Alginate-based encapsulation of extracts from beta Vulgaris cv. beet greens: Stability and controlled release under simulated gastrointestinal conditions

Effect of Chemical Degradation of Sodium Alginate on Capsaicin Encapsulation

Capsaicin is known as an oily extract of paprika that is characterized by pungent taste and bioactivity. It also may cause irritation to the mouth and stomach which is why is so important to immobilize capsaicin on a carrier to prevent it. The usage of alginate oligomers, which has an antioxidant potential compared to alginate, is of benefit because it may be used in the immobilization of bioactive substances that are fragile to oxidation. The purpose of this study was to use sodium alginate oligomers as a coating material in the encapsulation process of paprika oleoresin. Alginate oligomers were produced by chemical degradation with hydrogen peroxide. The characteristics of the samples were obtained by measuring the viscosity, the contact angle of the surface, and the surface tension of solutions. The obtained solution of alginate oligomers served as the carrier material for the immobilization of capsaicin. Capsules were prepared by ionic gelation using a calcium chloride solution as a crosslinking agent. In this way, capsules without and with the core (capsaicin) were prepared and their ability to scavenge free radicals (DPPH) and iron-reducing properties (FRAP) were determined. The stability of the capsules was examined by thermal decomposition and under conditions of the gastric and small intestine, and capsaicin content was detected using high-performance liquid chromatography. It was found that alginate oligomers could be used in the encapsulation of bioactive compounds and the efficiency was above 80%. Capsule production from alginate oligomers affected their thermal stability. The use of alginate derivatives as a carrier increased the antioxidant properties of the finished product, as well as its ability to reduce iron ions. The use of alginate oligomers as a coating material prevented the active substance from being released too early in the conditions of the small intestine, prolonged the stability of the capsules, and supported their durability in gastric conditions.

Design of Innovative Biocompatible Cellulose Nanostructures for the Delivery and Sustained Release of Curcumin

Poor aqueous solubility, stability and bioavailability of interesting bioactive compounds is a challenge in the development of bioactive formulations. Cellulose nanostructures are promising and sustainable carriers with unique features that may be used in enabling delivery strategies. In this work, cellulose nanocrystals (CNC) and cellulose nanofibers were investigated as carriers for the delivery of curcumin, a model liposoluble compound. Nanocellulose modification with the surfactant cetyltrimethylammonium bromide (CTAB), tannic acid and decylamine (TADA), and by TEMPO-mediated oxidation were also tested and compared. The carrier materials were characterized in terms of structural properties and surface charge, while the delivery systems were evaluated for their encapsulation and release properties. The release profile was assessed in conditions that mimic the gastric and intestinal fluids, and cytotoxicity studies were performed in intestinal cells to confirm safe application. Modification with CTAB and TADA resulted in high curcumin encapsulation efficiencies of 90 and 99%, respectively. While no curcumin was released from TADA-modified nanocellulose in simulated gastrointestinal conditions, CNC-CTAB allowed for a curcumin-sustained release of ca. 50% over 8 h. Furthermore, the CNC-CTAB delivery system showed no cytotoxic effects on Caco-2 intestinal cells up to 0.125 g/L, meaning that up to this concentration the system is safe to use. Overall, the use of the delivery systems allowed for the reduction in the cytotoxicity associated with higher curcumin concentrations, highlighting the potential of nanocellulose encapsulation systems.

Polyphenol Release and Antioxidant Activity of the Encapsulated Antioxidant Crude Extract from Cold Brew Spent Coffee Grounds under Simulated Food Processes and an In Vitro Static Gastrointestinal Model

An ionic gelation technique based on an alginate-calcium-based encapsulation process was prepared as the delivery matrix for antioxidant crude extracts from cold brew spent coffee grounds (350 mg/mL). All the encapsulated samples were treated with different simulated food processes, namely pH 3, pH 7, low-temperature long-time (LTLT) pasteurization, and high-temperature short-time (HTST) pasteurization, to evaluate the stability of the encapsulated matrices. The results showed that alginate (2%, w/v)/maltodextrin (2%, w/v) (CM), and alginate (2%, w/v)/inulin (5%, w/v) (CI) could enhance encapsulation efficiency (89.76 and 85.78%, respectively) and provide lower swelling behavior after being treated using the simulated food processes. Both CM and CI could control the release of antioxidants during the gastric phase (2.28-3.98 and 2.52-4.00%, respectively) and gradual release in the intestinal phase (6.80-11.78 and 4.16-12.72%, respectively) compared to pure alginate (CA). In addition, pasteurization treatment at pH 7.0 produced the highest accumulated release of total phenolic content (TPC) and antioxidant activity (DPPH) after digestion in the in vitro gastrointestinal system compared to the other simulated food processes. The thermal process resulted in a greater release of compounds from the encapsulated matrix during the gastric phase. On the other hand, the treatment with pH 3.0 resulted in the lowest accumulated release of TPC and DPPH (5.08 and 5.12%, respectively), which indicated phytochemical protection.

Optimization of Encapsulation by Ionic Gelation Technique of Cryoconcentrated Solution: A Response Surface Methodology and Evaluation of Physicochemical Characteristics Study

The objective of this study was to evaluate the optimal conditions to encapsulate cryoconcentrate solutions via ionic gelation technique. Hydrogel beads were prepared using alginate (1%, 2% and 3% (w/w)) and cornstarch (0.5%, 1% and 2% (w/w)). Later, a sucrose/acid gallic solution was concentrated through block freeze concentration (BFC) at three cycles. Thus, each solution was a mixture with the respective combination of alginate/cornstarch. The final solution was added drop-wise on a CaCl₂ solution, allowing the formation of calcium alginate-cornstarch hydrogel beads filled with sucrose/acid gallic solution or cryoconcentrated solution. The results showed that alginate at 2% (w/w) and cornstarch at 2% (w/w) had the best efficiency to encapsulate any solution, with values close to 63.3%, 90.2%, 97.7%, and 75.1%, and particle sizes of approximately 3.09, 2.82, 2.73, and 2.64 mm, for initial solution, cycle 1, cycle 2, and cycle 3, respectively. Moreover, all the samples presented spherical shape. Therefore, the appropriate content of alginate and cornstarch allows for increasing the amount of model cryoconcentrated solution inside of the hydrogel beads. Furthermore, the physicochemical and morphological characteristics of hydrogel beads can be focused for future food and/or pharmaceutical applications, utilizing juice or extract concentrated by BFC as the solution encapsulated.

Investigation of phytochemical composition and metabolite profiling in vivo of Beta vulgaris L

RATIONALE

Beta vulgaris L. has attracted increasing attention because of its broad application. The root of B. vulgaris L. (beetroot) possesses many excellent biological properties such as antianemic, anti-inflammatory, antihypertensive, antioxidant, anticarcinogenic, antipyretic, antibacterial, detoxicant, and diuretic. The chemical constituents of beetroot play a major role in the research on beetroot application and development. At present, no systematic identification study that focuses on the chemical constituents of beetroot has been reported.

METHODS

This study investigated a three-step strategy comprising phytochemical profiling, prototype profiling, and metabolism of its correlative metabolites in vivo using ultra-performance liquid chromatography tandem quadruple time-of-flight mass spectrometry (UPLC-QTOF-MS/MS).

RESULTS

UPLC-QTOF-MS/MS technique proved to be a rapid, sensitive, and reliable method for monitoring the specific ingredients as well as the whole chemical constituents in beetroot. In sum, 95 phytochemical compounds, 51 prototype compounds, and 37 derived metabolites in vivo were found in beetroot.

CONCLUSIONS

The main metabolic pathways were sulfonation, glucuronidation, methylation/sulfonation, and methylation. The present findings provided the phytochemical basis both in vitro and in vivo for future application.

Hepatoprotective activity of silymarin encapsulation against hepatic damage in albino rats

Liver fibrosis occurs due to liver injuries and toxins. Silymarin (SMR) extracted by the milk thistle seeds, is widely used such as herbal drug for its hepatoprotective properties. The purpose of this study to assess the properties of an optimized dose of encapsulated crude SMR on antidiabetic activity and liver fibrosis induced by paracetamol in male albino rat. Hepatic fibrosis was assessed by measuring liver enzymes. Results revealed that the consumption of encapsulated SMR, can effectively affluence the target and avoid the degradation of bioactive compound. Body weight of animal also significantly increased in each group during all the period. According to our optimized study, the long-term induction of SMR (300 mg/kg) significantly amplified survival time of rats with paracetamol induced hepatic injuries. The changes of liver fibrosis and the significant increase of hepatic enzyme biomarkers were also observed. In conclusion, the results suggest that SMR acts as a hepatoprotective agent by inhibiting the fibrogenisis and apoptosis in liver, as well as insulin resistance.

Effects of in vitro digestion-fermentation over global antioxidant response and short chain fatty acid production of beet waste extracts in Ca(ii)-alginate beads

The aim of the present work was to analyze the effect of in vitro gastrointestinal digestion-fermentation on antioxidant capacity, total phenols and production of short chain fatty acids (SCFAs) from biocompounds derived from beet waste (leaf and stem) encapsulated in different formulations of Ca(ii)-alginate beads. The encapsulated systems presented higher antioxidant capacity in different phases (digested and fermented) than the extracts without encapsulation, making Ca(ii)-alginate beads a suitable delivery vehicle. Levels of total phenolic compounds and antioxidant capacity of the fermented fraction were up to ten times higher than those of the digested fraction, boosted by the contribution of bioactive compounds from the by-product of beet as well as by sugars and biopolymers. Among the formulations used, those that had excipients (sugars and/or biopolymers) presented a better overall antioxidant response than the beads with just alginate. Guar gum and sucrose lead to a promising enhancement of Ca(ii)-alginate beads not only for preservation and protection but also in terms of stability under in vitro digestion-fermentation and production of SCFAs.

High-intensity ultrasound-assisted extraction of phenolic compounds from cowpea pods and its encapsulation in hydrogels

Currently and according to the growing worldwide interest in the revaluation of agricultural by-products, the use of legumes waste presents great potential to obtain bioactive compounds. In this context, an extract rich in phenolic compounds was obtained from Vigna unguiculata (cowpea) pods by optimizing the high-intensity ultrasound conditions (10 min and 36% of amplitude) using response surface methodology. Then, the extract was encapsulated in Ca(II)-alginate beads with the addition of arabic or guar gums or cowpea isolated proteins. A complete morphological study by image analysis and microstructural evaluation by SAXS has been carried out. Results showed that beads containing alginate and alginate-guar gum have the highest loading efficiency of total phenolic compounds (47 ± 5%) and antioxidant activity (44 ± 3%). However, the coupled effect of the cowpea extract and the isolated proteins (at it higher concentration) increased the antioxidant capacity of the beads due to the contribution of the phenolic compounds and the amino acids with anti-radical activity, reaching a value of 67 ± 3 % of inhibition of ABTS.+. Finally, the microstructural analyses revealed that cowpea pod extract increased the interconnectivity of the rods due to the presence of trivalent cations, conferring versatility, and larger coordination to the network. Also, it was observed that the addition of cowpea proteins produced more interconnected bigger and fewer compacts rods than beads containing only alginate, increasing 12 and 49 % the interconnection and the size, respectively, and decreasing 10 % their compactness. This research demonstrated the use of cowpea sub-products as a source of bioactive compounds that further modulate the microstructure of the hydrogel network, and the outstanding potential for being incorporated in techno-functional foods by using Ca(II)-alginate as a carrier.

A review on bioactive compounds of beet (Beta vulgaris L. subsp. vulgaris) with special emphasis on their beneficial effects on gut microbiota and gastrointestinal health

This review discusses the available literature concerning the bioactive compounds of beet (Beta vulgaris L.) and their ability to modulate the gut microbiota and parameters indicative of gastrointestinal health. Data of published literature characterize beet as a source of a variety of bioactive compounds (e.g. diet fiber, pectic-oligosaccharides, betalains and phenolics) with proven beneficial effects on human health. Beet extracts and pectin and pectic-oligosaccharides from beet have shown able to modulate positively gut microbiota composition and activity, with noticeable bifidogenic effects, in addition to stimulate the growth and metabolism of probiotics. Beet betalains and phenolics seem to increase the production of metabolites (e.g. short chain fatty acids) by gut microbiota and probiotics, which are linked with different beneficial effects on host health. The outstanding contents of betalains and phenolics with antioxidant, anti-inflammatory and anti-carcinogenic properties have been linked to the positive effects of beet on gastrointestinal health. Beet should be a healthy choice for use in domestic meal preparations and a source of ingredients to formulate added-value functionalized food products.