Encapsulation of Citrus By-Product Extracts by Spray-Drying and Freeze-Drying Using Combinations of Maltodextrin with Soybean Protein and ι-Carrageenan

Optimizing prodigiosin nanoencapsulation in different wall materials by freeze drying: Characterization and release kinetics

Prodigiosin, a microbial pigment, was produced using Serratia marcescens and encapsulated with β-cyclodextrin (BCD), maltodextrin (MD), gum Arabic (GA), and soy protein isolate (SPI) to enhance stability and bioavailability. Emulsions were prepared by dissolving wall materials (5 % w/v) in water, mixing with prodigiosin in ethanol (1:1), and adding Tween 80 as an emulsifier. The mixture was ultrasonicated, homogenized, and freeze-dried to form nanoparticles. Encapsulation efficiencies were 81.15 % (PBCDN), 76.93 % (PMDN), 89.15 % (PGAN), and 85.22 % (PSPIN). Particle size ranged from 115.63 to 181.42 nm, with PGAN having the largest size. FTIR confirmed successful encapsulation, while DSC indicated enhanced thermal stability, particularly in GA-based nanoparticles. In vitro release studies showed controlled release, with PGAN exhibiting the slowest release in gastric conditions. These results suggest GA is the most effective wall material for improving prodigiosin stability and controlled release for food, pharmaceutical, and cosmetic applications.

Merging microencapsulated garlic extract as a bioactive ingredient into manufacturing functional soft cheese

The study aimed to produce a functional soft cheese with garlic extract (GE). First, the GE was encapsulated using gum Arabic (GA) and whey protein isolate, and its characteristics [zeta-potential, particle size, Coacervates yield, Encapsulation efficiency and polydispersity index, scanning electron microscope (SEM)] were evaluated. The free GE (FGE) and encapsulated GE (EGE) were then added to UF-soft cheese formulation (0.2 and 0.4% w/w). The samples were kept for 30 days in a refrigerator and their physicochemical, sensory properties, Texture profile, SEM and radical-scavenging activity were examined. EGE UF-soft cheese exhibited more free-radical scavenging activity than FGE at the same concentration and control, 25.14, 22.12, and 13.64%, respectively. The EGE-fortified cheese had a harder and gummier texture, a more noticeable change than the FGE and control cheese. In comparison to FGE-fortified and control, the sensory attribute representing overall quality, especially that fortified with 0.2% EGE displays the highest value. The study demonstrates that the use of EGE in cheese fortification provides a healthy and promising approach to reducing the strong flavor of garlic and enhancing bioactivity in the production of functional soft cheese, offering up novel opportunities for the development of distinctive dairy products with functional features.

Valorization of okra waste: Microencapsulation of okra flower polyphenol-rich extract with maltodextrin and gum Arabic by freeze drying, spray drying, and microwave drying

Okra (Abelmoschus esculentus (L.) (Moench.)) flowers are under valorized byproducts of okra production. They are a rich source of nutrients and have shown strong antioxidant activity. This study has optimized the extraction of phenolics, flavonoids and antioxidants from okra flowers by response surface methodology. The effect of extraction temperature (26.4-93.6°C), time (6-75 min), and solvent volume (18-102 mL) was evaluated. The optimum extraction conditions were determined as 80°C, solvent volume of 85 mL, and extraction time of 61 min. The extract prepared at optimum conditions was then microencapsulated with maltodextrin, gum Arabic, and a combination of both (1:1) using different drying techniques (freeze drying, spray drying, and microwave drying). The physicochemical properties of the resulting products were analyzed and characterized using differential scanning calorimetry, scanning electron microscopy, and infrared spectroscopy. The drying method impacted the polyphenol levels and bioaccessibility, physical powder properties, and surface characteristics of the resultant product, while the microencapsulation method mainly impacted the polyphenol content, glass transition temperature, and polyphenol bioaccessibility to a lesser extent. Microencapsulation with maltodextrin resulted in powders with significantly higher quercetin-3-glucoside (90-100 mg/kg), and epicatechin (480-580 mg/kg) content. The combination of freeze drying with maltodextrin microencapsulation provided the highest content of various polyphenols and bioaccessibility, as well as a very low water activity (0.038 ± 0.000). However, the powder was less free-flowing compared to microwave drying and tended to have a lower solubility. Consequently, the optimum drying and microencapsulation method will be a compromise between the different importance afforded to each of the aforementioned parameters.

Utilization of Yeast Cells as Alternative Carriers in the Microencapsulation of Black Chokeberry (Aronia melanocarpa) Phenolic Extract

The structure of yeast cells, which are rich in bioactive compounds, makes them an attractive encapsulation vehicle due to their antioxidant, antibacterial, and antimutagenic properties. In this study, black chokeberry extract was encapsulated with different wall materials (maltodextrin, gum arabic, mixture of maltodextrin and gum arabic, plasmolyzed yeast, and non-plasmolyzed yeast) by freeze-drying. While the highest encapsulation efficiency was obtained with maltodextrin (98.82%), non-plasmolyzed yeast (86.58%) emerged as a viable alternative to gum arabic. The largest particle size was observed in plasmolyzed yeast microcapsules. Yeast-coated capsules exhibited a spheroidal morphology. Differential Scanning Calorimetry revealed high thermal stability for all microcapsules, with the gum arabic-coated microcapsules demonstrating the greatest stability. After the simulated gastric and intestinal fluid treatment, plasmolyzed yeast provided the highest retention, with 63.45% and 77.55% of phenolics, respectively. The highest 2,2-Diphenyl-1-picrylhydrazyl (DPPH) activities were found in yeast microcapsules, with no significant difference between them. In 2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+) scavenging activity, the least loss (approximately 10%) was observed in non-plasmolyzed yeast samples after intestinal digestion. These results showed that yeast can be used as an alternative coating material in the encapsulation of phenolics, and it contributes to the bioavailability of microcapsules with its protective effect during digestion.

Horseradish (Armoracia rusticana L.) leaf juice encapsulated within polysaccharides-blend-based carriers: Characterization and application as potential antioxidants in mayonnaise production

This study aimed to encapsulate cold-pressed horseradish leaf juice within maltodextrin/alginate (MD/AL), maltodextrin/guar gum (MD/GG), and maltodextrin/gum Arabic (MD/GA) by spray-drying, to characterize the encapsulates, and to test their potential as mayonnaise oxidation-preventing ingredients. The encapsulates exhibited desirable physicochemical, morphological, structural, and thermal properties, highlighting MD/GA-containing encapsulates, especially regarding high encapsulation yield (78.50 %). Also, encapsulates contained a significant amount of phenolics, which were stable during freezer storage. The encapsulates successfully delayed the mayonnaise oxidation: 31.91-38.94 % more than the synthetic antioxidant ethylenediaminetetraacetic acid, especially highlighting MD/AL-containing encapsulates. Also, the encapsulates improved product quality with a higher pH and lower acidity after storage compared to the controls. Overall acceptability of encapsulates-containing mayonnaises and commercial mayonnaise did not differ significantly. This study contributes to sustainable development by providing new insights into the valorization of horseradish leaves, as a promising alternative to synthetic additives to prolong the oxidative stability and shelf-life of high-oil-containing foods.

Valorization of Onion By-Products Bioactive Compounds by Spray Drying Encapsulation Technique

The increasing interest in sustainability has driven research into the utilization of food by-products. Onion by-products, rich in bioactive compounds, represent a valuable resource for developing functional ingredients; however, they are prone to degradation due to environmental factors such as light, heat, and oxygen, leading to reduced efficacy and increased spoilage. Microencapsulation represents an effective approach to meet important goals in the formulation of food products such as the protection against degradation or the control of interactions with other ingredients that may modify and impair their functionality. This study explores the microencapsulation of flavonoid-rich onion by-product extract through spray drying, employing various wall materials (maltodextrin and a mixture of maltodextrin/trehalose and maltodextrin/trehalose/inulin) and their effect on the chemical and physical properties of the powders such as encapsulation efficiency, total flavonoids content, moisture content, water activity, bulk density, and bulk tapped density. The storage stability was further evaluated. This research supports waste reduction and suggests strategies for developing functional ingredients with extended shelf life and controlled release properties.

Physicochemical Properties of Nanoencapsulated Essential Oils: Optimizing D-Limonene Preservation

Essential oils exhibit antioxidant properties but are prone to oxidative degradation under environmental conditions, making their preservation crucial. Therefore, the purpose of this work was to evaluate the physicochemical properties of nanoencapsulated essential oils (EOs) extracted from the peel of sweet lemon, mandarin, lime, and orange using four formulations of wall materials consisting of gum arabic (GA), maltodextrin (MD), and casein (CAS). The results showed that EOs from sweet lemon, mandarin, lime, and orange showed higher solubility (79.5% to 93.5%) when encapsulated with GA/MD. Likewise, EOs from sweet lemon showed the highest phenolic content when using GA/CAS (228.27 mg GAE/g sample), and the encapsulated EOs of sweet lemon and mandarin with GA/MD/CAS (1709 and 1599 μmol TE/g) had higher antioxidant capacity. On the other hand, higher encapsulation efficiency was obtained in EOs of lime encapsulated with GA/MD (68.5%), and the nanoencapsulates of EOs from sweet lemon with GA/MD had higher D-limonene content (613 ng/mL). Using gum arabic and maltodextrin increased the encapsulation efficiency and D-limonene content in EO of sweet lemon. On the other hand, the formulations with casein were the most efficient wall materials for retaining D-limonene from the EOs of mandarin, lime, and orange.

Microencapsulation of Grape Pomace Extracts with Alginate-Based Coatings by Freeze-Drying: Release Kinetics and In Vitro Bioaccessibility Assessment of Phenolic Compounds

The phenols from grape pomace have remarkable beneficial effects on health prevention due to their biological activity, but these are often limited by their bioaccessibility in the gastrointestinal tract. Encapsulation could protect the phenolics during digestion and influence the controlled release in such an intestine where their potential absorption occurs. The influence of freeze-drying encapsulation with sodium alginate (SA) and its combination with gum Arabic (SA-GA) and gelatin (SA-GEL) on the encapsulation efficiency (EE) of phenol-rich grape pomace extract and the bioaccessibility index (BI) of phenolics during simulated digestion in vitro was investigated. The addition of a second coating to SA improved the EE, and the highest EE was obtained with SA-GEL (97.02-98.30%). The release of phenolics followed Fick's law of diffusion and the Korsmeyer-Peppas model best fitted the experimental data. The highest BI was found for the total phenolics (66.2-123.2%) and individual phenolics (epicatechin gallate 958.9%, gallocatechin gallate 987.3%) using the SA-GEL coating were used. This study shows that freeze-dried encapsulated extracts have the potential to be used for the preparation of various formulations containing natural phenolic compounds with the aim of increasing their bioaccessibility compared to formulations containing non-encapsulated extracts.

Encapsulation of phenolic acids within food-grade carriers systems: a systematic review

Phenolic acids are natural compounds with potential therapeutic effects against various diseases. However, their incorporation into food and pharmaceutical products is limited by challenges such as instability, low solubility, and reduced bioavailability. This systematic review summarizes recent advances in phenolic acid encapsulation using food-grade carrier systems, focusing on proteins, lipids, and polysaccharides. Encapsulation efficiency, release behavior, and bioavailability are examined, as well as the potential health benefits of encapsulated phenolic acids in food products. Strategies to address limitations of current encapsulation systems are also proposed. Encapsulation has emerged as a promising method to enhance the stability and bioavailability of phenolic acids in food products, and various encapsulation technologies have been developed for this purpose. The use of proteins, lipids, and carbohydrates as carriers in food-grade encapsulation systems remains a common approach, but it is associated with certain limitations. Future research on phenolic acid encapsulation should focus on developing environmentally friendly, organic solvent-free, low-energy, scalable, and stable encapsulation systems, as well as co-encapsulation methods that combine multiple phenolic acids or phenolic acids with other bioactive substances to produce synergistic effects.

Microencapsulation of ultrasound-assisted phenolic extracts of sugar maple leaves: Characterization, in vitro gastrointestinal digestion, and storage stability

Sugar maple leaves (SML), usually considered residue plant biomass and discarded accordingly, contain a considerable amount of phenolic antioxidants. In this study, SML phenolics were extracted employing both advanced (homogenization pretreated ultrasound-assisted extraction) and conventional (maceration) methods followed by their encapsulation by freeze drying and spray drying using a combination of maltodextrin and gum arabic as coating agents. Detailed physicochemical analyses revealed that the encapsulated microparticles had high solubility (>90 %) and encapsulation efficiency (>95 %), acceptable thermal stability with good handling properties. Phenolic compounds were completely released from microparticles during simulated gastric conditions. The microparticles influenced the bioaccessibility of more than 43 % of the phenolic fraction in the intestinal phase. The antioxidant capacity of the microparticles was preserved during storage. These findings suggest the effectiveness of the microencapsulation process for producing high quality microparticles of SML phenolic extracts and the possibility of their use in the food, nutraceutical, bio-pharmaceutical sectors.

Ultrasound assisted extraction of red cabbage and encapsulation by freeze-drying: moisture sorption isotherms and thermodynamic characteristics of encapsulate

In the present study encapsulation of ultrasound assisted red cabbage extract was carried out using four different carrier agents such as maltodextrin, gum arbic, xanthan gum, and gellan gum. Among the four hydrocolloids investigated, maltodextrin was found to have the least destructive effect on anthocyanin content (14.87 mg C3G/g dw), TPC (54.51 ± 0.09 mg GAE/g dw), TFC (19.82 Mg RE/g dw) and antioxidant activity (74.15%) upon freeze-drying. Subsequently a storage study was conducted using maltodextrin as carrier agent at 25-50 °C. The Clausius-Clapeyron equation was used to evaluate the net isosteric heat (qst) of water adsorption. The differential entropy (ΔS) and qst decreased from 82.298 to 38.628 J/mol, and 27.518 kJ/mol to 12.505 kJ/mol, respectively as the moisture content increased from 2 to 14%. The value of isokinetic energy and Gibb's free energy were found to be 364.88 and - 1.596 kJ/mol for freeze dried red cabbage.

Graphical abstract

Comparison of physicochemical properties and oxidative stability of microencapsulated perilla oil powder prepared by freeze-drying and spray-drying

Perilla oil is vulnerable to lipid oxidation owing to its high linolenic acid content. Microencapsulation using freeze- and spray-drying methods was applied to enhance the oxidative stability and change the physicochemical properties of perilla oil. Freeze-dried powder (FDP) possessed 11.77 to 38.48% oil content, whereas spray-dried powder (SDP) had 8.90-27.83% oil content. Encapsulation efficiency ranged from 51.22 to 85.71% by freeze-drying and from 77.38 to 90.74% by spray-drying. The oxidative stability of powders depends on the oil content and production methods. Generally, FDP had higher oxidative stability and water solubility, and lower moisture content and water activity than SDP. The particle size of FDP (154.00-192.00 μm) in volume-weight mean diameter was 2.56-24.49 times larger than that of SDP (7.84-72.03 μm). SDP had a lower volatile content at the initial time of storage than FDP, while more volatiles were observed in SDP as storage time increased. The microencapsulation method should be selected appropriately depending on the target property or usage in food applications.

Effects of Maltodextrin and Gum Arabic Composition on the Physical and Antioxidant Activities of Dewaxed Stingless Bee Cerumen

BACKGROUND

Cerumen is a mixture of beeswax and plant resin made by stingless bees. It has antimicrobial and antioxidant properties and is often used in biological and therapeutic treatments. However, its adhesive characteristic makes cerumen challenging to process into powder.

METHODS

This study investigated the physical characteristics and antioxidant activity of the encapsulated freeze-dried dewaxed cerumen of Tetragonula laevicpes. The combination of coating materials at concentrations of 20%, 30% and 40% and carrier ratios of maltodextrin to gum arabic of 9:1, 5:5 and 3:7 were used to encapsulate dewaxed cerumen when freeze-dried; the control was maltodextrin at a concentration of 31.25%.

RESULTS

All carrier matrices showed high yields of >80% and similar powder characteristics of low moisture content, low water activity, high glass transition temperature and water dispersibility. Overall, antioxidant activities ranged from 69-80%, while the encapsulation efficiency of total phenolic content ranged from 46-68%. All carrier matrices show higher antioxidant activities than 31.25% maltodextrin, with the lowest antioxidant at 57%.

CONCLUSIONS

The carrier ratio of 5:5 resulted in better physical properties and retained 68% of polyphenolic activity in powders.

Comparative Analysis of Concurrent (CC), Mixed Flow (MX), and Combined Spray Drying Configurations on the Physicochemical Characteristics of Satsuma Mandarin (Citrus unshiu) Juice Powders

Satsuma mandarins are good sources of vitamin C and can be used as raw materials to produce novel plant-based food ingredients including satsuma mandarin juice powders (SJP). Food powders produced via spray drying often show thermal degradation due to the drying conditions and high drying air temperatures. The aim of this study was to evaluate the effect of using different spray drying configurations, including concurrent (CC), mixed flow (MX), and combined (CC + MX), at two inlet air temperatures (160 and 180 °C) on the physicochemical properties of SJP. Remarkably, SJP produced using the CC spray drying configuration exhibited a higher vitamin C content (3.56-4.01 mg/g) and lower moisture levels (15.18-16.35 g/100 g) than powders produced via MX or CC + MX. The vitamin C content of MX and CC + MX powders ranged from 2.88 to 3.33 mg/g. Meanwhile, all SJP had water activity values below 0.19. Furthermore, MX powders displayed the largest mean particle sizes (D50) (8.69-8.83 µm), higher agglomeration, and a rapid dissolution. Despite these differences, all SJP variants exhibited consistent color, surface area, and pore volumes. Notably, powders dried at higher inlet air temperatures (180 °C) showed less vitamin C content and increased thermal damage when compared with powders dried at 160 °C inlet air temperature. This study demonstrated the feasibility of producing high-quality SJP with an extended shelf life. SJP can be used as a novel plant-based ingredient in different food applications.

The Specific Encapsulation of Procyanidins from Litchi Peel and Coffee Pulp Extracts via Spray-Drying Using Green Polymers

Polyphenols called procyanidins can be extracted from agro-industrial waste like litchi peel and coffee pulp. However, their efficacy is limited due to instability, which hinders both the bioavailability and preservation of their activity. This study aims to establish the ideal encapsulation conditions required to preserve the procyanidin properties found in extracts taken from litchi peel and coffee pulp. To attain the maximum procyanidin encapsulation efficacy (EE), the Taguchi method was utilized to streamline the spray-drying conditions for different wall materials-maltodextrin (MD), whey protein (WP), citrus pectin (CP), and skim milk (SM). The optimized conditions consisted of feed flow (3, 4.5, and 6 mL/min), temperature (125, 150, and 175 °C), and airflow (30, 35, and 40 m3/h). The microcapsules were characterized using ABTS, DPPH, lipoperoxidation, and scanning electron microscopy. Objective evaluations revealed that MD was the most effective encapsulation material for the litchi extract, whereas WP was the optimal option for the coffee extract. Of all the factors considered in the spray-drying process, feed flow had the strongest impact. The spray-drying process for the litchi peel extracts achieved high procyanidin encapsulation efficiencies at a feed flow rate of 4.5 mL/min, a temperature of 150 °C, and an airflow rate of 35 m3/h. Meanwhile, the coffee extract spray drying achieved similar results at a feed flow rate of 4.5 mL/min, a temperature of 175 °C, and an airflow rate of 40 m3/h. Encapsulation efficiencies of 98.1% and 93.6% were observed for the litchi and coffee extracts, respectively, under the mentioned optimal conditions. The microencapsulation process was successful in preserving the antioxidant properties of procyanidins. The microcapsules' size ranged from 2.6 to 3.2 micrometers. The results imply that the phenolic compounds present in the extracts function as effective antioxidant agents.

Analysis of Lutein Content in Microencapsulated Marigold Flower Extract (Tagetes erecta L.) Using UHPLC-Q-Orbitrap-HRMS and Its Cytotoxicity in ARPE-19 Cells

Organic solvents are commonly used to extract lutein. However, they are toxic and are not environmental-friendly. There are only a few reports on the quantification of lutein. Therefore, this study aimed to determine a suitable extraction method by which to obtain lutein from marigold flower (Tagetes erecta L.), using coconut oil to evaluate the cytotoxicity of extract in ARPE-19 cells, to optimize the encapsulation process for the development of microencapsulated marigold flower extract, and to develop the method for analysis of lutein by using UHPLC-Q-Orbitrap-HRMS. Coconut oil was used for the extraction of marigold flowers with two different extraction methods: ultrasonication and microwave-assisted extraction. The UHPLC-Q-Orbitrap-HRMS condition for the analysis of lutein was successfully developed and validated. Marigold flower extract obtained using the microwave method had the highest lutein content of 27.22 ± 1.17 mg/g. A cytotoxicity study revealed that 16 µM of lutein from marigold extract was non-toxic to ARPE-19 cells. For the development of microencapsulated marigold extract, the ratio of oil to wall at 1:5 had the highest encapsulation efficiency and the highest lutein content. Extraction of lutein using coconut oil and the microwave method was the suitable method. The microencapsulated marigold extract can be applied for the development of functional ingredients.

Citrus By-Products as a Valuable Source of Biologically Active Compounds with Promising Pharmaceutical, Biological and Biomedical Potential

Citrus fruits processing results in the generation of huge amounts of citrus by-products, mainly peels, pulp, membranes, and seeds. Although they represent a major concern from both economical and environmental aspects, it is very important to emphasize that these by-products contain a rich source of value-added bioactive compounds with a wide spectrum of applications in the food, cosmetic, and pharmaceutical industries. The primary aim of this review is to highlight the great potential of isolated phytochemicals and extracts of individual citrus by-products with bioactive properties (e.g., antitumor, antimicrobial, antiviral, antidiabetic, antioxidant, and other beneficial activities with health-promoting abilities) and their potential in pharmaceutical, biomedical, and biological applications. This review on citrus by-products contains the following parts: structural and chemical characteristics; the utilization of citrus by-products; bioactivities of the present waxes and carotenoids, essential oils, pectins, and phenolic compounds; and citrus by-product formulations with enhanced biocactivities. A summary of the recent developments in applying citrus by-products for the treatment of different diseases and the protection of human health is also provided, emphasizing innovative methods for bioaccessibility enhancements (e.g., extract/component encapsulation, synthesis of biomass-derived nanoparticles, nanocarriers, or biofilm preparation). Based on the representative phytochemical groups, an evaluation of the recent studies of the past six years (from 2018 to 2023) reporting specific biological and health-promoting activities of citrus-based by-products is also provided. Finally, this review discusses advanced and modern approaches in pharmaceutical/biological formulations and drug delivery (e.g., carbon precursors for the preparation of nanoparticles with promising antimicrobial activity, the production of fluorescent nanoparticles with potential application as antitumor agents, and in cellular imaging). The recent studies implementing nanotechnology in food science and biotechnology could bring about new insights into providing innovative solutions for new pharmaceutical and medical discoveries.

Wall Materials for Encapsulating Bioactive Compounds via Spray-Drying: A Review

Spray-drying is a continuous encapsulation method that effectively preserves, stabilizes, and retards the degradation of bioactive compounds by encapsulating them within a wall material. The resulting capsules exhibit diverse characteristics influenced by factors such as operating conditions (e.g., air temperature and feed rate) and the interactions between the bioactive compounds and the wall material. This review aims to compile recent research (within the past 5 years) on spray-drying for bioactive compound encapsulation, emphasizing the significance of wall materials in spray-drying and their impact on encapsulation yield, efficiency, and capsule morphology.

Advances in extraction and purification of citrus flavonoids

Flavonoids are the representative active substances of citrus with various biological activities and high nutritional value. In order to evaluate and utilize citrus flavonoids, isolation and purification are necessary steps. This manuscript reviewed the research advances in the extraction and purification of citrus flavonoids. The structure classification, the plant and nutritional functions, and the biosynthesis of citrus flavonoids were summarized. The characteristics of citrus flavonoids and the selection of separation strategies were explained. The technical system of extraction and purification of citrus flavonoids was systematically described. Finally, outlook and research directions were proposed.

Spray-Drying Impact the Physicochemical Properties and Formation of Maillard Reaction Products Contributing to Antioxidant Activity of Camelina Press Cake Extract

Spray-drying is one of the most popular techniques in the food industry for converting liquid material from a fluid state into a form of dried particles to produce encapsulated or instant products. Instant products are considered as convenient foods; moreover, the goal of encapsulation is to close the bioactive compounds in a shell, preventing them from being affected by environmental factors. The purpose of this study was to examine the influence of spray-drying conditions, in particular three inlet temperatures, on the physicochemical and antioxidant properties of powders obtained from Camelina Press Cake Extract (CPE). The CPE was spray-dried at 140 °C, 160 °C and 180 °C. The solubility, Carr and Hausner Indexes, tapped densities and water activity of the powders were analyzed. The structural changes were also detected using FTIR spectroscopy. Additionally, the characteristics of the initial and reconstituted samples and their rheological properties were evaluated. The antioxidant potential, total polyphenols and flavonoids content, free amino acids, and the Maillard reaction products contents in the spray-dried powders were also evaluated. The results indicate a cascade of changes between the initial and reconstituted samples, and important changes in the bioactive potential of samples. The inlet temperature significantly influenced the solubility, flowability and particle sizes of the powders, as well as Maillard products formation. The results of the rheological measurements illustrate the changes after the reconstitution of extracts. This study indicates the optimal parameters of CPE spray-drying, those that yield favorable physicochemical and functional values, which may open up a promising path for CPE valorization, indicating its potential and the possibilities of its use.

Encapsulation of Rosemary Extracts using High Voltage Electrical Discharge in Calcium Alginate/Zein/Hydroxypropyl Methylcellulose Microparticles

The increased demand for functional food with added health benefits is directing industrial procedures toward more sustainable production of naturally added bioactive compounds. The objective of this research was to investigate the potential of bioactive compounds from rosemary extract obtained using high-voltage electrical discharge as a green extraction method, for microencapsulation as a protective method for future application in functional food. Four types of microparticles were made via the ionic gelation method using alginate (Alg), zein (Z), and hydroxypropyl methylcellulose (HPMC) biopolymers and were analyzed considering the physicochemical properties. The diameter of dry microparticles ranged from 651.29 to 1087.37 μm. The shape and morphology analysis of microparticles showed that the obtained microparticles were quite spherical with a granular surface. The high encapsulation efficiency was obtained with a loading capacity of polyphenols up to 11.31 ± 1.47 mg GAE/g (Alg/Z microparticles). The microencapsulation method showed protective effects for rosemary polyphenols against pH changes during digestion. Specifically, the addition of both zein and HPMC to calcium-alginate resulted in microparticles with a prolonged release for better availability of polyphenols in the intestine. This research background indicates that the release of rosemary extract is highly dependent on the initial biopolymer composition with high potential for further functional food applications.

Effects of Flavonoids and Phenols from Moringa oleifera Leaf Extracts on Biofilm Processes in Xanthomonas campestris pv. campestris

Xanthomonas campestris pv. campestris is the causal agent of black rot in crucifers, a plant disease with significant economic impact. Xanthomonadaceae is a large family of Gram-negative bacteria that cause symptoms by blocking water flow in plants by invading the xylem. To accomplish this, the main mechanism the bacteria use to adapt to environmental changes and colonize tissues is biofilm formation. In recent years, growing interest in natural antimicrobial compounds has led to the study of different phytocomplexes derived from plants. In this work, Moringa oleifera was selected, as its leaves are rich in phenols, essential oils, and vitamins that exert antibacterial activity. X. campestris pv. campestris biofilm, one of its major virulence factors, was studied. Biofilm formation and removal were analyzed on abiotic and biotic surfaces with and without M. oleifera leaf extracts. The data from the analysis show that Moringa oleifera leaf extracts and single phenols were able to inhibit biofilm growth on abiotic surfaces, but the activity of the whole phytocomplex was significantly higher compared to that of individual phenols. The effect of Moringa oleifera extracts on cabbage leaves in vivo was also found to be very important, as scanning electron microscopy showed that treatment with the extracts led to clear unblocking of the xylem, implying many advantages for use in black rot control.

Recent developments in citrus bioflavonoid encapsulation to reinforce controlled antioxidant delivery and generate therapeutic uses: Review

Citrus fruits contain numerous antioxidative biomolecules including phenolic acids, flavonols, flavanones, polymethoxyflavones (PMFs), and their derivatives. Previous in vitro and in vivo studies thoroughly investigated the antioxidant and therapeutic potential of bioflavonoids extracted from different citrus varieties and fruit fractions. Major bioflavonoids such as hesperidin, naringin, naringenin, and PMFs, had restricted their incorporation into food and health products due to their poor solubility, chemical stability and bioavailability. Considering these limitations, modern encapsulation methodologies such as hydrogelation, liposomal interactions, emulsifications, and nanoparticles have been designed to shield bioflavonoids with improved target distribution for therapeutic enhancements. The size, durability, and binding efficiency of bioflavonoid-loaded encapsulates were acquired by the optimized chemical and instrumental parameters such as solubility, gelation, dispersion, extrusion, and drying. Bioflavonoid-enriched encapsulates have been also proven to be effective against cancer, inflammation, neurodegeneration, and various other illnesses. However, in the future, newer natural binding agents with higher binding capacity might accelerate the encapsulating potential, controlled release, and enhanced bioavailability of citrus bioflavonoids. Overall, these modern encapsulation systems are currently leading to a new era of diet-based medicine, as demand for citrus fruit-based nutritional supplements and edibles grows.

From Sweet Corn By-Products to Carotenoid-Rich Encapsulates for Food Applications

In the present study, carotenoids were recovered from processing sweet corn by-products (SCB). The total carotenoid content determined in the SCB extract was 1.19 mg/100 g DW, and the principal carotenoids identified by the HPLC technique were zeaxanthin, β-cryptoxanthin and lutein. Freeze- and spray-drying techniques were applied for the encapsulation of SCB extract; for this purpose, four different wall materials were used: two proteins (soy and pea) and two carbohydrates (maltodextrin and inulin). The physicochemical characteristics of eight encapsulates were determined to assess their stability. The obtained results indicate that, by using the freeze-drying method, better water activity, moisture content as well as encapsulation efficiency were achieved. Spray-drying resulted in better flowing properties. All obtained encapsulates were microbiologically safe for food applications due to the fact that the obtained results are in agreement with the requirements for consumer safety, i.e., for further food applications and scale-up processes. Chemometric classification and ranking techniques were applied to observe potential grouping among the investigated encapsulates and to select the most favorable encapsulates regarding the used wall materials and encapsulation techniques for the assessment of sustainability in food products. The most suitable wall material and encapsulation technique for the assessment of sustainability in food products was produced by freeze-drying pea protein as a wall material (FDP).

Polysaccharides as Carriers of Polyphenols: Comparison of Freeze-Drying and Spray-Drying as Encapsulation Techniques

Polyphenols have received great attention as important phytochemicals beneficial for human health. They have a protective effect against cardiovascular disease, obesity, cancer and diabetes. The utilization of polyphenols as natural antioxidants, functional ingredients and supplements is limited due to their low stability caused by environmental and processing conditions, such as heat, light, oxygen, pH, enzymes and so forth. These disadvantages are overcome by the encapsulation of polyphenols by different methods in the presence of polyphenolic carriers. Different encapsulation technologies have been established with the purpose of decreasing polyphenol sensitivity and the creation of more efficient delivery systems. Among them, spray-drying and freeze-drying are the most common methods for polyphenol encapsulation. This review will provide an overview of scientific studies in which polyphenols from different sources were encapsulated using these two drying methods, as well as the impact of different polysaccharides used as carriers for encapsulation.

Impact of Freeze- and Spray-Drying Microencapsulation Techniques on β-Glucan Powder Biological Activity: A Comparative Study

The study compares the impact of freeze- and spray-drying (FD, SD) microencapsulation methods on the content of β-glucan, total polyphenols (TP), total flavonoids (TF), phenolic acids (PA), and antioxidant activity (AA) in commercially β-glucan powder (Pleurotus ostreatus) using maltodextrin as a carrier. Morphology (scanning electron microscopy- SEM), yield, moisture content (MC), and water activity (aw) were also evaluated in the samples. Our examinations revealed significant structural differences between powders microencapsulated by the drying methods. As compared to non-encapsulated powder, the SD powder with yield of 44.38 ± 0.55% exhibited more reduced (p < 0.05) values for aw (0.456 ± 0.001) and MC (8.90 ± 0.44%) than the FD one (yield: 27.97 ± 0.33%; aw: 0.506 ± 0.002; MC: 11.30 ± 0.28%). In addition, the highest values for β-glucan content (72.39 ± 0.38%), TPC (3.40 ± 0.17 mg GAE/g), and TFC (3.07 ± 0.29 mg QE/g) have been detected in the SD powder. Our results allow for the conclusion that the SD microencapsulation method using maltodextrin seems to be more powerful in terms of the β-glucan powder yield and its contents of β-glucan, TP, and TF as compared to the FD technique.

Recovery of Citric Acid from Citrus Peels: Ultrasound-Assisted Extraction Optimized by Response Surface Methodology

The production of citrus juice generates a large quantity of by-products, which are often discarded or used for animal feed. However, several studies have shown its richness in valuable compounds, namely organic acids. Thus, this work intended to valorize orange and lime peels as renewable sources of citric acid. An experimental design combining five levels of the independent variables time (2–45 min), ultrasonic power (50–500 W), and ethanol proportion (0–100%) was implemented and response surface methodology (RSM) was applied to optimize the extraction process. The UPLC-PDA analysis showed that orange peel presented a higher citric acid content than lime. For lime and orange peels, the extraction yield was maximized by sonicating at low power for 5.8 or 35.5 min, using a low ethanol proportion or only water as a solvent, respectively. Overall, optimal UAE conditions were defined for the sustainable extraction of citric acid from citrus by-products, thus contributing to its valorization and upcycling into natural food ingredients.

Effect of Extraction Methods and In Vitro Bio-Accessibility of Microencapsulated Lemon Extract

The extraction of bioactive compounds from fruits, such as lemon, has gained relevance because these compounds have beneficial properties for health, such as antioxidant and anticancer properties; however, the extraction method can significantly affect these properties. High hydrostatic pressure and ultrasound, as emerging extraction methods, constitute an alternative to conventional extraction, improving extractability and obtaining extracts rich in bioactive compounds. Therefore, lemon extracts (LEs) were obtained by conventional (orbital shaking), ultrasound-assisted, and high-hydrostatic-pressure extraction. Extracts were then microencapsulated with maltodextrin at 10% (M10), 20% (M20), and 30% (M30). The impact of microencapsulation on LEs physicochemical properties, phenolics (TPC), flavonoids (TFC) and relative bio-accessibility (RB) was evaluated. M30 promoted a higher microencapsulation efficiency for TPC and TFC, and a longer time required for microcapsules to dissolve in water, as moisture content, water activity and hygroscopicity decreased. The RBs of TPC and TFC were higher in microcapsules with M30, and lower when conventional extraction was used. The data suggest that microencapsulated LE is promising as it protects the bioactivity of phenolic compounds. In addition, this freeze-dried product can be utilized as a functional ingredient for food or supplement formulations.

Encapsulation of bioactive compounds extracted from Cucurbita moschata pumpkin waste: The multi-objective optimization study

AIM

Artificial neural network (ANN) development to find optimal carriers (pea protein-P, maltodextrin-M, and inulin-I) mixture for encapsulation of pumpkin waste bioactives (β-carotene and phenolics).

METHODS

Freeze-drying encapsulation and encapsulates characterisation in terms of bioactives contents and encapsulation efficiencies, water activity, hygroscopicity, densities, flowability, cohesiveness, particle size (laser diffraction), solubility, color (CIELab), morphological (SEM), stability and release properties.

RESULTS

Optimal encapsulates, OE-T (with highest total bioactives contents; P, M, and I of 53.9, 46.1, and 0%w/w) and OE-EE (with highest bioactives encapsulation efficiencies; P, M, and I of 45.5, 32.0, and 22.5%w/w) had particle diameters of 94.561 ± 1.341µm and 90.206 ± 0.571µm, span of 1.777 ± 0.094 and 1.588 ± 0.089, highest release at pH 7.4 of phenolics of 71.03%w/w after 72h and 66.22%w/w after 48h, and β-carotene of 43.67%w/w after 8h and 48.62%w/w after 6h, respectively.

CONCLUSION

ANN model for prediction of encapsulates' preparation, showed good anticipation properties (with gained determination coefficients of 1.000).

Novel Approaches in the Valorization of Agricultural Wastes and Their Applications

Worldwide, a huge amount of agricultural food wastes and byproducts containing valuable bioactive compounds are generated, especially throughout the entire supply chain. Minimizing food wastes and byproducts is the first option to avoid environmental problems, and to help the economy and the society. Although many countries implement policies to reduce food wastes and byproducts, and different management methods are available to utilize agricultural food wastes, they are still produced annually. Nanotechnological and biotechnological approaches are recently used as novel and green applications to valorize agricultural food wastes and improve their stability and applicability. In this Review, these approaches are covered in detail with given examples. Another valorization way of consumable food waste is using it for functional food production. This Review focuses on specific examples of functional foods with food waste as an ingredient. In addition, the problems and limitations of waste management and valorization methods are investigated, considering future perspectives.

Encapsulation of Blackberry Phenolics and Volatiles Using Apple Fibers and Disaccharides

The objective of this study was to determine the effect of disaccharides on the encapsulation of the phenolics and volatiles of blackberry juice with the use of apple fiber. For this purpose, apple fiber/blackberry microparticles were prepared as the control, as well as microparticles additionally containing disaccharides, i.e., sucrose or trehalose. Fiber:disaccharide ratios were 1:0.5, 1:1, and 1:2. Formulated microparticles were characterized for total phenolics, proanthocyanidins, individual phenolics, antioxidant activity, flavor profiles, and color parameters. Both applied disaccharides affected the encapsulation of phenolics and volatiles by the apple fibers. Control microparticles had a higher content of phenolics than microparticles with disaccharides. Comparing disaccharides, the microparticles with trehalose had a higher content of phenolics than the ones containing sucrose. The amount of proanthocyanidins in the control microparticles was 47.81 mg PB2/100 g; in trehalose, the microparticles ranged from 39.88 to 42.99 mg PB2/100 g, and in sucrose, the microparticles ranged from 12.98 to 26.42 mg PB2/100 g, depending on the fiber:disaccharide ratio. Cyanidin-3-glucoside was the dominant anthocyanin. Its amount in the control microparticles was 151.97 mg/100 g, while in the trehalose microparticles, this ranged from 111.97 to 142.56 mg /100 g and in sucrose microparticles, from 100.28 to 138.74 mg /100 g. On the other hand, microparticles with disaccharides had a higher content of volatiles than the control microparticles. Trehalose microparticles had a higher content of volatiles than sucrose ones. These results show that the formulation of microparticles, i.e., the selection of carriers, had an important role in the final quality of the encapsulates.

Apple Fibers as Carriers of Blackberry Juice Polyphenols: Development of Natural Functional Food Additives

Blackberry polyphenols possess various health-promoting properties. Since they are very sensitive to environmental conditions such as the presence of light, oxygen and high temperatures, the application of such compounds is restricted. Fibers are recognized as efficient carriers of polyphenols and are often used in polyphenols encapsulation. In the present study, the ability of apple fiber to adsorb blackberry juice polyphenols was examined. Freeze-dried apple fiber/blackberry juice complexes were prepared with different amounts of fibers (1%, 2%, 4%, 6%, 8% and 10%) and a constant amount of blackberry juice. Polyphenol profile, antioxidant activity, inhibition of the α-amylase, color parameters, as well as the IR spectra, of the obtained complexes were assessed. The results showed a negative effect of higher amounts of fiber (more than 2%) on the adsorption of polyphenols and the antioxidant activity of complexes. With the proper formulation, apple fibers can serve as polyphenol carriers, and thus the application as novel food additives can be considered.

Formulation of Nano/Micro-Carriers Loaded with an Enriched Extract of Coffee Silverskin: Physicochemical Properties, In Vitro Release Mechanism and In Silico Molecular Modeling

Designing strategies for an effective transformation of food waste into high-value products is a priority to address environmental sustainability concerns. Coffee silverskin is the major by-product of the coffee roasting industry, being rich in compounds with health benefits. Such composition gives it the potential to be transformed into high-value products. In this study, coffee silverskin extracts were enriched, regarding caffeine and chlorogenic acid contents, by adsorbent column chromatography. The compounds content increased 3.08- and 2.75-fold, respectively, compared to the original extract. The enriched fractions were loaded into nano-phytosomes or cholesterol-incorporated nano-phytosomes (first coating layers) to improve the physiochemical properties and permeation rate. These nano-lipid carriers were also subjected to a secondary coating with different natural polymers to improve protection and stability against degradation. In parallel, and for comparison, different natural polymers were also used as first coating layers. The produced particles were evaluated regarding product yield, encapsulation efficiency, loading capacity, particle size, surface charge, and in vitro release simulating gastrointestinal conditions. All samples exhibited anionic surface charge. FTIR and molecular docking confirmed interactions between the phytoconstituents and lipid bilayers. The best docking score was observed for 5-caffeoylquinic acid (chlorogenic acid) exhibiting a stronger hydrogen binding to the lipid bilayer. Among several kinetic models tested, the particle release mechanism fitted well with the First-order, Korsmeyer-Peppas, and Higuchi models. Moreover, most of the formulated particles followed the diffusion-Fick law and anomalous transport.

Exploring Gunnera tinctoria: From Nutritional and Anti-Tumoral Properties to Phytosome Development Following Structural Arrangement Based on Molecular Docking

Gunnera tinctoria, an underexplored invasive plant found in Azores, Portugal, was studied regarding its nutritional, antioxidant, and antitumoral properties. Higher antioxidant activity was found in baby leaves, followed by adult leaves and inflorescences. A phenolic fraction of the plant was enriched using adsorbent resin column chromatography (DiaionTM HP20LX, and Relite EXA90). Antitumoral effects were observed with the enriched fractions in breast (MCF-7) and pancreatic (AsPC-1) cancer cell lines, being more pronounced in the latter. To improve protection and membrane absorption rates of phenolic compounds, nano-phytosomes and cholesterol-conjugated phytosomes coated with natural polymers were loaded with the enriched fraction. The particles were characterized, and their physiochemical properties were evaluated and compared. All samples presented anionic charge and nanometer size in relation to the inner layer and micrometer size regarding the external layers. In addition, the molecular arrangement of phenolics within both types of phytosomes were studied for the first time by molecular docking. Polarity and molecular size were key factors on the molecular arrangement of the lipid bilayer. In conclusion, G. tinctoria showed to be an interesting source of nutrients and phenolic compounds with anti-tumoral potential. Moreover, phytosome loading with these compounds can increase their stability and bioavailability having in view future applications.

Strategies to increase the shelf life of meat and meat products with phenolic compounds

Oxidative reactions and microbial growth are the main processes involved in the loss of quality in meat products. Although the use of additives to improve the shelf life is a common practice in the meat industry, the current trends among consumers are pushing the researchers and professionals of the meat industry to reformulate meat products. Polyphenols are compounds with antioxidant and antimicrobial activity naturally found in several plants, fruits, and vegetables that can be used in the production of extracts and components in active packaging to improve the shelf life of meat products. This chapter aims to discuss the advances in terms of (1) encapsulation techniques to protect phenolic compounds; (2) production of active and edible packages rich on phenolic compounds; (3) use of phenolic-rich additives (free or encapsulated form) with non-thermal technologies to improve the shelf life of meat products; and (4) use of active packaging rich on phenolic compounds on meat products. Innovative strategies to encapsulated polyphenols and produce films are mainly centered in the use of innovative and emerging technologies (such as ultrasound and supercritical fluids). Moreover, the combined use of polyphenols and non-thermal technologies is a relevant approach to improve the shelf life of meat products, especially using high pressure processing. In terms of application of innovative films, nanomaterials have been largely explored and indicated as relevant strategy to preserve meat and meat products.

Valorization of Tomato Waste as a Source of Carotenoids

Fast-accumulating scientific evidence from many studies has revealed that fruits and vegetables are the main source of bioactive compounds; in most cases, wastes and byproducts generated by the food processing industry present similar or a higher content of antioxidant compounds. In recent years, the ever-growing amount of agricultural and food wastes has raised serious concerns from an environmental point of view. Therefore, there is an increasing interest in finding new ways for their processing toward safely upgrading these wastes for recovering high-value-added products with a sustainable approach. Among food waste, the abundance of bioactive compounds in byproducts derived from tomato suggests possibility of utilizing them as a low-cost source of antioxidants as functional ingredients. This contribution gives an overview of latest studies on the extraction methods of carotenoids from tomato waste, along with an evaluation of their antioxidant activity, as well as their industrial applications.

Citrus processing by-products: an overlooked repository of bioactive compounds

Citrus fruits contain plethora of bioactive compounds stored in edible as well as inedible part. Since, citrus fruits are processed mainly for juice, the residues are disposed in wastelands, hence, plenty of nutritional potential goes in vain. But if utilized wisely, the bioactive phytochemicals in citrus by-products have the ability to revolutionize the functional food industry. In the present review, the composition of citrus by-products in terms of bioactive components and their health benefits has been reviewed. Various extraction techniques used to extract these bioactives has been discussed and a brief overview of purification and utilization of the extracted compounds, in food and nutraceutical industry is also presented. Bioactives in citrus by-products are higher than the peeled fruit, which can be extracted, isolated and incorporated into food systems for development of health foods. From the studies reviewed, it was observed that research reported on utilization of citrus by-products is limited to mainly research labs; proper scale-up process and its adequate research commercialization is the need of hour to transform these bioactives into economical functional ingredients.

Optimization and Encapsulation of Phenolic Compounds Extracted from Maize Waste by Freeze-Drying, Spray-Drying, and Microwave-Drying Using Maltodextrin

Cornsilk is maize waste containing phenolic compounds. In this study, freeze-drying, spray-drying, and microwave-drying techniques were evaluated for the encapsulation of cornsilk's phenolic compounds using maltodextrin as wall material. The results of antioxidant properties showed that freeze-drying was more efficient than microwave-drying and spray-drying techniques. The highest recovery of phenolic compounds was obtained with freeze-drying. The microstructure, DSC, and FTIR data showed that the encapsulation process was effective, and freeze-drying was the best drying technique. The physical properties of the microparticles greatly changed with the drying techniques. This study revealed that the phenolic compounds of the cornsilk extract can be successfully encapsulated and valorized.