Resveratrol-loaded octenyl succinic anhydride modified starch emulsions and hydroxypropyl methylcellulose (HPMC) microparticles: Cytotoxicity and antioxidant bioactivity assessment after in vitro digestion

Hydroxypropyl methylcellulose (HPMC)-based microparticles and modified starch emulsions (OSA-MS) were loaded with resveratrol and characterized regarding their physicochemical and thermal properties. Both delivery systems were subject to an in vitro gastrointestinal digestion to assess the bioaccessibility of resveratrol. In addition, cell-based studies were conducted after in vitro digestion and cytotoxicity and oxidative stress were assessed. HPMC-based microparticles displayed higher average sizes (d) and lower polydispersity index (PDI) (d = 948 nm, PDI < 0.2) when compared to OSA-MS-based emulsions (d = 217 nm, PDI < 0.3). Both proved to protect resveratrol under digestive conditions, leading to an increase in bioaccessibility. Resveratrol-loaded HPMC-microparticles showed a higher bioaccessibility (56.7 %) than resveratrol-loaded emulsions (19.7 %). Digested samples were tested in differentiated co-cultures of Caco-2 and HT29-MTX, aiming at assessing cytotoxicity and oxidative stress, and a lack of cytotoxicity was observed for all samples. Results displayed an increasing antioxidant activity, with 1.6-fold and 1.4-fold increases over the antioxidant activity of free resveratrol, for HPMC-microparticles and OSA-MS nanoemulsions, respectively. Our results offer insight into physiological relevancy due to assessment post-digestion and highlight the protection that the use of micro-nano delivery systems can confer to resveratrol and their potential to be used as functional food ingredients capable of providing antioxidant benefits upon consumption.

Fruit-Carrot-Based Smoothies as Innovative Products with a Complex Matrix of Bioactive Compounds Effected on Activities of Selected Digestive Enzymes and Cholinesterases In Vitro

In this study, four different carrot varieties (purple, yellow, white, and orange) were used in the production of smoothies with raspberry, apple, pear, strawberry, and sour cherry juices. The in vitro inhibition effects against α- amylase, α- glucosidase, pancreatic lipase, acetylcholinesterase, and butyrylcholinesterase were measured, bioactive compounds, physicochemical characteristics, including sensorial features were described. The antioxidant activities of the studied samples were analyzed using the ORAC, ABTS, and FRAP methods. The raspberry-purple carrot smoothie showed the highest antioxidant activity against lipase and butyrylcholinesterase enzyme activity. The sour cherry-purple carrot smoothie showed the highest total soluble solids, total phenolic acid, total anthocyanins, and procyanidin contents; dry mass; and osmolality. Although the apple-white carrot smoothie achieved the highest acceptance after sensorial evaluation, it did not exhibit any potent biological activities. Thus, food products with purple carrot, raspberry, and sour cherry ingredients are suggested as functional and/or novel matrix compositions with high antioxidant potential.

Hyaluronic acid-Amphotericin B Nanocomplexes: a Promising Anti-Leishmanial Drug Delivery System

The development of an effective amphotericin B (AmB) formulation to replace actual treatments available for leishmaniasis, which present serious drawbacks, is a challenge. Here we report the development of hyaluronic...

Biopolymer interactions on emulsion-filled hydrogels: chemical, mechanical properties and microstructure

Bioactive carrier systems produced from natural and biodegradable compounds offer diverse applications in the food and drug sector, whether for protection, controlled delivery, texture modification or insertion of lipid compounds into aqueous systems. This study aimed to produce emulsion-filled hydrogels by sonication followed by ionic gelation, containing potato starch as the main compound (gelatinized or native), a low alginate concentration, and gelatin in the continuous phase. Emulsion-filled hydrogels were evaluated regarding chemical and physical structure, as well as morphology of hydrogels after simulated digestion. Slight intensity differences were observed between the FTIR spectra of hydrogels, reflecting water absorption, amorphous and crystalline structures. The chemical characteristics of hydrogels influenced the microstructure and stress at fracture. Hydrogel produced with gelatinized starch was harder than hydrogel with non-gelatinized starch. Regarding digestion assay, we postulated that alginate-gelatin network was degraded by swelling, while alginate-gelatin-starch gels were associated with an erosion mechanism, since its microstructure remained partially stable, only exposing the oil droplets at surface. These findings can provide different delivery and protection mechanisms, allowing varied applications.

Development of Active Barrier Multilayer Films Based on Electrospun Antimicrobial Hot-Tack Food Waste Derived Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and Cellulose Nanocrystal Interlayers

Active multilayer films based on polyhydroxyalkanoates (PHAs) with and without high barrier coatings of cellulose nanocrystals (CNCs) were herein successfully developed. To this end, an electrospun antimicrobial hot-tack layer made of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) derived from cheese whey, a by-product from the dairy industry, was deposited on a previously manufactured blown film of commercial food contact PHA-based resin. A hybrid combination of oregano essential oil (OEO) and zinc oxide nanoparticles (ZnONPs) were incorporated during the electrospinning process into the PHBV nanofibers at 2.5 and 2.25 wt%, respectively, in order to provide antimicrobial properties. A barrier CNC coating was also applied by casting from an aqueous solution of nanocellulose at 2 wt% using a rod at 1m/min. The whole multilayer structure was thereafter assembled in a pilot roll-to-roll laminating system, where the blown PHA-based film was located as the outer layers while the electrospun antimicrobial hot-tack PHBV layer and the barrier CNC coating were placed as interlayers. The resultant multilayer films, having a final thickness in the 130-150 µm range, were characterized to ascertain their potential in biodegradable food packaging. The multilayers showed contact transparency, interlayer adhesion, improved barrier to water and limonene vapors, and intermediate mechanical performance. Moreover, the films presented high antimicrobial and antioxidant activities in both open and closed systems for up to 15 days. Finally, the food safety of the multilayers was assessed by migration and cytotoxicity tests, demonstrating that the films are safe to use in both alcoholic and acid food simulants and they are also not cytotoxic for Caco-2 cells.

Emulsion-filled hydrogels for food applications: influence of pH on emulsion stability and a coating on microgel protection

Encapsulation structures for oral administration have been widely employed by the food, personal care, and pharmaceutical industries. Emulsion-filled microgels can be used to encapsulate bioactive compounds, allowing the entrapment of lipid droplets in biopolymer networks and promoting bioactive protection. The influence of pH and biopolymer concentration on the formation and structure of emulsions was evaluated, allowing the production of emulsion-filled hydrogels with potato starch as the main compound, a low alginate concentration, and gelatin in the continuous phase. Potato starch was used because it is generally recognized as safe (GRAS) and has phosphate groups, which allow electrostatic interactions with biopolymers and provide resistance to the network. Emulsion stability was achieved at pH 6, while complexation was verified under acidic conditions, which made the ionic gelation process unfeasible for the production of microgels. After defining the pH for emulsion production, microgels were formed by ionic gelation and coated microgels by electrostatic interactions, as evidenced by quartz crystal microbalance. The alginate and gelatin coating did not affect the morphology of the microparticles. An in vitro digestion assay showed that microgels composed mainly of potato starch were not degraded in the simulated mouth step. The coating layer provided extra microgel protection during digestion, demonstrating the ability of encapsulation systems to promote targeted delivery of bioactive compounds.

Characterization of the behavior of carotenoids from pitanga (Eugenia uniflora) and buriti (Mauritia flexuosa) during microemulsion production and in a dynamic gastrointestinal system

Uncommon tropical fruits are emerging as raw-material for new food products with health benefits. This work aimed at formulating and processing microemulsions from pitanga (Eugenia uniflora) and buriti (Mauritia flexuosa) fruits, since they are very rich in carotenoids (particularly lycopene and β-carotene), in order to encapsulate and increase carotenoids' bioaccessibility. Pitanga and buriti microemulsions were produced by applying a direct processing (high-speed homogenization at 15,000 rpm and ultrasound with 20 kHz probe at 40% amplitude) of the whole pulp together with surfactant (Tween 80 or Whey Protein Isolate at 2%) and corn oil (5%). All treatments (HSH-US for 0-4, 4-0, 4-4, 4-8 min-min) applied were able to increase the amount of carotenoid released. However, the processing also decreased the total amount of carotenoids in the whole pulp of studied fruits. The impact of processing during microemulsion production was not severe. The overall data suggest that the presence of surfactant and oil during processing may protect the carotenoids in fruits and microemulsions. Final recovery of total carotenoids, after passing the samples through a dynamic gastrointestinal system that simulates the human digestion, was higher for microemulsions than for whole pulps. High losses of total carotenoids in buriti and β-carotene and lycopene in pitanga occurred during jejunum and ileum phases. The present work confirms that it is possible to increase β-carotene and lycopene bioaccessibility from fruits by directly processing microemulsions (p < 0.01).