Yerba mate antioxidant powders obtained by co-crystallization: Stability during storage

The enzymatic modification of whey-proteins for spray drying encapsulation of Ginkgo-biloba extract

Ginkgo biloba extract (GBLE) contains many bioactives including flavonoids and terpene trilactones that play some pharmacological roles. These compounds are sensitive to operating conditions; so, encapsulation is a suitable approach to protect them. In this study, different carriers including maltodextrin (MD), and its combination with gum-Arabic (MD-GA), whey protein concentrate (MD-WPC), and whey-protein hydrolysate (MD-HWPC) were used to encapsulate GBLE. Powder production yield, physicochemical/functional characteristics, physical stability and flowability of particles were affected by the type and composition of carriers. FTIR results indicated the placement of phenolic compounds in the carrier matrix. The SEM images also showed the morphological changes of particles (especially the size, indentation and surface shrinkage) under the influence of various carriers. Microencapsulated powders formulated using MD-HWPC showed the highest values of TPC, DPPH, and ABTS and a lighter color which determined the suitability of this wall material (due to the improvement of surface activity and emulsifying properties of protein as a result of partial enzymatic hydrolysis) to protect the antioxidant properties of GBLE during spray-drying, improving the production yield and preserving physical and functional characteristics of the encapsulated powders.

Extraction and Encapsulation of Phytocompounds of Poniol Fruit via Co-Crystallization: Physicochemical Properties and Characterization

Poniol (Flacourtia jangomas) has beneficial health effects due to its high polyphenolic and good antioxidant activity content. This study aimed to encapsulate the Poniol fruit ethanolic extract to the sucrose matrix using the co-crystallization process and analyze the physicochemical properties of the co-crystalized product. The physicochemical property characterization of the sucrose co-crystallized with the Poniol extract (CC-PE) and the recrystallized sucrose (RC) samples was carried out through analyzing the total phenolic content (TPC), antioxidant activity, loading capacity, entrapment yield, bulk and traped densities, hygroscopicity, solubilization time, flowability, DSC, XRD, FTIR, and SEM. The result revealed that the CC-PE product had a good entrapment yield (76.38%) and could retain the TPC (29.25 mg GAE/100 g) and antioxidant properties (65.10%) even after the co-crystallization process. Compared to the RC sample, the results also showed that the CC-PE had relatively higher flowability and bulk density, lower hygroscopicity, and solubilization time, which are desirable properties for a powder product. The SEM analysis showed that the CC-PE sample has cavities or pores in the sucrose cubic crystals, which proposed that the entrapment was better. The XRD, DSC, and FTIR analyses also showed no changes in the sucrose crystal structure, thermal properties, and functional group bonding structure, respectively. From the results, we can conclude that co-crystallization increased sucrose's functional properties, and the co-crystallized product can be used as a carrier for phytochemical compounds. The CC-PE product with improved properties can also be utilized to develop nutraceuticals, functional foods, and pharmaceuticals.

Antioxidant Stability of Moringa Leaves Extract Powders Obtained by Cocrystallization, Vacuum Drying, and Plating

Cocrystallization, vacuum drying, and plating are three potential applications to preserve the antioxidant activity of moringa leaves. Moringa leaves extract was incorporated with sucrose at the same concentration (7 : 100, solid : solid) for all applications and stored for 30 days. This study aims to examine the effects of each application on the antioxidant stability of moringa leaves extract powders. Morphological properties by SEM showed that cocrystallized powders exhibited porous, agglomerated crystals, vacuum dried powders exhibited agglomerated crystals, and plated powders exhibited layered crystals. Based on XRD and hygroscopicity results, cocrystallization produced powders with the highest crystallinity, i.e., 69.11%, and the lowest hygroscopicity, i.e., 0.26 × 10−4 ± 0.02 × 10−4 g H2O/g solid/minute due to the slow water intake of the crystalline structure. Powders with the strongest initial antioxidant activity were obtained from cocrystallization, i.e., 3647.96 ± 20.29 ppm and followed by vacuum drying, i.e., 4378.51 ± 26.29 ppm. The least antioxidant activity was obtained from plating, i.e., 4733.46 ± 31.91 ppm. During 30 days of storage, powders obtained by cocrystallization maintained the most stable antioxidant activity (91.81–91.12%). The results indicated that the high temperature used in the process was likely to impact crystalline structure through the pore formation, which entrapped bioactive compounds and resulted in strong antioxidant activity. While, vacuum drying resulted in powders with a lower but increased antioxidant activity (84.06%–86.43%). In contrast to the other two applications, plating resulted in a decreased antioxidant activity (83.77–82.25%). This study suggests that application of cocrystallization produced moringa leaves extract powders with the strongest and most stable antioxidant activity during storage. Preserving the antioxidant stability of plant extract has been one of the major drives in the development of food encapsulation technology. Cocrystallization and vacuum drying are two relatively novel, less common techniques offering a simpler and more cost-effective method, but their effect on the antioxidant stability of moringa leaves extract has not yet been studied. This study discloses the effects of cocrystallization, vacuum drying, and plating (alternative extract incorporation method) on the antioxidant stability of moringa leaves extract powders. The results indicated that the three methods produced powders with high crystallinity and stable antioxidant stability during storage. Among the three methods, cocrystallization was the method that resulted in powders with the strongest and most stable antioxidant activity.

Encapsulation of ginger oleoresin in co-crystallized sucrose: development, characterization and storage stability

Ginger oleoresin was emulsified with gum acacia and encapsulated in a sucrose matrix by co-crystallization. The increased void space and surface area of sucrose provided a porous base for the incorporation of oleoresin. This co-crystallization led to modification from crystalline to irregular agglomerates, as evident from X-ray diffraction and differential scanning calorimetry. Hygroscopicity, water sorption isotherms and water activity demonstrated changes due to the change in crystallinity of sucrose. The active components such as [6]-, [8]- and [10]-gingerols and [6]-shogaol were quantified by HPLC. The encapsulation efficiency of [6]-gingerol was 45.59%. The storage kinetics at different relative humidity levels and temperatures indicated [6]-gingerol to be the most stable among the gingerols studied. A temperature of 25 °C and relative humidity of 33% proved to be the best storage conditions for the ginger flavoured sugar cubes. Thus, co-crystallization for the encapsulation of ginger oleoresin serves a dual purpose, i.e., protection and a mode of delivering a spicy flavour.

New Freeze-Dried Andean Blueberry Juice Powders for Potential Application as Functional Food Ingredients: Effect of Maltodextrin on Bioactive and Morphological Features

Andean blueberry (Vaccinium meridionale Swartz) fruits are an underutilized source of anthocyanins and other valuable bioactive phytochemicals. The purpose of this work was to obtain Andean blueberry juice powders via freeze-drying processing and evaluate the effect of maltodextrin as a drying aid on their physicochemical, technological, microstructural, and bioactive characteristics. Andean blueberry juices were mixed with variable proportions of maltodextrin (20–50%); freeze-dried; and characterized in terms of their tristimulus color, Fourier transform infrared spectra (FTIR), moisture content, water activity, morphology, water solubility, flow properties, total polyphenols and anthocyanins content, and DPPH^•-scavenging capacity. The powders obtained presented suitable characteristics in terms of their water activity (<0.5), solubility (>90%), and bioactive compound recovery (>70% for total phenolics, and >60% for total monomeric anthocyanins), with antioxidant activities up to 4 mg equivalent of gallic acid/g of dry matter. Although an increased content of maltodextrin resulted in lower concentrations of phytochemicals, as expected, it also favored an increased % recovery (over 90% of total phenolics at the highest maltodextrin proportion) and improved their flow properties. Freeze-dried juice powders are a potential alternative for the stabilization and value addition of this fruit as a new source of functionality for processed foods.

Improvement of Andean Blueberries Postharvest Preservation Using Carvacrol/Alginate-Edible Coatings

Edible coatings are attractive strategies for blueberries postharvest preservation. In this work, carvacrol/alginate coatings were developed for application on Andean blueberries. Coating formulations were prepared based on blends of sodium alginate (2% w/v), carvacrol (0%, 0.03%, 0.06% or 0.09%), glycerol, and water and applied to the fruits by dip-coating. Then, the fruits were immersed in a calcium batch to induce a crosslink reaction. Changes in the physicochemical and microbiological characteristics of the blueberries were monitored during 21 days of storage at 4 °C. Coated blueberries were better preserved throughout the 21 days of storage because of their lower respiration rate and water loss, in comparison with the uncoated ones. Besides, the coatings enhanced the appearance and the gloss of the fruits. Control fruits showed a significant decrease in the firmness, while, in the coated fruits, this critical postharvest quality was preserved during the entire storage. Coating formulations with 0.09% of carvacrol was the most effective in preventing mesophilic aerobic bacteria and molds/yeasts growth on the fruits during the storage. Edible carvacrol/alginate coatings can be considered as a useful alternative to complement the benefits of refrigerated storage by delaying post-harvest spoilage of Andean blueberries.

Optimizing the formulation of the functional beverage from the co-crystalized powder of Securigera securidaca seed extract

The co-crystalized powder prepared from Securigera securidaca seed extract was used for the formulation of a functional beverage in the study. In doing so, various ratios of co-crystalized powder from the plant extract, water, citric acid, mint essential oil, honey, apple extract, and stevia were mixed together. Three beverage formulas along with the control sample were prepared and evaluated by panelists using six-point hedonic scale. The formula containing 2 g of the extract powder was introduced as the best beverage from the panelists' perspective and received an average score. The samples were stored at 4 °C for 3 months and examined for pH, acidity, brix, turbidity, vitamin C, phenolic compounds, radical scavenging capacity, total microorganism count, molds and yeasts to evaluate shelf life. The pH and acidity changes were almost constant until day 60; but pH and acidity were decreased and increased in the last month, respectively. The brix changes were slight and had a slight decrease in the last month of storage. Although turbidity changes were small, they were associated with an increase over the storage time. Moreover, the beverage could well retain the phenolic compounds and the radical scavenging capacity and the antioxidant activity had a little change during storage. The changes trend in vitamin C was declining and equal to 16.85 mg/ml in the last month. No mold and yeast contamination were observed in any of the treatments according to ISO 21527 and mesophilic aerobic bacterial counts were in the range based on the ISO 4833. Hence, the herbal beverages produced with 2 g of the extract powder can replace industrial beverages given their proper chemical and microbial properties.

Application of nano/microencapsulated phenolic compounds against cancer

Nowadays, polyphenols as bioactive compounds are being used in producing anti-cancer drugs. Low stability against harsh environmental conditions, untargeted release, low solubility, and low absorption of pure phenolic molecules are significant barriers, which decrease the functions of polyphenols. Recently, the nanoencapsulation processes have been applied to overcome these restrictions, in which the anti-cancer activity of polyphenols has been noticeably increased. This review will focus on the anti-cancer activity of polyphenols, and the effect of loading polyphenolics into various micro/nanoencapsulation systems on their anti-cancer activity. Different encapsulation systems such as lipid and polymer based nanoparticles, and solid form of encapsulated phenolic molecules by nano-spray dryer and electrospinnig have been used for loading of polyphenols. Incorporation of phenolic molecules into various carriers inevitably increases their anti-cancer activity. Because, in this way, encapsulated cargos can provide a targeted release, which will increase the bioavailability of phenolic molecules and their functions such as absorption into cancer cell.

The effect of encapsulated plant extract of hyssop (Hyssopus officinalis L.) in biopolymer nanoemulsions of Lepidium perfoliatum and Orchis mascula on controlling oxidative stability of soybean oil

The aim of this study was to investigate the effect of encapsulation method on antioxidant properties of Hyssop (Hyssopus Officinalis L.) extract. The extracts of the Hyssop were obtained by ultrasound assisted techniques, and the amount of phenolic compounds was 117.43 ± 9.22 (mg of gallic acid per 100 g of extract). The antioxidant activity of extracts in concentrations of 100, 200, 300, and 400 ppm was measured using DPPH free radical scavenging method and compared with 100 ppm of TBHQ synthetic antioxidants. The results showed that by increasing in concentration of the extract, the antioxidant activity of the extract increased. The Lepidium perfoliatum seed gum and Orchis mascula were chosen as coating material. Encapsulation was performed by emulsion production method. The antioxidant effects of nanocapsules in oil during 40 days of storage at 60°C were measured, which increased the oxidation of oil over time. The lowest amount of oil oxidation during storage compared to control samples was observed in samples containing nano encapsulated Hyssop extract due to reducing in release rate of the extract during storage and more protection of the extract. The results of this study suggest that encapsulation is an effective way to increase the antioxidant activity of the extract and could be increased the shelf life of edible oils with natural antioxidants.

The antioxidant and physicochemical properties of microencapsulated bioactive compounds in Securigera securidaca (L.) seed extract by co-crystallization

Securigera securidaca seed is a good source of phenolic compounds with high antioxidant properties. Preservation and maintenance of natural antioxidants have always been a challenge and microencapsulation is a suitable method for this purpose. In this study, the chemical compounds of the plant seed extract were identified by GC/MS device. Bioactive compounds from the seed ethanolic extract were microencapsulated in the sucrose matrix during the co-crystallization process. The evaluations included total phenolic compounds, radical scavenging ability, production efficiency, moisture content, and flowability characteristics of the produced powders, such as compressibility index, Hausner ratio, and angle of repose. The results showed significant differences in the phenolic compounds and the radical scavenging ability between the control sample and the co-crystallized powder (P &lt; 0.05). The production efficiency and the moisture content of extract-containing co-crystallized powder were 84% and 0.14%, respectively. The particle size difference of the microencapsulated powder could significantly affect the powder flowability characteristics (P &lt; 0.05), and particles with a size of 1 mm showed better flowability behaviour. FT-IR charts for samples revealed chemical bonds specific to saccharose molecule indicating no changes in covalent bonds present in saccharose molecule structure after the process. Scanning electron microscope images showed the presence of vacant spaces and porosity in the structure of saccharose crystals formed during the process of crystallization. As a result, the co-crystallized powder obtained from the plant extract can be used as an appropriate antioxidant in the food and pharmaceutical formulations.

Ceratonia siliqua L. hydroethanolic extract obtained by ultrasonication: antioxidant activity, phenolic compounds profile and effects in yogurts functionalized with their free and microencapsulated forms

Bioactive extracts were obtained from powdered carob pulp through an ultrasound extraction process and then evaluated in terms of antioxidant activity. Ten minutes of ultrasonication at 375 Hz were the optimal conditions leading to an extract with the highest antioxidant effects. After its chemical characterization, which revealed the preponderance of gallotannins, the extract (free and microencapsulated) was incorporated in yogurts. The microspheres were prepared using an extract/sodium alginate ratio of 100/400 (mg mg(-1)) selected after testing different ratios. The yogurts with the free extract exhibited higher antioxidant activity than the samples added with the encapsulated extracts, showing the preserving role of alginate as a coating material. None of the forms significantly altered the yogurt's nutritional value. This study confirmed the efficiency of microencapsulation to stabilize functional ingredients in food matrices maintaining almost the structural integrity of polyphenols extracted from carob pulp and furthermore improving the antioxidant potency of the final product.

Non-Covalent Derivatives: Cocrystals and Eutectics

Non-covalent derivatives (NCDs) are formed by incorporating one (or more) coformer molecule(s) into the matrix of a parent molecule via non-covalent forces. These forces can include ionic forces, Van der Waals forces, hydrogen bonding, lipophilic-lipophilic interactions and pi-pi interactions. NCDs, in both cocrystal and eutectic forms, possess properties that are unique to their supramolecular matrix. These properties include critical product performance factors such as solubility, stability and bioavailability. NCDs have been used to tailor materials for a variety of applications and have the potential to be used in an even broader range of materials and processes. NCDs can be prepared using little or no solvent and none of the reagents typical to synthetic modifications. Thus, NCDs represent a powerfully versatile, environmentally-friendly and cost-effective opportunity.

Microencapsulation of bioactives for food applications

The potential of microencapsulation to protect bioactive compounds ensuring bioavailability maintenance is proved but requires further studies on its applicability and incentives by regulatory agencies.