) are types of chemicals found in plants and certain foods that promote good health, however they are sensitive to processing and environmental conditions. Microencapsulation by spray drying is a widely used and cost-effective approach to create a coating layer to surround and protect BCs and control their release, enabling the production of high functional products/ingredients with extended shelf life. In this process, wall materials determine protection efficiency, and physical properties, bioavailability, and storage stability of microencapsulated products. Therefore, an understanding of physicochemical properties of wall materials is essential for the successful and effective spray-dried microencapsulation process. Typically, polysaccharide-based wall materials are generated from more sustainable sources and have a wider range of physicochemical properties and applications compared to their protein-based counterparts. In this review, we highlight the essential physicochemical properties of polysaccharide-based wall materials for spray-dried microencapsulation of BCs including solubility, thermal stability, and emulsifying properties, rheological and film forming properties. We provide further insight into possibilities for the chemical structure modification of native wall materials and their controlled release behaviors. Finally, we summarize the most recent studies involving polysaccharide biopolymers as wall materials and/or emulsifiers in spray-dried microencapsulation of BCs.

Review on the extraction of bioactive compounds and characterization of fruit industry by-products

The by-products produced from fruit processing industries could be a potential hazard to environmental pollution. However, these by-products contain several biologically active molecules (essential fatty acid, phenolic compounds, flavonoids, coloring pigments, pectin, proteins, dietary fibers, and vitamins), which can be utilized for various applications in the food, pharmaceutical, cosmetic and textile industries. Nevertheless, during extraction, these bioactive compounds' recovery must be maximized using proper extraction technologies, keeping both economy and environment under consideration. In addition, the characteristics of the extract obtained from those by-products depend mainly on the parameters considered during the extraction process. In this review, an overview of different technologies used to extract bioactive compounds from fruit industry by-products such as seeds and peels has been briefly discussed, along with their mechanisms, process, advantages, disadvantages, and process parameters. In addition, the characteristics of the extracted bioactive compounds have also been briefly discussed in this review.

Environmentally Friendly Techniques for the Recovery of Polyphenols from Food By-Products and Their Impact on Polyphenol Oxidase: A Critical Review

Even though food by-products have many negative financial and environmental impacts, they contain a considerable quantity of precious bioactive compounds such as polyphenols. The recovery of these compounds from food wastes could diminish their adverse effects in different aspects. For doing this, various nonthermal and conventional methods are used. Since conventional extraction methods may cause plenty of problems, due to their heat production and extreme need for energy and solvent, many novel technologies such as microwave, ultrasound, cold plasma, pulsed electric field, pressurized liquid, and ohmic heating technology have been regarded as alternatives assisting the extraction process. This paper highlights the competence of mild technologies in the recovery of polyphenols from food by-products, the effect of these technologies on polyphenol oxidase, and the application of the recovered polyphenols in the food industry.

Eco-friendly approach towards isolation of colorant from Esfand for bio-mordanted silk dyeing

Sustainability in all applied fields particularly in textiles is to protect our globe, environment, and community, where green dyed products are playing their role. For the current study, Esfand (Peganum harmala) has been explored using a green isolation tool, i.e., ultrasonic (U.S.) rays, and applied onto fabric. Different dyeing parameters have been explored statistically through response surface methodology by employing temperature (50-80°C), time (25-65 min), extract volume (15-55 mL), salt (1-5 g/100 mL), and dye bath pH (4-7) through series of experiments. For developing new shades, green mordants such as elaichi, neem, turmeric, and zeera have been utilized. It has been found that exposure of 35 mL extract of 7 pH containing 3 g/100 mL of salt as exhausting agent to U.S. rays for 30 min for the dyeing of silk at 70°C for 45 min has given maximum color strength with reddish-yellow shades. Color characteristics obtained in the CIE Lab system reveal that 5% of turmeric as meta bio-mordant has given good quality reddish-yellow shades. It is found that U.S. rays have not only good potential to isolate colorant followed by dyeing of silk under reduced condition but also the application of bio-mordants have made the process more greener, sustainable, and cleaner.

Profiling of Phenolic Compounds of Fruit Peels of Different Ecotype Bananas Derived from Domestic and Imported Cultivars with Different Maturity

Banana is one of the most produced and consumed fruits in the world and its fruit peel accounts for about 40% of the total fresh quantity of ripe fruit, which is usually regarded as waste and poses serious environmental hazards. However, it is a promising source of natural bioactive compounds including phenolic compounds. Determination of the phenolic compounds in fruit peel from different cultivars and subgroups over a range of maturities provides convincing information for making full use of them. This study developed a sensitive and reliable analytical method—ultra-high performance liquid chromatography—coupled with electrospray ionization tandem mass spectrometry (UPLC-MS/MS) for measuring phenolic compounds in fruit peel from different ecotype cultivars and subgroups with different maturity. The results showed that quinic acid had the highest concentration ratio among the main phenolic compounds in the green/ripe peel of all banana cultivars; among all banana cultivars, the total phenolic compound contents of green banana peel were significantly higher than that of ripe banana peel; the total phenolic compound contents in the green/ripe fruit peel of non-dessert bananas were significantly higher than that of dessert bananas (green: non-dessert banana 1.48 ± 0.44 mg/g vs. dessert banana 0.97 ± 0.12 mg/g; ripe: non-dessert banana 0.26 ± 0.13 mg/g vs. dessert banana 0.19 ± 0.06 mg/g). These data provide a basis for the rational utilization of phenolic compound extractions from banana peel with huge biomass in the next step.

Valorization of Taiwan's Citrus depressa Hayata peels as a source of nobiletin and tangeretin using simple ultrasonic-assisted extraction

As the highest yield crop worldwide, citrus peels that possess bioactive compounds were discarded as a futile by-product. Ultrasonication with environmentally friendly solvent (50% ethanol and ddH₂O) were used in the present study to extract flavonoids from Citrus depressa Hayata peels with extraction period and fruit maturity as other variables. DPPH scavenging activity was investigated. Qualitative flavonoid content analysis was done by UV/Vis and FTIR-ATR spectra. Quantification of flavonoid using LC-MS/MS found that solvent type, fruit maturity, and ultrasonication period significantly affect the extracted flavonoid yield (p < 0.05). Extraction using 50% ethanol showed a higher yield than ddH₂O. Flavonoid content was also higher in unripe than ripe samples. Nobiletin, tangeretin, and rutin were dominant among the identified compounds in all sample treatments. Flavonoid content in Citrus depressa Hayata extract was found to negatively correlate to DPPH scavenging activity, which needs further research to identify other bioactivities of these flavonoids.

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Utilization of simple ultrasonication method with less preparation to extract flavonoids from Citrus depressa Hayata peels.

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Fruit maturity, extraction time and solvent preference significantly affect the yield of extracted flavonoid.

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Environmentally friendly solvent for extraction, deliver a comparable yield of flavonoid compounds to other methods.

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The negative correlation of extracted flavonoid to DPPH scavenging activity.

Optimization of Commercial Microwave Assisted-Extraction Conditions for Recovery of Phenolics from Lemon-Scented Tee Tree (Leptospermum petersonii) and Comparison with Other Extraction Techniques

The lemon-scented tea tree (LSTT) is an Australian native herb and is a rich source of essential oil and phenolics. The ETHOS X extraction system is known as a commercial microwave-assisted extraction (MAE) system for extracting bioactive compounds from plant materials. This study investigated the influence of soaking time, radiation time, microwave power, and sample to solvent ratio on the extraction efficiency of polyphenols and antioxidant properties from lemon-scented tea tree leaves and optimized the extraction conditions using response surface methodology (RSM). The effectiveness of ETHOS X was further compared with ultrasound-assisted extraction (UAE) and shaking water bath (SWB) techniques. The results revealed that soaking time did not significantly affect the recovery of phenolics from the leaves (p > 0.05). Thus, soaking is not required for the ETHOS X extraction of polyphenols from LSTT leaves. RSM was successfully applied to explore the impact of ETHOS X extraction conditions and optimize the extraction conditions. Radiation time significantly affects the recovery yield of phenolics (p < 0.05) positively, whereas irradiation power and sample to solvent ratio adversely influenced the extraction yields of phenolics. The optimal ETHOS X extraction conditions were: radiation time of 60 min, irradiation power of 600 W, and sample to solvent ratio of 2 g/100 mL. Under these conditions, 119.21 ± 7.09 mg of phenolic, 85.31 ± 4.55 mg of flavonoids, and 137.51 ± 12.52 mg of proanthocyanidins can be extracted from a gram of dried LSTT leaves. In comparison with UAE and SWB, ETHOS X is not more effective for the extraction of phenolics than UAE and SWB. However, this technique can save half of the solvent volume compared to UAE and SWB techniques.

Influence of the extraction method on the recovery of bioactive phenolic compounds from food industry by-products

Agro-foodindustries generate colossal amounts of non-edible waste and by-products, easily accessible as raw materials for up-cycling active phytochemicals. Phenolic compounds are particularly relevant in this field given their abundance in plant residues and the market interest of their functionalities (e.g. natural antioxidant activity) as part of nutraceutical, cosmetological and biomedical formulations. In "bench-to-bedside" achievements, sample extraction is essential because valorization benefits from matrix desorption and solubilization of targeted phytocompounds. Specifically, the composition and polarity of the extractant, the optimal sample particle size and sample:solvent ratio, as well as pH, pressure and temperature are strategic for the release and stability of mobilized species. On the other hand, current green chemistry environmental rules require extraction approaches that eliminate polluting consumables and reduce energy needs. Thus, the following pages provide an update on advanced technologies for the sustainable and efficient recovery of phenolics from plant matrices.

Chemical Characterization of Coffee Husks, a By-Product of Coffea arabica Production

Coffee husks are a major by-product of coffee production and are currently being underutilized. The aim of this work was to chemically characterize coffee husks to allow for an adequate evaluation of their potential for valorization. Blanched and non-blanched coffee husks were characterized for extractable and non-extractable phenolics, caffeine, trigonelline content, and for their polysaccharide and proximal composition. The total, soluble and insoluble fiber contents were determined, together with the husks’ technological properties. Antioxidant activity and bioaccessibility of phenolic compounds of coffee husks were evaluated. Two types of husk were studied: one comprised mostly of outer skin and pulp (CH1); and other comprised mostly of parchment (CH2). Blanching had positive effects on non-extractable phenolics, chlorogenic acid and on the bioaccessibility of phenolics, promoting small reductions in extractable phenolics, protocathecuic acid, caffeine and trigonelline contents. Blanched CH1 presented more appropriate properties than CH2 for potential applications in food. It also presented better antioxidant, hydration, and oil holding properties than those of other agri-food by-products. Tentatively identified polysaccharides included galactomannans, arabinogalactans type II, pectin and cellulose.