Optimization of spray drying parameters for encapsulation of Nettle (Urtica dioica L.) extract

Sweet tea extract encapsulated by different wall material combinations with improved physicochemical properties and bioactivity stability

Aim: To prepare sweet tea extract microcapsules (STEMs) via a spray-drying by applying different wall material formulations with maltodextrin (MD), inulin (IN), and gum arabic (GA). Methods: The microcapsules were characterised by yield, encapsulation efficiency (EE), particle size, sensory evaluation, morphology, attenuated total reflectance-Fourier transform infra-red spectroscopy and in vitro digestion studies. Results: The encapsulation improved the physicochemical properties and bioactivity stability of sweet tea extract (STE). MD5IN5 had the highest yield (56.33 ± 0.06% w/w) and the best EE (e.g. 88.84 ± 0.36% w/w of total flavonoids). MD9GA1 obtained the smallest particle size (642.13 ± 4.12 nm). MD9GA1 exhibited the highest retention of bioactive components, inhibition of α-glucosidase (96.85 ± 0.55%), α-amylase (57.58 ± 0.99%), angiotensin-converting enzyme (56.88 ± 2.20%), and the best antioxidant activity during in vitro gastrointestinal digestion. Conclusion: The encapsulation of STE can be an appropriate way for the valorisation of STE with improved properties.

Research on optimization of spray drying conditions, characteristics of anthocyanins extracted from Hibiscus sabdariffa L. flower, and application to marshmallows

Anthocyanin, a main-colored bioactive compound found in Hibiscus sabdariffa L., is well-known for a varied range of applications as food additives in foodstuff, and natural colorants in food, pharmaceutical, and printing industries. The study aimed to find out the suitable conditions for the spray-drying process to obtain anthocyanin powder from the extract as well as characterized the powder. In addition, the obtained powder was applied to marshmallows and determined the acceptability of appearance, quality, and scavenging capacity of the candy. The carrier of maltodextrin and gum arabic was selected for spray-drying, which had optimal conditions at 144°C and 7 mL/min, resulting in 100.22 mg/g anthocyanin content with an encapsulation efficiency of 93.87%. The obtained anthocyanin has appropriate moisture of 5.14%, quite appropriate bulk density, and tapped density, it also was high solubility, and poor flowability but easy compression. The shape of the particle by SEM analysis was low particle size (2-10 μm), wrinkled, unequal spherical size, rough surfaces with indentations, and slight cracks. The X-ray diffraction (XRD) spectrum of the sample had very low crystallinity and diffuse wide peaks revealing that anthocyanin still exists inside maltodextrin particles. The FT-IR spectrum had oscillations of characteristic groups of anthocyanin structure. Marshmallow samples added 5% anthocyanin powder gained high acceptability of appearance and maintained the scavenging capacity (DPPH) with an IC50 value of 7368.31 ppm after a month of storage.

Microencapsulation of bioactive compound extracts using maltodextrin and gum arabic by spray and freeze-drying techniques

Microencapsulation techniques establish a protective barrier around a sensitive compound, reducing vulnerability to external influences and offering controlled release. This work evaluates microencapsulation of Brazilian seed known as pink pepper (Schinus terebinthifolius) extract incorporated with green propolis extract, (main propolis font from the South America native plant Baccharis dracunculifolia DC) to enhancement antioxidant activity through synergic interaction, comparing to the extracts individually. Four treatments were produced using maltodextrin and combined with gum arabic as encapsulating agent, employing two different microencapsulation technique applied (spray drying and freeze drying) to assess their impact on physicochemical properties. The incorporation of gum arabic into matrix yielded higher encapsulation efficiency values, exhibiting significant differences for both encapsulation techniques. Combining the two encapsulation agents afforded greater protection of the bioactive compounds, resulting in an increase of approximately 31 % in the inhibition of the DPPH● radical. In controlled release analysis, maltodextrin exhibits the best protective effect on total phenolic compounds during intestinal release, whereas combining maltodextrin and gum arabic enhanced protection during gastric phase. Microcapsules may contribute to the protection of important bioactive compound, possessing a wide range of applications such as flavors encapsulation in food industry, lipids, antioxidants and pharmaceutical industry for controlled drug release.

Encapsulation of Pineapple Peel Extracts by Ionotropic Gelation Using Corn Starch, Weissella confusa Exopolysaccharide, and Sodium Alginate as Wall Materials

Phenolic compounds that are present in pineapple by-products offer many health benefits to the consumer; however, they are unstable to many environmental factors. For this reason, encapsulation is ideal for preserving their beneficial effects. In this work, extracts were obtained by the combined method of solid-state fermentation with Rhizopus oryzae and ultrasound. After this process, the encapsulation process was performed by ionotropic gelation using corn starch, sodium alginate, and Weissella confusa exopolysaccharide as wall material. The encapsulates produced presented a moisture content between 7.10 and 10.45% (w.b), a solubility of 53.06 ± 0.54%, and a wettability of 31.46 ± 2.02 s. The total phenolic content (TPC), antioxidant capacity of DPPH, and ABTS of the encapsulates were also determined, finding 232.55 ± 2.07 mg GAE/g d.m for TPC, 45.64 ± 0.9 µm Trolox/mg GAE for DPPH, and 51.69 ± 1.08 µm Trolox/mg GAE for ABTS. Additionally, ultrahigh performance liquid chromatography (UHPLC) analysis allowed us to identify and quantify six bioactive compounds: rosmarinic acid, caffeic acid, p-coumaric acid, ferulic acid, gallic acid, and quercetin. According to the above, using ionotropic gelation, it was possible to obtain microencapsulates containing bioactive compounds from pineapple peel extracts, which may have applications in the development of functional foods.

Nanoencapsulation of Phenolic Extracts from Native Potato Clones (Solanum tuberosum spp. andigena) by Spray Drying

Native potato clones grown in Peru contain bioactive compounds beneficial to human health. This study aimed to optimize the spray-drying nanoencapsulation of native potato phenolic extracts utilizing a central composite design and response surface methodology, obtaining the optimal treatment to an inlet temperature of 120 °C and an airflow of 141 L/h in the nano spray dryer B-90, which allowed maximizing the yield of encapsulation, antioxidant capacity (DPPH), encapsulation efficiency (EE), total phenolic compounds, and total flavonoids; on the other hand, it allowed minimizing hygroscopicity, water activity (Aw), and moisture. Instrumental characterization of the nanocapsules was also carried out, observing a gain in lightness, reddening of the color, and spherical nanoparticles of heterogeneous size (133.09-165.13 nm) with a negative ζ potential. Thermal, infrared, and morphological analyses confirmed the encapsulation of the core in the wall materials. Furthermore, an in vitro release study of phenolic compounds in an aqueous solution achieved a maximum value of 9.86 mg GAE/g after 12 h. Finally, the obtained nanocapsules could be used in the food and pharmaceutical industry.

Effect of Carrier Agents on Quality Parameters of Spray-Dried Encapsulated Diosgenin Powder and the Optimization of Process Parameters

Fenugreek seeds are a rich source of bioactive compounds, such as diosgenin, which is one of the most crucial steroidal sapogenins emerging in the field with its spectacular health benefits. Plant-based diosgenin is bitter in taste and has remarkably low consumption levels, making it unable to fulfil the role of improving health benefits. Diosgenin is spray dried to mask bitterness and astringent flavors with two different wall materials, such as maltodextrin (MD) and whey protein concentrate (WPC), separately. The spray-drying condition of the selected optimization process was inlet air temperature (IAT 150-170 °C), feed flow rate (FFR 300-500 mL/h), and carrier agent concentration (CAC 10-20%). The optimization of the process variable was conducted for producing optimized encapsulated diosgenin powder (EDP) with both MD and WPC. The selected parameters, such as yield, encapsulation efficiency, moisture content, antioxidant activity, hygroscopicity, and solubility, are investigated in this current work. Based on the experimental results, the significant R² values depict the model fitting to the responses. EDP revealed an optimization condition at 170 °C IAT, 500 mL/h FFR, and 20% CAC for MD and WPC. The highest responses were observed with WPC-EDP, such as yield at 82.25%, encapsulation efficiency at 88.60%, antioxidant activity at 53.95%, and hygroscopicity at 12.64%. MD-EDP revealed higher solubility at 96.64% and moisture content at 2.58%. EDP was studied using micrographs and diffractograms for the optimized samples, which revealed a smooth and dented surface with an amorphous nature for MD-EDP and WPC-EDP, respectively. EDP exhibited acceptable powder properties with regard to fulfilling the set purpose. EDP can be a better potential ingredient in different food matrices to act as a delivery vehicle for various health aliments.

Optimisation of liquorice extract microencapsulation and bioaccessibility of its bioactives

In this work, functional liquorice powder beverage (FLPB) with standardised glycyrrhizin (GL), glycyrrhetinic acid (GA), carbenoxolone (CBX), and liquiritin (LQ) contents, was produced by encapsulating Glycyrrhiza glabra extract with maltodextrin (MD) by spray drying. Encapsulation parameters of the FLPB were optimised as MD:GL 3.4:1, inlet temperature: 149 °C, and air flow: 8.9 L min−1. GL, GA, LQ, CBX, and yield in powdered beverage produced using these optimised parameters were 6.8 g L−1, 81.1 mg L−1, 24.7 mg L−1, 0.79 g L−1, and 30.95%, respectively. Moreover, the effect of the encapsulation on the bioaccessibility of GL, GA, CBX, and LQ bioactives in G. glabra was evaluated. According to the obtained results, FLPB exhibited a higher bioaccessibility index for GL, GA, CBX, and LQ compared to the aqueous extract.

Effect of Spray Drying Encapsulation on Nettle Leaf Extract Powder Properties, Polyphenols and Their Bioavailability

Nettle (Urtica dioica L.) is a plant rich in a health-promoting compounds such as polyphenols, which are sensitive and unstable compounds with low bioavailability, that need to be stabilized and protected from external influences. Therefore, the aim of this study was to examine how the temperature, type of carrier and sample to carrier ratio influence the physicochemical properties and encapsulation and loading capacity of the nettle leaf extract powder and examine the effect of encapsulation on the antioxidant capacity and bioavailability of polyphenols. The process yield ranged from 64.63–87.23%, moisture content from 1.4–7.29%, solubility from 94.76–98.53% and hygroscopicity from 13.35–32.92 g 100 g⁻¹. The highest encapsulation (98.67%) and loading (20.28%) capacities were achieved at 160 °C, β-CD:GA (3:1) and sample:carrier ratio of 1:3. Extracts encapsulated at selected conditions showed high antioxidant capacity and distinct polyphenolic profile comprised of 40 different compounds among which cinnamic acids were the most abundant. Moreover, the encapsulation increased the bioavailability of nettle leaf polyphenols, with the highest amount released in the intestinal phase. Thus, the obtained encapsulated extract represents a valuable source of polyphenols and may therefore be an excellent material for application in value-added and health-promoting products.

Ultrasound-assisted encapsulation of curcumin and fisetin into Saccharomyces cerevisiae cells: a multistage batch process protocol

Some of the challenges of yeast encapsulation protocols are low phytochemical internalization rates and limited intracellular compartment of yeasts. This study uses an ultrasound-assisted batch encapsulation (UABE) protocol to optimize the encapsulation of curcumin and fisetin by recovering non-encapsulated biomaterial and further incorporating it into non-loaded yeasts in three encapsulation stages (1ES, 2ES, and 3ES). The effect of selected acoustic energies (166.7 and 333.3 W L^-1 ) on the encapsulation efficiency (EE), yield (EY), and antioxidant activity retention were evaluated, and then, compared with a control process (without ultrasound treatment). Compared to the control, enhanced EEs were achieved for both curcumin (10.9% control to 58.5% UABE) and fisetin (18.6% control to 76.6% UABE) after 3ES and the use of 333.3 W L^-1 . Similarly, the yeast maximum loading capacity was improved from 6.6 to 13.4 mg g^-1 for curcumin; and from 11.1 to 26.4 mg g^-1 for fisetin after UABE protocol. The antioxidant activity of produced biocapsules was positively correlated with the bioactive loaded content of yeasts when ultrasound treatment was applied. Overall, results from this study provide valuable information regarding UABE processes, and moreover, bring new and creative perspectives for the ultrasound technology in the food industry.